plucky (7) qemu-storage-daemon-qmp-ref.7.gz
NAME
qemu-storage-daemon-qmp-ref - QEMU Storage Daemon QMP Reference Manual
Contents
• QEMU Storage Daemon QMP Reference Manual
• Common data types
• IoOperationType (Enum)
• OnOffAuto (Enum)
• OnOffSplit (Enum)
• StrOrNull (Alternate)
• OffAutoPCIBAR (Enum)
• PCIELinkSpeed (Enum)
• PCIELinkWidth (Enum)
• HostMemPolicy (Enum)
• NetFilterDirection (Enum)
• GrabToggleKeys (Enum)
• HumanReadableText (Object)
• Socket data types
• NetworkAddressFamily (Enum)
• InetSocketAddressBase (Object)
• InetSocketAddress (Object)
• UnixSocketAddress (Object)
• VsockSocketAddress (Object)
• FdSocketAddress (Object)
• InetSocketAddressWrapper (Object)
• UnixSocketAddressWrapper (Object)
• VsockSocketAddressWrapper (Object)
• FdSocketAddressWrapper (Object)
• SocketAddressLegacy (Object)
• SocketAddressType (Enum)
• SocketAddress (Object)
• Cryptography
• QCryptoTLSCredsEndpoint (Enum)
• QCryptoSecretFormat (Enum)
• QCryptoHashAlgo (Enum)
• QCryptoCipherAlgo (Enum)
• QCryptoCipherMode (Enum)
• QCryptoIVGenAlgo (Enum)
• QCryptoBlockFormat (Enum)
• QCryptoBlockOptionsBase (Object)
• QCryptoBlockOptionsQCow (Object)
• QCryptoBlockOptionsLUKS (Object)
• QCryptoBlockCreateOptionsLUKS (Object)
• QCryptoBlockOpenOptions (Object)
• QCryptoBlockCreateOptions (Object)
• QCryptoBlockInfoBase (Object)
• QCryptoBlockInfoLUKSSlot (Object)
• QCryptoBlockInfoLUKS (Object)
• QCryptoBlockInfo (Object)
• QCryptoBlockLUKSKeyslotState (Enum)
• QCryptoBlockAmendOptionsLUKS (Object)
• QCryptoBlockAmendOptions (Object)
• SecretCommonProperties (Object)
• SecretProperties (Object)
• SecretKeyringProperties (Object)
• TlsCredsProperties (Object)
• TlsCredsAnonProperties (Object)
• TlsCredsPskProperties (Object)
• TlsCredsX509Properties (Object)
• QCryptoAkCipherAlgo (Enum)
• QCryptoAkCipherKeyType (Enum)
• QCryptoRSAPaddingAlgo (Enum)
• QCryptoAkCipherOptionsRSA (Object)
• QCryptoAkCipherOptions (Object)
• Background jobs
• JobType (Enum)
• JobStatus (Enum)
• JobVerb (Enum)
• JOB_STATUS_CHANGE (Event)
• job-pause (Command)
• job-resume (Command)
• job-cancel (Command)
• job-complete (Command)
• job-dismiss (Command)
• job-finalize (Command)
• JobInfo (Object)
• query-jobs (Command)
• Block devices
• Block core (VM unrelated)
• Block device exports
• Character devices
• ChardevInfo (Object)
• query-chardev (Command)
• ChardevBackendInfo (Object)
• query-chardev-backends (Command)
• DataFormat (Enum)
• ringbuf-write (Command)
• ringbuf-read (Command)
• ChardevCommon (Object)
• ChardevFile (Object)
• ChardevHostdev (Object)
• ChardevSocket (Object)
• ChardevUdp (Object)
• ChardevMux (Object)
• ChardevStdio (Object)
• ChardevSpiceChannel (Object)
• ChardevSpicePort (Object)
• ChardevDBus (Object)
• ChardevVC (Object)
• ChardevRingbuf (Object)
• ChardevQemuVDAgent (Object)
• ChardevPty (Object)
• ChardevBackendKind (Enum)
• ChardevFileWrapper (Object)
• ChardevHostdevWrapper (Object)
• ChardevSocketWrapper (Object)
• ChardevUdpWrapper (Object)
• ChardevCommonWrapper (Object)
• ChardevMuxWrapper (Object)
• ChardevStdioWrapper (Object)
• ChardevSpiceChannelWrapper (Object)
• ChardevSpicePortWrapper (Object)
• ChardevQemuVDAgentWrapper (Object)
• ChardevDBusWrapper (Object)
• ChardevVCWrapper (Object)
• ChardevRingbufWrapper (Object)
• ChardevPtyWrapper (Object)
• ChardevBackend (Object)
• ChardevReturn (Object)
• chardev-add (Command)
• chardev-change (Command)
• chardev-remove (Command)
• chardev-send-break (Command)
• VSERPORT_CHANGE (Event)
• User authorization
• QAuthZListPolicy (Enum)
• QAuthZListFormat (Enum)
• QAuthZListRule (Object)
• AuthZListProperties (Object)
• AuthZListFileProperties (Object)
• AuthZPAMProperties (Object)
• AuthZSimpleProperties (Object)
• Transactions
• Abort (Object)
• ActionCompletionMode (Enum)
• TransactionActionKind (Enum)
• AbortWrapper (Object)
• BlockDirtyBitmapAddWrapper (Object)
• BlockDirtyBitmapWrapper (Object)
• BlockDirtyBitmapMergeWrapper (Object)
• BlockdevBackupWrapper (Object)
• BlockdevSnapshotWrapper (Object)
• BlockdevSnapshotInternalWrapper (Object)
• BlockdevSnapshotSyncWrapper (Object)
• DriveBackupWrapper (Object)
• TransactionAction (Object)
• TransactionProperties (Object)
• transaction (Command)
• QMP monitor control
• qmp_capabilities (Command)
• QMPCapability (Enum)
• VersionTriple (Object)
• VersionInfo (Object)
• query-version (Command)
• CommandInfo (Object)
• query-commands (Command)
• quit (Command)
• MonitorMode (Enum)
• MonitorOptions (Object)
• QMP introspection
• query-qmp-schema (Command)
• SchemaMetaType (Enum)
• SchemaInfo (Object)
• SchemaInfoBuiltin (Object)
• JSONType (Enum)
• SchemaInfoEnum (Object)
• SchemaInfoEnumMember (Object)
• SchemaInfoArray (Object)
• SchemaInfoObject (Object)
• SchemaInfoObjectMember (Object)
• SchemaInfoObjectVariant (Object)
• SchemaInfoAlternate (Object)
• SchemaInfoAlternateMember (Object)
• SchemaInfoCommand (Object)
• SchemaInfoEvent (Object)
• QEMU Object Model (QOM)
• ObjectPropertyInfo (Object)
• qom-list (Command)
• qom-get (Command)
• qom-set (Command)
• ObjectTypeInfo (Object)
• qom-list-types (Command)
• qom-list-properties (Command)
• CanHostSocketcanProperties (Object)
• ColoCompareProperties (Object)
• CryptodevBackendProperties (Object)
• CryptodevVhostUserProperties (Object)
• DBusVMStateProperties (Object)
• NetfilterInsert (Enum)
• NetfilterProperties (Object)
• FilterBufferProperties (Object)
• FilterDumpProperties (Object)
• FilterMirrorProperties (Object)
• FilterRedirectorProperties (Object)
• FilterRewriterProperties (Object)
• InputBarrierProperties (Object)
• InputLinuxProperties (Object)
• EventLoopBaseProperties (Object)
• IothreadProperties (Object)
• MainLoopProperties (Object)
• MemoryBackendProperties (Object)
• MemoryBackendFileProperties (Object)
• MemoryBackendMemfdProperties (Object)
• MemoryBackendShmProperties (Object)
• MemoryBackendEpcProperties (Object)
• PrManagerHelperProperties (Object)
• QtestProperties (Object)
• RemoteObjectProperties (Object)
• VfioUserServerProperties (Object)
• IOMMUFDProperties (Object)
• AcpiGenericInitiatorProperties (Object)
• AcpiGenericPortProperties (Object)
• RngProperties (Object)
• RngEgdProperties (Object)
• RngRandomProperties (Object)
• SevCommonProperties (Object)
• SevGuestProperties (Object)
• SevSnpGuestProperties (Object)
• ThreadContextProperties (Object)
• ObjectType (Enum)
• ObjectOptions (Object)
• object-add (Command)
• object-del (Command)
COMMON DATA TYPES
IoOperationType (Enum)
An enumeration of the I/O operation types
Values
read read operation
write write operation
Since
2.1
OnOffAuto (Enum)
An enumeration of three options: on, off, and auto
Values
auto QEMU selects the value between on and off
on Enabled
off Disabled
Since
2.2
OnOffSplit (Enum)
An enumeration of three values: on, off, and split
Values
on Enabled
off Disabled
split Mixed
Since
2.6
StrOrNull (Alternate)
This is a string value or the explicit lack of a string (null pointer in C). Intended for cases when
'optional absent' already has a different meaning.
Members
s: string
the string value
n: null
no string value
Since
2.10
OffAutoPCIBAR (Enum)
An enumeration of options for specifying a PCI BAR
Values
off The specified feature is disabled
auto The PCI BAR for the feature is automatically selected
bar0 PCI BAR0 is used for the feature
bar1 PCI BAR1 is used for the feature
bar2 PCI BAR2 is used for the feature
bar3 PCI BAR3 is used for the feature
bar4 PCI BAR4 is used for the feature
bar5 PCI BAR5 is used for the feature
Since
2.12
PCIELinkSpeed (Enum)
An enumeration of PCIe link speeds in units of GT/s
Values
2_5 2.5GT/s
5 5.0GT/s
8 8.0GT/s
16 16.0GT/s
32 32.0GT/s (since 9.0)
64 64.0GT/s (since 9.0)
Since
4.0
PCIELinkWidth (Enum)
An enumeration of PCIe link width
Values
1 x1
2 x2
4 x4
8 x8
12 x12
16 x16
32 x32
Since
4.0
HostMemPolicy (Enum)
Host memory policy types
Values
default
restore default policy, remove any nondefault policy
preferred
set the preferred host nodes for allocation
bind a strict policy that restricts memory allocation to the host nodes specified
interleave
memory allocations are interleaved across the set of host nodes specified
Since
2.1
NetFilterDirection (Enum)
Indicates whether a netfilter is attached to a netdev's transmit queue or receive queue or both.
Values
all the filter is attached both to the receive and the transmit queue of the netdev (default).
rx the filter is attached to the receive queue of the netdev, where it will receive packets sent to
the netdev.
tx the filter is attached to the transmit queue of the netdev, where it will receive packets sent by
the netdev.
Since
2.5
GrabToggleKeys (Enum)
Key combinations to toggle input-linux between host and guest.
Values
ctrl-ctrl
left and right control key
alt-alt
left and right alt key
shift-shift
left and right shift key
meta-meta
left and right meta key
scrolllock
scroll lock key
ctrl-scrolllock
either control key and scroll lock key
Since
4.0
HumanReadableText (Object)
Members
human-readable-text: string
Formatted output intended for humans.
Since
6.2
SOCKET DATA TYPES
NetworkAddressFamily (Enum)
The network address family
Values
ipv4 IPV4 family
ipv6 IPV6 family
unix unix socket
vsock vsock family (since 2.8)
unknown
otherwise
Since
2.1
InetSocketAddressBase (Object)
Members
host: string
host part of the address
port: string
port part of the address
InetSocketAddress (Object)
Captures a socket address or address range in the Internet namespace.
Members
numeric: boolean (optional)
true if the host/port are guaranteed to be numeric, false if name resolution should be attempted.
Defaults to false. (Since 2.9)
to: int (optional)
If present, this is range of possible addresses, with port between port and to.
ipv4: boolean (optional)
whether to accept IPv4 addresses, default try both IPv4 and IPv6
ipv6: boolean (optional)
whether to accept IPv6 addresses, default try both IPv4 and IPv6
keep-alive: boolean (optional)
enable keep-alive when connecting to this socket. Not supported for passive sockets. (Since 4.2)
mptcp: boolean (optional) (If: HAVE_IPPROTO_MPTCP)
enable multi-path TCP. (Since 6.1)
The members of InetSocketAddressBase
Since
1.3
UnixSocketAddress (Object)
Captures a socket address in the local ("Unix socket") namespace.
Members
path: string
filesystem path to use
abstract: boolean (optional) (If: CONFIG_LINUX)
if true, this is a Linux abstract socket address. path will be prefixed by a null byte, and
optionally padded with null bytes. Defaults to false. (Since 5.1)
tight: boolean (optional) (If: CONFIG_LINUX)
if false, pad an abstract socket address with enough null bytes to make it fill struct sockaddr_un
member sun_path. Defaults to true. (Since 5.1)
Since
1.3
VsockSocketAddress (Object)
Captures a socket address in the vsock namespace.
Members
cid: string
unique host identifier
port: string
port
NOTE:
String types are used to allow for possible future hostname or service resolution support.
Since
2.8
FdSocketAddress (Object)
A file descriptor name or number.
Members
str: string
decimal is for file descriptor number, otherwise it's a file descriptor name. Named file
descriptors are permitted in monitor commands, in combination with the 'getfd' command. Decimal
file descriptors are permitted at startup or other contexts where no monitor context is active.
Since
1.2
InetSocketAddressWrapper (Object)
Members
data: InetSocketAddress
internet domain socket address
Since
1.3
UnixSocketAddressWrapper (Object)
Members
data: UnixSocketAddress
UNIX domain socket address
Since
1.3
VsockSocketAddressWrapper (Object)
Members
data: VsockSocketAddress
VSOCK domain socket address
Since
2.8
FdSocketAddressWrapper (Object)
Members
data: FdSocketAddress
file descriptor name or number
Since
1.3
SocketAddressLegacy (Object)
Captures the address of a socket, which could also be a named file descriptor
Members
type: SocketAddressType
Transport type
The members of InetSocketAddressWrapper when type is "inet"
The members of UnixSocketAddressWrapper when type is "unix"
The members of VsockSocketAddressWrapper when type is "vsock"
The members of FdSocketAddressWrapper when type is "fd"
Since
1.3
SocketAddressType (Enum)
Available SocketAddress types
Values
inet Internet address
unix Unix domain socket
vsock VMCI address
fd Socket file descriptor
Since
2.9
SocketAddress (Object)
Captures the address of a socket, which could also be a socket file descriptor
Members
type: SocketAddressType
Transport type
The members of InetSocketAddress when type is "inet"
The members of UnixSocketAddress when type is "unix"
The members of VsockSocketAddress when type is "vsock"
The members of FdSocketAddress when type is "fd"
Since
2.9
CRYPTOGRAPHY
QCryptoTLSCredsEndpoint (Enum)
The type of network endpoint that will be using the credentials. Most types of credential require
different setup / structures depending on whether they will be used in a server versus a client.
Values
client the network endpoint is acting as the client
server the network endpoint is acting as the server
Since
2.5
QCryptoSecretFormat (Enum)
The data format that the secret is provided in
Values
raw raw bytes. When encoded in JSON only valid UTF-8 sequences can be used
base64 arbitrary base64 encoded binary data
Since
2.6
QCryptoHashAlgo (Enum)
The supported algorithms for computing content digests
Values
md5 MD5. Should not be used in any new code, legacy compat only
sha1 SHA-1. Should not be used in any new code, legacy compat only
sha224 SHA-224. (since 2.7)
sha256 SHA-256. Current recommended strong hash.
sha384 SHA-384. (since 2.7)
sha512 SHA-512. (since 2.7)
ripemd160
RIPEMD-160. (since 2.7)
sm3 SM3. (since 9.2.0)
Since
2.6
QCryptoCipherAlgo (Enum)
The supported algorithms for content encryption ciphers
Values
aes-128
AES with 128 bit / 16 byte keys
aes-192
AES with 192 bit / 24 byte keys
aes-256
AES with 256 bit / 32 byte keys
des DES with 56 bit / 8 byte keys. Do not use except in VNC. (since 6.1)
3des 3DES(EDE) with 192 bit / 24 byte keys (since 2.9)
cast5-128
Cast5 with 128 bit / 16 byte keys
serpent-128
Serpent with 128 bit / 16 byte keys
serpent-192
Serpent with 192 bit / 24 byte keys
serpent-256
Serpent with 256 bit / 32 byte keys
twofish-128
Twofish with 128 bit / 16 byte keys
twofish-192
Twofish with 192 bit / 24 byte keys
twofish-256
Twofish with 256 bit / 32 byte keys
sm4 SM4 with 128 bit / 16 byte keys (since 9.0)
Since
2.6
QCryptoCipherMode (Enum)
The supported modes for content encryption ciphers
Values
ecb Electronic Code Book
cbc Cipher Block Chaining
xts XEX with tweaked code book and ciphertext stealing
ctr Counter (Since 2.8)
Since
2.6
QCryptoIVGenAlgo (Enum)
The supported algorithms for generating initialization vectors for full disk encryption. The 'plain'
generator should not be used for disks with sector numbers larger than 2^32, except where compatibility
with pre-existing Linux dm-crypt volumes is required.
Values
plain 64-bit sector number truncated to 32-bits
plain64
64-bit sector number
essiv 64-bit sector number encrypted with a hash of the encryption key
Since
2.6
QCryptoBlockFormat (Enum)
The supported full disk encryption formats
Values
qcow QCow/QCow2 built-in AES-CBC encryption. Use only for liberating data from old images.
luks LUKS encryption format. Recommended for new images
Since
2.6
QCryptoBlockOptionsBase (Object)
The common options that apply to all full disk encryption formats
Members
format: QCryptoBlockFormat
the encryption format
Since
2.6
QCryptoBlockOptionsQCow (Object)
The options that apply to QCow/QCow2 AES-CBC encryption format
Members
key-secret: string (optional)
the ID of a QCryptoSecret object providing the decryption key. Mandatory except when probing
image for metadata only.
Since
2.6
QCryptoBlockOptionsLUKS (Object)
The options that apply to LUKS encryption format
Members
key-secret: string (optional)
the ID of a QCryptoSecret object providing the decryption key. Mandatory except when probing
image for metadata only.
Since
2.6
QCryptoBlockCreateOptionsLUKS (Object)
The options that apply to LUKS encryption format initialization
Members
cipher-alg: QCryptoCipherAlgo (optional)
the cipher algorithm for data encryption Currently defaults to 'aes-256'.
cipher-mode: QCryptoCipherMode (optional)
the cipher mode for data encryption Currently defaults to 'xts'
ivgen-alg: QCryptoIVGenAlgo (optional)
the initialization vector generator Currently defaults to 'plain64'
ivgen-hash-alg: QCryptoHashAlgo (optional)
the initialization vector generator hash Currently defaults to 'sha256'
hash-alg: QCryptoHashAlgo (optional)
the master key hash algorithm Currently defaults to 'sha256'
iter-time: int (optional)
number of milliseconds to spend in PBKDF passphrase processing. Currently defaults to 2000.
(since 2.8)
The members of QCryptoBlockOptionsLUKS
Since
2.6
QCryptoBlockOpenOptions (Object)
The options that are available for all encryption formats when opening an existing volume
Members
The members of QCryptoBlockOptionsBase
The members of QCryptoBlockOptionsQCow when format is "qcow"
The members of QCryptoBlockOptionsLUKS when format is "luks"
Since
2.6
QCryptoBlockCreateOptions (Object)
The options that are available for all encryption formats when initializing a new volume
Members
The members of QCryptoBlockOptionsBase
The members of QCryptoBlockOptionsQCow when format is "qcow"
The members of QCryptoBlockCreateOptionsLUKS when format is "luks"
Since
2.6
QCryptoBlockInfoBase (Object)
The common information that applies to all full disk encryption formats
Members
format: QCryptoBlockFormat
the encryption format
Since
2.7
QCryptoBlockInfoLUKSSlot (Object)
Information about the LUKS block encryption key slot options
Members
active: boolean
whether the key slot is currently in use
key-offset: int
offset to the key material in bytes
iters: int (optional)
number of PBKDF2 iterations for key material
stripes: int (optional)
number of stripes for splitting key material
Since
2.7
QCryptoBlockInfoLUKS (Object)
Information about the LUKS block encryption options
Members
cipher-alg: QCryptoCipherAlgo
the cipher algorithm for data encryption
cipher-mode: QCryptoCipherMode
the cipher mode for data encryption
ivgen-alg: QCryptoIVGenAlgo
the initialization vector generator
ivgen-hash-alg: QCryptoHashAlgo (optional)
the initialization vector generator hash
hash-alg: QCryptoHashAlgo
the master key hash algorithm
detached-header: boolean
whether the LUKS header is detached (Since 9.0)
payload-offset: int
offset to the payload data in bytes
master-key-iters: int
number of PBKDF2 iterations for key material
uuid: string
unique identifier for the volume
slots: array of QCryptoBlockInfoLUKSSlot
information about each key slot
Since
2.7
QCryptoBlockInfo (Object)
Information about the block encryption options
Members
The members of QCryptoBlockInfoBase
The members of QCryptoBlockInfoLUKS when format is "luks"
Since
2.7
QCryptoBlockLUKSKeyslotState (Enum)
Defines state of keyslots that are affected by the update
Values
active The slots contain the given password and marked as active
inactive
The slots are erased (contain garbage) and marked as inactive
Since
5.1
QCryptoBlockAmendOptionsLUKS (Object)
This struct defines the update parameters that activate/de-activate set of keyslots
Members
state: QCryptoBlockLUKSKeyslotState
the desired state of the keyslots
new-secret: string (optional)
The ID of a QCryptoSecret object providing the password to be written into added active keyslots
old-secret: string (optional)
Optional (for deactivation only) If given will deactivate all keyslots that match password located
in QCryptoSecret with this ID
iter-time: int (optional)
Optional (for activation only) Number of milliseconds to spend in PBKDF passphrase processing for
the newly activated keyslot. Currently defaults to 2000.
keyslot: int (optional)
Optional. ID of the keyslot to activate/deactivate. For keyslot activation, keyslot should not
be active already (this is unsafe to update an active keyslot), but possible if 'force' parameter
is given. If keyslot is not given, first free keyslot will be written.
For keyslot deactivation, this parameter specifies the exact keyslot to deactivate
secret: string (optional)
Optional. The ID of a QCryptoSecret object providing the password to use to retrieve current
master key. Defaults to the same secret that was used to open the image
Since
5.1
QCryptoBlockAmendOptions (Object)
The options that are available for all encryption formats when amending encryption settings
Members
The members of QCryptoBlockOptionsBase
The members of QCryptoBlockAmendOptionsLUKS when format is "luks"
Since
5.1
SecretCommonProperties (Object)
Properties for objects of classes derived from secret-common.
Members
format: QCryptoSecretFormat (optional)
the data format that the secret is provided in (default: raw)
keyid: string (optional)
the name of another secret that should be used to decrypt the provided data. If not present, the
data is assumed to be unencrypted.
iv: string (optional)
the random initialization vector used for encryption of this particular secret. Should be a
base64 encrypted string of the 16-byte IV. Mandatory if keyid is given. Ignored if keyid is
absent.
Since
2.6
SecretProperties (Object)
Properties for secret objects.
Either data or file must be provided, but not both.
Members
data: string (optional)
the associated with the secret from
file: string (optional)
the filename to load the data associated with the secret from
The members of SecretCommonProperties
Since
2.6
SecretKeyringProperties (Object)
Properties for secret_keyring objects.
Members
serial: int
serial number that identifies a key to get from the kernel
The members of SecretCommonProperties
Since
5.1
If
CONFIG_SECRET_KEYRING
TlsCredsProperties (Object)
Properties for objects of classes derived from tls-creds.
Members
verify-peer: boolean (optional)
if true the peer credentials will be verified once the handshake is completed. This is a no-op
for anonymous credentials. (default: true)
dir: string (optional)
the path of the directory that contains the credential files
endpoint: QCryptoTLSCredsEndpoint (optional)
whether the QEMU network backend that uses the credentials will be acting as a client or as a
server (default: client)
priority: string (optional)
a gnutls priority string as described at https://gnutls.org/manual/html_node/Priority-Strings.html
Since
2.5
TlsCredsAnonProperties (Object)
Properties for tls-creds-anon objects.
Members
The members of TlsCredsProperties
Since
2.5
TlsCredsPskProperties (Object)
Properties for tls-creds-psk objects.
Members
username: string (optional)
the username which will be sent to the server. For clients only. If absent, "qemu" is sent and
the property will read back as an empty string.
The members of TlsCredsProperties
Since
3.0
TlsCredsX509Properties (Object)
Properties for tls-creds-x509 objects.
Members
sanity-check: boolean (optional)
if true, perform some sanity checks before using the credentials (default: true)
passwordid: string (optional)
For the server-key.pem and client-key.pem files which contain sensitive private keys, it is
possible to use an encrypted version by providing the passwordid parameter. This provides the ID
of a previously created secret object containing the password for decryption.
The members of TlsCredsProperties
Since
2.5
QCryptoAkCipherAlgo (Enum)
The supported algorithms for asymmetric encryption ciphers
Values
rsa RSA algorithm
Since
7.1
QCryptoAkCipherKeyType (Enum)
The type of asymmetric keys.
Values
public public key
private
private key
Since
7.1
QCryptoRSAPaddingAlgo (Enum)
The padding algorithm for RSA.
Values
raw no padding used
pkcs1 pkcs1#v1.5
Since
7.1
QCryptoAkCipherOptionsRSA (Object)
Specific parameters for RSA algorithm.
Members
hash-alg: QCryptoHashAlgo
QCryptoHashAlgo
padding-alg: QCryptoRSAPaddingAlgo
QCryptoRSAPaddingAlgo
Since
7.1
QCryptoAkCipherOptions (Object)
The options that are available for all asymmetric key algorithms when creating a new QCryptoAkCipher.
Members
alg: QCryptoAkCipherAlgo
encryption cipher algorithm
The members of QCryptoAkCipherOptionsRSA when alg is "rsa"
Since
7.1
BACKGROUND JOBS
JobType (Enum)
Type of a background job.
Values
commit block commit job type, see "block-commit"
stream block stream job type, see "block-stream"
mirror drive mirror job type, see "drive-mirror"
backup drive backup job type, see "drive-backup"
create image creation job type, see "blockdev-create" (since 3.0)
amend image options amend job type, see "x-blockdev-amend" (since 5.1)
snapshot-load
snapshot load job type, see "snapshot-load" (since 6.0)
snapshot-save
snapshot save job type, see "snapshot-save" (since 6.0)
snapshot-delete
snapshot delete job type, see "snapshot-delete" (since 6.0)
Since
1.7
JobStatus (Enum)
Indicates the present state of a given job in its lifetime.
Values
undefined
Erroneous, default state. Should not ever be visible.
created
The job has been created, but not yet started.
running
The job is currently running.
paused The job is running, but paused. The pause may be requested by either the QMP user or by internal
processes.
ready The job is running, but is ready for the user to signal completion. This is used for long-running
jobs like mirror that are designed to run indefinitely.
standby
The job is ready, but paused. This is nearly identical to paused. The job may return to ready or
otherwise be canceled.
waiting
The job is waiting for other jobs in the transaction to converge to the waiting state. This
status will likely not be visible for the last job in a transaction.
pending
The job has finished its work, but has finalization steps that it needs to make prior to
completing. These changes will require manual intervention via job-finalize if auto-finalize was
set to false. These pending changes may still fail.
aborting
The job is in the process of being aborted, and will finish with an error. The job will
afterwards report that it is concluded. This status may not be visible to the management process.
concluded
The job has finished all work. If auto-dismiss was set to false, the job will remain in the query
list until it is dismissed via job-dismiss.
null The job is in the process of being dismantled. This state should not ever be visible externally.
Since
2.12
JobVerb (Enum)
Represents command verbs that can be applied to a job.
Values
cancel see job-cancel
pause see job-pause
resume see job-resume
set-speed
see block-job-set-speed
complete
see job-complete
dismiss
see job-dismiss
finalize
see job-finalize
change see block-job-change (since 8.2)
Since
2.12
JOB_STATUS_CHANGE (Event)
Emitted when a job transitions to a different status.
Arguments
id: string
The job identifier
status: JobStatus
The new job status
Since
3.0
job-pause (Command)
Pause an active job.
This command returns immediately after marking the active job for pausing. Pausing an already paused job
is an error.
The job will pause as soon as possible, which means transitioning into the PAUSED state if it was
RUNNING, or into STANDBY if it was READY. The corresponding JOB_STATUS_CHANGE event will be emitted.
Cancelling a paused job automatically resumes it.
Arguments
id: string
The job identifier.
Since
3.0
job-resume (Command)
Resume a paused job.
This command returns immediately after resuming a paused job. Resuming an already running job is an
error.
Arguments
id: string
The job identifier.
Since
3.0
job-cancel (Command)
Instruct an active background job to cancel at the next opportunity. This command returns immediately
after marking the active job for cancellation.
The job will cancel as soon as possible and then emit a JOB_STATUS_CHANGE event. Usually, the status
will change to ABORTING, but it is possible that a job successfully completes (e.g. because it was
almost done and there was no opportunity to cancel earlier than completing the job) and transitions to
PENDING instead.
Arguments
id: string
The job identifier.
Since
3.0
job-complete (Command)
Manually trigger completion of an active job in the READY state.
Arguments
id: string
The job identifier.
Since
3.0
job-dismiss (Command)
Deletes a job that is in the CONCLUDED state. This command only needs to be run explicitly for jobs that
don't have automatic dismiss enabled.
This command will refuse to operate on any job that has not yet reached its terminal state,
JOB_STATUS_CONCLUDED. For jobs that make use of JOB_READY event, job-cancel or job-complete will still
need to be used as appropriate.
Arguments
id: string
The job identifier.
Since
3.0
job-finalize (Command)
Instructs all jobs in a transaction (or a single job if it is not part of any transaction) to finalize
any graph changes and do any necessary cleanup. This command requires that all involved jobs are in the
PENDING state.
For jobs in a transaction, instructing one job to finalize will force ALL jobs in the transaction to
finalize, so it is only necessary to instruct a single member job to finalize.
Arguments
id: string
The identifier of any job in the transaction, or of a job that is not part of any transaction.
Since
3.0
JobInfo (Object)
Information about a job.
Members
id: string
The job identifier
type: JobType
The kind of job that is being performed
status: JobStatus
Current job state/status
current-progress: int
Progress made until now. The unit is arbitrary and the value can only meaningfully be used for
the ratio of current-progress to total-progress. The value is monotonically increasing.
total-progress: int
Estimated current-progress value at the completion of the job. This value can arbitrarily change
while the job is running, in both directions.
error: string (optional)
If this field is present, the job failed; if it is still missing in the CONCLUDED state, this
indicates successful completion.
The value is a human-readable error message to describe the reason for the job failure. It should
not be parsed by applications.
Since
3.0
query-jobs (Command)
Return information about jobs.
Returns
a list with a JobInfo for each active job
Since
3.0
BLOCK DEVICES
Block core (VM unrelated)
SnapshotInfo (Object)
Members
id: string
unique snapshot id
name: string
user chosen name
vm-state-size: int
size of the VM state
date-sec: int
UTC date of the snapshot in seconds
date-nsec: int
fractional part in nano seconds to be used with date-sec
vm-clock-sec: int
VM clock relative to boot in seconds
vm-clock-nsec: int
fractional part in nano seconds to be used with vm-clock-sec
icount: int (optional)
Current instruction count. Appears when execution record/replay is enabled. Used for
"time-traveling" to match the moment in the recorded execution with the snapshots. This counter
may be obtained through query-replay command (since 5.2)
Since
1.3
ImageInfoSpecificQCow2EncryptionBase (Object)
Members
format: BlockdevQcow2EncryptionFormat
The encryption format
Since
2.10
ImageInfoSpecificQCow2Encryption (Object)
Members
The members of ImageInfoSpecificQCow2EncryptionBase
The members of QCryptoBlockInfoLUKS when format is "luks"
Since
2.10
ImageInfoSpecificQCow2 (Object)
Members
compat: string
compatibility level
data-file: string (optional)
the filename of the external data file that is stored in the image and used as a default for
opening the image (since: 4.0)
data-file-raw: boolean (optional)
True if the external data file must stay valid as a standalone (read-only) raw image without
looking at qcow2 metadata (since: 4.0)
extended-l2: boolean (optional)
true if the image has extended L2 entries; only valid for compat >= 1.1 (since 5.2)
lazy-refcounts: boolean (optional)
on or off; only valid for compat >= 1.1
corrupt: boolean (optional)
true if the image has been marked corrupt; only valid for compat >= 1.1 (since 2.2)
refcount-bits: int
width of a refcount entry in bits (since 2.3)
encrypt: ImageInfoSpecificQCow2Encryption (optional)
details about encryption parameters; only set if image is encrypted (since 2.10)
bitmaps: array of Qcow2BitmapInfo (optional)
A list of qcow2 bitmap details (since 4.0)
compression-type: Qcow2CompressionType
the image cluster compression method (since 5.1)
Since
1.7
ImageInfoSpecificVmdk (Object)
Members
create-type: string
The create type of VMDK image
cid: int
Content id of image
parent-cid: int
Parent VMDK image's cid
extents: array of VmdkExtentInfo
List of extent files
Since
1.7
VmdkExtentInfo (Object)
Information about a VMDK extent file
Members
filename: string
Name of the extent file
format: string
Extent type (e.g. FLAT or SPARSE)
virtual-size: int
Number of bytes covered by this extent
cluster-size: int (optional)
Cluster size in bytes (for non-flat extents)
compressed: boolean (optional)
Whether this extent contains compressed data
Since
8.0
ImageInfoSpecificRbd (Object)
Members
encryption-format: RbdImageEncryptionFormat (optional)
Image encryption format
Since
6.1
ImageInfoSpecificFile (Object)
Members
extent-size-hint: int (optional)
Extent size hint (if available)
Since
8.0
ImageInfoSpecificKind (Enum)
Values
luks Since 2.7
rbd Since 6.1
file Since 8.0
qcow2 Not documented
vmdk Not documented
Since
1.7
ImageInfoSpecificQCow2Wrapper (Object)
Members
data: ImageInfoSpecificQCow2
image information specific to QCOW2
Since
1.7
ImageInfoSpecificVmdkWrapper (Object)
Members
data: ImageInfoSpecificVmdk
image information specific to VMDK
Since
6.1
ImageInfoSpecificLUKSWrapper (Object)
Members
data: QCryptoBlockInfoLUKS
image information specific to LUKS
Since
2.7
ImageInfoSpecificRbdWrapper (Object)
Members
data: ImageInfoSpecificRbd
image information specific to RBD
Since
6.1
ImageInfoSpecificFileWrapper (Object)
Members
data: ImageInfoSpecificFile
image information specific to files
Since
8.0
ImageInfoSpecific (Object)
A discriminated record of image format specific information structures.
Members
type: ImageInfoSpecificKind
block driver name
The members of ImageInfoSpecificQCow2Wrapper when type is "qcow2"
The members of ImageInfoSpecificVmdkWrapper when type is "vmdk"
The members of ImageInfoSpecificLUKSWrapper when type is "luks"
The members of ImageInfoSpecificRbdWrapper when type is "rbd"
The members of ImageInfoSpecificFileWrapper when type is "file"
Since
1.7
BlockNodeInfo (Object)
Information about a QEMU image file
Members
filename: string
name of the image file
format: string
format of the image file
virtual-size: int
maximum capacity in bytes of the image
actual-size: int (optional)
actual size on disk in bytes of the image
dirty-flag: boolean (optional)
true if image is not cleanly closed
cluster-size: int (optional)
size of a cluster in bytes
encrypted: boolean (optional)
true if the image is encrypted
compressed: boolean (optional)
true if the image is compressed (Since 1.7)
backing-filename: string (optional)
name of the backing file
full-backing-filename: string (optional)
full path of the backing file
backing-filename-format: string (optional)
the format of the backing file
snapshots: array of SnapshotInfo (optional)
list of VM snapshots
format-specific: ImageInfoSpecific (optional)
structure supplying additional format-specific information (since 1.7)
Since
8.0
ImageInfo (Object)
Information about a QEMU image file, and potentially its backing image
Members
backing-image: ImageInfo (optional)
info of the backing image
The members of BlockNodeInfo
Since
1.3
BlockChildInfo (Object)
Information about all nodes in the block graph starting at some node, annotated with information about
that node in relation to its parent.
Members
name: string
Child name of the root node in the BlockGraphInfo struct, in its role as the child of some
undescribed parent node
info: BlockGraphInfo
Block graph information starting at this node
Since
8.0
BlockGraphInfo (Object)
Information about all nodes in a block (sub)graph in the form of BlockNodeInfo data. The base
BlockNodeInfo struct contains the information for the (sub)graph's root node.
Members
children: array of BlockChildInfo
Array of links to this node's child nodes' information
The members of BlockNodeInfo
Since
8.0
ImageCheck (Object)
Information about a QEMU image file check
Members
filename: string
name of the image file checked
format: string
format of the image file checked
check-errors: int
number of unexpected errors occurred during check
image-end-offset: int (optional)
offset (in bytes) where the image ends, this field is present if the driver for the image format
supports it
corruptions: int (optional)
number of corruptions found during the check if any
leaks: int (optional)
number of leaks found during the check if any
corruptions-fixed: int (optional)
number of corruptions fixed during the check if any
leaks-fixed: int (optional)
number of leaks fixed during the check if any
total-clusters: int (optional)
total number of clusters, this field is present if the driver for the image format supports it
allocated-clusters: int (optional)
total number of allocated clusters, this field is present if the driver for the image format
supports it
fragmented-clusters: int (optional)
total number of fragmented clusters, this field is present if the driver for the image format
supports it
compressed-clusters: int (optional)
total number of compressed clusters, this field is present if the driver for the image format
supports it
Since
1.4
MapEntry (Object)
Mapping information from a virtual block range to a host file range
Members
start: int
virtual (guest) offset of the first byte described by this entry
length: int
the number of bytes of the mapped virtual range
data: boolean
reading the image will actually read data from a file (in particular, if offset is present this
means that the sectors are not simply preallocated, but contain actual data in raw format)
zero: boolean
whether the virtual blocks read as zeroes
compressed: boolean
true if the data is stored compressed (since 8.2)
depth: int
number of layers (0 = top image, 1 = top image's backing file, ..., n - 1 = bottom image (where n
is the number of images in the chain)) before reaching one for which the range is allocated
present: boolean
true if this layer provides the data, false if adding a backing layer could impact this region
(since 6.1)
offset: int (optional)
if present, the image file stores the data for this range in raw format at the given (host) offset
filename: string (optional)
filename that is referred to by offset
Since
2.6
BlockdevCacheInfo (Object)
Cache mode information for a block device
Members
writeback: boolean
true if writeback mode is enabled
direct: boolean
true if the host page cache is bypassed (O_DIRECT)
no-flush: boolean
true if flush requests are ignored for the device
Since
2.3
BlockDeviceInfo (Object)
Information about the backing device for a block device.
Members
file: string
the filename of the backing device
node-name: string (optional)
the name of the block driver node (Since 2.0)
ro: boolean
true if the backing device was open read-only
drv: string
the name of the block format used to open the backing device. As of 0.14 this can be: 'blkdebug',
'bochs', 'cloop', 'cow', 'dmg', 'file', 'file', 'ftp', 'ftps', 'host_cdrom', 'host_device',
'http', 'https', 'luks', 'nbd', 'parallels', 'qcow', 'qcow2', 'raw', 'vdi', 'vmdk', 'vpc', 'vvfat'
2.2: 'archipelago' added, 'cow' dropped 2.3: 'host_floppy' deprecated 2.5: 'host_floppy' dropped
2.6: 'luks' added 2.8: 'replication' added, 'tftp' dropped 2.9: 'archipelago' dropped
backing_file: string (optional)
the name of the backing file (for copy-on-write)
backing_file_depth: int
number of files in the backing file chain (since: 1.2)
encrypted: boolean
true if the backing device is encrypted
detect_zeroes: BlockdevDetectZeroesOptions
detect and optimize zero writes (Since 2.1)
bps: int
total throughput limit in bytes per second is specified
bps_rd: int
read throughput limit in bytes per second is specified
bps_wr: int
write throughput limit in bytes per second is specified
iops: int
total I/O operations per second is specified
iops_rd: int
read I/O operations per second is specified
iops_wr: int
write I/O operations per second is specified
image: ImageInfo
the info of image used (since: 1.6)
bps_max: int (optional)
total throughput limit during bursts, in bytes (Since 1.7)
bps_rd_max: int (optional)
read throughput limit during bursts, in bytes (Since 1.7)
bps_wr_max: int (optional)
write throughput limit during bursts, in bytes (Since 1.7)
iops_max: int (optional)
total I/O operations per second during bursts, in bytes (Since 1.7)
iops_rd_max: int (optional)
read I/O operations per second during bursts, in bytes (Since 1.7)
iops_wr_max: int (optional)
write I/O operations per second during bursts, in bytes (Since 1.7)
bps_max_length: int (optional)
maximum length of the bps_max burst period, in seconds. (Since 2.6)
bps_rd_max_length: int (optional)
maximum length of the bps_rd_max burst period, in seconds. (Since 2.6)
bps_wr_max_length: int (optional)
maximum length of the bps_wr_max burst period, in seconds. (Since 2.6)
iops_max_length: int (optional)
maximum length of the iops burst period, in seconds. (Since 2.6)
iops_rd_max_length: int (optional)
maximum length of the iops_rd_max burst period, in seconds. (Since 2.6)
iops_wr_max_length: int (optional)
maximum length of the iops_wr_max burst period, in seconds. (Since 2.6)
iops_size: int (optional)
an I/O size in bytes (Since 1.7)
group: string (optional)
throttle group name (Since 2.4)
cache: BlockdevCacheInfo
the cache mode used for the block device (since: 2.3)
write_threshold: int
configured write threshold for the device. 0 if disabled. (Since 2.3)
dirty-bitmaps: array of BlockDirtyInfo (optional)
dirty bitmaps information (only present if node has one or more dirty bitmaps) (Since 4.2)
Since
0.14
BlockDeviceIoStatus (Enum)
An enumeration of block device I/O status.
Values
ok The last I/O operation has succeeded
failed The last I/O operation has failed
nospace
The last I/O operation has failed due to a no-space condition
Since
1.0
BlockDirtyInfo (Object)
Block dirty bitmap information.
Members
name: string (optional)
the name of the dirty bitmap (Since 2.4)
count: int
number of dirty bytes according to the dirty bitmap
granularity: int
granularity of the dirty bitmap in bytes (since 1.4)
recording: boolean
true if the bitmap is recording new writes from the guest. (since 4.0)
busy: boolean
true if the bitmap is in-use by some operation (NBD or jobs) and cannot be modified via QMP or
used by another operation. (since 4.0)
persistent: boolean
true if the bitmap was stored on disk, is scheduled to be stored on disk, or both. (since 4.0)
inconsistent: boolean (optional)
true if this is a persistent bitmap that was improperly stored. Implies persistent to be true;
recording and busy to be false. This bitmap cannot be used. To remove it, use
block-dirty-bitmap-remove. (Since 4.0)
Since
1.3
Qcow2BitmapInfoFlags (Enum)
An enumeration of flags that a bitmap can report to the user.
Values
in-use This flag is set by any process actively modifying the qcow2 file, and cleared when the updated
bitmap is flushed to the qcow2 image. The presence of this flag in an offline image means that
the bitmap was not saved correctly after its last usage, and may contain inconsistent data.
auto The bitmap must reflect all changes of the virtual disk by any application that would write to
this qcow2 file.
Since
4.0
Qcow2BitmapInfo (Object)
Qcow2 bitmap information.
Members
name: string
the name of the bitmap
granularity: int
granularity of the bitmap in bytes
flags: array of Qcow2BitmapInfoFlags
flags of the bitmap
Since
4.0
BlockLatencyHistogramInfo (Object)
Block latency histogram.
Members
boundaries: array of int
list of interval boundary values in nanoseconds, all greater than zero and in ascending order.
For example, the list [10, 50, 100] produces the following histogram intervals: [0, 10), [10, 50),
[50, 100), [100, +inf).
bins: array of int
list of io request counts corresponding to histogram intervals, one more element than boundaries
has. For the example above, bins may be something like [3, 1, 5, 2], and corresponding histogram
looks like:
5| *
4| *
3| * *
2| * * *
1| * * * *
+------------------
10 50 100
Since
4.0
BlockInfo (Object)
Block device information. This structure describes a virtual device and the backing device associated
with it.
Members
device: string
The device name associated with the virtual device.
qdev: string (optional)
The qdev ID, or if no ID is assigned, the QOM path of the block device. (since 2.10)
type: string
This field is returned only for compatibility reasons, it should not be used (always returns
'unknown')
removable: boolean
True if the device supports removable media.
locked: boolean
True if the guest has locked this device from having its media removed
tray_open: boolean (optional)
True if the device's tray is open (only present if it has a tray)
io-status: BlockDeviceIoStatus (optional)
BlockDeviceIoStatus. Only present if the device supports it and the VM is configured to stop on
errors (supported device models: virtio-blk, IDE, SCSI except scsi-generic)
inserted: BlockDeviceInfo (optional)
BlockDeviceInfo describing the device if media is present
Since
0.14
BlockMeasureInfo (Object)
Image file size calculation information. This structure describes the size requirements for creating a
new image file.
The size requirements depend on the new image file format. File size always equals virtual disk size for
the 'raw' format, even for sparse POSIX files. Compact formats such as 'qcow2' represent unallocated and
zero regions efficiently so file size may be smaller than virtual disk size.
The values are upper bounds that are guaranteed to fit the new image file. Subsequent modification, such
as internal snapshot or further bitmap creation, may require additional space and is not covered here.
Members
required: int
Size required for a new image file, in bytes, when copying just allocated guest-visible contents.
fully-allocated: int
Image file size, in bytes, once data has been written to all sectors, when copying just
guest-visible contents.
bitmaps: int (optional)
Additional size required if all the top-level bitmap metadata in the source image were to be
copied to the destination, present only when source and destination both support persistent
bitmaps. (since 5.1)
Since
2.10
query-block (Command)
Get a list of BlockInfo for all virtual block devices.
Returns
a list of BlockInfo describing each virtual block device. Filter nodes that were created implicitly are
skipped over.
Since
0.14
Example:
-> { "execute": "query-block" }
<- {
"return":[
{
"io-status": "ok",
"device":"ide0-hd0",
"locked":false,
"removable":false,
"inserted":{
"ro":false,
"drv":"qcow2",
"encrypted":false,
"file":"disks/test.qcow2",
"backing_file_depth":1,
"bps":1000000,
"bps_rd":0,
"bps_wr":0,
"iops":1000000,
"iops_rd":0,
"iops_wr":0,
"bps_max": 8000000,
"bps_rd_max": 0,
"bps_wr_max": 0,
"iops_max": 0,
"iops_rd_max": 0,
"iops_wr_max": 0,
"iops_size": 0,
"detect_zeroes": "on",
"write_threshold": 0,
"image":{
"filename":"disks/test.qcow2",
"format":"qcow2",
"virtual-size":2048000,
"backing_file":"base.qcow2",
"full-backing-filename":"disks/base.qcow2",
"backing-filename-format":"qcow2",
"snapshots":[
{
"id": "1",
"name": "snapshot1",
"vm-state-size": 0,
"date-sec": 10000200,
"date-nsec": 12,
"vm-clock-sec": 206,
"vm-clock-nsec": 30
}
],
"backing-image":{
"filename":"disks/base.qcow2",
"format":"qcow2",
"virtual-size":2048000
}
}
},
"qdev": "ide_disk",
"type":"unknown"
},
{
"io-status": "ok",
"device":"ide1-cd0",
"locked":false,
"removable":true,
"qdev": "/machine/unattached/device[23]",
"tray_open": false,
"type":"unknown"
},
{
"device":"floppy0",
"locked":false,
"removable":true,
"qdev": "/machine/unattached/device[20]",
"type":"unknown"
},
{
"device":"sd0",
"locked":false,
"removable":true,
"type":"unknown"
}
]
}
BlockDeviceTimedStats (Object)
Statistics of a block device during a given interval of time.
Members
interval_length: int
Interval used for calculating the statistics, in seconds.
min_rd_latency_ns: int
Minimum latency of read operations in the defined interval, in nanoseconds.
min_wr_latency_ns: int
Minimum latency of write operations in the defined interval, in nanoseconds.
min_zone_append_latency_ns: int
Minimum latency of zone append operations in the defined interval, in nanoseconds (since 8.1)
min_flush_latency_ns: int
Minimum latency of flush operations in the defined interval, in nanoseconds.
max_rd_latency_ns: int
Maximum latency of read operations in the defined interval, in nanoseconds.
max_wr_latency_ns: int
Maximum latency of write operations in the defined interval, in nanoseconds.
max_zone_append_latency_ns: int
Maximum latency of zone append operations in the defined interval, in nanoseconds (since 8.1)
max_flush_latency_ns: int
Maximum latency of flush operations in the defined interval, in nanoseconds.
avg_rd_latency_ns: int
Average latency of read operations in the defined interval, in nanoseconds.
avg_wr_latency_ns: int
Average latency of write operations in the defined interval, in nanoseconds.
avg_zone_append_latency_ns: int
Average latency of zone append operations in the defined interval, in nanoseconds (since 8.1)
avg_flush_latency_ns: int
Average latency of flush operations in the defined interval, in nanoseconds.
avg_rd_queue_depth: number
Average number of pending read operations in the defined interval.
avg_wr_queue_depth: number
Average number of pending write operations in the defined interval.
avg_zone_append_queue_depth: number
Average number of pending zone append operations in the defined interval (since 8.1).
Since
2.5
BlockDeviceStats (Object)
Statistics of a virtual block device or a block backing device.
Members
rd_bytes: int
The number of bytes read by the device.
wr_bytes: int
The number of bytes written by the device.
zone_append_bytes: int
The number of bytes appended by the zoned devices (since 8.1)
unmap_bytes: int
The number of bytes unmapped by the device (Since 4.2)
rd_operations: int
The number of read operations performed by the device.
wr_operations: int
The number of write operations performed by the device.
zone_append_operations: int
The number of zone append operations performed by the zoned devices (since 8.1)
flush_operations: int
The number of cache flush operations performed by the device (since 0.15)
unmap_operations: int
The number of unmap operations performed by the device (Since 4.2)
rd_total_time_ns: int
Total time spent on reads in nanoseconds (since 0.15).
wr_total_time_ns: int
Total time spent on writes in nanoseconds (since 0.15).
zone_append_total_time_ns: int
Total time spent on zone append writes in nanoseconds (since 8.1)
flush_total_time_ns: int
Total time spent on cache flushes in nanoseconds (since 0.15).
unmap_total_time_ns: int
Total time spent on unmap operations in nanoseconds (Since 4.2)
wr_highest_offset: int
The offset after the greatest byte written to the device. The intended use of this information is
for growable sparse files (like qcow2) that are used on top of a physical device.
rd_merged: int
Number of read requests that have been merged into another request (Since 2.3).
wr_merged: int
Number of write requests that have been merged into another request (Since 2.3).
zone_append_merged: int
Number of zone append requests that have been merged into another request (since 8.1)
unmap_merged: int
Number of unmap requests that have been merged into another request (Since 4.2)
idle_time_ns: int (optional)
Time since the last I/O operation, in nanoseconds. If the field is absent it means that there
haven't been any operations yet (Since 2.5).
failed_rd_operations: int
The number of failed read operations performed by the device (Since 2.5)
failed_wr_operations: int
The number of failed write operations performed by the device (Since 2.5)
failed_zone_append_operations: int
The number of failed zone append write operations performed by the zoned devices (since 8.1)
failed_flush_operations: int
The number of failed flush operations performed by the device (Since 2.5)
failed_unmap_operations: int
The number of failed unmap operations performed by the device (Since 4.2)
invalid_rd_operations: int
The number of invalid read operations performed by the device (Since 2.5)
invalid_wr_operations: int
The number of invalid write operations performed by the device (Since 2.5)
invalid_zone_append_operations: int
The number of invalid zone append operations performed by the zoned device (since 8.1)
invalid_flush_operations: int
The number of invalid flush operations performed by the device (Since 2.5)
invalid_unmap_operations: int
The number of invalid unmap operations performed by the device (Since 4.2)
account_invalid: boolean
Whether invalid operations are included in the last access statistics (Since 2.5)
account_failed: boolean
Whether failed operations are included in the latency and last access statistics (Since 2.5)
timed_stats: array of BlockDeviceTimedStats
Statistics specific to the set of previously defined intervals of time (Since 2.5)
rd_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (Since 4.0)
wr_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (Since 4.0)
zone_append_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (since 8.1)
flush_latency_histogram: BlockLatencyHistogramInfo (optional)
BlockLatencyHistogramInfo. (Since 4.0)
Since
0.14
BlockStatsSpecificFile (Object)
File driver statistics
Members
discard-nb-ok: int
The number of successful discard operations performed by the driver.
discard-nb-failed: int
The number of failed discard operations performed by the driver.
discard-bytes-ok: int
The number of bytes discarded by the driver.
Since
4.2
BlockStatsSpecificNvme (Object)
NVMe driver statistics
Members
completion-errors: int
The number of completion errors.
aligned-accesses: int
The number of aligned accesses performed by the driver.
unaligned-accesses: int
The number of unaligned accesses performed by the driver.
Since
5.2
BlockStatsSpecific (Object)
Block driver specific statistics
Members
driver: BlockdevDriver
block driver name
The members of BlockStatsSpecificFile when driver is "file"
The members of BlockStatsSpecificFile when driver is "host_device" (If: HAVE_HOST_BLOCK_DEVICE)
The members of BlockStatsSpecificNvme when driver is "nvme"
Since
4.2
BlockStats (Object)
Statistics of a virtual block device or a block backing device.
Members
device: string (optional)
If the stats are for a virtual block device, the name corresponding to the virtual block device.
node-name: string (optional)
The node name of the device. (Since 2.3)
qdev: string (optional)
The qdev ID, or if no ID is assigned, the QOM path of the block device. (since 3.0)
stats: BlockDeviceStats
A BlockDeviceStats for the device.
driver-specific: BlockStatsSpecific (optional)
Optional driver-specific stats. (Since 4.2)
parent: BlockStats (optional)
This describes the file block device if it has one. Contains recursively the statistics of the
underlying protocol (e.g. the host file for a qcow2 image). If there is no underlying protocol,
this field is omitted
backing: BlockStats (optional)
This describes the backing block device if it has one. (Since 2.0)
Since
0.14
query-blockstats (Command)
Query the BlockStats for all virtual block devices.
Arguments
query-nodes: boolean (optional)
If true, the command will query all the block nodes that have a node name, in a list which will
include "parent" information, but not "backing". If false or omitted, the behavior is as before -
query all the device backends, recursively including their "parent" and "backing". Filter nodes
that were created implicitly are skipped over in this mode. (Since 2.3)
Returns
A list of BlockStats for each virtual block devices.
Since
0.14
Example:
-> { "execute": "query-blockstats" }
<- {
"return":[
{
"device":"ide0-hd0",
"parent":{
"stats":{
"wr_highest_offset":3686448128,
"wr_bytes":9786368,
"wr_operations":751,
"rd_bytes":122567168,
"rd_operations":36772
"wr_total_times_ns":313253456
"rd_total_times_ns":3465673657
"flush_total_times_ns":49653
"flush_operations":61,
"rd_merged":0,
"wr_merged":0,
"idle_time_ns":2953431879,
"account_invalid":true,
"account_failed":false
}
},
"stats":{
"wr_highest_offset":2821110784,
"wr_bytes":9786368,
"wr_operations":692,
"rd_bytes":122739200,
"rd_operations":36604
"flush_operations":51,
"wr_total_times_ns":313253456
"rd_total_times_ns":3465673657
"flush_total_times_ns":49653,
"rd_merged":0,
"wr_merged":0,
"idle_time_ns":2953431879,
"account_invalid":true,
"account_failed":false
},
"qdev": "/machine/unattached/device[23]"
},
{
"device":"ide1-cd0",
"stats":{
"wr_highest_offset":0,
"wr_bytes":0,
"wr_operations":0,
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0,
"rd_merged":0,
"wr_merged":0,
"account_invalid":false,
"account_failed":false
},
"qdev": "/machine/unattached/device[24]"
},
{
"device":"floppy0",
"stats":{
"wr_highest_offset":0,
"wr_bytes":0,
"wr_operations":0,
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0,
"rd_merged":0,
"wr_merged":0,
"account_invalid":false,
"account_failed":false
},
"qdev": "/machine/unattached/device[16]"
},
{
"device":"sd0",
"stats":{
"wr_highest_offset":0,
"wr_bytes":0,
"wr_operations":0,
"rd_bytes":0,
"rd_operations":0
"flush_operations":0,
"wr_total_times_ns":0
"rd_total_times_ns":0
"flush_total_times_ns":0,
"rd_merged":0,
"wr_merged":0,
"account_invalid":false,
"account_failed":false
}
}
]
}
BlockdevOnError (Enum)
An enumeration of possible behaviors for errors on I/O operations. The exact meaning depends on whether
the I/O was initiated by a guest or by a block job
Values
report for guest operations, report the error to the guest; for jobs, cancel the job
ignore ignore the error, only report a QMP event (BLOCK_IO_ERROR or BLOCK_JOB_ERROR). The backup, mirror
and commit block jobs retry the failing request later and may still complete successfully. The
stream block job continues to stream and will complete with an error.
enospc same as stop on ENOSPC, same as report otherwise.
stop for guest operations, stop the virtual machine; for jobs, pause the job
auto inherit the error handling policy of the backend (since: 2.7)
Since
1.3
MirrorSyncMode (Enum)
An enumeration of possible behaviors for the initial synchronization phase of storage mirroring.
Values
top copies data in the topmost image to the destination
full copies data from all images to the destination
none only copy data written from now on
incremental
only copy data described by the dirty bitmap. (since: 2.4)
bitmap only copy data described by the dirty bitmap. (since: 4.2) Behavior on completion is determined
by the BitmapSyncMode.
Since
1.3
BitmapSyncMode (Enum)
An enumeration of possible behaviors for the synchronization of a bitmap when used for data copy
operations.
Values
on-success
The bitmap is only synced when the operation is successful. This is the behavior always used for
'INCREMENTAL' backups.
never The bitmap is never synchronized with the operation, and is treated solely as a read-only manifest
of blocks to copy.
always The bitmap is always synchronized with the operation, regardless of whether or not the operation
was successful.
Since
4.2
MirrorCopyMode (Enum)
An enumeration whose values tell the mirror block job when to trigger writes to the target.
Values
background
copy data in background only.
write-blocking
when data is written to the source, write it (synchronously) to the target as well. In addition,
data is copied in background just like in background mode.
Since
3.0
BlockJobInfoMirror (Object)
Information specific to mirror block jobs.
Members
actively-synced: boolean
Whether the source is actively synced to the target, i.e. same data and new writes are done
synchronously to both.
Since
8.2
BlockJobInfo (Object)
Information about a long-running block device operation.
Members
type: JobType
the job type ('stream' for image streaming)
device: string
The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int
Estimated offset value at the completion of the job. This value can arbitrarily change while the
job is running, in both directions.
offset: int
Progress made until now. The unit is arbitrary and the value can only meaningfully be used for
the ratio of offset to len. The value is monotonically increasing.
busy: boolean
false if the job is known to be in a quiescent state, with no pending I/O. (Since 1.3)
paused: boolean
whether the job is paused or, if busy is true, will pause itself as soon as possible. (Since 1.3)
speed: int
the rate limit, bytes per second
io-status: BlockDeviceIoStatus
the status of the job (since 1.3)
ready: boolean
true if the job may be completed (since 2.2)
status: JobStatus
Current job state/status (since 2.12)
auto-finalize: boolean
Job will finalize itself when PENDING, moving to the CONCLUDED state. (since 2.12)
auto-dismiss: boolean
Job will dismiss itself when CONCLUDED, moving to the NULL state and disappearing from the query
list. (since 2.12)
error: string (optional)
Error information if the job did not complete successfully. Not set if the job completed
successfully. (since 2.12.1)
The members of BlockJobInfoMirror when type is "mirror"
Since
1.1
query-block-jobs (Command)
Return information about long-running block device operations.
Returns
a list of BlockJobInfo for each active block job
Since
1.1
block_resize (Command)
Resize a block image while a guest is running.
Either device or node-name must be set but not both.
Arguments
device: string (optional)
the name of the device to get the image resized
node-name: string (optional)
graph node name to get the image resized (Since 2.0)
size: int
new image size in bytes
Errors
• If device is not a valid block device, DeviceNotFound
Since
0.14
Example:
-> { "execute": "block_resize",
"arguments": { "device": "scratch", "size": 1073741824 } }
<- { "return": {} }
NewImageMode (Enum)
An enumeration that tells QEMU how to set the backing file path in a new image file.
Values
existing
QEMU should look for an existing image file.
absolute-paths
QEMU should create a new image with absolute paths for the backing file. If there is no backing
file available, the new image will not be backed either.
Since
1.1
BlockdevSnapshotSync (Object)
Either device or node-name must be set but not both.
Members
device: string (optional)
the name of the device to take a snapshot of.
node-name: string (optional)
graph node name to generate the snapshot from (Since 2.0)
snapshot-file: string
the target of the new overlay image. If the file exists, or if it is a device, the overlay will
be created in the existing file/device. Otherwise, a new file will be created.
snapshot-node-name: string (optional)
the graph node name of the new image (Since 2.0)
format: string (optional)
the format of the overlay image, default is 'qcow2'.
mode: NewImageMode (optional)
whether and how QEMU should create a new image, default is 'absolute-paths'.
BlockdevSnapshot (Object)
Members
node: string
device or node name that will have a snapshot taken.
overlay: string
reference to the existing block device that will become the overlay of node, as part of taking the
snapshot. It must not have a current backing file (this can be achieved by passing "backing":
null to blockdev-add).
Since
2.5
BackupPerf (Object)
Optional parameters for backup. These parameters don't affect functionality, but may significantly
affect performance.
Members
use-copy-range: boolean (optional)
Use copy offloading. Default false.
max-workers: int (optional)
Maximum number of parallel requests for the sustained background copying process. Doesn't
influence copy-before-write operations. Default 64.
max-chunk: int (optional)
Maximum request length for the sustained background copying process. Doesn't influence
copy-before-write operations. 0 means unlimited. If max-chunk is non-zero then it should not be
less than job cluster size which is calculated as maximum of target image cluster size and 64k.
Default 0.
min-cluster-size: int (optional)
Minimum size of blocks used by copy-before-write and background copy operations. Has to be a
power of 2. No effect if smaller than the maximum of the target's cluster size and 64 KiB.
Default 0. (Since 9.2)
Since
6.0
BackupCommon (Object)
Members
job-id: string (optional)
identifier for the newly-created block job. If omitted, the device name will be used. (Since
2.7)
device: string
the device name or node-name of a root node which should be copied.
sync: MirrorSyncMode
what parts of the disk image should be copied to the destination (all the disk, only the sectors
allocated in the topmost image, from a dirty bitmap, or only new I/O).
speed: int (optional)
the maximum speed, in bytes per second. The default is 0, for unlimited.
bitmap: string (optional)
The name of a dirty bitmap to use. Must be present if sync is "bitmap" or "incremental". Can be
present if sync is "full" or "top". Must not be present otherwise. (Since 2.4 (drive-backup),
3.1 (blockdev-backup))
bitmap-mode: BitmapSyncMode (optional)
Specifies the type of data the bitmap should contain after the operation concludes. Must be
present if a bitmap was provided, Must NOT be present otherwise. (Since 4.2)
compress: boolean (optional)
true to compress data, if the target format supports it. (default: false) (since 2.8)
on-source-error: BlockdevOnError (optional)
the action to take on an error on the source, default 'report'. 'stop' and 'enospc' can only be
used if the block device supports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional)
the action to take on an error on the target, default 'report' (no limitations, since this applies
to a different block device than device).
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has finished its work, waiting for
block-job-finalize before making any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since 2.12)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and
awaits block-job-dismiss. When true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 2.12)
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that the backup job inserts into the
graph above node specified by drive. If this option is not given, a node name is autogenerated.
(Since: 4.2)
discard-source: boolean (optional)
Discard blocks on source which have already been copied to the target. (Since 9.1)
x-perf: BackupPerf (optional)
Performance options. (Since 6.0)
Features
unstable
Member x-perf is experimental.
NOTE:
on-source-error and on-target-error only affect background I/O. If an error occurs during a guest
write request, the device's rerror/werror actions will be used.
Since
4.2
DriveBackup (Object)
Members
target: string
the target of the new image. If the file exists, or if it is a device, the existing file/device
will be used as the new destination. If it does not exist, a new file will be created.
format: string (optional)
the format of the new destination, default is to probe if mode is 'existing', else the format of
the source
mode: NewImageMode (optional)
whether and how QEMU should create a new image, default is 'absolute-paths'.
The members of BackupCommon
Since
1.6
BlockdevBackup (Object)
Members
target: string
the device name or node-name of the backup target node.
The members of BackupCommon
Since
2.3
blockdev-snapshot-sync (Command)
Takes a synchronous snapshot of a block device.
Arguments
The members of BlockdevSnapshotSync
Errors
• If device is not a valid block device, DeviceNotFound
Since
0.14
Example:
-> { "execute": "blockdev-snapshot-sync",
"arguments": { "device": "ide-hd0",
"snapshot-file":
"/some/place/my-image",
"format": "qcow2" } }
<- { "return": {} }
blockdev-snapshot (Command)
Takes a snapshot of a block device.
Take a snapshot, by installing 'node' as the backing image of 'overlay'. Additionally, if 'node' is
associated with a block device, the block device changes to using 'overlay' as its new active image.
Arguments
The members of BlockdevSnapshot
Features
allow-write-only-overlay
If present, the check whether this operation is safe was relaxed so that it can be used to change
backing file of a destination of a blockdev-mirror. (since 5.0)
Since
2.5
Example:
-> { "execute": "blockdev-add",
"arguments": { "driver": "qcow2",
"node-name": "node1534",
"file": { "driver": "file",
"filename": "hd1.qcow2" },
"backing": null } }
<- { "return": {} }
-> { "execute": "blockdev-snapshot",
"arguments": { "node": "ide-hd0",
"overlay": "node1534" } }
<- { "return": {} }
change-backing-file (Command)
Change the backing file in the image file metadata. This does not cause QEMU to reopen the image file to
reparse the backing filename (it may, however, perform a reopen to change permissions from r/o -> r/w ->
r/o, if needed). The new backing file string is written into the image file metadata, and the QEMU
internal strings are updated.
Arguments
image-node-name: string
The name of the block driver state node of the image to modify. The "device" argument is used to
verify "image-node-name" is in the chain described by "device".
device: string
The device name or node-name of the root node that owns image-node-name.
backing-file: string
The string to write as the backing file. This string is not validated, so care should be taken
when specifying the string or the image chain may not be able to be reopened again.
Errors
• If "device" does not exist or cannot be determined, DeviceNotFound
Since
2.1
block-commit (Command)
Live commit of data from overlay image nodes into backing nodes - i.e., writes data between 'top' and
'base' into 'base'.
If top == base, that is an error. If top has no overlays on top of it, or if it is in use by a writer,
the job will not be completed by itself. The user needs to complete the job with the block-job-complete
command after getting the ready event. (Since 2.0)
If the base image is smaller than top, then the base image will be resized to be the same size as top.
If top is smaller than the base image, the base will not be truncated. If you want the base image size
to match the size of the smaller top, you can safely truncate it yourself once the commit operation
successfully completes.
Arguments
job-id: string (optional)
identifier for the newly-created block job. If omitted, the device name will be used. (Since
2.7)
device: string
the device name or node-name of a root node
base-node: string (optional)
The node name of the backing image to write data into. If not specified, this is the deepest
backing image. (since: 3.1)
base: string (optional)
Same as base-node, except that it is a file name rather than a node name. This must be the exact
filename string that was used to open the node; other strings, even if addressing the same file,
are not accepted
top-node: string (optional)
The node name of the backing image within the image chain which contains the topmost data to be
committed down. If not specified, this is the active layer. (since: 3.1)
top: string (optional)
Same as top-node, except that it is a file name rather than a node name. This must be the exact
filename string that was used to open the node; other strings, even if addressing the same file,
are not accepted
backing-file: string (optional)
The backing file string to write into the overlay image of 'top'. If 'top' does not have an
overlay image, or if 'top' is in use by a writer, specifying a backing file string is an error.
This filename is not validated. If a pathname string is such that it cannot be resolved by QEMU,
that means that subsequent QMP or HMP commands must use node-names for the image in question, as
filename lookup methods will fail.
If not specified, QEMU will automatically determine the backing file string to use, or error out
if there is no obvious choice. Care should be taken when specifying the string, to specify a
valid filename or protocol. (Since 2.1)
backing-mask-protocol: boolean (optional)
If true, replace any protocol mentioned in the 'backing file format' with 'raw', rather than
storing the protocol name as the backing format. Can be used even when no image header will be
updated (default false; since 9.0).
speed: int (optional)
the maximum speed, in bytes per second
on-error: BlockdevOnError (optional)
the action to take on an error. 'ignore' means that the request should be retried. (default:
report; Since: 5.0)
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that the commit job inserts into the
graph above top. If this option is not given, a node name is autogenerated. (Since: 2.9)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has finished its work, waiting for
block-job-finalize before making any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since 3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and
awaits block-job-dismiss. When true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Features
deprecated
Members base and top are deprecated. Use base-node and top-node instead.
Errors
• If device does not exist, DeviceNotFound
Since
1.3
Example:
-> { "execute": "block-commit",
"arguments": { "device": "virtio0",
"top": "/tmp/snap1.qcow2" } }
<- { "return": {} }
drive-backup (Command)
Start a point-in-time copy of a block device to a new destination. The status of ongoing drive-backup
operations can be checked with query-block-jobs where the BlockJobInfo.type field has the value 'backup'.
The operation can be stopped before it has completed using the block-job-cancel command.
Arguments
The members of DriveBackup
Features
deprecated
This command is deprecated. Use blockdev-backup instead.
Errors
• If device is not a valid block device, GenericError
Since
1.6
Example:
-> { "execute": "drive-backup",
"arguments": { "device": "drive0",
"sync": "full",
"target": "backup.img" } }
<- { "return": {} }
blockdev-backup (Command)
Start a point-in-time copy of a block device to a new destination. The status of ongoing blockdev-backup
operations can be checked with query-block-jobs where the BlockJobInfo.type field has the value 'backup'.
The operation can be stopped before it has completed using the block-job-cancel command.
Arguments
The members of BlockdevBackup
Errors
• If device is not a valid block device, DeviceNotFound
Since
2.3
Example:
-> { "execute": "blockdev-backup",
"arguments": { "device": "src-id",
"sync": "full",
"target": "tgt-id" } }
<- { "return": {} }
query-named-block-nodes (Command)
Get the named block driver list
Arguments
flat: boolean (optional)
Omit the nested data about backing image ("backing-image" key) if true. Default is false (Since
5.0)
Returns
the list of BlockDeviceInfo
Since
2.0
Example:
-> { "execute": "query-named-block-nodes" }
<- { "return": [ { "ro":false,
"drv":"qcow2",
"encrypted":false,
"file":"disks/test.qcow2",
"node-name": "my-node",
"backing_file_depth":1,
"detect_zeroes":"off",
"bps":1000000,
"bps_rd":0,
"bps_wr":0,
"iops":1000000,
"iops_rd":0,
"iops_wr":0,
"bps_max": 8000000,
"bps_rd_max": 0,
"bps_wr_max": 0,
"iops_max": 0,
"iops_rd_max": 0,
"iops_wr_max": 0,
"iops_size": 0,
"write_threshold": 0,
"image":{
"filename":"disks/test.qcow2",
"format":"qcow2",
"virtual-size":2048000,
"backing_file":"base.qcow2",
"full-backing-filename":"disks/base.qcow2",
"backing-filename-format":"qcow2",
"snapshots":[
{
"id": "1",
"name": "snapshot1",
"vm-state-size": 0,
"date-sec": 10000200,
"date-nsec": 12,
"vm-clock-sec": 206,
"vm-clock-nsec": 30
}
],
"backing-image":{
"filename":"disks/base.qcow2",
"format":"qcow2",
"virtual-size":2048000
}
} } ] }
XDbgBlockGraphNodeType (Enum)
Values
block-backend
corresponds to BlockBackend
block-job
corresponds to BlockJob
block-driver
corresponds to BlockDriverState
Since
4.0
XDbgBlockGraphNode (Object)
Members
id: int
Block graph node identifier. This id is generated only for x-debug-query-block-graph and does not
relate to any other identifiers in Qemu.
type: XDbgBlockGraphNodeType
Type of graph node. Can be one of block-backend, block-job or block-driver-state.
name: string
Human readable name of the node. Corresponds to node-name for block-driver-state nodes; is not
guaranteed to be unique in the whole graph (with block-jobs and block-backends).
Since
4.0
BlockPermission (Enum)
Enum of base block permissions.
Values
consistent-read
A user that has the "permission" of consistent reads is guaranteed that their view of the contents
of the block device is complete and self-consistent, representing the contents of a disk at a
specific point. For most block devices (including their backing files) this is true, but the
property cannot be maintained in a few situations like for intermediate nodes of a commit block
job.
write This permission is required to change the visible disk contents.
write-unchanged
This permission (which is weaker than BLK_PERM_WRITE) is both enough and required for writes to
the block node when the caller promises that the visible disk content doesn't change. As the
BLK_PERM_WRITE permission is strictly stronger, either is sufficient to perform an unchanging
write.
resize This permission is required to change the size of a block node.
Since
4.0
XDbgBlockGraphEdge (Object)
Block Graph edge description for x-debug-query-block-graph.
Members
parent: int
parent id
child: int
child id
name: string
name of the relation (examples are 'file' and 'backing')
perm: array of BlockPermission
granted permissions for the parent operating on the child
shared-perm: array of BlockPermission
permissions that can still be granted to other users of the child while it is still attached to
this parent
Since
4.0
XDbgBlockGraph (Object)
Block Graph - list of nodes and list of edges.
Members
nodes: array of XDbgBlockGraphNode
Not documented
edges: array of XDbgBlockGraphEdge
Not documented
Since
4.0
x-debug-query-block-graph (Command)
Get the block graph.
Features
unstable
This command is meant for debugging.
Since
4.0
drive-mirror (Command)
Start mirroring a block device's writes to a new destination. target specifies the target of the new
image. If the file exists, or if it is a device, it will be used as the new destination for writes. If
it does not exist, a new file will be created. format specifies the format of the mirror image, default
is to probe if mode='existing', else the format of the source.
Arguments
The members of DriveMirror
Errors
• If device is not a valid block device, GenericError
Since
1.3
Example:
-> { "execute": "drive-mirror",
"arguments": { "device": "ide-hd0",
"target": "/some/place/my-image",
"sync": "full",
"format": "qcow2" } }
<- { "return": {} }
DriveMirror (Object)
A set of parameters describing drive mirror setup.
Members
job-id: string (optional)
identifier for the newly-created block job. If omitted, the device name will be used. (Since
2.7)
device: string
the device name or node-name of a root node whose writes should be mirrored.
target: string
the target of the new image. If the file exists, or if it is a device, the existing file/device
will be used as the new destination. If it does not exist, a new file will be created.
format: string (optional)
the format of the new destination, default is to probe if mode is 'existing', else the format of
the source
node-name: string (optional)
the new block driver state node name in the graph (Since 2.1)
replaces: string (optional)
with sync=full graph node name to be replaced by the new image when a whole image copy is done.
This can be used to repair broken Quorum files. By default, device is replaced, although
implicitly created filters on it are kept. (Since 2.1)
mode: NewImageMode (optional)
whether and how QEMU should create a new image, default is 'absolute-paths'.
speed: int (optional)
the maximum speed, in bytes per second
sync: MirrorSyncMode
what parts of the disk image should be copied to the destination (all the disk, only the sectors
allocated in the topmost image, or only new I/O).
granularity: int (optional)
granularity of the dirty bitmap, default is 64K if the image format doesn't have clusters, 4K if
the clusters are smaller than that, else the cluster size. Must be a power of 2 between 512 and
64M (since 1.4).
buf-size: int (optional)
maximum amount of data in flight from source to target (since 1.4).
on-source-error: BlockdevOnError (optional)
the action to take on an error on the source, default 'report'. 'stop' and 'enospc' can only be
used if the block device supports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional)
the action to take on an error on the target, default 'report' (no limitations, since this applies
to a different block device than device).
unmap: boolean (optional)
Whether to try to unmap target sectors where source has only zero. If true, and target
unallocated sectors will read as zero, target image sectors will be unmapped; otherwise, zeroes
will be written. Both will result in identical contents. Default is true. (Since 2.4)
copy-mode: MirrorCopyMode (optional)
when to copy data to the destination; defaults to 'background' (Since: 3.0)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has finished its work, waiting for
block-job-finalize before making any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since 3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and
awaits block-job-dismiss. When true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Since
1.3
BlockDirtyBitmap (Object)
Members
node: string
name of device/node which the bitmap is tracking
name: string
name of the dirty bitmap
Since
2.4
BlockDirtyBitmapAdd (Object)
Members
node: string
name of device/node which the bitmap is tracking
name: string
name of the dirty bitmap (must be less than 1024 bytes)
granularity: int (optional)
the bitmap granularity, default is 64k for block-dirty-bitmap-add
persistent: boolean (optional)
the bitmap is persistent, i.e. it will be saved to the corresponding block device image file on
its close. For now only Qcow2 disks support persistent bitmaps. Default is false for
block-dirty-bitmap-add. (Since: 2.10)
disabled: boolean (optional)
the bitmap is created in the disabled state, which means that it will not track drive changes.
The bitmap may be enabled with block-dirty-bitmap-enable. Default is false. (Since: 4.0)
Since
2.4
BlockDirtyBitmapOrStr (Alternate)
Members
local: string
name of the bitmap, attached to the same node as target bitmap.
external: BlockDirtyBitmap
bitmap with specified node
Since
4.1
BlockDirtyBitmapMerge (Object)
Members
node: string
name of device/node which the target bitmap is tracking
target: string
name of the destination dirty bitmap
bitmaps: array of BlockDirtyBitmapOrStr
name(s) of the source dirty bitmap(s) at node and/or fully specified BlockDirtyBitmap elements.
The latter are supported since 4.1.
Since
4.0
block-dirty-bitmap-add (Command)
Create a dirty bitmap with a name on the node, and start tracking the writes.
Arguments
The members of BlockDirtyBitmapAdd
Errors
• If node is not a valid block device or node, DeviceNotFound
• If name is already taken, GenericError
Since
2.4
Example:
-> { "execute": "block-dirty-bitmap-add",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-remove (Command)
Stop write tracking and remove the dirty bitmap that was created with block-dirty-bitmap-add. If the
bitmap is persistent, remove it from its storage too.
Arguments
The members of BlockDirtyBitmap
Errors
• If node is not a valid block device or node, DeviceNotFound
• If name is not found, GenericError
• if name is frozen by an operation, GenericError
Since
2.4
Example:
-> { "execute": "block-dirty-bitmap-remove",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-clear (Command)
Clear (reset) a dirty bitmap on the device, so that an incremental backup from this point in time forward
will only backup clusters modified after this clear operation.
Arguments
The members of BlockDirtyBitmap
Errors
• If node is not a valid block device, DeviceNotFound
• If name is not found, GenericError
Since
2.4
Example:
-> { "execute": "block-dirty-bitmap-clear",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-enable (Command)
Enables a dirty bitmap so that it will begin tracking disk changes.
Arguments
The members of BlockDirtyBitmap
Errors
• If node is not a valid block device, DeviceNotFound
• If name is not found, GenericError
Since
4.0
Example:
-> { "execute": "block-dirty-bitmap-enable",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-disable (Command)
Disables a dirty bitmap so that it will stop tracking disk changes.
Arguments
The members of BlockDirtyBitmap
Errors
• If node is not a valid block device, DeviceNotFound
• If name is not found, GenericError
Since
4.0
Example:
-> { "execute": "block-dirty-bitmap-disable",
"arguments": { "node": "drive0", "name": "bitmap0" } }
<- { "return": {} }
block-dirty-bitmap-merge (Command)
Merge dirty bitmaps listed in bitmaps to the target dirty bitmap. Dirty bitmaps in bitmaps will be
unchanged, except if it also appears as the target bitmap. Any bits already set in target will still be
set after the merge, i.e., this operation does not clear the target. On error, target is unchanged.
The resulting bitmap will count as dirty any clusters that were dirty in any of the source bitmaps. This
can be used to achieve backup checkpoints, or in simpler usages, to copy bitmaps.
Arguments
The members of BlockDirtyBitmapMerge
Errors
• If node is not a valid block device, DeviceNotFound
• If any bitmap in bitmaps or target is not found, GenericError
• If any of the bitmaps have different sizes or granularities, GenericError
Since
4.0
Example:
-> { "execute": "block-dirty-bitmap-merge",
"arguments": { "node": "drive0", "target": "bitmap0",
"bitmaps": ["bitmap1"] } }
<- { "return": {} }
BlockDirtyBitmapSha256 (Object)
SHA256 hash of dirty bitmap data
Members
sha256: string
ASCII representation of SHA256 bitmap hash
Since
2.10
x-debug-block-dirty-bitmap-sha256 (Command)
Get bitmap SHA256.
Arguments
The members of BlockDirtyBitmap
Features
unstable
This command is meant for debugging.
Returns
BlockDirtyBitmapSha256
Errors
• If node is not a valid block device, DeviceNotFound
• If name is not found or if hashing has failed, GenericError
Since
2.10
blockdev-mirror (Command)
Start mirroring a block device's writes to a new destination.
Arguments
job-id: string (optional)
identifier for the newly-created block job. If omitted, the device name will be used. (Since
2.7)
device: string
The device name or node-name of a root node whose writes should be mirrored.
target: string
the id or node-name of the block device to mirror to. This mustn't be attached to guest.
replaces: string (optional)
with sync=full graph node name to be replaced by the new image when a whole image copy is done.
This can be used to repair broken Quorum files. By default, device is replaced, although
implicitly created filters on it are kept.
speed: int (optional)
the maximum speed, in bytes per second
sync: MirrorSyncMode
what parts of the disk image should be copied to the destination (all the disk, only the sectors
allocated in the topmost image, or only new I/O).
granularity: int (optional)
granularity of the dirty bitmap, default is 64K if the image format doesn't have clusters, 4K if
the clusters are smaller than that, else the cluster size. Must be a power of 2 between 512 and
64M
buf-size: int (optional)
maximum amount of data in flight from source to target
on-source-error: BlockdevOnError (optional)
the action to take on an error on the source, default 'report'. 'stop' and 'enospc' can only be
used if the block device supports io-status (see BlockInfo).
on-target-error: BlockdevOnError (optional)
the action to take on an error on the target, default 'report' (no limitations, since this applies
to a different block device than device).
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that the mirror job inserts into the
graph above device. If this option is not given, a node name is autogenerated. (Since: 2.9)
copy-mode: MirrorCopyMode (optional)
when to copy data to the destination; defaults to 'background' (Since: 3.0)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has finished its work, waiting for
block-job-finalize before making any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since 3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and
awaits block-job-dismiss. When true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Since
2.6
Example:
-> { "execute": "blockdev-mirror",
"arguments": { "device": "ide-hd0",
"target": "target0",
"sync": "full" } }
<- { "return": {} }
BlockIOThrottle (Object)
A set of parameters describing block throttling.
Members
device: string (optional)
Block device name
id: string (optional)
The name or QOM path of the guest device (since: 2.8)
bps: int
total throughput limit in bytes per second
bps_rd: int
read throughput limit in bytes per second
bps_wr: int
write throughput limit in bytes per second
iops: int
total I/O operations per second
iops_rd: int
read I/O operations per second
iops_wr: int
write I/O operations per second
bps_max: int (optional)
total throughput limit during bursts, in bytes (Since 1.7)
bps_rd_max: int (optional)
read throughput limit during bursts, in bytes (Since 1.7)
bps_wr_max: int (optional)
write throughput limit during bursts, in bytes (Since 1.7)
iops_max: int (optional)
total I/O operations per second during bursts, in bytes (Since 1.7)
iops_rd_max: int (optional)
read I/O operations per second during bursts, in bytes (Since 1.7)
iops_wr_max: int (optional)
write I/O operations per second during bursts, in bytes (Since 1.7)
bps_max_length: int (optional)
maximum length of the bps_max burst period, in seconds. It must only be set if bps_max is set as
well. Defaults to 1. (Since 2.6)
bps_rd_max_length: int (optional)
maximum length of the bps_rd_max burst period, in seconds. It must only be set if bps_rd_max is
set as well. Defaults to 1. (Since 2.6)
bps_wr_max_length: int (optional)
maximum length of the bps_wr_max burst period, in seconds. It must only be set if bps_wr_max is
set as well. Defaults to 1. (Since 2.6)
iops_max_length: int (optional)
maximum length of the iops burst period, in seconds. It must only be set if iops_max is set as
well. Defaults to 1. (Since 2.6)
iops_rd_max_length: int (optional)
maximum length of the iops_rd_max burst period, in seconds. It must only be set if iops_rd_max is
set as well. Defaults to 1. (Since 2.6)
iops_wr_max_length: int (optional)
maximum length of the iops_wr_max burst period, in seconds. It must only be set if iops_wr_max is
set as well. Defaults to 1. (Since 2.6)
iops_size: int (optional)
an I/O size in bytes (Since 1.7)
group: string (optional)
throttle group name (Since 2.4)
Features
deprecated
Member device is deprecated. Use id instead.
Since
1.1
ThrottleLimits (Object)
Limit parameters for throttling. Since some limit combinations are illegal, limits should always be set
in one transaction. All fields are optional. When setting limits, if a field is missing the current
value is not changed.
Members
iops-total: int (optional)
limit total I/O operations per second
iops-total-max: int (optional)
I/O operations burst
iops-total-max-length: int (optional)
length of the iops-total-max burst period, in seconds It must only be set if iops-total-max is set
as well.
iops-read: int (optional)
limit read operations per second
iops-read-max: int (optional)
I/O operations read burst
iops-read-max-length: int (optional)
length of the iops-read-max burst period, in seconds It must only be set if iops-read-max is set
as well.
iops-write: int (optional)
limit write operations per second
iops-write-max: int (optional)
I/O operations write burst
iops-write-max-length: int (optional)
length of the iops-write-max burst period, in seconds It must only be set if iops-write-max is set
as well.
bps-total: int (optional)
limit total bytes per second
bps-total-max: int (optional)
total bytes burst
bps-total-max-length: int (optional)
length of the bps-total-max burst period, in seconds. It must only be set if bps-total-max is set
as well.
bps-read: int (optional)
limit read bytes per second
bps-read-max: int (optional)
total bytes read burst
bps-read-max-length: int (optional)
length of the bps-read-max burst period, in seconds It must only be set if bps-read-max is set as
well.
bps-write: int (optional)
limit write bytes per second
bps-write-max: int (optional)
total bytes write burst
bps-write-max-length: int (optional)
length of the bps-write-max burst period, in seconds It must only be set if bps-write-max is set
as well.
iops-size: int (optional)
when limiting by iops max size of an I/O in bytes
Since
2.11
ThrottleGroupProperties (Object)
Properties for throttle-group objects.
Members
limits: ThrottleLimits (optional)
limits to apply for this throttle group
x-iops-total: int (optional)
Not documented
x-iops-total-max: int (optional)
Not documented
x-iops-total-max-length: int (optional)
Not documented
x-iops-read: int (optional)
Not documented
x-iops-read-max: int (optional)
Not documented
x-iops-read-max-length: int (optional)
Not documented
x-iops-write: int (optional)
Not documented
x-iops-write-max: int (optional)
Not documented
x-iops-write-max-length: int (optional)
Not documented
x-bps-total: int (optional)
Not documented
x-bps-total-max: int (optional)
Not documented
x-bps-total-max-length: int (optional)
Not documented
x-bps-read: int (optional)
Not documented
x-bps-read-max: int (optional)
Not documented
x-bps-read-max-length: int (optional)
Not documented
x-bps-write: int (optional)
Not documented
x-bps-write-max: int (optional)
Not documented
x-bps-write-max-length: int (optional)
Not documented
x-iops-size: int (optional)
Not documented
Features
unstable
All members starting with x- are aliases for the same key without x- in the limits object. This
is not a stable interface and may be removed or changed incompatibly in the future. Use limits
for a supported stable interface.
Since
2.11
block-stream (Command)
Copy data from a backing file into a block device.
The block streaming operation is performed in the background until the entire backing file has been
copied. This command returns immediately once streaming has started. The status of ongoing block
streaming operations can be checked with query-block-jobs. The operation can be stopped before it has
completed using the block-job-cancel command.
The node that receives the data is called the top image, can be located in any part of the chain (but
always above the base image; see below) and can be specified using its device or node name. Earlier qemu
versions only allowed 'device' to name the top level node; presence of the 'base-node' parameter during
introspection can be used as a witness of the enhanced semantics of 'device'.
If a base file is specified then sectors are not copied from that base file and its backing chain. This
can be used to stream a subset of the backing file chain instead of flattening the entire image. When
streaming completes the image file will have the base file as its backing file, unless that node was
changed while the job was running. In that case, base's parent's backing (or filtered, whichever exists)
child (i.e., base at the beginning of the job) will be the new backing file.
On successful completion the image file is updated to drop the backing file and the BLOCK_JOB_COMPLETED
event is emitted.
In case device is a filter node, block-stream modifies the first non-filter overlay node below it to
point to the new backing node instead of modifying device itself.
Arguments
job-id: string (optional)
identifier for the newly-created block job. If omitted, the device name will be used. (Since
2.7)
device: string
the device or node name of the top image
base: string (optional)
the common backing file name. It cannot be set if base-node or bottom is also set.
base-node: string (optional)
the node name of the backing file. It cannot be set if base or bottom is also set. (Since 2.8)
bottom: string (optional)
the last node in the chain that should be streamed into top. It cannot be set if base or
base-node is also set. It cannot be filter node. (Since 6.0)
backing-file: string (optional)
The backing file string to write into the top image. This filename is not validated.
If a pathname string is such that it cannot be resolved by QEMU, that means that subsequent QMP or
HMP commands must use node-names for the image in question, as filename lookup methods will fail.
If not specified, QEMU will automatically determine the backing file string to use, or error out
if there is no obvious choice. Care should be taken when specifying the string, to specify a
valid filename or protocol. (Since 2.1)
backing-mask-protocol: boolean (optional)
If true, replace any protocol mentioned in the 'backing file format' with 'raw', rather than
storing the protocol name as the backing format. Can be used even when no image header will be
updated (default false; since 9.0).
speed: int (optional)
the maximum speed, in bytes per second
on-error: BlockdevOnError (optional)
the action to take on an error (default report). 'stop' and 'enospc' can only be used if the
block device supports io-status (see BlockInfo). (Since 1.3)
filter-node-name: string (optional)
the node name that should be assigned to the filter driver that the stream job inserts into the
graph above device. If this option is not given, a node name is autogenerated. (Since: 6.0)
auto-finalize: boolean (optional)
When false, this job will wait in a PENDING state after it has finished its work, waiting for
block-job-finalize before making any block graph changes. When true, this job will automatically
perform its abort or commit actions. Defaults to true. (Since 3.1)
auto-dismiss: boolean (optional)
When false, this job will wait in a CONCLUDED state after it has completely ceased all work, and
awaits block-job-dismiss. When true, this job will automatically disappear from the query list
without user intervention. Defaults to true. (Since 3.1)
Errors
• If device does not exist, DeviceNotFound.
Since
1.1
Example:
-> { "execute": "block-stream",
"arguments": { "device": "virtio0",
"base": "/tmp/master.qcow2" } }
<- { "return": {} }
block-job-set-speed (Command)
Set maximum speed for a background block operation.
This command can only be issued when there is an active block job.
Throttling can be disabled by setting the speed to 0.
Arguments
device: string
The job identifier. This used to be a device name (hence the name of the parameter), but since
QEMU 2.7 it can have other values.
speed: int
the maximum speed, in bytes per second, or 0 for unlimited. Defaults to 0.
Errors
• If no background operation is active on this device, DeviceNotActive
Since
1.1
block-job-cancel (Command)
Stop an active background block operation.
This command returns immediately after marking the active background block operation for cancellation.
It is an error to call this command if no operation is in progress.
The operation will cancel as soon as possible and then emit the BLOCK_JOB_CANCELLED event. Before that
happens the job is still visible when enumerated using query-block-jobs.
Note that if you issue 'block-job-cancel' after 'drive-mirror' has indicated (via the event
BLOCK_JOB_READY) that the source and destination are synchronized, then the event triggered by this
command changes to BLOCK_JOB_COMPLETED, to indicate that the mirroring has ended and the destination now
has a point-in-time copy tied to the time of the cancellation.
For streaming, the image file retains its backing file unless the streaming operation happens to complete
just as it is being cancelled. A new streaming operation can be started at a later time to finish
copying all data from the backing file.
Arguments
device: string
The job identifier. This used to be a device name (hence the name of the parameter), but since
QEMU 2.7 it can have other values.
force: boolean (optional)
If true, and the job has already emitted the event BLOCK_JOB_READY, abandon the job immediately
(even if it is paused) instead of waiting for the destination to complete its final
synchronization (since 1.3)
Errors
• If no background operation is active on this device, DeviceNotActive
Since
1.1
block-job-pause (Command)
Pause an active background block operation.
This command returns immediately after marking the active background block operation for pausing. It is
an error to call this command if no operation is in progress or if the job is already paused.
The operation will pause as soon as possible. No event is emitted when the operation is actually paused.
Cancelling a paused job automatically resumes it.
Arguments
device: string
The job identifier. This used to be a device name (hence the name of the parameter), but since
QEMU 2.7 it can have other values.
Errors
• If no background operation is active on this device, DeviceNotActive
Since
1.3
block-job-resume (Command)
Resume an active background block operation.
This command returns immediately after resuming a paused background block operation. It is an error to
call this command if no operation is in progress or if the job is not paused.
This command also clears the error status of the job.
Arguments
device: string
The job identifier. This used to be a device name (hence the name of the parameter), but since
QEMU 2.7 it can have other values.
Errors
• If no background operation is active on this device, DeviceNotActive
Since
1.3
block-job-complete (Command)
Manually trigger completion of an active background block operation. This is supported for drive
mirroring, where it also switches the device to write to the target path only. The ability to complete
is signaled with a BLOCK_JOB_READY event.
This command completes an active background block operation synchronously. The ordering of this
command's return with the BLOCK_JOB_COMPLETED event is not defined. Note that if an I/O error occurs
during the processing of this command: 1) the command itself will fail; 2) the error will be processed
according to the rerror/werror arguments that were specified when starting the operation.
A cancelled or paused job cannot be completed.
Arguments
device: string
The job identifier. This used to be a device name (hence the name of the parameter), but since
QEMU 2.7 it can have other values.
Errors
• If no background operation is active on this device, DeviceNotActive
Since
1.3
block-job-dismiss (Command)
For jobs that have already concluded, remove them from the block-job-query list. This command only needs
to be run for jobs which were started with QEMU 2.12+ job lifetime management semantics.
This command will refuse to operate on any job that has not yet reached its terminal state,
JOB_STATUS_CONCLUDED. For jobs that make use of the BLOCK_JOB_READY event, block-job-cancel or
block-job-complete will still need to be used as appropriate.
Arguments
id: string
The job identifier.
Since
2.12
block-job-finalize (Command)
Once a job that has manual=true reaches the pending state, it can be instructed to finalize any graph
changes and do any necessary cleanup via this command. For jobs in a transaction, instructing one job to
finalize will force ALL jobs in the transaction to finalize, so it is only necessary to instruct a single
member job to finalize.
Arguments
id: string
The job identifier.
Since
2.12
BlockJobChangeOptionsMirror (Object)
Members
copy-mode: MirrorCopyMode
Switch to this copy mode. Currently, only the switch from 'background' to 'write-blocking' is
implemented.
Since
8.2
BlockJobChangeOptions (Object)
Block job options that can be changed after job creation.
Members
id: string
The job identifier
type: JobType
The job type
The members of BlockJobChangeOptionsMirror when type is "mirror"
Since
8.2
block-job-change (Command)
Change the block job's options.
Arguments
The members of BlockJobChangeOptions
Since
8.2
BlockdevDiscardOptions (Enum)
Determines how to handle discard requests.
Values
ignore Ignore the request
unmap Forward as an unmap request
Since
2.9
BlockdevDetectZeroesOptions (Enum)
Describes the operation mode for the automatic conversion of plain zero writes by the OS to driver
specific optimized zero write commands.
Values
off Disabled (default)
on Enabled
unmap Enabled and even try to unmap blocks if possible. This requires also that BlockdevDiscardOptions
is set to unmap for this device.
Since
2.1
BlockdevAioOptions (Enum)
Selects the AIO backend to handle I/O requests
Values
threads
Use qemu's thread pool
native Use native AIO backend (only Linux and Windows)
io_uring (If: CONFIG_LINUX_IO_URING)
Use linux io_uring (since 5.0)
Since
2.9
BlockdevCacheOptions (Object)
Includes cache-related options for block devices
Members
direct: boolean (optional)
enables use of O_DIRECT (bypass the host page cache; default: false)
no-flush: boolean (optional)
ignore any flush requests for the device (default: false)
Since
2.9
BlockdevDriver (Enum)
Drivers that are supported in block device operations.
Values
throttle
Since 2.11
nvme Since 2.12
copy-on-read
Since 3.0
blklogwrites
Since 3.0
blkreplay
Since 4.2
compress
Since 5.0
copy-before-write
Since 6.2
snapshot-access
Since 7.0
blkdebug
Not documented
blkverify
Not documented
bochs Not documented
cloop Not documented
dmg Not documented
file Not documented
ftp Not documented
ftps Not documented
gluster
Not documented
host_cdrom (If: HAVE_HOST_BLOCK_DEVICE)
Not documented
host_device (If: HAVE_HOST_BLOCK_DEVICE)
Not documented
http Not documented
https Not documented
io_uring (If: CONFIG_BLKIO)
Not documented
iscsi Not documented
luks Not documented
nbd Not documented
nfs Not documented
null-aio
Not documented
null-co
Not documented
nvme-io_uring (If: CONFIG_BLKIO)
Not documented
parallels
Not documented
preallocate
Not documented
qcow Not documented
qcow2 Not documented
qed Not documented
quorum Not documented
raw Not documented
rbd Not documented
replication (If: CONFIG_REPLICATION)
Not documented
ssh Not documented
vdi Not documented
vhdx Not documented
virtio-blk-vfio-pci (If: CONFIG_BLKIO)
Not documented
virtio-blk-vhost-user (If: CONFIG_BLKIO)
Not documented
virtio-blk-vhost-vdpa (If: CONFIG_BLKIO)
Not documented
vmdk Not documented
vpc Not documented
vvfat Not documented
Features
deprecated
Member gluster is deprecated because GlusterFS development ceased.
Since
2.9
BlockdevOptionsFile (Object)
Driver specific block device options for the file backend.
Members
filename: string
path to the image file
pr-manager: string (optional)
the id for the object that will handle persistent reservations for this device (default: none,
forward the commands via SG_IO; since 2.11)
aio: BlockdevAioOptions (optional)
AIO backend (default: threads) (since: 2.8)
aio-max-batch: int (optional)
maximum number of requests to batch together into a single submission in the AIO backend. The
smallest value between this and the aio-max-batch value of the IOThread object is chosen. 0 means
that the AIO backend will handle it automatically. (default: 0, since 6.2)
locking: OnOffAuto (optional)
whether to enable file locking. If set to 'auto', only enable when Open File Descriptor (OFD)
locking API is available (default: auto, since 2.10)
drop-cache: boolean (optional) (If: CONFIG_LINUX)
invalidate page cache during live migration. This prevents stale data on the migration
destination with cache.direct=off. Currently only supported on Linux hosts. (default: on, since:
4.0)
x-check-cache-dropped: boolean (optional)
whether to check that page cache was dropped on live migration. May cause noticeable delays if
the image file is large, do not use in production. (default: off) (since: 3.0)
Features
dynamic-auto-read-only
If present, enabled auto-read-only means that the driver will open the image read-only at first,
dynamically reopen the image file read-write when the first writer is attached to the node and
reopen read-only when the last writer is detached. This allows giving QEMU write permissions only
on demand when an operation actually needs write access.
unstable
Member x-check-cache-dropped is meant for debugging.
Since
2.9
BlockdevOptionsNull (Object)
Driver specific block device options for the null backend.
Members
size: int (optional)
size of the device in bytes.
latency-ns: int (optional)
emulated latency (in nanoseconds) in processing requests. Default to zero which completes
requests immediately. (Since 2.4)
read-zeroes: boolean (optional)
if true, reads from the device produce zeroes; if false, the buffer is left unchanged. (default:
false; since: 4.1)
Since
2.9
BlockdevOptionsNVMe (Object)
Driver specific block device options for the NVMe backend.
Members
device: string
PCI controller address of the NVMe device in format hhhh:bb:ss.f (host:bus:slot.function)
namespace: int
namespace number of the device, starting from 1.
Note that the PCI device must have been unbound from any host kernel driver before instructing QEMU to
add the blockdev.
Since
2.12
BlockdevOptionsVVFAT (Object)
Driver specific block device options for the vvfat protocol.
Members
dir: string
directory to be exported as FAT image
fat-type: int (optional)
FAT type: 12, 16 or 32
floppy: boolean (optional)
whether to export a floppy image (true) or partitioned hard disk (false; default)
label: string (optional)
set the volume label, limited to 11 bytes. FAT16 and FAT32 traditionally have some restrictions
on labels, which are ignored by most operating systems. Defaults to "QEMU VVFAT". (since 2.4)
rw: boolean (optional)
whether to allow write operations (default: false)
Since
2.9
BlockdevOptionsGenericFormat (Object)
Driver specific block device options for image format that have no option besides their data source.
Members
file: BlockdevRef
reference to or definition of the data source block device
Since
2.9
BlockdevOptionsLUKS (Object)
Driver specific block device options for LUKS.
Members
key-secret: string (optional)
the ID of a QCryptoSecret object providing the decryption key (since 2.6). Mandatory except when
doing a metadata-only probe of the image.
header: BlockdevRef (optional)
block device holding a detached LUKS header. (since 9.0)
The members of BlockdevOptionsGenericFormat
Since
2.9
BlockdevOptionsGenericCOWFormat (Object)
Driver specific block device options for image format that have no option besides their data source and
an optional backing file.
Members
backing: BlockdevRefOrNull (optional)
reference to or definition of the backing file block device, null disables the backing file
entirely. Defaults to the backing file stored the image file.
The members of BlockdevOptionsGenericFormat
Since
2.9
Qcow2OverlapCheckMode (Enum)
General overlap check modes.
Values
none Do not perform any checks
constant
Perform only checks which can be done in constant time and without reading anything from disk
cached Perform only checks which can be done without reading anything from disk
all Perform all available overlap checks
Since
2.9
Qcow2OverlapCheckFlags (Object)
Structure of flags for each metadata structure. Setting a field to 'true' makes QEMU guard that Qcow2
format structure against unintended overwriting. See Qcow2 format specification for detailed information
on these structures. The default value is chosen according to the template given.
Members
template: Qcow2OverlapCheckMode (optional)
Specifies a template mode which can be adjusted using the other flags, defaults to 'cached'
main-header: boolean (optional)
Qcow2 format header
active-l1: boolean (optional)
Qcow2 active L1 table
active-l2: boolean (optional)
Qcow2 active L2 table
refcount-table: boolean (optional)
Qcow2 refcount table
refcount-block: boolean (optional)
Qcow2 refcount blocks
snapshot-table: boolean (optional)
Qcow2 snapshot table
inactive-l1: boolean (optional)
Qcow2 inactive L1 tables
inactive-l2: boolean (optional)
Qcow2 inactive L2 tables
bitmap-directory: boolean (optional)
Qcow2 bitmap directory (since 3.0)
Since
2.9
Qcow2OverlapChecks (Alternate)
Specifies which metadata structures should be guarded against unintended overwriting.
Members
flags: Qcow2OverlapCheckFlags
set of flags for separate specification of each metadata structure type
mode: Qcow2OverlapCheckMode
named mode which chooses a specific set of flags
Since
2.9
BlockdevQcowEncryptionFormat (Enum)
Values
aes AES-CBC with plain64 initialization vectors
Since
2.10
BlockdevQcowEncryption (Object)
Members
format: BlockdevQcowEncryptionFormat
encryption format
The members of QCryptoBlockOptionsQCow when format is "aes"
Since
2.10
BlockdevOptionsQcow (Object)
Driver specific block device options for qcow.
Members
encrypt: BlockdevQcowEncryption (optional)
Image decryption options. Mandatory for encrypted images, except when doing a metadata-only probe
of the image.
The members of BlockdevOptionsGenericCOWFormat
Since
2.10
BlockdevQcow2EncryptionFormat (Enum)
Values
aes AES-CBC with plain64 initialization vectors
luks Not documented
Since
2.10
BlockdevQcow2Encryption (Object)
Members
format: BlockdevQcow2EncryptionFormat
encryption format
The members of QCryptoBlockOptionsQCow when format is "aes"
The members of QCryptoBlockOptionsLUKS when format is "luks"
Since
2.10
BlockdevOptionsPreallocate (Object)
Filter driver intended to be inserted between format and protocol node and do preallocation in protocol
node on write.
Members
prealloc-align: int (optional)
on preallocation, align file length to this number, default 1048576 (1M)
prealloc-size: int (optional)
how much to preallocate, default 134217728 (128M)
The members of BlockdevOptionsGenericFormat
Since
6.0
BlockdevOptionsQcow2 (Object)
Driver specific block device options for qcow2.
Members
lazy-refcounts: boolean (optional)
whether to enable the lazy refcounts feature (default is taken from the image file)
pass-discard-request: boolean (optional)
whether discard requests to the qcow2 device should be forwarded to the data source
pass-discard-snapshot: boolean (optional)
whether discard requests for the data source should be issued when a snapshot operation (e.g.
deleting a snapshot) frees clusters in the qcow2 file
pass-discard-other: boolean (optional)
whether discard requests for the data source should be issued on other occasions where a cluster
gets freed
discard-no-unref: boolean (optional)
when enabled, data clusters will remain preallocated when they are no longer used, e.g. because
they are discarded or converted to zero clusters. As usual, whether the old data is discarded or
kept on the protocol level (i.e. in the image file) depends on the setting of the
pass-discard-request option. Keeping the clusters preallocated prevents qcow2 fragmentation that
would otherwise be caused by freeing and re-allocating them later. Besides potential performance
degradation, such fragmentation can lead to increased allocation of clusters past the end of the
image file, resulting in image files whose file length can grow much larger than their guest disk
size would suggest. If image file length is of concern (e.g. when storing qcow2 images directly
on block devices), you should consider enabling this option. (since 8.1)
overlap-check: Qcow2OverlapChecks (optional)
which overlap checks to perform for writes to the image, defaults to 'cached' (since 2.2)
cache-size: int (optional)
the maximum total size of the L2 table and refcount block caches in bytes (since 2.2)
l2-cache-size: int (optional)
the maximum size of the L2 table cache in bytes (since 2.2)
l2-cache-entry-size: int (optional)
the size of each entry in the L2 cache in bytes. It must be a power of two between 512 and the
cluster size. The default value is the cluster size (since 2.12)
refcount-cache-size: int (optional)
the maximum size of the refcount block cache in bytes (since 2.2)
cache-clean-interval: int (optional)
clean unused entries in the L2 and refcount caches. The interval is in seconds. The default
value is 600 on supporting platforms, and 0 on other platforms. 0 disables this feature. (since
2.5)
encrypt: BlockdevQcow2Encryption (optional)
Image decryption options. Mandatory for encrypted images, except when doing a metadata-only probe
of the image. (since 2.10)
data-file: BlockdevRef (optional)
reference to or definition of the external data file. This may only be specified for images that
require an external data file. If it is not specified for such an image, the data file name is
loaded from the image file. (since 4.0)
The members of BlockdevOptionsGenericCOWFormat
Since
2.9
SshHostKeyCheckMode (Enum)
Values
none Don't check the host key at all
hash Compare the host key with a given hash
known_hosts
Check the host key against the known_hosts file
Since
2.12
SshHostKeyCheckHashType (Enum)
Values
md5 The given hash is an md5 hash
sha1 The given hash is an sha1 hash
sha256 The given hash is an sha256 hash
Since
2.12
SshHostKeyHash (Object)
Members
type: SshHostKeyCheckHashType
The hash algorithm used for the hash
hash: string
The expected hash value
Since
2.12
SshHostKeyCheck (Object)
Members
mode: SshHostKeyCheckMode
How to check the host key
The members of SshHostKeyHash when mode is "hash"
Since
2.12
BlockdevOptionsSsh (Object)
Members
server: InetSocketAddress
host address
path: string
path to the image on the host
user: string (optional)
user as which to connect, defaults to current local user name
host-key-check: SshHostKeyCheck (optional)
Defines how and what to check the host key against (default: known_hosts)
Since
2.9
BlkdebugEvent (Enum)
Trigger events supported by blkdebug.
Values
l1_shrink_write_table
write zeros to the l1 table to shrink image. (since 2.11)
l1_shrink_free_l2_clusters
discard the l2 tables. (since 2.11)
cor_write
a write due to copy-on-read (since 2.11)
cluster_alloc_space
an allocation of file space for a cluster (since 4.1)
none triggers once at creation of the blkdebug node (since 4.1)
l1_update
Not documented
l1_grow_alloc_table
Not documented
l1_grow_write_table
Not documented
l1_grow_activate_table
Not documented
l2_load
Not documented
l2_update
Not documented
l2_update_compressed
Not documented
l2_alloc_cow_read
Not documented
l2_alloc_write
Not documented
read_aio
Not documented
read_backing_aio
Not documented
read_compressed
Not documented
write_aio
Not documented
write_compressed
Not documented
vmstate_load
Not documented
vmstate_save
Not documented
cow_read
Not documented
cow_write
Not documented
reftable_load
Not documented
reftable_grow
Not documented
reftable_update
Not documented
refblock_load
Not documented
refblock_update
Not documented
refblock_update_part
Not documented
refblock_alloc
Not documented
refblock_alloc_hookup
Not documented
refblock_alloc_write
Not documented
refblock_alloc_write_blocks
Not documented
refblock_alloc_write_table
Not documented
refblock_alloc_switch_table
Not documented
cluster_alloc
Not documented
cluster_alloc_bytes
Not documented
cluster_free
Not documented
flush_to_os
Not documented
flush_to_disk
Not documented
pwritev_rmw_head
Not documented
pwritev_rmw_after_head
Not documented
pwritev_rmw_tail
Not documented
pwritev_rmw_after_tail
Not documented
pwritev
Not documented
pwritev_zero
Not documented
pwritev_done
Not documented
empty_image_prepare
Not documented
Since
2.9
BlkdebugIOType (Enum)
Kinds of I/O that blkdebug can inject errors in.
Values
read .bdrv_co_preadv()
write .bdrv_co_pwritev()
write-zeroes
.bdrv_co_pwrite_zeroes()
discard
.bdrv_co_pdiscard()
flush .bdrv_co_flush_to_disk()
block-status
.bdrv_co_block_status()
Since
4.1
BlkdebugInjectErrorOptions (Object)
Describes a single error injection for blkdebug.
Members
event: BlkdebugEvent
trigger event
state: int (optional)
the state identifier blkdebug needs to be in to actually trigger the event; defaults to "any"
iotype: BlkdebugIOType (optional)
the type of I/O operations on which this error should be injected; defaults to "all read, write,
write-zeroes, discard, and flush operations" (since: 4.1)
errno: int (optional)
error identifier (errno) to be returned; defaults to EIO
sector: int (optional)
specifies the sector index which has to be affected in order to actually trigger the event;
defaults to "any sector"
once: boolean (optional)
disables further events after this one has been triggered; defaults to false
immediately: boolean (optional)
fail immediately; defaults to false
Since
2.9
BlkdebugSetStateOptions (Object)
Describes a single state-change event for blkdebug.
Members
event: BlkdebugEvent
trigger event
state: int (optional)
the current state identifier blkdebug needs to be in; defaults to "any"
new_state: int
the state identifier blkdebug is supposed to assume if this event is triggered
Since
2.9
BlockdevOptionsBlkdebug (Object)
Driver specific block device options for blkdebug.
Members
image: BlockdevRef
underlying raw block device (or image file)
config: string (optional)
filename of the configuration file
align: int (optional)
required alignment for requests in bytes, must be positive power of 2, or 0 for default
max-transfer: int (optional)
maximum size for I/O transfers in bytes, must be positive multiple of align and of the underlying
file's request alignment (but need not be a power of 2), or 0 for default (since 2.10)
opt-write-zero: int (optional)
preferred alignment for write zero requests in bytes, must be positive multiple of align and of
the underlying file's request alignment (but need not be a power of 2), or 0 for default (since
2.10)
max-write-zero: int (optional)
maximum size for write zero requests in bytes, must be positive multiple of align, of
opt-write-zero, and of the underlying file's request alignment (but need not be a power of 2), or
0 for default (since 2.10)
opt-discard: int (optional)
preferred alignment for discard requests in bytes, must be positive multiple of align and of the
underlying file's request alignment (but need not be a power of 2), or 0 for default (since 2.10)
max-discard: int (optional)
maximum size for discard requests in bytes, must be positive multiple of align, of opt-discard,
and of the underlying file's request alignment (but need not be a power of 2), or 0 for default
(since 2.10)
inject-error: array of BlkdebugInjectErrorOptions (optional)
array of error injection descriptions
set-state: array of BlkdebugSetStateOptions (optional)
array of state-change descriptions
take-child-perms: array of BlockPermission (optional)
Permissions to take on image in addition to what is necessary anyway (which depends on how the
blkdebug node is used). Defaults to none. (since 5.0)
unshare-child-perms: array of BlockPermission (optional)
Permissions not to share on image in addition to what cannot be shared anyway (which depends on
how the blkdebug node is used). Defaults to none. (since 5.0)
Since
2.9
BlockdevOptionsBlklogwrites (Object)
Driver specific block device options for blklogwrites.
Members
file: BlockdevRef
block device
log: BlockdevRef
block device used to log writes to file
log-sector-size: int (optional)
sector size used in logging writes to file, determines granularity of offsets and sizes of writes
(default: 512)
log-append: boolean (optional)
append to an existing log (default: false)
log-super-update-interval: int (optional)
interval of write requests after which the log super block is updated to disk (default: 4096)
Since
3.0
BlockdevOptionsBlkverify (Object)
Driver specific block device options for blkverify.
Members
test: BlockdevRef
block device to be tested
raw: BlockdevRef
raw image used for verification
Since
2.9
BlockdevOptionsBlkreplay (Object)
Driver specific block device options for blkreplay.
Members
image: BlockdevRef
disk image which should be controlled with blkreplay
Since
4.2
QuorumReadPattern (Enum)
An enumeration of quorum read patterns.
Values
quorum read all the children and do a quorum vote on reads
fifo read only from the first child that has not failed
Since
2.9
BlockdevOptionsQuorum (Object)
Driver specific block device options for Quorum
Members
blkverify: boolean (optional)
true if the driver must print content mismatch set to false by default
children: array of BlockdevRef
the children block devices to use
vote-threshold: int
the vote limit under which a read will fail
rewrite-corrupted: boolean (optional)
rewrite corrupted data when quorum is reached (Since 2.1)
read-pattern: QuorumReadPattern (optional)
choose read pattern and set to quorum by default (Since 2.2)
Since
2.9
BlockdevOptionsGluster (Object)
Driver specific block device options for Gluster
Members
volume: string
name of gluster volume where VM image resides
path: string
absolute path to image file in gluster volume
server: array of SocketAddress
gluster servers description
debug: int (optional)
libgfapi log level (default '4' which is Error) (Since 2.8)
logfile: string (optional)
libgfapi log file (default /dev/stderr) (Since 2.8)
Since
2.9
BlockdevOptionsIoUring (Object)
Driver specific block device options for the io_uring backend.
Members
filename: string
path to the image file
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsNvmeIoUring (Object)
Driver specific block device options for the nvme-io_uring backend.
Members
path: string
path to the NVMe namespace's character device (e.g. /dev/ng0n1).
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVfioPci (Object)
Driver specific block device options for the virtio-blk-vfio-pci backend.
Members
path: string
path to the PCI device's sysfs directory (e.g. /sys/bus/pci/devices/0000:00:01.0).
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVhostUser (Object)
Driver specific block device options for the virtio-blk-vhost-user backend.
Members
path: string
path to the vhost-user UNIX domain socket.
Since
7.2
If
CONFIG_BLKIO
BlockdevOptionsVirtioBlkVhostVdpa (Object)
Driver specific block device options for the virtio-blk-vhost-vdpa backend.
Members
path: string
path to the vhost-vdpa character device.
Features
fdset Member path supports the special "/dev/fdset/N" path (since 8.1)
Since
7.2
If
CONFIG_BLKIO
IscsiTransport (Enum)
An enumeration of libiscsi transport types
Values
tcp Not documented
iser Not documented
Since
2.9
IscsiHeaderDigest (Enum)
An enumeration of header digests supported by libiscsi
Values
crc32c Not documented
none Not documented
crc32c-none
Not documented
none-crc32c
Not documented
Since
2.9
BlockdevOptionsIscsi (Object)
Driver specific block device options for iscsi
Members
transport: IscsiTransport
The iscsi transport type
portal: string
The address of the iscsi portal
target: string
The target iqn name
lun: int (optional)
LUN to connect to. Defaults to 0.
user: string (optional)
User name to log in with. If omitted, no CHAP authentication is performed.
password-secret: string (optional)
The ID of a QCryptoSecret object providing the password for the login. This option is required if
user is specified.
initiator-name: string (optional)
The iqn name we want to identify to the target as. If this option is not specified, an initiator
name is generated automatically.
header-digest: IscsiHeaderDigest (optional)
The desired header digest. Defaults to none-crc32c.
timeout: int (optional)
Timeout in seconds after which a request will timeout. 0 means no timeout and is the default.
Since
2.9
RbdAuthMode (Enum)
Values
cephx Not documented
none Not documented
Since
3.0
RbdImageEncryptionFormat (Enum)
Values
luks-any
Used for opening either luks or luks2 (Since 8.0)
luks Not documented
luks2 Not documented
Since
6.1
RbdEncryptionOptionsLUKSBase (Object)
Members
key-secret: string
ID of a QCryptoSecret object providing a passphrase for unlocking the encryption
Since
6.1
RbdEncryptionCreateOptionsLUKSBase (Object)
Members
cipher-alg: QCryptoCipherAlgo (optional)
The encryption algorithm
The members of RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKS (Object)
Members
The members of RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKS2 (Object)
Members
The members of RbdEncryptionOptionsLUKSBase
Since
6.1
RbdEncryptionOptionsLUKSAny (Object)
Members
The members of RbdEncryptionOptionsLUKSBase
Since
8.0
RbdEncryptionCreateOptionsLUKS (Object)
Members
The members of RbdEncryptionCreateOptionsLUKSBase
Since
6.1
RbdEncryptionCreateOptionsLUKS2 (Object)
Members
The members of RbdEncryptionCreateOptionsLUKSBase
Since
6.1
RbdEncryptionOptions (Object)
Members
format: RbdImageEncryptionFormat
Encryption format.
parent: RbdEncryptionOptions (optional)
Parent image encryption options (for cloned images). Can be left unspecified if this cloned image
is encrypted using the same format and secret as its parent image (i.e. not explicitly formatted)
or if its parent image is not encrypted. (Since 8.0)
The members of RbdEncryptionOptionsLUKS when format is "luks"
The members of RbdEncryptionOptionsLUKS2 when format is "luks2"
The members of RbdEncryptionOptionsLUKSAny when format is "luks-any"
Since
6.1
RbdEncryptionCreateOptions (Object)
Members
format: RbdImageEncryptionFormat
Encryption format.
The members of RbdEncryptionCreateOptionsLUKS when format is "luks"
The members of RbdEncryptionCreateOptionsLUKS2 when format is "luks2"
Since
6.1
BlockdevOptionsRbd (Object)
Members
pool: string
Ceph pool name.
namespace: string (optional)
Rados namespace name in the Ceph pool. (Since 5.0)
image: string
Image name in the Ceph pool.
conf: string (optional)
path to Ceph configuration file. Values in the configuration file will be overridden by options
specified via QAPI.
snapshot: string (optional)
Ceph snapshot name.
encrypt: RbdEncryptionOptions (optional)
Image encryption options. (Since 6.1)
user: string (optional)
Ceph id name.
auth-client-required: array of RbdAuthMode (optional)
Acceptable authentication modes. This maps to Ceph configuration option "auth_client_required".
(Since 3.0)
key-secret: string (optional)
ID of a QCryptoSecret object providing a key for cephx authentication. This maps to Ceph
configuration option "key". (Since 3.0)
server: array of InetSocketAddressBase (optional)
Monitor host address and port. This maps to the "mon_host" Ceph option.
Since
2.9
ReplicationMode (Enum)
An enumeration of replication modes.
Values
primary
Primary mode, the vm's state will be sent to secondary QEMU.
secondary
Secondary mode, receive the vm's state from primary QEMU.
Since
2.9
If
CONFIG_REPLICATION
BlockdevOptionsReplication (Object)
Driver specific block device options for replication
Members
mode: ReplicationMode
the replication mode
top-id: string (optional)
In secondary mode, node name or device ID of the root node who owns the replication node chain.
Must not be given in primary mode.
The members of BlockdevOptionsGenericFormat
Since
2.9
If
CONFIG_REPLICATION
NFSTransport (Enum)
An enumeration of NFS transport types
Values
inet TCP transport
Since
2.9
NFSServer (Object)
Captures the address of the socket
Members
type: NFSTransport
transport type used for NFS (only TCP supported)
host: string
host address for NFS server
Since
2.9
BlockdevOptionsNfs (Object)
Driver specific block device option for NFS
Members
server: NFSServer
host address
path: string
path of the image on the host
user: int (optional)
UID value to use when talking to the server (defaults to 65534 on Windows and getuid() on unix)
group: int (optional)
GID value to use when talking to the server (defaults to 65534 on Windows and getgid() in unix)
tcp-syn-count: int (optional)
number of SYNs during the session establishment (defaults to libnfs default)
readahead-size: int (optional)
set the readahead size in bytes (defaults to libnfs default)
page-cache-size: int (optional)
set the pagecache size in bytes (defaults to libnfs default)
debug: int (optional)
set the NFS debug level (max 2) (defaults to libnfs default)
Since
2.9
BlockdevOptionsCurlBase (Object)
Driver specific block device options shared by all protocols supported by the curl backend.
Members
url: string
URL of the image file
readahead: int (optional)
Size of the read-ahead cache; must be a multiple of 512 (defaults to 256 kB)
timeout: int (optional)
Timeout for connections, in seconds (defaults to 5)
username: string (optional)
Username for authentication (defaults to none)
password-secret: string (optional)
ID of a QCryptoSecret object providing a password for authentication (defaults to no password)
proxy-username: string (optional)
Username for proxy authentication (defaults to none)
proxy-password-secret: string (optional)
ID of a QCryptoSecret object providing a password for proxy authentication (defaults to no
password)
Since
2.9
BlockdevOptionsCurlHttp (Object)
Driver specific block device options for HTTP connections over the curl backend. URLs must start with "‐
http://".
Members
cookie: string (optional)
List of cookies to set; format is "name1=content1; name2=content2;" as explained by
CURLOPT_COOKIE(3). Defaults to no cookies.
cookie-secret: string (optional)
ID of a QCryptoSecret object providing the cookie data in a secure way. See cookie for the
format. (since 2.10)
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlHttps (Object)
Driver specific block device options for HTTPS connections over the curl backend. URLs must start with
"https://".
Members
cookie: string (optional)
List of cookies to set; format is "name1=content1; name2=content2;" as explained by
CURLOPT_COOKIE(3). Defaults to no cookies.
sslverify: boolean (optional)
Whether to verify the SSL certificate's validity (defaults to true)
cookie-secret: string (optional)
ID of a QCryptoSecret object providing the cookie data in a secure way. See cookie for the
format. (since 2.10)
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlFtp (Object)
Driver specific block device options for FTP connections over the curl backend. URLs must start with "‐
ftp://".
Members
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsCurlFtps (Object)
Driver specific block device options for FTPS connections over the curl backend. URLs must start with
"ftps://".
Members
sslverify: boolean (optional)
Whether to verify the SSL certificate's validity (defaults to true)
The members of BlockdevOptionsCurlBase
Since
2.9
BlockdevOptionsNbd (Object)
Driver specific block device options for NBD.
Members
server: SocketAddress
NBD server address
export: string (optional)
export name
tls-creds: string (optional)
TLS credentials ID
tls-hostname: string (optional)
TLS hostname override for certificate validation (Since 7.0)
x-dirty-bitmap: string (optional)
A metadata context name such as "qemu:dirty-bitmap:NAME" or "qemu:allocation-depth" to query in
place of the traditional "base:allocation" block status (see NBD_OPT_LIST_META_CONTEXT in the NBD
protocol; and yes, naming this option x-context would have made more sense) (since 3.0)
reconnect-delay: int (optional)
On an unexpected disconnect, the nbd client tries to connect again until succeeding or
encountering a serious error. During the first reconnect-delay seconds, all requests are paused
and will be rerun on a successful reconnect. After that time, any delayed requests and all future
requests before a successful reconnect will immediately fail. Default 0 (Since 4.2)
open-timeout: int (optional)
In seconds. If zero, the nbd driver tries the connection only once, and fails to open if the
connection fails. If non-zero, the nbd driver will repeat connection attempts until successful or
until open-timeout seconds have elapsed. Default 0 (Since 7.0)
Features
unstable
Member x-dirty-bitmap is experimental.
Since
2.9
BlockdevOptionsRaw (Object)
Driver specific block device options for the raw driver.
Members
offset: int (optional)
position where the block device starts
size: int (optional)
the assumed size of the device
The members of BlockdevOptionsGenericFormat
Since
2.9
BlockdevOptionsThrottle (Object)
Driver specific block device options for the throttle driver
Members
throttle-group: string
the name of the throttle-group object to use. It must already exist.
file: BlockdevRef
reference to or definition of the data source block device
Since
2.11
BlockdevOptionsCor (Object)
Driver specific block device options for the copy-on-read driver.
Members
bottom: string (optional)
The name of a non-filter node (allocation-bearing layer) that limits the COR operations in the
backing chain (inclusive), so that no data below this node will be copied by this filter. If
option is absent, the limit is not applied, so that data from all backing layers may be copied.
The members of BlockdevOptionsGenericFormat
Since
6.0
OnCbwError (Enum)
An enumeration of possible behaviors for copy-before-write operation failures.
Values
break-guest-write
report the error to the guest. This way, the guest will not be able to overwrite areas that
cannot be backed up, so the backup process remains valid.
break-snapshot
continue guest write. Doing so will make the provided snapshot state invalid and any backup or
export process based on it will finally fail.
Since
7.1
BlockdevOptionsCbw (Object)
Driver specific block device options for the copy-before-write driver, which does so called
copy-before-write operations: when data is written to the filter, the filter first reads corresponding
blocks from its file child and copies them to target child. After successfully copying, the write
request is propagated to file child. If copying fails, the original write request is failed too and no
data is written to file child.
Members
target: BlockdevRef
The target for copy-before-write operations.
bitmap: BlockDirtyBitmap (optional)
If specified, copy-before-write filter will do copy-before-write operations only for dirty regions
of the bitmap. Bitmap size must be equal to length of file and target child of the filter. Note
also, that bitmap is used only to initialize internal bitmap of the process, so further
modifications (or removing) of specified bitmap doesn't influence the filter. (Since 7.0)
on-cbw-error: OnCbwError (optional)
Behavior on failure of copy-before-write operation. Default is break-guest-write. (Since 7.1)
cbw-timeout: int (optional)
Zero means no limit. Non-zero sets the timeout in seconds for copy-before-write operation. When
a timeout occurs, the respective copy-before-write operation will fail, and the on-cbw-error
parameter will decide how this failure is handled. Default 0. (Since 7.1)
min-cluster-size: int (optional)
Minimum size of blocks used by copy-before-write operations. Has to be a power of 2. No effect
if smaller than the maximum of the target's cluster size and 64 KiB. Default 0. (Since 9.2)
The members of BlockdevOptionsGenericFormat
Since
6.2
BlockdevOptions (Object)
Options for creating a block device. Many options are available for all block devices, independent of
the block driver:
Members
driver: BlockdevDriver
block driver name
node-name: string (optional)
the node name of the new node (Since 2.0). This option is required on the top level of
blockdev-add. Valid node names start with an alphabetic character and may contain only
alphanumeric characters, '-', '.' and '_'. Their maximum length is 31 characters.
discard: BlockdevDiscardOptions (optional)
discard-related options (default: ignore)
cache: BlockdevCacheOptions (optional)
cache-related options
read-only: boolean (optional)
whether the block device should be read-only (default: false). Note that some block drivers
support only read-only access, either generally or in certain configurations. In this case, the
default value does not work and the option must be specified explicitly.
auto-read-only: boolean (optional)
if true and read-only is false, QEMU may automatically decide not to open the image read-write as
requested, but fall back to read-only instead (and switch between the modes later), e.g. depending
on whether the image file is writable or whether a writing user is attached to the node (default:
false, since 3.1)
detect-zeroes: BlockdevDetectZeroesOptions (optional)
detect and optimize zero writes (Since 2.1) (default: off)
force-share: boolean (optional)
force share all permission on added nodes. Requires read-only=true. (Since 2.10)
The members of BlockdevOptionsBlkdebug when driver is "blkdebug"
The members of BlockdevOptionsBlklogwrites when driver is "blklogwrites"
The members of BlockdevOptionsBlkverify when driver is "blkverify"
The members of BlockdevOptionsBlkreplay when driver is "blkreplay"
The members of BlockdevOptionsGenericFormat when driver is "bochs"
The members of BlockdevOptionsGenericFormat when driver is "cloop"
The members of BlockdevOptionsGenericFormat when driver is "compress"
The members of BlockdevOptionsCbw when driver is "copy-before-write"
The members of BlockdevOptionsCor when driver is "copy-on-read"
The members of BlockdevOptionsGenericFormat when driver is "dmg"
The members of BlockdevOptionsFile when driver is "file"
The members of BlockdevOptionsCurlFtp when driver is "ftp"
The members of BlockdevOptionsCurlFtps when driver is "ftps"
The members of BlockdevOptionsGluster when driver is "gluster"
The members of BlockdevOptionsFile when driver is "host_cdrom" (If: HAVE_HOST_BLOCK_DEVICE)
The members of BlockdevOptionsFile when driver is "host_device" (If: HAVE_HOST_BLOCK_DEVICE)
The members of BlockdevOptionsCurlHttp when driver is "http"
The members of BlockdevOptionsCurlHttps when driver is "https"
The members of BlockdevOptionsIoUring when driver is "io_uring" (If: CONFIG_BLKIO)
The members of BlockdevOptionsIscsi when driver is "iscsi"
The members of BlockdevOptionsLUKS when driver is "luks"
The members of BlockdevOptionsNbd when driver is "nbd"
The members of BlockdevOptionsNfs when driver is "nfs"
The members of BlockdevOptionsNull when driver is "null-aio"
The members of BlockdevOptionsNull when driver is "null-co"
The members of BlockdevOptionsNVMe when driver is "nvme"
The members of BlockdevOptionsNvmeIoUring when driver is "nvme-io_uring" (If: CONFIG_BLKIO)
The members of BlockdevOptionsGenericFormat when driver is "parallels"
The members of BlockdevOptionsPreallocate when driver is "preallocate"
The members of BlockdevOptionsQcow2 when driver is "qcow2"
The members of BlockdevOptionsQcow when driver is "qcow"
The members of BlockdevOptionsGenericCOWFormat when driver is "qed"
The members of BlockdevOptionsQuorum when driver is "quorum"
The members of BlockdevOptionsRaw when driver is "raw"
The members of BlockdevOptionsRbd when driver is "rbd"
The members of BlockdevOptionsReplication when driver is "replication" (If: CONFIG_REPLICATION)
The members of BlockdevOptionsGenericFormat when driver is "snapshot-access"
The members of BlockdevOptionsSsh when driver is "ssh"
The members of BlockdevOptionsThrottle when driver is "throttle"
The members of BlockdevOptionsGenericFormat when driver is "vdi"
The members of BlockdevOptionsGenericFormat when driver is "vhdx"
The members of BlockdevOptionsVirtioBlkVfioPci when driver is "virtio-blk-vfio-pci" (If: CONFIG_BLKIO)
The members of BlockdevOptionsVirtioBlkVhostUser when driver is "virtio-blk-vhost-user" (If:
CONFIG_BLKIO)
The members of BlockdevOptionsVirtioBlkVhostVdpa when driver is "virtio-blk-vhost-vdpa" (If:
CONFIG_BLKIO)
The members of BlockdevOptionsGenericCOWFormat when driver is "vmdk"
The members of BlockdevOptionsGenericFormat when driver is "vpc"
The members of BlockdevOptionsVVFAT when driver is "vvfat"
Since
2.9
BlockdevRef (Alternate)
Reference to a block device.
Members
definition: BlockdevOptions
defines a new block device inline
reference: string
references the ID of an existing block device
Since
2.9
BlockdevRefOrNull (Alternate)
Reference to a block device.
Members
definition: BlockdevOptions
defines a new block device inline
reference: string
references the ID of an existing block device. An empty string means that no block device should
be referenced. Deprecated; use null instead.
null: null
No block device should be referenced (since 2.10)
Since
2.9
blockdev-add (Command)
Creates a new block device.
Arguments
The members of BlockdevOptions
Since
2.9
Example:
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "test1",
"file": {
"driver": "file",
"filename": "test.qcow2"
}
}
}
<- { "return": {} }
Example:
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "node0",
"discard": "unmap",
"cache": {
"direct": true
},
"file": {
"driver": "file",
"filename": "/tmp/test.qcow2"
},
"backing": {
"driver": "raw",
"file": {
"driver": "file",
"filename": "/dev/fdset/4"
}
}
}
}
<- { "return": {} }
blockdev-reopen (Command)
Reopens one or more block devices using the given set of options. Any option not specified will be reset
to its default value regardless of its previous status. If an option cannot be changed or a particular
driver does not support reopening then the command will return an error. All devices in the list are
reopened in one transaction, so if one of them fails then the whole transaction is cancelled.
The command receives a list of block devices to reopen. For each one of them, the top-level node-name
option (from BlockdevOptions) must be specified and is used to select the block device to be reopened.
Other node-name options must be either omitted or set to the current name of the appropriate node. This
command won't change any node name and any attempt to do it will result in an error.
In the case of options that refer to child nodes, the behavior of this command depends on the value:
1. A set of options (BlockdevOptions): the child is reopened with the specified set of options.
2. A reference to the current child: the child is reopened using its existing set of options.
3. A reference to a different node: the current child is replaced with the specified one.
4. NULL: the current child (if any) is detached.
Options (1) and (2) are supported in all cases. Option (3) is supported for file and backing, and option
(4) for backing only.
Unlike with blockdev-add, the backing option must always be present unless the node being reopened does
not have a backing file and its image does not have a default backing file name as part of its metadata.
Arguments
options: array of BlockdevOptions
Not documented
Since
6.1
blockdev-del (Command)
Deletes a block device that has been added using blockdev-add. The command will fail if the node is
attached to a device or is otherwise being used.
Arguments
node-name: string
Name of the graph node to delete.
Since
2.9
Example:
-> { "execute": "blockdev-add",
"arguments": {
"driver": "qcow2",
"node-name": "node0",
"file": {
"driver": "file",
"filename": "test.qcow2"
}
}
}
<- { "return": {} }
-> { "execute": "blockdev-del",
"arguments": { "node-name": "node0" }
}
<- { "return": {} }
BlockdevCreateOptionsFile (Object)
Driver specific image creation options for file.
Members
filename: string
Filename for the new image file
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed values: off, falloc (if
CONFIG_POSIX_FALLOCATE), full (if CONFIG_POSIX))
nocow: boolean (optional)
Turn off copy-on-write (valid only on btrfs; default: off)
extent-size-hint: int (optional)
Extent size hint to add to the image file; 0 for not adding an extent size hint (default: 1 MB,
since 5.1)
Since
2.12
BlockdevCreateOptionsGluster (Object)
Driver specific image creation options for gluster.
Members
location: BlockdevOptionsGluster
Where to store the new image file
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed values: off, falloc (if
CONFIG_GLUSTERFS_FALLOCATE), full (if CONFIG_GLUSTERFS_ZEROFILL))
Since
2.12
BlockdevCreateOptionsLUKS (Object)
Driver specific image creation options for LUKS.
Members
file: BlockdevRef (optional)
Node to create the image format on, mandatory except when 'preallocation' is not requested
header: BlockdevRef (optional)
Block device holding a detached LUKS header. (since 9.0)
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (since: 4.2) (default: off; allowed values: off, metadata,
falloc, full)
The members of QCryptoBlockCreateOptionsLUKS
Since
2.12
BlockdevCreateOptionsNfs (Object)
Driver specific image creation options for NFS.
Members
location: BlockdevOptionsNfs
Where to store the new image file
size: int
Size of the virtual disk in bytes
Since
2.12
BlockdevCreateOptionsParallels (Object)
Driver specific image creation options for parallels.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
cluster-size: int (optional)
Cluster size in bytes (default: 1 MB)
Since
2.12
BlockdevCreateOptionsQcow (Object)
Driver specific image creation options for qcow.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
backing-file: string (optional)
File name of the backing file if a backing file should be used
encrypt: QCryptoBlockCreateOptions (optional)
Encryption options if the image should be encrypted
Since
2.12
BlockdevQcow2Version (Enum)
Values
v2 The original QCOW2 format as introduced in qemu 0.10 (version 2)
v3 The extended QCOW2 format as introduced in qemu 1.1 (version 3)
Since
2.12
Qcow2CompressionType (Enum)
Compression type used in qcow2 image file
Values
zlib zlib compression, see <http://zlib.net/>
zstd (If: CONFIG_ZSTD)
zstd compression, see <http://github.com/facebook/zstd>
Since
5.1
BlockdevCreateOptionsQcow2 (Object)
Driver specific image creation options for qcow2.
Members
file: BlockdevRef
Node to create the image format on
data-file: BlockdevRef (optional)
Node to use as an external data file in which all guest data is stored so that only metadata
remains in the qcow2 file (since: 4.0)
data-file-raw: boolean (optional)
True if the external data file must stay valid as a standalone (read-only) raw image without
looking at qcow2 metadata (default: false; since: 4.0)
extended-l2: boolean (optional)
True to make the image have extended L2 entries (default: false; since 5.2)
size: int
Size of the virtual disk in bytes
version: BlockdevQcow2Version (optional)
Compatibility level (default: v3)
backing-file: string (optional)
File name of the backing file if a backing file should be used
backing-fmt: BlockdevDriver (optional)
Name of the block driver to use for the backing file
encrypt: QCryptoBlockCreateOptions (optional)
Encryption options if the image should be encrypted
cluster-size: int (optional)
qcow2 cluster size in bytes (default: 65536)
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed values: off, falloc, full, metadata)
lazy-refcounts: boolean (optional)
True if refcounts may be updated lazily (default: off)
refcount-bits: int (optional)
Width of reference counts in bits (default: 16)
compression-type: Qcow2CompressionType (optional)
The image cluster compression method (default: zlib, since 5.1)
Since
2.12
BlockdevCreateOptionsQed (Object)
Driver specific image creation options for qed.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
backing-file: string (optional)
File name of the backing file if a backing file should be used
backing-fmt: BlockdevDriver (optional)
Name of the block driver to use for the backing file
cluster-size: int (optional)
Cluster size in bytes (default: 65536)
table-size: int (optional)
L1/L2 table size (in clusters)
Since
2.12
BlockdevCreateOptionsRbd (Object)
Driver specific image creation options for rbd/Ceph.
Members
location: BlockdevOptionsRbd
Where to store the new image file. This location cannot point to a snapshot.
size: int
Size of the virtual disk in bytes
cluster-size: int (optional)
RBD object size
encrypt: RbdEncryptionCreateOptions (optional)
Image encryption options. (Since 6.1)
Since
2.12
BlockdevVmdkSubformat (Enum)
Subformat options for VMDK images
Values
monolithicSparse
Single file image with sparse cluster allocation
monolithicFlat
Single flat data image and a descriptor file
twoGbMaxExtentSparse
Data is split into 2GB (per virtual LBA) sparse extent files, in addition to a descriptor file
twoGbMaxExtentFlat
Data is split into 2GB (per virtual LBA) flat extent files, in addition to a descriptor file
streamOptimized
Single file image sparse cluster allocation, optimized for streaming over network.
Since
4.0
BlockdevVmdkAdapterType (Enum)
Adapter type info for VMDK images
Values
ide Not documented
buslogic
Not documented
lsilogic
Not documented
legacyESX
Not documented
Since
4.0
BlockdevCreateOptionsVmdk (Object)
Driver specific image creation options for VMDK.
Members
file: BlockdevRef
Where to store the new image file. This refers to the image file for monolithcSparse and
streamOptimized format, or the descriptor file for other formats.
size: int
Size of the virtual disk in bytes
extents: array of BlockdevRef (optional)
Where to store the data extents. Required for monolithcFlat, twoGbMaxExtentSparse and
twoGbMaxExtentFlat formats. For monolithicFlat, only one entry is required; for twoGbMaxExtent*
formats, the number of entries required is calculated as extent_number = virtual_size / 2GB.
Providing more extents than will be used is an error.
subformat: BlockdevVmdkSubformat (optional)
The subformat of the VMDK image. Default: "monolithicSparse".
backing-file: string (optional)
The path of backing file. Default: no backing file is used.
adapter-type: BlockdevVmdkAdapterType (optional)
The adapter type used to fill in the descriptor. Default: ide.
hwversion: string (optional)
Hardware version. The meaningful options are "4" or "6". Default: "4".
toolsversion: string (optional)
VMware guest tools version. Default: "2147483647" (Since 6.2)
zeroed-grain: boolean (optional)
Whether to enable zeroed-grain feature for sparse subformats. Default: false.
Since
4.0
BlockdevCreateOptionsSsh (Object)
Driver specific image creation options for SSH.
Members
location: BlockdevOptionsSsh
Where to store the new image file
size: int
Size of the virtual disk in bytes
Since
2.12
BlockdevCreateOptionsVdi (Object)
Driver specific image creation options for VDI.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
preallocation: PreallocMode (optional)
Preallocation mode for the new image (default: off; allowed values: off, metadata)
Since
2.12
BlockdevVhdxSubformat (Enum)
Values
dynamic
Growing image file
fixed Preallocated fixed-size image file
Since
2.12
BlockdevCreateOptionsVhdx (Object)
Driver specific image creation options for vhdx.
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
log-size: int (optional)
Log size in bytes, must be a multiple of 1 MB (default: 1 MB)
block-size: int (optional)
Block size in bytes, must be a multiple of 1 MB and not larger than 256 MB (default: automatically
choose a block size depending on the image size)
subformat: BlockdevVhdxSubformat (optional)
vhdx subformat (default: dynamic)
block-state-zero: boolean (optional)
Force use of payload blocks of type 'ZERO'. Non-standard, but default. Do not set to 'off' when
using 'qemu-img convert' with subformat=dynamic.
Since
2.12
BlockdevVpcSubformat (Enum)
Values
dynamic
Growing image file
fixed Preallocated fixed-size image file
Since
2.12
BlockdevCreateOptionsVpc (Object)
Driver specific image creation options for vpc (VHD).
Members
file: BlockdevRef
Node to create the image format on
size: int
Size of the virtual disk in bytes
subformat: BlockdevVpcSubformat (optional)
vhdx subformat (default: dynamic)
force-size: boolean (optional)
Force use of the exact byte size instead of rounding to the next size that can be represented in
CHS geometry (default: false)
Since
2.12
BlockdevCreateOptions (Object)
Options for creating an image format on a given node.
Members
driver: BlockdevDriver
block driver to create the image format
The members of BlockdevCreateOptionsFile when driver is "file"
The members of BlockdevCreateOptionsGluster when driver is "gluster"
The members of BlockdevCreateOptionsLUKS when driver is "luks"
The members of BlockdevCreateOptionsNfs when driver is "nfs"
The members of BlockdevCreateOptionsParallels when driver is "parallels"
The members of BlockdevCreateOptionsQcow when driver is "qcow"
The members of BlockdevCreateOptionsQcow2 when driver is "qcow2"
The members of BlockdevCreateOptionsQed when driver is "qed"
The members of BlockdevCreateOptionsRbd when driver is "rbd"
The members of BlockdevCreateOptionsSsh when driver is "ssh"
The members of BlockdevCreateOptionsVdi when driver is "vdi"
The members of BlockdevCreateOptionsVhdx when driver is "vhdx"
The members of BlockdevCreateOptionsVmdk when driver is "vmdk"
The members of BlockdevCreateOptionsVpc when driver is "vpc"
Since
2.12
blockdev-create (Command)
Starts a job to create an image format on a given node. The job is automatically finalized, but a manual
job-dismiss is required.
Arguments
job-id: string
Identifier for the newly created job.
options: BlockdevCreateOptions
Options for the image creation.
Since
3.0
BlockdevAmendOptionsLUKS (Object)
Driver specific image amend options for LUKS.
Members
The members of QCryptoBlockAmendOptionsLUKS
Since
5.1
BlockdevAmendOptionsQcow2 (Object)
Driver specific image amend options for qcow2. For now, only encryption options can be amended
Members
encrypt: QCryptoBlockAmendOptions (optional)
Encryption options to be amended
Since
5.1
BlockdevAmendOptions (Object)
Options for amending an image format
Members
driver: BlockdevDriver
Block driver of the node to amend.
The members of BlockdevAmendOptionsLUKS when driver is "luks"
The members of BlockdevAmendOptionsQcow2 when driver is "qcow2"
Since
5.1
x-blockdev-amend (Command)
Starts a job to amend format specific options of an existing open block device The job is automatically
finalized, but a manual job-dismiss is required.
Arguments
job-id: string
Identifier for the newly created job.
node-name: string
Name of the block node to work on
options: BlockdevAmendOptions
Options (driver specific)
force: boolean (optional)
Allow unsafe operations, format specific For luks that allows erase of the last active keyslot
(permanent loss of data), and replacement of an active keyslot (possible loss of data if IO error
happens)
Features
unstable
This command is experimental.
Since
5.1
BlockErrorAction (Enum)
An enumeration of action that has been taken when a DISK I/O occurs
Values
ignore error has been ignored
report error has been reported to the device
stop error caused VM to be stopped
Since
2.1
BLOCK_IMAGE_CORRUPTED (Event)
Emitted when a disk image is being marked corrupt. The image can be identified by its device or node
name. The 'device' field is always present for compatibility reasons, but it can be empty ("") if the
image does not have a device name associated.
Arguments
device: string
device name. This is always present for compatibility reasons, but it can be empty ("") if the
image does not have a device name associated.
node-name: string (optional)
node name (Since: 2.4)
msg: string
informative message for human consumption, such as the kind of corruption being detected. It
should not be parsed by machine as it is not guaranteed to be stable
offset: int (optional)
if the corruption resulted from an image access, this is the host's access offset into the image
size: int (optional)
if the corruption resulted from an image access, this is the access size
fatal: boolean
if set, the image is marked corrupt and therefore unusable after this event and must be repaired
(Since 2.2; before, every BLOCK_IMAGE_CORRUPTED event was fatal)
NOTE:
If action is "stop", a STOP event will eventually follow the BLOCK_IO_ERROR event.
Example:
<- { "event": "BLOCK_IMAGE_CORRUPTED",
"data": { "device": "", "node-name": "drive", "fatal": false,
"msg": "L2 table offset 0x2a2a2a00 unaligned (L1 index: 0)" },
"timestamp": { "seconds": 1648243240, "microseconds": 906060 } }
Since
1.7
BLOCK_IO_ERROR (Event)
Emitted when a disk I/O error occurs
Arguments
qom-path: string
path to the device object in the QOM tree (since 9.2)
device: string
device name. This is always present for compatibility reasons, but it can be empty ("") if the
image does not have a device name associated.
node-name: string (optional)
node name. Note that errors may be reported for the root node that is directly attached to a
guest device rather than for the node where the error occurred. The node name is not present if
the drive is empty. (Since: 2.8)
operation: IoOperationType
I/O operation
action: BlockErrorAction
action that has been taken
nospace: boolean (optional)
true if I/O error was caused due to a no-space condition. This key is only present if
query-block's io-status is present, please see query-block documentation for more information
(since: 2.2)
reason: string
human readable string describing the error cause. (This field is a debugging aid for humans, it
should not be parsed by applications) (since: 2.2)
NOTE:
If action is "stop", a STOP event will eventually follow the BLOCK_IO_ERROR event.
NOTE:
This event is rate-limited.
Since
0.13
Example:
<- { "event": "BLOCK_IO_ERROR",
"data": { "qom-path": "/machine/unattached/device[0]",
"device": "ide0-hd1",
"node-name": "#block212",
"operation": "write",
"action": "stop",
"reason": "No space left on device" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_COMPLETED (Event)
Emitted when a block job has completed
Arguments
type: JobType
job type
device: string
The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int
maximum progress value
offset: int
current progress value. On success this is equal to len. On failure this is less than len
speed: int
rate limit, bytes per second
error: string (optional)
error message. Only present on failure. This field contains a human-readable error message.
There are no semantics other than that streaming has failed and clients should not try to
interpret the error string
Since
1.1
Example:
<- { "event": "BLOCK_JOB_COMPLETED",
"data": { "type": "stream", "device": "virtio-disk0",
"len": 10737418240, "offset": 10737418240,
"speed": 0 },
"timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
BLOCK_JOB_CANCELLED (Event)
Emitted when a block job has been cancelled
Arguments
type: JobType
job type
device: string
The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int
maximum progress value
offset: int
current progress value. On success this is equal to len. On failure this is less than len
speed: int
rate limit, bytes per second
Since
1.1
Example:
<- { "event": "BLOCK_JOB_CANCELLED",
"data": { "type": "stream", "device": "virtio-disk0",
"len": 10737418240, "offset": 134217728,
"speed": 0 },
"timestamp": { "seconds": 1267061043, "microseconds": 959568 } }
BLOCK_JOB_ERROR (Event)
Emitted when a block job encounters an error
Arguments
device: string
The job identifier. Originally the device name but other values are allowed since QEMU 2.7
operation: IoOperationType
I/O operation
action: BlockErrorAction
action that has been taken
Since
1.3
Example:
<- { "event": "BLOCK_JOB_ERROR",
"data": { "device": "ide0-hd1",
"operation": "write",
"action": "stop" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_READY (Event)
Emitted when a block job is ready to complete
Arguments
type: JobType
job type
device: string
The job identifier. Originally the device name but other values are allowed since QEMU 2.7
len: int
maximum progress value
offset: int
current progress value. On success this is equal to len. On failure this is less than len
speed: int
rate limit, bytes per second
NOTE:
The "ready to complete" status is always reset by a BLOCK_JOB_ERROR event.
Since
1.3
Example:
<- { "event": "BLOCK_JOB_READY",
"data": { "device": "drive0", "type": "mirror", "speed": 0,
"len": 2097152, "offset": 2097152 },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
BLOCK_JOB_PENDING (Event)
Emitted when a block job is awaiting explicit authorization to finalize graph changes via
block-job-finalize. If this job is part of a transaction, it will not emit this event until the
transaction has converged first.
Arguments
type: JobType
job type
id: string
The job identifier.
Since
2.12
Example:
<- { "event": "BLOCK_JOB_PENDING",
"data": { "type": "mirror", "id": "backup_1" },
"timestamp": { "seconds": 1265044230, "microseconds": 450486 } }
PreallocMode (Enum)
Preallocation mode of QEMU image file
Values
off no preallocation
metadata
preallocate only for metadata
falloc like full preallocation but allocate disk space by posix_fallocate() rather than writing data.
full preallocate all data by writing it to the device to ensure disk space is really available. This
data may or may not be zero, depending on the image format and storage. full preallocation also
sets up metadata correctly.
Since
2.2
BLOCK_WRITE_THRESHOLD (Event)
Emitted when writes on block device reaches or exceeds the configured write threshold. For
thin-provisioned devices, this means the device should be extended to avoid pausing for disk exhaustion.
The event is one shot. Once triggered, it needs to be re-registered with another
block-set-write-threshold command.
Arguments
node-name: string
graph node name on which the threshold was exceeded.
amount-exceeded: int
amount of data which exceeded the threshold, in bytes.
write-threshold: int
last configured threshold, in bytes.
Since
2.3
block-set-write-threshold (Command)
Change the write threshold for a block drive. An event will be delivered if a write to this block drive
crosses the configured threshold. The threshold is an offset, thus must be non-negative. Default is no
write threshold. Setting the threshold to zero disables it.
This is useful to transparently resize thin-provisioned drives without the guest OS noticing.
Arguments
node-name: string
graph node name on which the threshold must be set.
write-threshold: int
configured threshold for the block device, bytes. Use 0 to disable the threshold.
Since
2.3
Example:
-> { "execute": "block-set-write-threshold",
"arguments": { "node-name": "mydev",
"write-threshold": 17179869184 } }
<- { "return": {} }
x-blockdev-change (Command)
Dynamically reconfigure the block driver state graph. It can be used to add, remove, insert or replace a
graph node. Currently only the Quorum driver implements this feature to add or remove its child. This
is useful to fix a broken quorum child.
If node is specified, it will be inserted under parent. child may not be specified in this case. If
both parent and child are specified but node is not, child will be detached from parent.
Arguments
parent: string
the id or name of the parent node.
child: string (optional)
the name of a child under the given parent node.
node: string (optional)
the name of the node that will be added.
Features
unstable
This command is experimental, and its API is not stable. It does not support all kinds of
operations, all kinds of children, nor all block drivers.
FIXME Removing children from a quorum node means introducing gaps in the child indices. This
cannot be represented in the 'children' list of BlockdevOptionsQuorum, as returned by
.bdrv_refresh_filename().
Warning: The data in a new quorum child MUST be consistent with that of the rest of the array.
Since
2.7
Example: Add a new node to a quorum
-> { "execute": "blockdev-add",
"arguments": {
"driver": "raw",
"node-name": "new_node",
"file": { "driver": "file",
"filename": "test.raw" } } }
<- { "return": {} }
-> { "execute": "x-blockdev-change",
"arguments": { "parent": "disk1",
"node": "new_node" } }
<- { "return": {} }
Example: Delete a quorum's node
-> { "execute": "x-blockdev-change",
"arguments": { "parent": "disk1",
"child": "children.1" } }
<- { "return": {} }
x-blockdev-set-iothread (Command)
Move node and its children into the iothread. If iothread is null then move node and its children into
the main loop.
The node must not be attached to a BlockBackend.
Arguments
node-name: string
the name of the block driver node
iothread: StrOrNull
the name of the IOThread object or null for the main loop
force: boolean (optional)
true if the node and its children should be moved when a BlockBackend is already attached
Features
unstable
This command is experimental and intended for test cases that need control over IOThreads only.
Since
2.12
Example: Move a node into an IOThread
-> { "execute": "x-blockdev-set-iothread",
"arguments": { "node-name": "disk1",
"iothread": "iothread0" } }
<- { "return": {} }
Example: Move a node into the main loop
-> { "execute": "x-blockdev-set-iothread",
"arguments": { "node-name": "disk1",
"iothread": null } }
<- { "return": {} }
QuorumOpType (Enum)
An enumeration of the quorum operation types
Values
read read operation
write write operation
flush flush operation
Since
2.6
QUORUM_FAILURE (Event)
Emitted by the Quorum block driver if it fails to establish a quorum
Arguments
reference: string
device name if defined else node name
sector-num: int
number of the first sector of the failed read operation
sectors-count: int
failed read operation sector count
NOTE:
This event is rate-limited.
Since
2.0
Example:
<- { "event": "QUORUM_FAILURE",
"data": { "reference": "usr1", "sector-num": 345435, "sectors-count": 5 },
"timestamp": { "seconds": 1344522075, "microseconds": 745528 } }
QUORUM_REPORT_BAD (Event)
Emitted to report a corruption of a Quorum file
Arguments
type: QuorumOpType
quorum operation type (Since 2.6)
error: string (optional)
error message. Only present on failure. This field contains a human-readable error message.
There are no semantics other than that the block layer reported an error and clients should not
try to interpret the error string.
node-name: string
the graph node name of the block driver state
sector-num: int
number of the first sector of the failed read operation
sectors-count: int
failed read operation sector count
NOTE:
This event is rate-limited.
Since
2.0
Example: Read operation
<- { "event": "QUORUM_REPORT_BAD",
"data": { "node-name": "node0", "sector-num": 345435, "sectors-count": 5,
"type": "read" },
"timestamp": { "seconds": 1344522075, "microseconds": 745528 } }
Example: Flush operation
<- { "event": "QUORUM_REPORT_BAD",
"data": { "node-name": "node0", "sector-num": 0, "sectors-count": 2097120,
"type": "flush", "error": "Broken pipe" },
"timestamp": { "seconds": 1456406829, "microseconds": 291763 } }
BlockdevSnapshotInternal (Object)
Members
device: string
the device name or node-name of a root node to generate the snapshot from
name: string
the name of the internal snapshot to be created
Since
1.7
blockdev-snapshot-internal-sync (Command)
Synchronously take an internal snapshot of a block device, when the format of the image used supports it.
If the name is an empty string, or a snapshot with name already exists, the operation will fail.
Arguments
The members of BlockdevSnapshotInternal
Errors
• If device is not a valid block device, GenericError
• If any snapshot matching name exists, or name is empty, GenericError
• If the format of the image used does not support it, GenericError
NOTE:
Only some image formats such as qcow2 and rbd support internal snapshots.
Since
1.7
Example:
-> { "execute": "blockdev-snapshot-internal-sync",
"arguments": { "device": "ide-hd0",
"name": "snapshot0" }
}
<- { "return": {} }
blockdev-snapshot-delete-internal-sync (Command)
Synchronously delete an internal snapshot of a block device, when the format of the image used support
it. The snapshot is identified by name or id or both. One of the name or id is required. Return
SnapshotInfo for the successfully deleted snapshot.
Arguments
device: string
the device name or node-name of a root node to delete the snapshot from
id: string (optional)
optional the snapshot's ID to be deleted
name: string (optional)
optional the snapshot's name to be deleted
Returns
SnapshotInfo
Errors
• If device is not a valid block device, GenericError
• If snapshot not found, GenericError
• If the format of the image used does not support it, GenericError
• If id and name are both not specified, GenericError
Since
1.7
Example:
-> { "execute": "blockdev-snapshot-delete-internal-sync",
"arguments": { "device": "ide-hd0",
"name": "snapshot0" }
}
<- { "return": {
"id": "1",
"name": "snapshot0",
"vm-state-size": 0,
"date-sec": 1000012,
"date-nsec": 10,
"vm-clock-sec": 100,
"vm-clock-nsec": 20,
"icount": 220414
}
}
DummyBlockCoreForceArrays (Object)
Not used by QMP; hack to let us use BlockGraphInfoList internally
Members
unused-block-graph-info: array of BlockGraphInfo
Not documented
Since
8.0
Block device exports
NbdServerOptions (Object)
Keep this type consistent with the nbd-server-start arguments. The only intended difference is using
SocketAddress instead of SocketAddressLegacy.
Members
addr: SocketAddress
Address on which to listen.
tls-creds: string (optional)
ID of the TLS credentials object (since 2.6).
tls-authz: string (optional)
ID of the QAuthZ authorization object used to validate the client's x509 distinguished name. This
object is is only resolved at time of use, so can be deleted and recreated on the fly while the
NBD server is active. If missing, it will default to denying access (since 4.0).
max-connections: int (optional)
The maximum number of connections to allow at the same time, 0 for unlimited. Setting this to 1
also stops the server from advertising multiple client support (since 5.2; default: 100)
Since
4.2
nbd-server-start (Command)
Start an NBD server listening on the given host and port. Block devices can then be exported using
nbd-server-add. The NBD server will present them as named exports; for example, another QEMU instance
could refer to them as "nbd:HOST:PORT:exportname=NAME".
Keep this type consistent with the NbdServerOptions type. The only intended difference is using
SocketAddressLegacy instead of SocketAddress.
Arguments
addr: SocketAddressLegacy
Address on which to listen.
tls-creds: string (optional)
ID of the TLS credentials object (since 2.6).
tls-authz: string (optional)
ID of the QAuthZ authorization object used to validate the client's x509 distinguished name. This
object is is only resolved at time of use, so can be deleted and recreated on the fly while the
NBD server is active. If missing, it will default to denying access (since 4.0).
max-connections: int (optional)
The maximum number of connections to allow at the same time, 0 for unlimited. Setting this to 1
also stops the server from advertising multiple client support (since 5.2; default: 100).
Errors
• if the server is already running
Since
1.3
BlockExportOptionsNbdBase (Object)
An NBD block export (common options shared between nbd-server-add and the NBD branch of
block-export-add).
Members
name: string (optional)
Export name. If unspecified, the device parameter is used as the export name. (Since 2.12)
description: string (optional)
Free-form description of the export, up to 4096 bytes. (Since 5.0)
Since
5.0
BlockExportOptionsNbd (Object)
An NBD block export (distinct options used in the NBD branch of block-export-add).
Members
bitmaps: array of BlockDirtyBitmapOrStr (optional)
Also export each of the named dirty bitmaps reachable from device, so the NBD client can use
NBD_OPT_SET_META_CONTEXT with the metadata context name "qemu:dirty-bitmap:BITMAP" to inspect each
bitmap. Since 7.1 bitmap may be specified by node/name pair.
allocation-depth: boolean (optional)
Also export the allocation depth map for device, so the NBD client can use
NBD_OPT_SET_META_CONTEXT with the metadata context name "qemu:allocation-depth" to inspect
allocation details. (since 5.2)
The members of BlockExportOptionsNbdBase
Since
5.2
BlockExportOptionsVhostUserBlk (Object)
A vhost-user-blk block export.
Members
addr: SocketAddress
The vhost-user socket on which to listen. Both 'unix' and 'fd' SocketAddress types are supported.
Passed fds must be UNIX domain sockets.
logical-block-size: int (optional)
Logical block size in bytes. Defaults to 512 bytes.
num-queues: int (optional)
Number of request virtqueues. Must be greater than 0. Defaults to 1.
Since
5.2
FuseExportAllowOther (Enum)
Possible allow_other modes for FUSE exports.
Values
off Do not pass allow_other as a mount option.
on Pass allow_other as a mount option.
auto Try mounting with allow_other first, and if that fails, retry without allow_other.
Since
6.1
BlockExportOptionsFuse (Object)
Options for exporting a block graph node on some (file) mountpoint as a raw image.
Members
mountpoint: string
Path on which to export the block device via FUSE. This must point to an existing regular file.
growable: boolean (optional)
Whether writes beyond the EOF should grow the block node accordingly. (default: false)
allow-other: FuseExportAllowOther (optional)
If this is off, only qemu's user is allowed access to this export. That cannot be changed even
with chmod or chown. Enabling this option will allow other users access to the export with the
FUSE mount option "allow_other". Note that using allow_other as a non-root user requires
user_allow_other to be enabled in the global fuse.conf configuration file. In auto mode (the
default), the FUSE export driver will first attempt to mount the export with allow_other, and if
that fails, try again without. (since 6.1; default: auto)
Since
6.0
If
CONFIG_FUSE
BlockExportOptionsVduseBlk (Object)
A vduse-blk block export.
Members
name: string
the name of VDUSE device (must be unique across the host).
num-queues: int (optional)
the number of virtqueues. Defaults to 1.
queue-size: int (optional)
the size of virtqueue. Defaults to 256.
logical-block-size: int (optional)
Logical block size in bytes. Range [512, PAGE_SIZE] and must be power of 2. Defaults to 512
bytes.
serial: string (optional)
the serial number of virtio block device. Defaults to empty string.
Since
7.1
NbdServerAddOptions (Object)
An NBD block export, per legacy nbd-server-add command.
Members
device: string
The device name or node name of the node to be exported
writable: boolean (optional)
Whether clients should be able to write to the device via the NBD connection (default false).
bitmap: string (optional)
Also export a single dirty bitmap reachable from device, so the NBD client can use
NBD_OPT_SET_META_CONTEXT with the metadata context name "qemu:dirty-bitmap:BITMAP" to inspect the
bitmap (since 4.0).
The members of BlockExportOptionsNbdBase
Since
5.0
nbd-server-add (Command)
Export a block node to QEMU's embedded NBD server.
The export name will be used as the id for the resulting block export.
Arguments
The members of NbdServerAddOptions
Features
deprecated
This command is deprecated. Use block-export-add instead.
Errors
• if the server is not running
• if an export with the same name already exists
Since
1.3
BlockExportRemoveMode (Enum)
Mode for removing a block export.
Values
safe Remove export if there are no existing connections, fail otherwise.
hard Drop all connections immediately and remove export.
Since
2.12
nbd-server-remove (Command)
Remove NBD export by name.
Arguments
name: string
Block export id.
mode: BlockExportRemoveMode (optional)
Mode of command operation. See BlockExportRemoveMode description. Default is 'safe'.
Features
deprecated
This command is deprecated. Use block-export-del instead.
Errors
• if the server is not running
• if export is not found
• if mode is 'safe' and there are existing connections
Since
2.12
nbd-server-stop (Command)
Stop QEMU's embedded NBD server, and unregister all devices previously added via nbd-server-add.
Since
1.3
BlockExportType (Enum)
An enumeration of block export types
Values
nbd NBD export
vhost-user-blk (If: CONFIG_VHOST_USER_BLK_SERVER)
vhost-user-blk export (since 5.2)
fuse (If: CONFIG_FUSE)
FUSE export (since: 6.0)
vduse-blk (If: CONFIG_VDUSE_BLK_EXPORT)
vduse-blk export (since 7.1)
Since
4.2
BlockExportOptions (Object)
Describes a block export, i.e. how single node should be exported on an external interface.
Members
type: BlockExportType
Block export type
id: string
A unique identifier for the block export (across all export types)
node-name: string
The node name of the block node to be exported (since: 5.2)
writable: boolean (optional)
True if clients should be able to write to the export (default false)
writethrough: boolean (optional)
If true, caches are flushed after every write request to the export before completion is
signalled. (since: 5.2; default: false)
iothread: string (optional)
The name of the iothread object where the export will run. The default is to use the thread
currently associated with the block node. (since: 5.2)
fixed-iothread: boolean (optional)
True prevents the block node from being moved to another thread while the export is active. If
true and iothread is given, export creation fails if the block node cannot be moved to the
iothread. The default is false. (since: 5.2)
The members of BlockExportOptionsNbd when type is "nbd"
The members of BlockExportOptionsVhostUserBlk when type is "vhost-user-blk" (If:
CONFIG_VHOST_USER_BLK_SERVER)
The members of BlockExportOptionsFuse when type is "fuse" (If: CONFIG_FUSE)
The members of BlockExportOptionsVduseBlk when type is "vduse-blk" (If: CONFIG_VDUSE_BLK_EXPORT)
Since
4.2
block-export-add (Command)
Creates a new block export.
Arguments
The members of BlockExportOptions
Since
5.2
block-export-del (Command)
Request to remove a block export. This drops the user's reference to the export, but the export may
still stay around after this command returns until the shutdown of the export has completed.
Arguments
id: string
Block export id.
mode: BlockExportRemoveMode (optional)
Mode of command operation. See BlockExportRemoveMode description. Default is 'safe'.
Errors
• if the export is not found
• if mode is 'safe' and the export is still in use (e.g. by existing client connections)
Since
5.2
BLOCK_EXPORT_DELETED (Event)
Emitted when a block export is removed and its id can be reused.
Arguments
id: string
Block export id.
Since
5.2
BlockExportInfo (Object)
Information about a single block export.
Members
id: string
The unique identifier for the block export
type: BlockExportType
The block export type
node-name: string
The node name of the block node that is exported
shutting-down: boolean
True if the export is shutting down (e.g. after a block-export-del command, but before the
shutdown has completed)
Since
5.2
query-block-exports (Command)
Returns
A list of BlockExportInfo describing all block exports
Since
5.2
CHARACTER DEVICES
ChardevInfo (Object)
Information about a character device.
Members
label: string
the label of the character device
filename: string
the filename of the character device
frontend-open: boolean
shows whether the frontend device attached to this backend (e.g. with the chardev=... option) is
in open or closed state (since 2.1)
NOTE:
filename is encoded using the QEMU command line character device encoding. See the QEMU man page for
details.
Since
0.14
query-chardev (Command)
Returns information about current character devices.
Returns
a list of ChardevInfo
Since
0.14
Example:
-> { "execute": "query-chardev" }
<- {
"return": [
{
"label": "charchannel0",
"filename": "unix:/var/lib/libvirt/qemu/seabios.rhel6.agent,server=on",
"frontend-open": false
},
{
"label": "charmonitor",
"filename": "unix:/var/lib/libvirt/qemu/seabios.rhel6.monitor,server=on",
"frontend-open": true
},
{
"label": "charserial0",
"filename": "pty:/dev/pts/2",
"frontend-open": true
}
]
}
ChardevBackendInfo (Object)
Information about a character device backend
Members
name: string
The backend name
Since
2.0
query-chardev-backends (Command)
Returns information about character device backends.
Returns
a list of ChardevBackendInfo
Since
2.0
Example:
-> { "execute": "query-chardev-backends" }
<- {
"return":[
{
"name":"udp"
},
{
"name":"tcp"
},
{
"name":"unix"
},
{
"name":"spiceport"
}
]
}
DataFormat (Enum)
An enumeration of data format.
Values
utf8 Data is a UTF-8 string (RFC 3629)
base64 Data is Base64 encoded binary (RFC 3548)
Since
1.4
ringbuf-write (Command)
Write to a ring buffer character device.
Arguments
device: string
the ring buffer character device name
data: string
data to write
format: DataFormat (optional)
data encoding (default 'utf8').
• base64: data must be base64 encoded text. Its binary decoding gets written.
• utf8: data's UTF-8 encoding is written
• data itself is always Unicode regardless of format, like any other string.
Since
1.4
Example:
-> { "execute": "ringbuf-write",
"arguments": { "device": "foo",
"data": "abcdefgh",
"format": "utf8" } }
<- { "return": {} }
ringbuf-read (Command)
Read from a ring buffer character device.
Arguments
device: string
the ring buffer character device name
size: int
how many bytes to read at most
format: DataFormat (optional)
data encoding (default 'utf8').
• base64: the data read is returned in base64 encoding.
• utf8: the data read is interpreted as UTF-8. Bug: can screw up when the buffer contains invalid
UTF-8 sequences, NUL characters, after the ring buffer lost data, and when reading stops because
the size limit is reached.
• The return value is always Unicode regardless of format, like any other string.
Returns
data read from the device
Since
1.4
Example:
-> { "execute": "ringbuf-read",
"arguments": { "device": "foo",
"size": 1000,
"format": "utf8" } }
<- { "return": "abcdefgh" }
ChardevCommon (Object)
Configuration shared across all chardev backends
Members
logfile: string (optional)
The name of a logfile to save output
logappend: boolean (optional)
true to append instead of truncate (default to false to truncate)
Since
2.6
ChardevFile (Object)
Configuration info for file chardevs.
Members
in: string (optional)
The name of the input file
out: string
The name of the output file
append: boolean (optional)
Open the file in append mode (default false to truncate) (Since 2.6)
The members of ChardevCommon
Since
1.4
ChardevHostdev (Object)
Configuration info for device and pipe chardevs.
Members
device: string
The name of the special file for the device, i.e. /dev/ttyS0 on Unix or COM1: on Windows
The members of ChardevCommon
Since
1.4
ChardevSocket (Object)
Configuration info for (stream) socket chardevs.
Members
addr: SocketAddressLegacy
socket address to listen on (server=true) or connect to (server=false)
tls-creds: string (optional)
the ID of the TLS credentials object (since 2.6)
tls-authz: string (optional)
the ID of the QAuthZ authorization object against which the client's x509 distinguished name will
be validated. This object is only resolved at time of use, so can be deleted and recreated on the
fly while the chardev server is active. If missing, it will default to denying access (since 4.0)
server: boolean (optional)
create server socket (default: true)
wait: boolean (optional)
wait for incoming connection on server sockets (default: false). Silently ignored with server:
false. This use is deprecated.
nodelay: boolean (optional)
set TCP_NODELAY socket option (default: false)
telnet: boolean (optional)
enable telnet protocol on server sockets (default: false)
tn3270: boolean (optional)
enable tn3270 protocol on server sockets (default: false) (Since: 2.10)
websocket: boolean (optional)
enable websocket protocol on server sockets (default: false) (Since: 3.1)
reconnect: int (optional)
For a client socket, if a socket is disconnected, then attempt a reconnect after the given number
of seconds. Setting this to zero disables this function. The use of this member is deprecated,
use reconnect-ms instead. (default: 0) (Since: 2.2)
reconnect-ms: int (optional)
For a client socket, if a socket is disconnected, then attempt a reconnect after the given number
of milliseconds. Setting this to zero disables this function. This member is mutually exclusive
with reconnect. (default: 0) (Since: 9.2)
The members of ChardevCommon
Features
deprecated
Member reconnect is deprecated. Use reconnect-ms instead.
Since
1.4
ChardevUdp (Object)
Configuration info for datagram socket chardevs.
Members
remote: SocketAddressLegacy
remote address
local: SocketAddressLegacy (optional)
local address
The members of ChardevCommon
Since
1.5
ChardevMux (Object)
Configuration info for mux chardevs.
Members
chardev: string
name of the base chardev.
The members of ChardevCommon
Since
1.5
ChardevStdio (Object)
Configuration info for stdio chardevs.
Members
signal: boolean (optional)
Allow signals (such as SIGINT triggered by ^C) be delivered to qemu. Default: true.
The members of ChardevCommon
Since
1.5
ChardevSpiceChannel (Object)
Configuration info for spice vm channel chardevs.
Members
type: string
kind of channel (for example vdagent).
The members of ChardevCommon
Since
1.5
If
CONFIG_SPICE
ChardevSpicePort (Object)
Configuration info for spice port chardevs.
Members
fqdn: string
name of the channel (see docs/spice-port-fqdn.txt)
The members of ChardevCommon
Since
1.5
If
CONFIG_SPICE
ChardevDBus (Object)
Configuration info for DBus chardevs.
Members
name: string
name of the channel (following docs/spice-port-fqdn.txt)
The members of ChardevCommon
Since
7.0
If
CONFIG_DBUS_DISPLAY
ChardevVC (Object)
Configuration info for virtual console chardevs.
Members
width: int (optional)
console width, in pixels
height: int (optional)
console height, in pixels
cols: int (optional)
console width, in chars
rows: int (optional)
console height, in chars
The members of ChardevCommon
NOTE:
The options are only effective when the VNC or SDL graphical display backend is active. They are
ignored with the GTK, Spice, VNC and D-Bus display backends.
Since
1.5
ChardevRingbuf (Object)
Configuration info for ring buffer chardevs.
Members
size: int (optional)
ring buffer size, must be power of two, default is 65536
The members of ChardevCommon
Since
1.5
ChardevQemuVDAgent (Object)
Configuration info for qemu vdagent implementation.
Members
mouse: boolean (optional)
enable/disable mouse, default is enabled.
clipboard: boolean (optional)
enable/disable clipboard, default is disabled.
The members of ChardevCommon
Since
6.1
If
CONFIG_SPICE_PROTOCOL
ChardevPty (Object)
Configuration info for pty implementation.
Members
path: string (optional)
optional path to create a symbolic link that points to the allocated PTY
The members of ChardevCommon
Since
9.2
ChardevBackendKind (Enum)
Values
file regular files
serial (If: HAVE_CHARDEV_SERIAL)
serial host device
parallel (If: HAVE_CHARDEV_PARALLEL)
parallel host device
pipe pipes (since 1.5)
socket stream socket
udp datagram socket (since 1.5)
pty pseudo-terminal
null provides no input, throws away output
mux (since 1.5)
msmouse
emulated Microsoft serial mouse (since 1.5)
wctablet
emulated Wacom Penpartner serial tablet (since 2.9)
braille (If: CONFIG_BRLAPI)
Baum Braille device (since 1.5)
testdev
device for test-suite control (since 2.2)
stdio standard I/O (since 1.5)
console (If: CONFIG_WIN32)
Windows console (since 1.5)
spicevmc (If: CONFIG_SPICE)
spice vm channel (since 1.5)
spiceport (If: CONFIG_SPICE)
Spice port channel (since 1.5)
qemu-vdagent (If: CONFIG_SPICE_PROTOCOL)
Spice vdagent (since 6.1)
dbus (If: CONFIG_DBUS_DISPLAY)
D-Bus channel (since 7.0)
vc virtual console (since 1.5)
ringbuf
memory ring buffer (since 1.6)
memory synonym for ringbuf (since 1.5)
Features
deprecated
Member memory is deprecated. Use ringbuf instead.
Since
1.4
ChardevFileWrapper (Object)
Members
data: ChardevFile
Configuration info for file chardevs
Since
1.4
ChardevHostdevWrapper (Object)
Members
data: ChardevHostdev
Configuration info for device and pipe chardevs
Since
1.4
ChardevSocketWrapper (Object)
Members
data: ChardevSocket
Configuration info for (stream) socket chardevs
Since
1.4
ChardevUdpWrapper (Object)
Members
data: ChardevUdp
Configuration info for datagram socket chardevs
Since
1.5
ChardevCommonWrapper (Object)
Members
data: ChardevCommon
Configuration shared across all chardev backends
Since
2.6
ChardevMuxWrapper (Object)
Members
data: ChardevMux
Configuration info for mux chardevs
Since
1.5
ChardevStdioWrapper (Object)
Members
data: ChardevStdio
Configuration info for stdio chardevs
Since
1.5
ChardevSpiceChannelWrapper (Object)
Members
data: ChardevSpiceChannel
Configuration info for spice vm channel chardevs
Since
1.5
If
CONFIG_SPICE
ChardevSpicePortWrapper (Object)
Members
data: ChardevSpicePort
Configuration info for spice port chardevs
Since
1.5
If
CONFIG_SPICE
ChardevQemuVDAgentWrapper (Object)
Members
data: ChardevQemuVDAgent
Configuration info for qemu vdagent implementation
Since
6.1
If
CONFIG_SPICE_PROTOCOL
ChardevDBusWrapper (Object)
Members
data: ChardevDBus
Configuration info for DBus chardevs
Since
7.0
If
CONFIG_DBUS_DISPLAY
ChardevVCWrapper (Object)
Members
data: ChardevVC
Configuration info for virtual console chardevs
Since
1.5
ChardevRingbufWrapper (Object)
Members
data: ChardevRingbuf
Configuration info for ring buffer chardevs
Since
1.5
ChardevPtyWrapper (Object)
Members
data: ChardevPty
Configuration info for pty chardevs
Since
9.2
ChardevBackend (Object)
Configuration info for the new chardev backend.
Members
type: ChardevBackendKind
backend type
The members of ChardevFileWrapper when type is "file"
The members of ChardevHostdevWrapper when type is "serial" (If: HAVE_CHARDEV_SERIAL)
The members of ChardevHostdevWrapper when type is "parallel" (If: HAVE_CHARDEV_PARALLEL)
The members of ChardevHostdevWrapper when type is "pipe"
The members of ChardevSocketWrapper when type is "socket"
The members of ChardevUdpWrapper when type is "udp"
The members of ChardevPtyWrapper when type is "pty"
The members of ChardevCommonWrapper when type is "null"
The members of ChardevMuxWrapper when type is "mux"
The members of ChardevCommonWrapper when type is "msmouse"
The members of ChardevCommonWrapper when type is "wctablet"
The members of ChardevCommonWrapper when type is "braille" (If: CONFIG_BRLAPI)
The members of ChardevCommonWrapper when type is "testdev"
The members of ChardevStdioWrapper when type is "stdio"
The members of ChardevCommonWrapper when type is "console" (If: CONFIG_WIN32)
The members of ChardevSpiceChannelWrapper when type is "spicevmc" (If: CONFIG_SPICE)
The members of ChardevSpicePortWrapper when type is "spiceport" (If: CONFIG_SPICE)
The members of ChardevQemuVDAgentWrapper when type is "qemu-vdagent" (If: CONFIG_SPICE_PROTOCOL)
The members of ChardevDBusWrapper when type is "dbus" (If: CONFIG_DBUS_DISPLAY)
The members of ChardevVCWrapper when type is "vc"
The members of ChardevRingbufWrapper when type is "ringbuf"
The members of ChardevRingbufWrapper when type is "memory"
Since
1.4
ChardevReturn (Object)
Return info about the chardev backend just created.
Members
pty: string (optional)
name of the slave pseudoterminal device, present if and only if a chardev of type 'pty' was
created
Since
1.4
chardev-add (Command)
Add a character device backend
Arguments
id: string
the chardev's ID, must be unique
backend: ChardevBackend
backend type and parameters
Returns
ChardevReturn.
Since
1.4
Example:
-> { "execute" : "chardev-add",
"arguments" : { "id" : "foo",
"backend" : { "type" : "null", "data" : {} } } }
<- { "return": {} }
Example:
-> { "execute" : "chardev-add",
"arguments" : { "id" : "bar",
"backend" : { "type" : "file",
"data" : { "out" : "/tmp/bar.log" } } } }
<- { "return": {} }
Example:
-> { "execute" : "chardev-add",
"arguments" : { "id" : "baz",
"backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }
chardev-change (Command)
Change a character device backend
Arguments
id: string
the chardev's ID, must exist
backend: ChardevBackend
new backend type and parameters
Returns
ChardevReturn.
Since
2.10
Example:
-> { "execute" : "chardev-change",
"arguments" : { "id" : "baz",
"backend" : { "type" : "pty", "data" : {} } } }
<- { "return": { "pty" : "/dev/pty/42" } }
Example:
-> {"execute" : "chardev-change",
"arguments" : {
"id" : "charchannel2",
"backend" : {
"type" : "socket",
"data" : {
"addr" : {
"type" : "unix" ,
"data" : {
"path" : "/tmp/charchannel2.socket"
}
},
"server" : true,
"wait" : false }}}}
<- {"return": {}}
chardev-remove (Command)
Remove a character device backend
Arguments
id: string
the chardev's ID, must exist and not be in use
Since
1.4
Example:
-> { "execute": "chardev-remove", "arguments": { "id" : "foo" } }
<- { "return": {} }
chardev-send-break (Command)
Send a break to a character device
Arguments
id: string
the chardev's ID, must exist
Since
2.10
Example:
-> { "execute": "chardev-send-break", "arguments": { "id" : "foo" } }
<- { "return": {} }
VSERPORT_CHANGE (Event)
Emitted when the guest opens or closes a virtio-serial port.
Arguments
id: string
device identifier of the virtio-serial port
open: boolean
true if the guest has opened the virtio-serial port
NOTE:
This event is rate-limited.
Since
2.1
Example:
<- { "event": "VSERPORT_CHANGE",
"data": { "id": "channel0", "open": true },
"timestamp": { "seconds": 1401385907, "microseconds": 422329 } }
USER AUTHORIZATION
QAuthZListPolicy (Enum)
The authorization policy result
Values
deny deny access
allow allow access
Since
4.0
QAuthZListFormat (Enum)
The authorization policy match format
Values
exact an exact string match
glob string with ? and * shell wildcard support
Since
4.0
QAuthZListRule (Object)
A single authorization rule.
Members
match: string
a string or glob to match against a user identity
policy: QAuthZListPolicy
the result to return if match evaluates to true
format: QAuthZListFormat (optional)
the format of the match rule (default 'exact')
Since
4.0
AuthZListProperties (Object)
Properties for authz-list objects.
Members
policy: QAuthZListPolicy (optional)
Default policy to apply when no rule matches (default: deny)
rules: array of QAuthZListRule (optional)
Authorization rules based on matching user
Since
4.0
AuthZListFileProperties (Object)
Properties for authz-listfile objects.
Members
filename: string
File name to load the configuration from. The file must contain valid JSON for
AuthZListProperties.
refresh: boolean (optional)
If true, inotify is used to monitor the file, automatically reloading changes. If an error occurs
during reloading, all authorizations will fail until the file is next successfully loaded.
(default: true if the binary was built with CONFIG_INOTIFY1, false otherwise)
Since
4.0
AuthZPAMProperties (Object)
Properties for authz-pam objects.
Members
service: string
PAM service name to use for authorization
Since
4.0
AuthZSimpleProperties (Object)
Properties for authz-simple objects.
Members
identity: string
Identifies the allowed user. Its format depends on the network service that authorization object
is associated with. For authorizing based on TLS x509 certificates, the identity must be the x509
distinguished name.
Since
4.0
TRANSACTIONS
Abort (Object)
This action can be used to test transaction failure.
Since
1.6
ActionCompletionMode (Enum)
An enumeration of Transactional completion modes.
Values
individual
Do not attempt to cancel any other Actions if any Actions fail after the Transaction request
succeeds. All Actions that can complete successfully will do so without waiting on others. This
is the default.
grouped
If any Action fails after the Transaction succeeds, cancel all Actions. Actions do not complete
until all Actions are ready to complete. May be rejected by Actions that do not support this
completion mode.
Since
2.5
TransactionActionKind (Enum)
Values
abort Since 1.6
block-dirty-bitmap-add
Since 2.5
block-dirty-bitmap-remove
Since 4.2
block-dirty-bitmap-clear
Since 2.5
block-dirty-bitmap-enable
Since 4.0
block-dirty-bitmap-disable
Since 4.0
block-dirty-bitmap-merge
Since 4.0
blockdev-backup
Since 2.3
blockdev-snapshot
Since 2.5
blockdev-snapshot-internal-sync
Since 1.7
blockdev-snapshot-sync
since 1.1
drive-backup
Since 1.6
Features
deprecated
Member drive-backup is deprecated. Use member blockdev-backup instead.
Since
1.1
AbortWrapper (Object)
Members
data: Abort
Not documented
Since
1.6
BlockDirtyBitmapAddWrapper (Object)
Members
data: BlockDirtyBitmapAdd
Not documented
Since
2.5
BlockDirtyBitmapWrapper (Object)
Members
data: BlockDirtyBitmap
Not documented
Since
2.5
BlockDirtyBitmapMergeWrapper (Object)
Members
data: BlockDirtyBitmapMerge
Not documented
Since
4.0
BlockdevBackupWrapper (Object)
Members
data: BlockdevBackup
Not documented
Since
2.3
BlockdevSnapshotWrapper (Object)
Members
data: BlockdevSnapshot
Not documented
Since
2.5
BlockdevSnapshotInternalWrapper (Object)
Members
data: BlockdevSnapshotInternal
Not documented
Since
1.7
BlockdevSnapshotSyncWrapper (Object)
Members
data: BlockdevSnapshotSync
Not documented
Since
1.1
DriveBackupWrapper (Object)
Members
data: DriveBackup
Not documented
Since
1.6
TransactionAction (Object)
A discriminated record of operations that can be performed with transaction.
Members
type: TransactionActionKind
the operation to be performed
The members of AbortWrapper when type is "abort"
The members of BlockDirtyBitmapAddWrapper when type is "block-dirty-bitmap-add"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-remove"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-clear"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-enable"
The members of BlockDirtyBitmapWrapper when type is "block-dirty-bitmap-disable"
The members of BlockDirtyBitmapMergeWrapper when type is "block-dirty-bitmap-merge"
The members of BlockdevBackupWrapper when type is "blockdev-backup"
The members of BlockdevSnapshotWrapper when type is "blockdev-snapshot"
The members of BlockdevSnapshotInternalWrapper when type is "blockdev-snapshot-internal-sync"
The members of BlockdevSnapshotSyncWrapper when type is "blockdev-snapshot-sync"
The members of DriveBackupWrapper when type is "drive-backup"
Since
1.1
TransactionProperties (Object)
Optional arguments to modify the behavior of a Transaction.
Members
completion-mode: ActionCompletionMode (optional)
Controls how jobs launched asynchronously by Actions will complete or fail as a group. See
ActionCompletionMode for details.
Since
2.5
transaction (Command)
Executes a number of transactionable QMP commands atomically. If any operation fails, then the entire
set of actions will be abandoned and the appropriate error returned.
For external snapshots, the dictionary contains the device, the file to use for the new snapshot, and the
format. The default format, if not specified, is qcow2.
Each new snapshot defaults to being created by QEMU (wiping any contents if the file already exists), but
it is also possible to reuse an externally-created file. In the latter case, you should ensure that the
new image file has the same contents as the current one; QEMU cannot perform any meaningful check.
Typically this is achieved by using the current image file as the backing file for the new image.
On failure, the original disks pre-snapshot attempt will be used.
For internal snapshots, the dictionary contains the device and the snapshot's name. If an internal
snapshot matching name already exists, the request will be rejected. Only some image formats support it,
for example, qcow2, and rbd,
On failure, qemu will try delete the newly created internal snapshot in the transaction. When an I/O
error occurs during deletion, the user needs to fix it later with qemu-img or other command.
Arguments
actions: array of TransactionAction
List of TransactionAction; information needed for the respective operations.
properties: TransactionProperties (optional)
structure of additional options to control the execution of the transaction. See
TransactionProperties for additional detail.
Errors
• Any errors from commands in the transaction
NOTE:
The transaction aborts on the first failure. Therefore, there will be information on only one failed
operation returned in an error condition, and subsequent actions will not have been attempted.
Since
1.1
Example:
-> { "execute": "transaction",
"arguments": { "actions": [
{ "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd0",
"snapshot-file": "/some/place/my-image",
"format": "qcow2" } },
{ "type": "blockdev-snapshot-sync", "data" : { "node-name": "myfile",
"snapshot-file": "/some/place/my-image2",
"snapshot-node-name": "node3432",
"mode": "existing",
"format": "qcow2" } },
{ "type": "blockdev-snapshot-sync", "data" : { "device": "ide-hd1",
"snapshot-file": "/some/place/my-image2",
"mode": "existing",
"format": "qcow2" } },
{ "type": "blockdev-snapshot-internal-sync", "data" : {
"device": "ide-hd2",
"name": "snapshot0" } } ] } }
<- { "return": {} }
QMP MONITOR CONTROL
qmp_capabilities (Command)
Enable QMP capabilities.
Arguments
enable: array of QMPCapability (optional)
An optional list of QMPCapability values to enable. The client must not enable any capability
that is not mentioned in the QMP greeting message. If the field is not provided, it means no QMP
capabilities will be enabled. (since 2.12)
Example:
-> { "execute": "qmp_capabilities",
"arguments": { "enable": [ "oob" ] } }
<- { "return": {} }
NOTE:
This command is valid exactly when first connecting: it must be issued before any other command will
be accepted, and will fail once the monitor is accepting other commands. (see QEMU Machine Protocol
Specification)
NOTE:
The QMP client needs to explicitly enable QMP capabilities, otherwise all the QMP capabilities will be
turned off by default.
Since
0.13
QMPCapability (Enum)
Enumeration of capabilities to be advertised during initial client connection, used for agreeing on
particular QMP extension behaviors.
Values
oob QMP ability to support out-of-band requests. (Please refer to qmp-spec.rst for more information
on OOB)
Since
2.12
VersionTriple (Object)
A three-part version number.
Members
major: int
The major version number.
minor: int
The minor version number.
micro: int
The micro version number.
Since
2.4
VersionInfo (Object)
A description of QEMU's version.
Members
qemu: VersionTriple
The version of QEMU. By current convention, a micro version of 50 signifies a development branch.
A micro version greater than or equal to 90 signifies a release candidate for the next minor
version. A micro version of less than 50 signifies a stable release.
package: string
QEMU will always set this field to an empty string. Downstream versions of QEMU should set this
to a non-empty string. The exact format depends on the downstream however it highly recommended
that a unique name is used.
Since
0.14
query-version (Command)
Returns the current version of QEMU.
Returns
A VersionInfo object describing the current version of QEMU.
Since
0.14
Example:
-> { "execute": "query-version" }
<- {
"return":{
"qemu":{
"major":0,
"minor":11,
"micro":5
},
"package":""
}
}
CommandInfo (Object)
Information about a QMP command
Members
name: string
The command name
Since
0.14
query-commands (Command)
Return a list of supported QMP commands by this server
Returns
A list of CommandInfo for all supported commands
Since
0.14
Example:
-> { "execute": "query-commands" }
<- {
"return":[
{
"name":"query-balloon"
},
{
"name":"system_powerdown"
},
...
]
}
This example has been shortened as the real response is too long.
quit (Command)
This command will cause the QEMU process to exit gracefully. While every attempt is made to send the QMP
response before terminating, this is not guaranteed. When using this interface, a premature EOF would
not be unexpected.
Since
0.14
Example:
-> { "execute": "quit" }
<- { "return": {} }
MonitorMode (Enum)
An enumeration of monitor modes.
Values
readline
HMP monitor (human-oriented command line interface)
control
QMP monitor (JSON-based machine interface)
Since
5.0
MonitorOptions (Object)
Options to be used for adding a new monitor.
Members
id: string (optional)
Name of the monitor
mode: MonitorMode (optional)
Selects the monitor mode (default: readline in the system emulator, control in
qemu-storage-daemon)
pretty: boolean (optional)
Enables pretty printing (QMP only)
chardev: string
Name of a character device to expose the monitor on
Since
5.0
QMP INTROSPECTION
query-qmp-schema (Command)
Command query-qmp-schema exposes the QMP wire ABI as an array of SchemaInfo. This lets QMP clients
figure out what commands and events are available in this QEMU, and their parameters and results.
However, the SchemaInfo can't reflect all the rules and restrictions that apply to QMP. It's interface
introspection (figuring out what's there), not interface specification. The specification is in the QAPI
schema.
Furthermore, while we strive to keep the QMP wire format backwards-compatible across qemu versions, the
introspection output is not guaranteed to have the same stability. For example, one version of qemu may
list an object member as an optional non-variant, while another lists the same member only through the
object's variants; or the type of a member may change from a generic string into a specific enum or from
one specific type into an alternate that includes the original type alongside something else.
Returns
array of SchemaInfo, where each element describes an entity in the ABI: command, event, type, ...
The order of the various SchemaInfo is unspecified; however, all names are guaranteed to be unique (no
name will be duplicated with different meta-types).
NOTE:
The QAPI schema is also used to help define internal interfaces, by defining QAPI types. These are
not part of the QMP wire ABI, and therefore not returned by this command.
Since
2.5
SchemaMetaType (Enum)
This is a SchemaInfo's meta type, i.e. the kind of entity it describes.
Values
builtin
a predefined type such as 'int' or 'bool'.
enum an enumeration type
array an array type
object an object type (struct or union)
alternate
an alternate type
command
a QMP command
event a QMP event
Since
2.5
SchemaInfo (Object)
Members
name: string
the entity's name, inherited from base. The SchemaInfo is always referenced by this name.
Commands and events have the name defined in the QAPI schema. Unlike command and event names,
type names are not part of the wire ABI. Consequently, type names are meaningless strings here,
although they are still guaranteed unique regardless of meta-type.
meta-type: SchemaMetaType
the entity's meta type, inherited from base.
features: array of string (optional)
names of features associated with the entity, in no particular order. (since 4.1 for object
types, 4.2 for commands, 5.0 for the rest)
The members of SchemaInfoBuiltin when meta-type is "builtin"
The members of SchemaInfoEnum when meta-type is "enum"
The members of SchemaInfoArray when meta-type is "array"
The members of SchemaInfoObject when meta-type is "object"
The members of SchemaInfoAlternate when meta-type is "alternate"
The members of SchemaInfoCommand when meta-type is "command"
The members of SchemaInfoEvent when meta-type is "event"
Since
2.5
SchemaInfoBuiltin (Object)
Additional SchemaInfo members for meta-type 'builtin'.
Members
json-type: JSONType
the JSON type used for this type on the wire.
Since
2.5
JSONType (Enum)
The four primitive and two structured types according to RFC 8259 section 1, plus 'int' (split off
'number'), plus the obvious top type 'value'.
Values
string JSON string
number JSON number
int JSON number that is an integer
boolean
literal false or true
null literal null
object JSON object
array JSON array
value any JSON value
Since
2.5
SchemaInfoEnum (Object)
Additional SchemaInfo members for meta-type 'enum'.
Members
members: array of SchemaInfoEnumMember
the enum type's members, in no particular order (since 6.2).
values: array of string
the enumeration type's member names, in no particular order. Redundant with members. Just for
backward compatibility.
Features
deprecated
Member values is deprecated. Use members instead.
Values of this type are JSON string on the wire.
Since
2.5
SchemaInfoEnumMember (Object)
An object member.
Members
name: string
the member's name, as defined in the QAPI schema.
features: array of string (optional)
names of features associated with the member, in no particular order.
Since
6.2
SchemaInfoArray (Object)
Additional SchemaInfo members for meta-type 'array'.
Members
element-type: string
the array type's element type.
Values of this type are JSON array on the wire.
Since
2.5
SchemaInfoObject (Object)
Additional SchemaInfo members for meta-type 'object'.
Members
members: array of SchemaInfoObjectMember
the object type's (non-variant) members, in no particular order.
tag: string (optional)
the name of the member serving as type tag. An element of members with this name must exist.
variants: array of SchemaInfoObjectVariant (optional)
variant members, i.e. additional members that depend on the type tag's value. Present exactly
when tag is present. The variants are in no particular order, and may even differ from the order
of the values of the enum type of the tag.
Values of this type are JSON object on the wire.
Since
2.5
SchemaInfoObjectMember (Object)
An object member.
Members
name: string
the member's name, as defined in the QAPI schema.
type: string
the name of the member's type.
default: value (optional)
default when used as command parameter. If absent, the parameter is mandatory. If present, the
value must be null. The parameter is optional, and behavior when it's missing is not specified
here. Future extension: if present and non-null, the parameter is optional, and defaults to this
value.
features: array of string (optional)
names of features associated with the member, in no particular order. (since 5.0)
Since
2.5
SchemaInfoObjectVariant (Object)
The variant members for a value of the type tag.
Members
case: string
a value of the type tag.
type: string
the name of the object type that provides the variant members when the type tag has value case.
Since
2.5
SchemaInfoAlternate (Object)
Additional SchemaInfo members for meta-type 'alternate'.
Members
members: array of SchemaInfoAlternateMember
the alternate type's members, in no particular order. The members' wire encoding is distinct, see
How to use the QAPI code generator section Alternate types.
On the wire, this can be any of the members.
Since
2.5
SchemaInfoAlternateMember (Object)
An alternate member.
Members
type: string
the name of the member's type.
Since
2.5
SchemaInfoCommand (Object)
Additional SchemaInfo members for meta-type 'command'.
Members
arg-type: string
the name of the object type that provides the command's parameters.
ret-type: string
the name of the command's result type.
allow-oob: boolean (optional)
whether the command allows out-of-band execution, defaults to false (Since: 2.12)
Since
2.5
SchemaInfoEvent (Object)
Additional SchemaInfo members for meta-type 'event'.
Members
arg-type: string
the name of the object type that provides the event's parameters.
Since
2.5
QEMU OBJECT MODEL (QOM)
ObjectPropertyInfo (Object)
Members
name: string
the name of the property
type: string
the type of the property. This will typically come in one of four forms:
1. A primitive type such as 'u8', 'u16', 'bool', 'str', or 'double'. These types are mapped to
the appropriate JSON type.
2. A child type in the form 'child<subtype>' where subtype is a qdev device type name. Child
properties create the composition tree.
3. A link type in the form 'link<subtype>' where subtype is a qdev device type name. Link
properties form the device model graph.
description: string (optional)
if specified, the description of the property.
default-value: value (optional)
the default value, if any (since 5.0)
Since
1.2
qom-list (Command)
This command will list any properties of a object given a path in the object model.
Arguments
path: string
the path within the object model. See qom-get for a description of this parameter.
Returns
a list of ObjectPropertyInfo that describe the properties of the object.
Since
1.2
Example:
-> { "execute": "qom-list",
"arguments": { "path": "/chardevs" } }
<- { "return": [ { "name": "type", "type": "string" },
{ "name": "parallel0", "type": "child<chardev-vc>" },
{ "name": "serial0", "type": "child<chardev-vc>" },
{ "name": "mon0", "type": "child<chardev-stdio>" } ] }
qom-get (Command)
This command will get a property from a object model path and return the value.
Arguments
path: string
The path within the object model. There are two forms of supported paths--absolute and partial
paths.
Absolute paths are derived from the root object and can follow child<> or link<> properties.
Since they can follow link<> properties, they can be arbitrarily long. Absolute paths look like
absolute filenames and are prefixed with a leading slash.
Partial paths look like relative filenames. They do not begin with a prefix. The matching rules
for partial paths are subtle but designed to make specifying objects easy. At each level of the
composition tree, the partial path is matched as an absolute path. The first match is not
returned. At least two matches are searched for. A successful result is only returned if only
one match is found. If more than one match is found, a flag is return to indicate that the match
was ambiguous.
property: string
The property name to read
Returns
The property value. The type depends on the property type. child<> and link<> properties are returned
as #str pathnames. All integer property types (u8, u16, etc) are returned as #int.
Since
1.2
Example: Use absolute path
-> { "execute": "qom-get",
"arguments": { "path": "/machine/unattached/device[0]",
"property": "hotplugged" } }
<- { "return": false }
Example: Use partial path
-> { "execute": "qom-get",
"arguments": { "path": "unattached/sysbus",
"property": "type" } }
<- { "return": "System" }
qom-set (Command)
This command will set a property from a object model path.
Arguments
path: string
see qom-get for a description of this parameter
property: string
the property name to set
value: value
a value who's type is appropriate for the property type. See qom-get for a description of type
mapping.
Since
1.2
Example:
-> { "execute": "qom-set",
"arguments": { "path": "/machine",
"property": "graphics",
"value": false } }
<- { "return": {} }
ObjectTypeInfo (Object)
This structure describes a search result from qom-list-types
Members
name: string
the type name found in the search
abstract: boolean (optional)
the type is abstract and can't be directly instantiated. Omitted if false. (since 2.10)
parent: string (optional)
Name of parent type, if any (since 2.10)
Since
1.1
qom-list-types (Command)
This command will return a list of types given search parameters
Arguments
implements: string (optional)
if specified, only return types that implement this type name
abstract: boolean (optional)
if true, include abstract types in the results
Returns
a list of ObjectTypeInfo or an empty list if no results are found
Since
1.1
qom-list-properties (Command)
List properties associated with a QOM object.
Arguments
typename: string
the type name of an object
NOTE:
Objects can create properties at runtime, for example to describe links between different devices
and/or objects. These properties are not included in the output of this command.
Returns
a list of ObjectPropertyInfo describing object properties
Since
2.12
CanHostSocketcanProperties (Object)
Properties for can-host-socketcan objects.
Members
if: string
interface name of the host system CAN bus to connect to
canbus: string
object ID of the can-bus object to connect to the host interface
Since
2.12
If
CONFIG_LINUX
ColoCompareProperties (Object)
Properties for colo-compare objects.
Members
primary_in: string
name of the character device backend to use for the primary input (incoming packets are redirected
to outdev)
secondary_in: string
name of the character device backend to use for secondary input (incoming packets are only
compared to the input on primary_in and then dropped)
outdev: string
name of the character device backend to use for output
iothread: string
name of the iothread to run in
notify_dev: string (optional)
name of the character device backend to be used to communicate with the remote colo-frame (only
for Xen COLO)
compare_timeout: int (optional)
the maximum time to hold a packet from primary_in for comparison with an incoming packet on
secondary_in in milliseconds (default: 3000)
expired_scan_cycle: int (optional)
the interval at which colo-compare checks whether packets from primary have timed out, in
milliseconds (default: 3000)
max_queue_size: int (optional)
the maximum number of packets to keep in the queue for comparing with incoming packets from
secondary_in. If the queue is full and additional packets are received, the additional packets
are dropped. (default: 1024)
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
Since
2.8
CryptodevBackendProperties (Object)
Properties for cryptodev-backend and cryptodev-backend-builtin objects.
Members
queues: int (optional)
the number of queues for the cryptodev backend. Ignored for cryptodev-backend and must be 1 for
cryptodev-backend-builtin. (default: 1)
throttle-bps: int (optional)
limit total bytes per second (Since 8.0)
throttle-ops: int (optional)
limit total operations per second (Since 8.0)
Since
2.8
CryptodevVhostUserProperties (Object)
Properties for cryptodev-vhost-user objects.
Members
chardev: string
the name of a Unix domain socket character device that connects to the vhost-user server
The members of CryptodevBackendProperties
Since
2.12
If
CONFIG_VHOST_CRYPTO
DBusVMStateProperties (Object)
Properties for dbus-vmstate objects.
Members
addr: string
the name of the DBus bus to connect to
id-list: string (optional)
a comma separated list of DBus IDs of helpers whose data should be included in the VM state on
migration
Since
5.0
NetfilterInsert (Enum)
Indicates where to insert a netfilter relative to a given other filter.
Values
before insert before the specified filter
behind insert behind the specified filter
Since
5.0
NetfilterProperties (Object)
Properties for objects of classes derived from netfilter.
Members
netdev: string
id of the network device backend to filter
queue: NetFilterDirection (optional)
indicates which queue(s) to filter (default: all)
status: string (optional)
indicates whether the filter is enabled ("on") or disabled ("off") (default: "on")
position: string (optional)
specifies where the filter should be inserted in the filter list. "head" means the filter is
inserted at the head of the filter list, before any existing filters. "tail" means the filter is
inserted at the tail of the filter list, behind any existing filters (default). "id=<id>" means
the filter is inserted before or behind the filter specified by <id>, depending on the insert
property. (default: "tail")
insert: NetfilterInsert (optional)
where to insert the filter relative to the filter given in position. Ignored if position is
"head" or "tail". (default: behind)
Since
2.5
FilterBufferProperties (Object)
Properties for filter-buffer objects.
Members
interval: int
a non-zero interval in microseconds. All packets arriving in the given interval are delayed until
the end of the interval.
The members of NetfilterProperties
Since
2.5
FilterDumpProperties (Object)
Properties for filter-dump objects.
Members
file: string
the filename where the dumped packets should be stored
maxlen: int (optional)
maximum number of bytes in a packet that are stored (default: 65536)
The members of NetfilterProperties
Since
2.5
FilterMirrorProperties (Object)
Properties for filter-mirror objects.
Members
outdev: string
the name of a character device backend to which all incoming packets are mirrored
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
The members of NetfilterProperties
Since
2.6
FilterRedirectorProperties (Object)
Properties for filter-redirector objects.
At least one of indev or outdev must be present. If both are present, they must not refer to the same
character device backend.
Members
indev: string (optional)
the name of a character device backend from which packets are received and redirected to the
filtered network device
outdev: string (optional)
the name of a character device backend to which all incoming packets are redirected
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
The members of NetfilterProperties
Since
2.6
FilterRewriterProperties (Object)
Properties for filter-rewriter objects.
Members
vnet_hdr_support: boolean (optional)
if true, vnet header support is enabled (default: false)
The members of NetfilterProperties
Since
2.8
InputBarrierProperties (Object)
Properties for input-barrier objects.
Members
name: string
the screen name as declared in the screens section of barrier.conf
server: string (optional)
hostname of the Barrier server (default: "localhost")
port: string (optional)
TCP port of the Barrier server (default: "24800")
x-origin: string (optional)
x coordinate of the leftmost pixel on the guest screen (default: "0")
y-origin: string (optional)
y coordinate of the topmost pixel on the guest screen (default: "0")
width: string (optional)
the width of secondary screen in pixels (default: "1920")
height: string (optional)
the height of secondary screen in pixels (default: "1080")
Since
4.2
InputLinuxProperties (Object)
Properties for input-linux objects.
Members
evdev: string
the path of the host evdev device to use
grab_all: boolean (optional)
if true, grab is toggled for all devices (e.g. both keyboard and mouse) instead of just one device
(default: false)
repeat: boolean (optional)
enables auto-repeat events (default: false)
grab-toggle: GrabToggleKeys (optional)
the key or key combination that toggles device grab (default: ctrl-ctrl)
Since
2.6
If
CONFIG_LINUX
EventLoopBaseProperties (Object)
Common properties for event loops
Members
aio-max-batch: int (optional)
maximum number of requests in a batch for the AIO engine, 0 means that the engine will use its
default. (default: 0)
thread-pool-min: int (optional)
minimum number of threads reserved in the thread pool (default:0)
thread-pool-max: int (optional)
maximum number of threads the thread pool can contain (default:64)
Since
7.1
IothreadProperties (Object)
Properties for iothread objects.
Members
poll-max-ns: int (optional)
the maximum number of nanoseconds to busy wait for events. 0 means polling is disabled (default:
32768 on POSIX hosts, 0 otherwise)
poll-grow: int (optional)
the multiplier used to increase the polling time when the algorithm detects it is missing events
due to not polling long enough. 0 selects a default behaviour (default: 0)
poll-shrink: int (optional)
the divisor used to decrease the polling time when the algorithm detects it is spending too long
polling without encountering events. 0 selects a default behaviour (default: 0)
The members of EventLoopBaseProperties
The aio-max-batch option is available since 6.1.
Since
2.0
MainLoopProperties (Object)
Properties for the main-loop object.
Members
The members of EventLoopBaseProperties
Since
7.1
MemoryBackendProperties (Object)
Properties for objects of classes derived from memory-backend.
Members
merge: boolean (optional)
if true, mark the memory as mergeable (default depends on the machine type)
dump: boolean (optional)
if true, include the memory in core dumps (default depends on the machine type)
host-nodes: array of int (optional)
the list of NUMA host nodes to bind the memory to
policy: HostMemPolicy (optional)
the NUMA policy (default: 'default')
prealloc: boolean (optional)
if true, preallocate memory (default: false)
prealloc-threads: int (optional)
number of CPU threads to use for prealloc (default: 1)
prealloc-context: string (optional)
thread context to use for creation of preallocation threads (default: none) (since 7.2)
share: boolean (optional)
if false, the memory is private to QEMU; if true, it is shared (default false for backends
memory-backend-file and memory-backend-ram, true for backends memory-backend-epc,
memory-backend-memfd, and memory-backend-shm)
reserve: boolean (optional)
if true, reserve swap space (or huge pages) if applicable (default: true) (since 6.1)
size: int
size of the memory region in bytes
x-use-canonical-path-for-ramblock-id: boolean (optional)
if true, the canonical path is used for ramblock-id. Disable this for 4.0 machine types or older
to allow migration with newer QEMU versions. (default: false generally, but true for machine
types <= 4.0)
NOTE:
prealloc=true and reserve=false cannot be set at the same time. With reserve=true, the behavior
depends on the operating system: for example, Linux will not reserve swap space for shared file
mappings -- "not applicable". In contrast, reserve=false will bail out if it cannot be configured
accordingly.
Since
2.1
MemoryBackendFileProperties (Object)
Properties for memory-backend-file objects.
Members
align: int (optional)
the base address alignment when QEMU mmap(2)s mem-path. Some backend stores specified by mem-path
require an alignment different than the default one used by QEMU, e.g. the device DAX /dev/dax0.0
requires 2M alignment rather than 4K. In such cases, users can specify the required alignment via
this option. 0 selects a default alignment (currently the page size). (default: 0)
offset: int (optional)
the offset into the target file that the region starts at. You can use this option to back
multiple regions with a single file. Must be a multiple of the page size. (default: 0) (since
8.1)
discard-data: boolean (optional)
if true, the file contents can be destroyed when QEMU exits, to avoid unnecessarily flushing data
to the backing file. Note that discard-data is only an optimization, and QEMU might not discard
file contents if it aborts unexpectedly or is terminated using SIGKILL. (default: false)
mem-path: string
the path to either a shared memory or huge page filesystem mount
pmem: boolean (optional) (If: CONFIG_LIBPMEM)
specifies whether the backing file specified by mem-path is in host persistent memory that can be
accessed using the SNIA NVM programming model (e.g. Intel NVDIMM).
readonly: boolean (optional)
if true, the backing file is opened read-only; if false, it is opened read-write. (default:
false)
rom: OnOffAuto (optional)
whether to create Read Only Memory (ROM) that cannot be modified by the VM. Any write attempts to
such ROM will be denied. Most use cases want writable RAM instead of ROM. However, selected use
cases, like R/O NVDIMMs, can benefit from ROM. If set to 'on', create ROM; if set to 'off',
create writable RAM; if set to 'auto', the value of the readonly property is used. This property
is primarily helpful when we want to have proper RAM in configurations that would traditionally
create ROM before this property was introduced: VM templating, where we want to open a file
readonly (readonly set to true) and mark the memory to be private for QEMU (share set to false).
For this use case, we need writable RAM instead of ROM, and want to set this property to 'off'.
(default: auto, since 8.2)
The members of MemoryBackendProperties
Since
2.1
MemoryBackendMemfdProperties (Object)
Properties for memory-backend-memfd objects.
Members
hugetlb: boolean (optional)
if true, the file to be created resides in the hugetlbfs filesystem (default: false)
hugetlbsize: int (optional)
the hugetlb page size on systems that support multiple hugetlb page sizes (it must be a power of 2
value supported by the system). 0 selects a default page size. This option is ignored if hugetlb
is false. (default: 0)
seal: boolean (optional)
if true, create a sealed-file, which will block further resizing of the memory (default: true)
The members of MemoryBackendProperties
Since
2.12
If
CONFIG_LINUX
MemoryBackendShmProperties (Object)
Properties for memory-backend-shm objects.
This memory backend supports only shared memory, which is the default.
Members
The members of MemoryBackendProperties
Since
9.1
If
CONFIG_POSIX
MemoryBackendEpcProperties (Object)
Properties for memory-backend-epc objects.
The merge boolean option is false by default with epc
The dump boolean option is false by default with epc
Members
The members of MemoryBackendProperties
Since
6.2
If
CONFIG_LINUX
PrManagerHelperProperties (Object)
Properties for pr-manager-helper objects.
Members
path: string
the path to a Unix domain socket for connecting to the external helper
Since
2.11
If
CONFIG_LINUX
QtestProperties (Object)
Properties for qtest objects.
Members
chardev: string
the chardev to be used to receive qtest commands on.
log: string (optional)
the path to a log file
Since
6.0
RemoteObjectProperties (Object)
Properties for x-remote-object objects.
Members
fd: string
file descriptor name previously passed via 'getfd' command
devid: string
the id of the device to be associated with the file descriptor
Since
6.0
VfioUserServerProperties (Object)
Properties for x-vfio-user-server objects.
Members
socket: SocketAddress
socket to be used by the libvfio-user library
device: string
the ID of the device to be emulated at the server
Since
7.1
IOMMUFDProperties (Object)
Properties for iommufd objects.
Members
fd: string (optional)
file descriptor name previously passed via 'getfd' command, which represents a pre-opened
/dev/iommu. This allows the iommufd object to be shared across several subsystems (VFIO, VDPA,
...), and the file descriptor to be shared with other process, e.g. DPDK. (default: QEMU opens
/dev/iommu by itself)
Since
9.0
AcpiGenericInitiatorProperties (Object)
Properties for acpi-generic-initiator objects.
Members
pci-dev: string
PCI device ID to be associated with the node
node: int
NUMA node associated with the PCI device
Since
9.0
AcpiGenericPortProperties (Object)
Properties for acpi-generic-port objects.
Members
pci-bus: string
QOM path of the PCI bus of the hostbridge associated with this SRAT Generic Port Affinity
Structure. This is the same as the bus parameter for the root ports attached to this host bridge.
The resulting SRAT Generic Port Affinity Structure will refer to the ACPI object in DSDT that
represents the host bridge (e.g. ACPI0016 for CXL host bridges). See ACPI 6.5 Section 5.2.16.7
for more information.
node: int
Similar to a NUMA node ID, but instead of providing a reference point used for defining NUMA
distances and access characteristics to memory or from an initiator (e.g. CPU), this node defines
the boundary point between non-discoverable system buses which must be described by firmware, and
a discoverable bus. NUMA distances and access characteristics are defined to and from that point.
For system software to establish full initiator to target characteristics this information must be
combined with information retrieved from the discoverable part of the path. An example would use
CDAT (see UEFI.org) information read from devices and switches in conjunction with link
characteristics read from PCIe Configuration space. To get the full path latency from CPU to CXL
attached DRAM CXL device: Add the latency from CPU to Generic Port (from HMAT indexed via the the
node ID in this SRAT structure) to that for CXL bus links, the latency across intermediate
switches and from the EP port to the actual memory. Bandwidth is more complex as there may be
interleaving across multiple devices and shared links in the path.
Since
9.2
RngProperties (Object)
Properties for objects of classes derived from rng.
Members
opened: boolean (optional)
if true, the device is opened immediately when applying this option and will probably fail when
processing the next option. Don't use; only provided for compatibility. (default: false)
Features
deprecated
Member opened is deprecated. Setting true doesn't make sense, and false is already the default.
Since
1.3
RngEgdProperties (Object)
Properties for rng-egd objects.
Members
chardev: string
the name of a character device backend that provides the connection to the RNG daemon
The members of RngProperties
Since
1.3
RngRandomProperties (Object)
Properties for rng-random objects.
Members
filename: string (optional)
the filename of the device on the host to obtain entropy from (default: "/dev/urandom")
The members of RngProperties
Since
1.3
If
CONFIG_POSIX
SevCommonProperties (Object)
Properties common to objects that are derivatives of sev-common.
Members
sev-device: string (optional)
SEV device to use (default: "/dev/sev")
cbitpos: int (optional)
C-bit location in page table entry (default: 0)
reduced-phys-bits: int
number of bits in physical addresses that become unavailable when SEV is enabled
kernel-hashes: boolean (optional)
if true, add hashes of kernel/initrd/cmdline to a designated guest firmware page for measured boot
with -kernel (default: false) (since 6.2)
Since
9.1
SevGuestProperties (Object)
Properties for sev-guest objects.
Members
dh-cert-file: string (optional)
guest owners DH certificate (encoded with base64)
session-file: string (optional)
guest owners session parameters (encoded with base64)
policy: int (optional)
SEV policy value (default: 0x1)
handle: int (optional)
SEV firmware handle (default: 0)
legacy-vm-type: OnOffAuto (optional)
Use legacy KVM_SEV_INIT KVM interface for creating the VM. The newer KVM_SEV_INIT2 interface,
from Linux >= 6.10, syncs additional vCPU state when initializing the VMSA structures, which will
result in a different guest measurement. Set this to 'on' to force compatibility with older QEMU
or kernel versions that rely on legacy KVM_SEV_INIT behavior. 'auto' will behave identically to
'on', but will automatically switch to using KVM_SEV_INIT2 if the user specifies any additional
options that require it. If set to 'off', QEMU will require KVM_SEV_INIT2 unconditionally.
(default: off) (since 9.1)
The members of SevCommonProperties
Since
2.12
SevSnpGuestProperties (Object)
Properties for sev-snp-guest objects. Most of these are direct arguments for the KVM_SNP_* interfaces
documented in the Linux kernel source under Documentation/arch/x86/amd-memory-encryption.rst, which are
in turn closely coupled with the SNP_INIT/SNP_LAUNCH_* firmware commands documented in the SEV-SNP
Firmware ABI Specification (Rev 0.9).
More usage information is also available in the QEMU source tree under docs/amd-memory-encryption.
Members
policy: int (optional)
the 'POLICY' parameter to the SNP_LAUNCH_START command, as defined in the SEV-SNP firmware ABI
(default: 0x30000)
guest-visible-workarounds: string (optional)
16-byte, base64-encoded blob to report hypervisor-defined workarounds, corresponding to the
'GOSVW' parameter of the SNP_LAUNCH_START command defined in the SEV-SNP firmware ABI (default:
all-zero)
id-block: string (optional)
96-byte, base64-encoded blob to provide the 'ID Block' structure for the SNP_LAUNCH_FINISH command
defined in the SEV-SNP firmware ABI (default: all-zero)
id-auth: string (optional)
4096-byte, base64-encoded blob to provide the 'ID Authentication Information Structure' for the
SNP_LAUNCH_FINISH command defined in the SEV-SNP firmware ABI (default: all-zero)
author-key-enabled: boolean (optional)
true if 'id-auth' blob contains the 'AUTHOR_KEY' field defined SEV-SNP firmware ABI (default:
false)
host-data: string (optional)
32-byte, base64-encoded, user-defined blob to provide to the guest, as documented for the
'HOST_DATA' parameter of the SNP_LAUNCH_FINISH command in the SEV-SNP firmware ABI (default:
all-zero)
vcek-disabled: boolean (optional)
Guests are by default allowed to choose between VLEK (Versioned Loaded Endorsement Key) or VCEK
(Versioned Chip Endorsement Key) when requesting attestation reports from firmware. Set this to
true to disable the use of VCEK. (default: false) (since: 9.1)
The members of SevCommonProperties
Since
9.1
ThreadContextProperties (Object)
Properties for thread context objects.
Members
cpu-affinity: array of int (optional)
the list of host CPU numbers used as CPU affinity for all threads created in the thread context
(default: QEMU main thread CPU affinity)
node-affinity: array of int (optional)
the list of host node numbers that will be resolved to a list of host CPU numbers used as CPU
affinity. This is a shortcut for specifying the list of host CPU numbers belonging to the host
nodes manually by setting cpu-affinity. (default: QEMU main thread affinity)
Since
7.2
ObjectType (Enum)
Values
acpi-generic-initiator
Not documented
acpi-generic-port
Not documented
authz-list
Not documented
authz-listfile
Not documented
authz-pam
Not documented
authz-simple
Not documented
can-bus
Not documented
can-host-socketcan (If: CONFIG_LINUX)
Not documented
colo-compare
Not documented
cryptodev-backend
Not documented
cryptodev-backend-builtin
Not documented
cryptodev-backend-lkcf
Not documented
cryptodev-vhost-user (If: CONFIG_VHOST_CRYPTO)
Not documented
dbus-vmstate
Not documented
filter-buffer
Not documented
filter-dump
Not documented
filter-mirror
Not documented
filter-redirector
Not documented
filter-replay
Not documented
filter-rewriter
Not documented
input-barrier
Not documented
input-linux (If: CONFIG_LINUX)
Not documented
iommufd
Not documented
iothread
Not documented
main-loop
Not documented
memory-backend-epc (If: CONFIG_LINUX)
Not documented
memory-backend-file
Not documented
memory-backend-memfd (If: CONFIG_LINUX)
Not documented
memory-backend-ram
Not documented
memory-backend-shm (If: CONFIG_POSIX)
Not documented
pef-guest
Not documented
pr-manager-helper (If: CONFIG_LINUX)
Not documented
qtest Not documented
rng-builtin
Not documented
rng-egd
Not documented
rng-random (If: CONFIG_POSIX)
Not documented
secret Not documented
secret_keyring (If: CONFIG_SECRET_KEYRING)
Not documented
sev-guest
Not documented
sev-snp-guest
Not documented
thread-context
Not documented
s390-pv-guest
Not documented
throttle-group
Not documented
tls-creds-anon
Not documented
tls-creds-psk
Not documented
tls-creds-x509
Not documented
tls-cipher-suites
Not documented
x-remote-object
Not documented
x-vfio-user-server
Not documented
Features
unstable
Members x-remote-object and x-vfio-user-server are experimental.
Since
6.0
ObjectOptions (Object)
Describes the options of a user creatable QOM object.
Members
qom-type: ObjectType
the class name for the object to be created
id: string
the name of the new object
The members of AcpiGenericInitiatorProperties when qom-type is "acpi-generic-initiator"
The members of AcpiGenericPortProperties when qom-type is "acpi-generic-port"
The members of AuthZListProperties when qom-type is "authz-list"
The members of AuthZListFileProperties when qom-type is "authz-listfile"
The members of AuthZPAMProperties when qom-type is "authz-pam"
The members of AuthZSimpleProperties when qom-type is "authz-simple"
The members of CanHostSocketcanProperties when qom-type is "can-host-socketcan" (If: CONFIG_LINUX)
The members of ColoCompareProperties when qom-type is "colo-compare"
The members of CryptodevBackendProperties when qom-type is "cryptodev-backend"
The members of CryptodevBackendProperties when qom-type is "cryptodev-backend-builtin"
The members of CryptodevBackendProperties when qom-type is "cryptodev-backend-lkcf"
The members of CryptodevVhostUserProperties when qom-type is "cryptodev-vhost-user" (If:
CONFIG_VHOST_CRYPTO)
The members of DBusVMStateProperties when qom-type is "dbus-vmstate"
The members of FilterBufferProperties when qom-type is "filter-buffer"
The members of FilterDumpProperties when qom-type is "filter-dump"
The members of FilterMirrorProperties when qom-type is "filter-mirror"
The members of FilterRedirectorProperties when qom-type is "filter-redirector"
The members of NetfilterProperties when qom-type is "filter-replay"
The members of FilterRewriterProperties when qom-type is "filter-rewriter"
The members of InputBarrierProperties when qom-type is "input-barrier"
The members of InputLinuxProperties when qom-type is "input-linux" (If: CONFIG_LINUX)
The members of IOMMUFDProperties when qom-type is "iommufd"
The members of IothreadProperties when qom-type is "iothread"
The members of MainLoopProperties when qom-type is "main-loop"
The members of MemoryBackendEpcProperties when qom-type is "memory-backend-epc" (If: CONFIG_LINUX)
The members of MemoryBackendFileProperties when qom-type is "memory-backend-file"
The members of MemoryBackendMemfdProperties when qom-type is "memory-backend-memfd" (If: CONFIG_LINUX)
The members of MemoryBackendProperties when qom-type is "memory-backend-ram"
The members of MemoryBackendShmProperties when qom-type is "memory-backend-shm" (If: CONFIG_POSIX)
The members of PrManagerHelperProperties when qom-type is "pr-manager-helper" (If: CONFIG_LINUX)
The members of QtestProperties when qom-type is "qtest"
The members of RngProperties when qom-type is "rng-builtin"
The members of RngEgdProperties when qom-type is "rng-egd"
The members of RngRandomProperties when qom-type is "rng-random" (If: CONFIG_POSIX)
The members of SecretProperties when qom-type is "secret"
The members of SecretKeyringProperties when qom-type is "secret_keyring" (If: CONFIG_SECRET_KEYRING)
The members of SevGuestProperties when qom-type is "sev-guest"
The members of SevSnpGuestProperties when qom-type is "sev-snp-guest"
The members of ThreadContextProperties when qom-type is "thread-context"
The members of ThrottleGroupProperties when qom-type is "throttle-group"
The members of TlsCredsAnonProperties when qom-type is "tls-creds-anon"
The members of TlsCredsPskProperties when qom-type is "tls-creds-psk"
The members of TlsCredsX509Properties when qom-type is "tls-creds-x509"
The members of TlsCredsProperties when qom-type is "tls-cipher-suites"
The members of RemoteObjectProperties when qom-type is "x-remote-object"
The members of VfioUserServerProperties when qom-type is "x-vfio-user-server"
Since
6.0
object-add (Command)
Create a QOM object.
Arguments
The members of ObjectOptions
Errors
• Error if qom-type is not a valid class name
Since
2.0
Example:
-> { "execute": "object-add",
"arguments": { "qom-type": "rng-random", "id": "rng1",
"filename": "/dev/hwrng" } }
<- { "return": {} }
object-del (Command)
Remove a QOM object.
Arguments
id: string
the name of the QOM object to remove
Errors
• Error if id is not a valid id for a QOM object
Since
2.0
Example:
-> { "execute": "object-del", "arguments": { "id": "rng1" } }
<- { "return": {} }
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