Provided by: qemu-kvm_1.0+noroms-0ubuntu13_amd64 bug

NAME

       qemu-doc - QEMU Emulator User Documentation

SYNOPSIS

       usage: qemu [options] [disk_image]

DESCRIPTION

       The QEMU PC System emulator simulates the following peripherals:

       -   i440FX host PCI bridge and PIIX3 PCI to ISA bridge

       -   Cirrus CLGD 5446 PCI VGA card or dummy VGA card with Bochs VESA extensions (hardware
           level, including all non standard modes).

       -   PS/2 mouse and keyboard

       -   2 PCI IDE interfaces with hard disk and CD-ROM support

       -   Floppy disk

       -   PCI and ISA network adapters

       -   Serial ports

       -   Creative SoundBlaster 16 sound card

       -   ENSONIQ AudioPCI ES1370 sound card

       -   Intel 82801AA AC97 Audio compatible sound card

       -   Intel HD Audio Controller and HDA codec

       -   Adlib (OPL2) - Yamaha YM3812 compatible chip

       -   Gravis Ultrasound GF1 sound card

       -   CS4231A compatible sound card

       -   PCI UHCI USB controller and a virtual USB hub.

       SMP is supported with up to 255 CPUs.

       Note that adlib, gus and cs4231a are only available when QEMU was configured with
       --audio-card-list option containing the name(s) of required card(s).

       QEMU uses the PC BIOS from the Bochs project and the Plex86/Bochs LGPL VGA BIOS.

       QEMU uses YM3812 emulation by Tatsuyuki Satoh.

       QEMU uses GUS emulation (GUSEMU32 <http://www.deinmeister.de/gusemu/>) by Tibor "TS"
       SchA~Xtz.

       Note that, by default, GUS shares IRQ(7) with parallel ports and so qemu must be told to
       not have parallel ports to have working GUS

               qemu dos.img -soundhw gus -parallel none

       Alternatively:

               qemu dos.img -device gus,irq=5

       Or some other unclaimed IRQ.

       CS4231A is the chip used in Windows Sound System and GUSMAX products

OPTIONS

       disk_image is a raw hard disk image for IDE hard disk 0. Some targets do not need a disk
       image.

       Standard options:

       -h  Display help and exit

       -version
           Display version information and exit

       -machine [type=]name[,prop=value[,...]]
           Select the emulated machine by name. Use "-machine ?" to list available machines.
           Supported machine properties are:

           accel=accels1[:accels2[:...]]
               This is used to enable an accelerator. Depending on the target architecture, kvm,
               xen, or tcg can be available. By default, tcg is used. If there is more than one
               accelerator specified, the next one is used if the previous one fails to
               initialize.

       -cpu model
           Select CPU model (-cpu ? for list and additional feature selection)

       -smp n[,cores=cores][,threads=threads][,sockets=sockets][,maxcpus=maxcpus]
           Simulate an SMP system with n CPUs. On the PC target, up to 255 CPUs are supported. On
           Sparc32 target, Linux limits the number of usable CPUs to 4.  For the PC target, the
           number of cores per socket, the number of threads per cores and the total number of
           sockets can be specified. Missing values will be computed. If any on the three values
           is given, the total number of CPUs n can be omitted. maxcpus specifies the maximum
           number of hotpluggable CPUs.

       -numa opts
           Simulate a multi node NUMA system. If mem and cpus are omitted, resources are split
           equally.

       -fda file
       -fdb file
           Use file as floppy disk 0/1 image. You can use the host floppy by using /dev/fd0 as
           filename.

       -hda file
       -hdb file
       -hdc file
       -hdd file
           Use file as hard disk 0, 1, 2 or 3 image.

       -cdrom file
           Use file as CD-ROM image (you cannot use -hdc and -cdrom at the same time). You can
           use the host CD-ROM by using /dev/cdrom as filename.

       -drive option[,option[,option[,...]]]
           Define a new drive. Valid options are:

           file=file
               This option defines which disk image to use with this drive. If the filename
               contains comma, you must double it (for instance, "file=my,,file" to use file
               "my,file").

               Special files such as iSCSI devices can be specified using protocol specific URLs.
               See the section for "Device URL Syntax" for more information.

           if=interface
               This option defines on which type on interface the drive is connected.  Available
               types are: ide, scsi, sd, mtd, floppy, pflash, virtio.

           bus=bus,unit=unit
               These options define where is connected the drive by defining the bus number and
               the unit id.

           index=index
               This option defines where is connected the drive by using an index in the list of
               available connectors of a given interface type.

           media=media
               This option defines the type of the media: disk or cdrom.

           cyls=c,heads=h,secs=s[,trans=t]
               These options have the same definition as they have in -hdachs.

           snapshot=snapshot
               snapshot is "on" or "off" and allows to enable snapshot for given drive (see
               -snapshot).

           cache=cache
               cache is "none", "writeback", "unsafe", "directsync" or "writethrough" and
               controls how the host cache is used to access block data.

           aio=aio
               aio is "threads", or "native" and selects between pthread based disk I/O and
               native Linux AIO.

           format=format
               Specify which disk format will be used rather than detecting the format.  Can be
               used to specifiy format=raw to avoid interpreting an untrusted format header.

           serial=serial
               This option specifies the serial number to assign to the device.

           addr=addr
               Specify the controller's PCI address (if=virtio only).

           werror=action,rerror=action
               Specify which action to take on write and read errors. Valid actions are: "ignore"
               (ignore the error and try to continue), "stop" (pause QEMU), "report" (report the
               error to the guest), "enospc" (pause QEMU only if the host disk is full; report
               the error to the guest otherwise).  The default setting is werror=enospc and
               rerror=report.

           readonly
               Open drive file as read-only. Guest write attempts will fail.

           By default, writethrough caching is used for all block device.  This means that the
           host page cache will be used to read and write data but write notification will be
           sent to the guest only when the data has been reported as written by the storage
           subsystem.

           Writeback caching will report data writes as completed as soon as the data is present
           in the host page cache.  This is safe as long as you trust your host.  If your host
           crashes or loses power, then the guest may experience data corruption.

           The host page cache can be avoided entirely with cache=none.  This will attempt to do
           disk IO directly to the guests memory.  QEMU may still perform an internal copy of the
           data.

           The host page cache can be avoided while only sending write notifications to the guest
           when the data has been reported as written by the storage subsystem using
           cache=directsync.

           Some block drivers perform badly with cache=writethrough, most notably, qcow2.  If
           performance is more important than correctness, cache=writeback should be used with
           qcow2.

           In case you don't care about data integrity over host failures, use cache=unsafe. This
           option tells qemu that it never needs to write any data to the disk but can instead
           keeps things in cache. If anything goes wrong, like your host losing power, the disk
           storage getting disconnected accidently, etc. you're image will most probably be
           rendered unusable.   When using the -snapshot option, unsafe caching is always used.

           Instead of -cdrom you can use:

                   qemu -drive file=file,index=2,media=cdrom

           Instead of -hda, -hdb, -hdc, -hdd, you can use:

                   qemu -drive file=file,index=0,media=disk
                   qemu -drive file=file,index=1,media=disk
                   qemu -drive file=file,index=2,media=disk
                   qemu -drive file=file,index=3,media=disk

           You can connect a CDROM to the slave of ide0:

                   qemu -drive file=file,if=ide,index=1,media=cdrom

           If you don't specify the "file=" argument, you define an empty drive:

                   qemu -drive if=ide,index=1,media=cdrom

           You can connect a SCSI disk with unit ID 6 on the bus #0:

                   qemu -drive file=file,if=scsi,bus=0,unit=6

           Instead of -fda, -fdb, you can use:

                   qemu -drive file=file,index=0,if=floppy
                   qemu -drive file=file,index=1,if=floppy

           By default, interface is "ide" and index is automatically incremented:

                   qemu -drive file=a -drive file=b"

           is interpreted like:

                   qemu -hda a -hdb b

       -set
           TODO

       -global
           TODO

       -mtdblock file
           Use file as on-board Flash memory image.

       -sd file
           Use file as SecureDigital card image.

       -pflash file
           Use file as a parallel flash image.

       -boot [order=drives][,once=drives][,menu=on|off][,splash=sp_name][,splash-time=sp_time]
           Specify boot order drives as a string of drive letters. Valid drive letters depend on
           the target achitecture. The x86 PC uses: a, b (floppy 1 and 2), c (first hard disk), d
           (first CD-ROM), n-p (Etherboot from network adapter 1-4), hard disk boot is the
           default. To apply a particular boot order only on the first startup, specify it via
           once.

           Interactive boot menus/prompts can be enabled via menu=on as far as firmware/BIOS
           supports them. The default is non-interactive boot.

           A splash picture could be passed to bios, enabling user to show it as logo, when
           option splash=sp_name is given and menu=on, If firmware/BIOS supports them. Currently
           Seabios for X86 system support it.  limitation: The splash file could be a jpeg file
           or a BMP file in 24 BPP format(true color). The resolution should be supported by the
           SVGA mode, so the recommended is 320x240, 640x480, 800x640.

                   # try to boot from network first, then from hard disk
                   qemu -boot order=nc
                   # boot from CD-ROM first, switch back to default order after reboot
                   qemu -boot once=d
                   # boot with a splash picture for 5 seconds.
                   qemu -boot menu=on,splash=/root/boot.bmp,splash-time=5000

           Note: The legacy format '-boot drives' is still supported but its use is discouraged
           as it may be removed from future versions.

       -snapshot
           Write to temporary files instead of disk image files. In this case, the raw disk image
           you use is not written back. You can however force the write back by pressing C-a s.

       -m megs
           Set virtual RAM size to megs megabytes. Default is 128 MiB.  Optionally, a suffix of
           "M" or "G" can be used to signify a value in megabytes or gigabytes respectively.

       -mem-path path
           Allocate guest RAM from a temporarily created file in path.

       -mem-prealloc
           Preallocate memory when using -mem-path.

       -k language
           Use keyboard layout language (for example "fr" for French). This option is only needed
           where it is not easy to get raw PC keycodes (e.g. on Macs, with some X11 servers or
           with a VNC display). You don't normally need to use it on PC/Linux or PC/Windows
           hosts.

           The available layouts are:

                   ar  de-ch  es  fo     fr-ca  hu  ja  mk     no  pt-br  sv
                   da  en-gb  et  fr     fr-ch  is  lt  nl     pl  ru     th
                   de  en-us  fi  fr-be  hr     it  lv  nl-be  pt  sl     tr

           The default is "en-us".

       -audio-help
           Will show the audio subsystem help: list of drivers, tunable parameters.

       -soundhw card1[,card2,...] or -soundhw all
           Enable audio and selected sound hardware. Use ? to print all available sound hardware.

                   qemu -soundhw sb16,adlib disk.img
                   qemu -soundhw es1370 disk.img
                   qemu -soundhw ac97 disk.img
                   qemu -soundhw hda disk.img
                   qemu -soundhw all disk.img
                   qemu -soundhw ?

           Note that Linux's i810_audio OSS kernel (for AC97) module might require manually
           specifying clocking.

                   modprobe i810_audio clocking=48000

       USB options:

       -usb
           Enable the USB driver (will be the default soon)

       -usbdevice devname
           Add the USB device devname.

           mouse
               Virtual Mouse. This will override the PS/2 mouse emulation when activated.

           tablet
               Pointer device that uses absolute coordinates (like a touchscreen). This means
               qemu is able to report the mouse position without having to grab the mouse. Also
               overrides the PS/2 mouse emulation when activated.

           disk:[format=format]:file
               Mass storage device based on file. The optional format argument will be used
               rather than detecting the format. Can be used to specifiy "format=raw" to avoid
               interpreting an untrusted format header.

           host:bus.addr
               Pass through the host device identified by bus.addr (Linux only).

           host:vendor_id:product_id
               Pass through the host device identified by vendor_id:product_id (Linux only).

           serial:[vendorid=vendor_id][,productid=product_id]:dev
               Serial converter to host character device dev, see "-serial" for the available
               devices.

           braille
               Braille device.  This will use BrlAPI to display the braille output on a real or
               fake device.

           net:options
               Network adapter that supports CDC ethernet and RNDIS protocols.

       -device driver[,prop[=value][,...]]
           Add device driver.  prop=value sets driver properties.  Valid properties depend on the
           driver.  To get help on possible drivers and properties, use "-device ?" and "-device
           driver,?".

           File system options:

       -fsdev
       fsdriver,id=id,path=path,[security_model=security_model][,writeout=writeout][,readonly]
           Define a new file system device. Valid options are:

           fsdriver
               This option specifies the fs driver backend to use.  Currently "local" and
               "handle" file system drivers are supported.

           id=id
               Specifies identifier for this device

           path=path
               Specifies the export path for the file system device. Files under this path will
               be available to the 9p client on the guest.

           security_model=security_model
               Specifies the security model to be used for this export path.  Supported security
               models are "passthrough", "mapped" and "none".  In "passthrough" security model,
               files are stored using the same credentials as they are created on the guest. This
               requires qemu to run as root. In "mapped" security model, some of the file
               attributes like uid, gid, mode bits and link target are stored as file attributes.
               Directories exported by this security model cannot interact with other unix tools.
               "none" security model is same as passthrough except the sever won't report
               failures if it fails to set file attributes like ownership. Security model is
               mandatory only for local fsdriver. Other fsdrivers (like handle) don't take
               security model as a parameter.

           writeout=writeout
               This is an optional argument. The only supported value is "immediate".  This means
               that host page cache will be used to read and write data but write notification
               will be sent to the guest only when the data has been reported as written by the
               storage subsystem.

           readonly
               Enables exporting 9p share as a readonly mount for guests. By default read-write
               access is given.

           -fsdev option is used along with -device driver "virtio-9p-pci".

       -device virtio-9p-pci,fsdev=id,mount_tag=mount_tag
           Options for virtio-9p-pci driver are:

           fsdev=id
               Specifies the id value specified along with -fsdev option

           mount_tag=mount_tag
               Specifies the tag name to be used by the guest to mount this export point

           Virtual File system pass-through options:

       -virtfs
       fsdriver,path=path,mount_tag=mount_tag,security_model=security_model[,writeout=writeout][,readonly]
           The general form of a Virtual File system pass-through options are:

           fsdriver
               This option specifies the fs driver backend to use.  Currently "local" and
               "handle" file system drivers are supported.

           id=id
               Specifies identifier for this device

           path=path
               Specifies the export path for the file system device. Files under this path will
               be available to the 9p client on the guest.

           security_model=security_model
               Specifies the security model to be used for this export path.  Supported security
               models are "passthrough", "mapped" and "none".  In "passthrough" security model,
               files are stored using the same credentials as they are created on the guest. This
               requires qemu to run as root. In "mapped" security model, some of the file
               attributes like uid, gid, mode bits and link target are stored as file attributes.
               Directories exported by this security model cannot interact with other unix tools.
               "none" security model is same as passthrough except the sever won't report
               failures if it fails to set file attributes like ownership. Security model is
               mandatory only for local fsdriver. Other fsdrivers (like handle) don't take
               security model as a parameter.

           writeout=writeout
               This is an optional argument. The only supported value is "immediate".  This means
               that host page cache will be used to read and write data but write notification
               will be sent to the guest only when the data has been reported as written by the
               storage subsystem.

           readonly
               Enables exporting 9p share as a readonly mount for guests. By default read-write
               access is given.

       -virtfs_synth
           Create synthetic file system image

       -name name
           Sets the name of the guest.  This name will be displayed in the SDL window caption.
           The name will also be used for the VNC server.  Also optionally set the top visible
           process name in Linux.

       -uuid uuid
           Set system UUID.

       Display options:

       -display type
           Select type of display to use. This option is a replacement for the old style
           -sdl/-curses/... options. Valid values for type are

           sdl Display video output via SDL (usually in a separate graphics window; see the SDL
               documentation for other possibilities).

           curses
               Display video output via curses. For graphics device models which support a text
               mode, QEMU can display this output using a curses/ncurses interface. Nothing is
               displayed when the graphics device is in graphical mode or if the graphics device
               does not support a text mode. Generally only the VGA device models support text
               mode.

           none
               Do not display video output. The guest will still see an emulated graphics card,
               but its output will not be displayed to the QEMU user. This option differs from
               the -nographic option in that it only affects what is done with video output;
               -nographic also changes the destination of the serial and parallel port data.

           vnc Start a VNC server on display <arg>

       -nographic
           Normally, QEMU uses SDL to display the VGA output. With this option, you can totally
           disable graphical output so that QEMU is a simple command line application. The
           emulated serial port is redirected on the console. Therefore, you can still use QEMU
           to debug a Linux kernel with a serial console.

       -curses
           Normally, QEMU uses SDL to display the VGA output.  With this option, QEMU can display
           the VGA output when in text mode using a curses/ncurses interface.  Nothing is
           displayed in graphical mode.

       -no-frame
           Do not use decorations for SDL windows and start them using the whole available screen
           space. This makes the using QEMU in a dedicated desktop workspace more convenient.

       -alt-grab
           Use Ctrl-Alt-Shift to grab mouse (instead of Ctrl-Alt). Note that this also affects
           the special keys (for fullscreen, monitor-mode switching, etc).

       -ctrl-grab
           Use Right-Ctrl to grab mouse (instead of Ctrl-Alt). Note that this also affects the
           special keys (for fullscreen, monitor-mode switching, etc).

       -no-quit
           Disable SDL window close capability.

       -sdl
           Enable SDL.

       -spice option[,option[,...]]
           Enable the spice remote desktop protocol. Valid options are

           port=<nr>
               Set the TCP port spice is listening on for plaintext channels.

           addr=<addr>
               Set the IP address spice is listening on.  Default is any address.

           ipv4
           ipv6
               Force using the specified IP version.

           password=<secret>
               Set the password you need to authenticate.

           sasl
               Require that the client use SASL to authenticate with the spice.  The exact choice
               of authentication method used is controlled from the system / user's SASL
               configuration file for the 'qemu' service. This is typically found in
               /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, an environment
               variable SASL_CONF_PATH can be used to make it search alternate locations for the
               service config.  While some SASL auth methods can also provide data encryption (eg
               GSSAPI), it is recommended that SASL always be combined with the 'tls' and 'x509'
               settings to enable use of SSL and server certificates. This ensures a data
               encryption preventing compromise of authentication credentials.

           disable-ticketing
               Allow client connects without authentication.

           disable-copy-paste
               Disable copy paste between the client and the guest.

           tls-port=<nr>
               Set the TCP port spice is listening on for encrypted channels.

           x509-dir=<dir>
               Set the x509 file directory. Expects same filenames as -vnc $display,x509=$dir

           x509-key-file=<file>
           x509-key-password=<file>
           x509-cert-file=<file>
           x509-cacert-file=<file>
           x509-dh-key-file=<file>
               The x509 file names can also be configured individually.

           tls-ciphers=<list>
               Specify which ciphers to use.

           tls-channel=[main|display|inputs|record|playback|tunnel]
           plaintext-channel=[main|display|inputs|record|playback|tunnel]
               Force specific channel to be used with or without TLS encryption.  The options can
               be specified multiple times to configure multiple channels.  The special name
               "default" can be used to set the default mode.  For channels which are not
               explicitly forced into one mode the spice client is allowed to pick tls/plaintext
               as he pleases.

           image-compression=[auto_glz|auto_lz|quic|glz|lz|off]
               Configure image compression (lossless).  Default is auto_glz.

           jpeg-wan-compression=[auto|never|always]
           zlib-glz-wan-compression=[auto|never|always]
               Configure wan image compression (lossy for slow links).  Default is auto.

           streaming-video=[off|all|filter]
               Configure video stream detection.  Default is filter.

           agent-mouse=[on|off]
               Enable/disable passing mouse events via vdagent.  Default is on.

           playback-compression=[on|off]
               Enable/disable audio stream compression (using celt 0.5.1).  Default is on.

       -portrait
           Rotate graphical output 90 deg left (only PXA LCD).

       -rotate
           Rotate graphical output some deg left (only PXA LCD).

       -vga type
           Select type of VGA card to emulate. Valid values for type are

           cirrus
               Cirrus Logic GD5446 Video card. All Windows versions starting from Windows 95
               should recognize and use this graphic card. For optimal performances, use 16 bit
               color depth in the guest and the host OS.  (This one is the default)

           std Standard VGA card with Bochs VBE extensions.  If your guest OS supports the VESA
               2.0 VBE extensions (e.g. Windows XP) and if you want to use high resolution modes
               (>= 1280x1024x16) then you should use this option.

           vmware
               VMWare SVGA-II compatible adapter. Use it if you have sufficiently recent
               XFree86/XOrg server or Windows guest with a driver for this card.

           qxl QXL paravirtual graphic card.  It is VGA compatible (including VESA 2.0 VBE
               support).  Works best with qxl guest drivers installed though.  Recommended choice
               when using the spice protocol.

           none
               Disable VGA card.

       -full-screen
           Start in full screen.

       -g widthxheight[xdepth]
           Set the initial graphical resolution and depth (PPC, SPARC only).

       -vnc display[,option[,option[,...]]]
           Normally, QEMU uses SDL to display the VGA output.  With this option, you can have
           QEMU listen on VNC display display and redirect the VGA display over the VNC session.
           It is very useful to enable the usb tablet device when using this option (option
           -usbdevice tablet). When using the VNC display, you must use the -k parameter to set
           the keyboard layout if you are not using en-us. Valid syntax for the display is

           host:d
               TCP connections will only be allowed from host on display d.  By convention the
               TCP port is 5900+d. Optionally, host can be omitted in which case the server will
               accept connections from any host.

           unix:path
               Connections will be allowed over UNIX domain sockets where path is the location of
               a unix socket to listen for connections on.

           none
               VNC is initialized but not started. The monitor "change" command can be used to
               later start the VNC server.

           Following the display value there may be one or more option flags separated by commas.
           Valid options are

           reverse
               Connect to a listening VNC client via a "reverse" connection. The client is
               specified by the display. For reverse network connections (host:d,"reverse"), the
               d argument is a TCP port number, not a display number.

           password
               Require that password based authentication is used for client connections.  The
               password must be set separately using the "change" command in the pcsys_monitor

           tls Require that client use TLS when communicating with the VNC server. This uses
               anonymous TLS credentials so is susceptible to a man-in-the-middle attack. It is
               recommended that this option be combined with either the x509 or x509verify
               options.

           x509=/path/to/certificate/dir
               Valid if tls is specified. Require that x509 credentials are used for negotiating
               the TLS session. The server will send its x509 certificate to the client. It is
               recommended that a password be set on the VNC server to provide authentication of
               the client when this is used. The path following this option specifies where the
               x509 certificates are to be loaded from.  See the vnc_security section for details
               on generating certificates.

           x509verify=/path/to/certificate/dir
               Valid if tls is specified. Require that x509 credentials are used for negotiating
               the TLS session. The server will send its x509 certificate to the client, and
               request that the client send its own x509 certificate.  The server will validate
               the client's certificate against the CA certificate, and reject clients when
               validation fails. If the certificate authority is trusted, this is a sufficient
               authentication mechanism. You may still wish to set a password on the VNC server
               as a second authentication layer. The path following this option specifies where
               the x509 certificates are to be loaded from. See the vnc_security section for
               details on generating certificates.

           sasl
               Require that the client use SASL to authenticate with the VNC server.  The exact
               choice of authentication method used is controlled from the system / user's SASL
               configuration file for the 'qemu' service. This is typically found in
               /etc/sasl2/qemu.conf. If running QEMU as an unprivileged user, an environment
               variable SASL_CONF_PATH can be used to make it search alternate locations for the
               service config.  While some SASL auth methods can also provide data encryption (eg
               GSSAPI), it is recommended that SASL always be combined with the 'tls' and 'x509'
               settings to enable use of SSL and server certificates. This ensures a data
               encryption preventing compromise of authentication credentials. See the
               vnc_security section for details on using SASL authentication.

           acl Turn on access control lists for checking of the x509 client certificate and SASL
               party. For x509 certs, the ACL check is made against the certificate's
               distinguished name. This is something that looks like
               "C=GB,O=ACME,L=Boston,CN=bob". For SASL party, the ACL check is made against the
               username, which depending on the SASL plugin, may include a realm component, eg
               "bob" or "bob@EXAMPLE.COM".  When the acl flag is set, the initial access list
               will be empty, with a "deny" policy. Thus no one will be allowed to use the VNC
               server until the ACLs have been loaded. This can be achieved using the "acl"
               monitor command.

           lossy
               Enable lossy compression methods (gradient, JPEG, ...). If this option is set, VNC
               client may receive lossy framebuffer updates depending on its encoding settings.
               Enabling this option can save a lot of bandwidth at the expense of quality.

           non-adaptive
               Disable adaptive encodings. Adaptive encodings are enabled by default.  An
               adaptive encoding will try to detect frequently updated screen regions, and send
               updates in these regions using a lossy encoding (like JPEG).  This can be really
               helpful to save bandwidth when playing videos. Disabling adaptive encodings allows
               to restore the original static behavior of encodings like Tight.

       i386 target only:

       -win2k-hack
           Use it when installing Windows 2000 to avoid a disk full bug. After Windows 2000 is
           installed, you no longer need this option (this option slows down the IDE transfers).

       -no-fd-bootchk
           Disable boot signature checking for floppy disks in Bochs BIOS. It may be needed to
           boot from old floppy disks.  TODO: check reference to Bochs BIOS.

       -no-acpi
           Disable ACPI (Advanced Configuration and Power Interface) support. Use it if your
           guest OS complains about ACPI problems (PC target machine only).

       -no-hpet
           Disable HPET support.

       -balloon none
           Disable balloon device.

       -balloon virtio[,addr=addr]
           Enable virtio balloon device (default), optionally with PCI address addr.

       -acpitable [sig=str][,rev=n][,oem_id=str][,oem_table_id=str][,oem_rev=n]
       [,asl_compiler_id=str][,asl_compiler_rev=n][,data=file1[:file2]...]
           Add ACPI table with specified header fields and context from specified files.  For
           file=, take whole ACPI table from the specified files, including all ACPI headers
           (possible overridden by other options).  For data=, only data portion of the table is
           used, all header information is specified in the command line.

       -smbios file=binary
           Load SMBIOS entry from binary file.

       -smbios type=0[,vendor=str][,version=str][,date=str][,release=%d.%d]
           Specify SMBIOS type 0 fields

       -smbios type=1[,manufacturer=str][,product=str]
       [,version=str][,serial=str][,uuid=uuid][,sku=str] [,family=str]
           Specify SMBIOS type 1 fields

       Network options:

       -net nic[,vlan=n][,macaddr=mac][,model=type] [,name=name][,addr=addr][,vectors=v]
           Create a new Network Interface Card and connect it to VLAN n (n = 0 is the default).
           The NIC is an e1000 by default on the PC target. Optionally, the MAC address can be
           changed to mac, the device address set to addr (PCI cards only), and a name can be
           assigned for use in monitor commands.  Optionally, for PCI cards, you can specify the
           number v of MSI-X vectors that the card should have; this option currently only
           affects virtio cards; set v = 0 to disable MSI-X. If no -net option is specified, a
           single NIC is created.  Qemu can emulate several different models of network card.
           Valid values for type are "virtio", "i82551", "i82557b", "i82559er", "ne2k_pci",
           "ne2k_isa", "pcnet", "rtl8139", "e1000", "smc91c111", "lance" and "mcf_fec".  Not all
           devices are supported on all targets.  Use -net nic,model=?  for a list of available
           devices for your target.

       -net user[,option][,option][,...]
           Use the user mode network stack which requires no administrator privilege to run.
           Valid options are:

           vlan=n
               Connect user mode stack to VLAN n (n = 0 is the default).

           name=name
               Assign symbolic name for use in monitor commands.

           net=addr[/mask]
               Set IP network address the guest will see. Optionally specify the netmask, either
               in the form a.b.c.d or as number of valid top-most bits. Default is 10.0.2.0/24.

           host=addr
               Specify the guest-visible address of the host. Default is the 2nd IP in the guest
               network, i.e. x.x.x.2.

           restrict=on|off
               If this option is enabled, the guest will be isolated, i.e. it will not be able to
               contact the host and no guest IP packets will be routed over the host to the
               outside. This option does not affect any explicitly set forwarding rules.

           hostname=name
               Specifies the client hostname reported by the builtin DHCP server.

           dhcpstart=addr
               Specify the first of the 16 IPs the built-in DHCP server can assign. Default is
               the 15th to 31st IP in the guest network, i.e. x.x.x.15 to x.x.x.31.

           dns=addr
               Specify the guest-visible address of the virtual nameserver. The address must be
               different from the host address. Default is the 3rd IP in the guest network, i.e.
               x.x.x.3.

           tftp=dir
               When using the user mode network stack, activate a built-in TFTP server. The files
               in dir will be exposed as the root of a TFTP server.  The TFTP client on the guest
               must be configured in binary mode (use the command "bin" of the Unix TFTP client).

           bootfile=file
               When using the user mode network stack, broadcast file as the BOOTP filename. In
               conjunction with tftp, this can be used to network boot a guest from a local
               directory.

               Example (using pxelinux):

                       qemu -hda linux.img -boot n -net user,tftp=/path/to/tftp/files,bootfile=/pxelinux.0

           smb=dir[,smbserver=addr]
               When using the user mode network stack, activate a built-in SMB server so that
               Windows OSes can access to the host files in dir transparently. The IP address of
               the SMB server can be set to addr. By default the 4th IP in the guest network is
               used, i.e. x.x.x.4.

               In the guest Windows OS, the line:

                       10.0.2.4 smbserver

               must be added in the file C:\WINDOWS\LMHOSTS (for windows 9x/Me) or
               C:\WINNT\SYSTEM32\DRIVERS\ETC\LMHOSTS (Windows NT/2000).

               Then dir can be accessed in \smbserver\qemu.

               Note that a SAMBA server must be installed on the host OS.  QEMU was tested
               successfully with smbd versions from Red Hat 9, Fedora Core 3 and OpenSUSE 11.x.

           hostfwd=[tcp|udp]:[hostaddr]:hostport-[guestaddr]:guestport
               Redirect incoming TCP or UDP connections to the host port hostport to the guest IP
               address guestaddr on guest port guestport. If guestaddr is not specified, its
               value is x.x.x.15 (default first address given by the built-in DHCP server). By
               specifying hostaddr, the rule can be bound to a specific host interface. If no
               connection type is set, TCP is used. This option can be given multiple times.

               For example, to redirect host X11 connection from screen 1 to guest screen 0, use
               the following:

                       # on the host
                       qemu -net user,hostfwd=tcp:127.0.0.1:6001-:6000 [...]
                       # this host xterm should open in the guest X11 server
                       xterm -display :1

               To redirect telnet connections from host port 5555 to telnet port on the guest,
               use the following:

                       # on the host
                       qemu -net user,hostfwd=tcp::5555-:23 [...]
                       telnet localhost 5555

               Then when you use on the host "telnet localhost 5555", you connect to the guest
               telnet server.

           guestfwd=[tcp]:server:port-dev
               Forward guest TCP connections to the IP address server on port port to the
               character device dev. This option can be given multiple times.

           Note: Legacy stand-alone options -tftp, -bootp, -smb and -redir are still processed
           and applied to -net user. Mixing them with the new configuration syntax gives
           undefined results. Their use for new applications is discouraged as they will be
           removed from future versions.

       -net tap[,vlan=n][,name=name][,fd=h][,ifname=name] [,script=file][,downscript=dfile]
           Connect the host TAP network interface name to VLAN n, use the network script file to
           configure it and the network script dfile to deconfigure it. If name is not provided,
           the OS automatically provides one. fd=h can be used to specify the handle of an
           already opened host TAP interface. The default network configure script is
           /etc/qemu-ifup and the default network deconfigure script is /etc/qemu-ifdown. Use
           script=no or downscript=no to disable script execution. Example:

                   qemu linux.img -net nic -net tap

           More complicated example (two NICs, each one connected to a TAP device)

                   qemu linux.img -net nic,vlan=0 -net tap,vlan=0,ifname=tap0 \
                   -net nic,vlan=1 -net tap,vlan=1,ifname=tap1

       -net socket[,vlan=n][,name=name][,fd=h] [,listen=[host]:port][,connect=host:port]
           Connect the VLAN n to a remote VLAN in another QEMU virtual machine using a TCP socket
           connection. If listen is specified, QEMU waits for incoming connections on port (host
           is optional). connect is used to connect to another QEMU instance using the listen
           option. fd=h specifies an already opened TCP socket.

           Example:

                   # launch a first QEMU instance
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,listen=:1234
                   # connect the VLAN 0 of this instance to the VLAN 0
                   # of the first instance
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
                   -net socket,connect=127.0.0.1:1234

       -net socket[,vlan=n][,name=name][,fd=h][,mcast=maddr:port[,localaddr=addr]]
           Create a VLAN n shared with another QEMU virtual machines using a UDP multicast
           socket, effectively making a bus for every QEMU with same multicast address maddr and
           port.  NOTES:

           1.  Several QEMU can be running on different hosts and share same bus (assuming
               correct multicast setup for these hosts).

           2.  mcast support is compatible with User Mode Linux (argument ethN=mcast), see
               <http://user-mode-linux.sf.net>.

           3.  Use fd=h to specify an already opened UDP multicast socket.

           Example:

                   # launch one QEMU instance
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,mcast=230.0.0.1:1234
                   # launch another QEMU instance on same "bus"
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
                   -net socket,mcast=230.0.0.1:1234
                   # launch yet another QEMU instance on same "bus"
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:58 \
                   -net socket,mcast=230.0.0.1:1234

           Example (User Mode Linux compat.):

                   # launch QEMU instance (note mcast address selected
                   # is UML's default)
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,mcast=239.192.168.1:1102
                   # launch UML
                   /path/to/linux ubd0=/path/to/root_fs eth0=mcast

           Example (send packets from host's 1.2.3.4):

                   qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,mcast=239.192.168.1:1102,localaddr=1.2.3.4

       -net vde[,vlan=n][,name=name][,sock=socketpath]
       [,port=n][,group=groupname][,mode=octalmode]
           Connect VLAN n to PORT n of a vde switch running on host and listening for incoming
           connections on socketpath. Use GROUP groupname and MODE octalmode to change default
           ownership and permissions for communication port. This option is only available if
           QEMU has been compiled with vde support enabled.

           Example:

                   # launch vde switch
                   vde_switch -F -sock /tmp/myswitch
                   # launch QEMU instance
                   qemu linux.img -net nic -net vde,sock=/tmp/myswitch

       -net dump[,vlan=n][,file=file][,len=len]
           Dump network traffic on VLAN n to file file (qemu-vlan0.pcap by default).  At most len
           bytes (64k by default) per packet are stored. The file format is libpcap, so it can be
           analyzed with tools such as tcpdump or Wireshark.

       -net none
           Indicate that no network devices should be configured. It is used to override the
           default configuration (-net nic -net user) which is activated if no -net options are
           provided.

       Character device options:

       The general form of a character device option is:

       -chardev backend ,id=id [,mux=on|off] [,options]
           Backend is one of: null, socket, udp, msmouse, vc, file, pipe, console, serial, pty,
           stdio, braille, tty, parport, spicevmc.  The specific backend will determine the
           applicable options.

           All devices must have an id, which can be any string up to 127 characters long.  It is
           used to uniquely identify this device in other command line directives.

           A character device may be used in multiplexing mode by multiple front-ends.  The key
           sequence of Control-a and c will rotate the input focus between attached front-ends.
           Specify mux=on to enable this mode.

           Options to each backend are described below.

       -chardev null ,id=id
           A void device. This device will not emit any data, and will drop any data it receives.
           The null backend does not take any options.

       -chardev socket ,id=id [TCP options or unix options] [,server] [,nowait] [,telnet]
           Create a two-way stream socket, which can be either a TCP or a unix socket. A unix
           socket will be created if path is specified. Behaviour is undefined if TCP options are
           specified for a unix socket.

           server specifies that the socket shall be a listening socket.

           nowait specifies that QEMU should not block waiting for a client to connect to a
           listening socket.

           telnet specifies that traffic on the socket should interpret telnet escape sequences.

           TCP and unix socket options are given below:

           TCP options: port=port [,host=host] [,to=to] [,ipv4] [,ipv6] [,nodelay]
               host for a listening socket specifies the local address to be bound.  For a
               connecting socket species the remote host to connect to. host is optional for
               listening sockets. If not specified it defaults to 0.0.0.0.

               port for a listening socket specifies the local port to be bound. For a connecting
               socket specifies the port on the remote host to connect to.  port can be given as
               either a port number or a service name.  port is required.

               to is only relevant to listening sockets. If it is specified, and port cannot be
               bound, QEMU will attempt to bind to subsequent ports up to and including to until
               it succeeds. to must be specified as a port number.

               ipv4 and ipv6 specify that either IPv4 or IPv6 must be used.  If neither is
               specified the socket may use either protocol.

               nodelay disables the Nagle algorithm.

           unix options: path=path
               path specifies the local path of the unix socket. path is required.

       -chardev udp ,id=id [,host=host] ,port=port [,localaddr=localaddr] [,localport=localport]
       [,ipv4] [,ipv6]
           Sends all traffic from the guest to a remote host over UDP.

           host specifies the remote host to connect to. If not specified it defaults to
           "localhost".

           port specifies the port on the remote host to connect to. port is required.

           localaddr specifies the local address to bind to. If not specified it defaults to
           0.0.0.0.

           localport specifies the local port to bind to. If not specified any available local
           port will be used.

           ipv4 and ipv6 specify that either IPv4 or IPv6 must be used.  If neither is specified
           the device may use either protocol.

       -chardev msmouse ,id=id
           Forward QEMU's emulated msmouse events to the guest. msmouse does not take any
           options.

       -chardev vc ,id=id [[,width=width] [,height=height]] [[,cols=cols] [,rows=rows]]
           Connect to a QEMU text console. vc may optionally be given a specific size.

           width and height specify the width and height respectively of the console, in pixels.

           cols and rows specify that the console be sized to fit a text console with the given
           dimensions.

       -chardev file ,id=id ,path=path
           Log all traffic received from the guest to a file.

           path specifies the path of the file to be opened. This file will be created if it does
           not already exist, and overwritten if it does. path is required.

       -chardev pipe ,id=id ,path=path
           Create a two-way connection to the guest. The behaviour differs slightly between
           Windows hosts and other hosts:

           On Windows, a single duplex pipe will be created at \.pipe\path.

           On other hosts, 2 pipes will be created called path.in and path.out. Data written to
           path.in will be received by the guest. Data written by the guest can be read from
           path.out. QEMU will not create these fifos, and requires them to be present.

           path forms part of the pipe path as described above. path is required.

       -chardev console ,id=id
           Send traffic from the guest to QEMU's standard output. console does not take any
           options.

           console is only available on Windows hosts.

       -chardev serial ,id=id ,path=path
           Send traffic from the guest to a serial device on the host.

           serial is only available on Windows hosts.

           path specifies the name of the serial device to open.

       -chardev pty ,id=id
           Create a new pseudo-terminal on the host and connect to it. pty does not take any
           options.

           pty is not available on Windows hosts.

       -chardev stdio ,id=id [,signal=on|off]
           Connect to standard input and standard output of the qemu process.

           signal controls if signals are enabled on the terminal, that includes exiting QEMU
           with the key sequence Control-c. This option is enabled by default, use signal=off to
           disable it.

           stdio is not available on Windows hosts.

       -chardev braille ,id=id
           Connect to a local BrlAPI server. braille does not take any options.

       -chardev tty ,id=id ,path=path
           Connect to a local tty device.

           tty is only available on Linux, Sun, FreeBSD, NetBSD, OpenBSD and DragonFlyBSD hosts.

           path specifies the path to the tty. path is required.

       -chardev parport ,id=id ,path=path
           parport is only available on Linux, FreeBSD and DragonFlyBSD hosts.

           Connect to a local parallel port.

           path specifies the path to the parallel port device. path is required.

       -chardev spicevmc ,id=id ,debug=debug, name=name
           spicevmc is only available when spice support is built in.

           debug debug level for spicevmc

           name name of spice channel to connect to

           Connect to a spice virtual machine channel, such as vdiport.

       Device URL Syntax:

       In addition to using normal file images for the emulated storage devices, QEMU can also
       use networked resources such as iSCSI devices. These are specified using a special URL
       syntax.

       iSCSI
           iSCSI support allows QEMU to access iSCSI resources directly and use as images for the
           guest storage. Both disk and cdrom images are supported.

           Syntax for specifying iSCSI LUNs is "iscsi://<target-ip>[:<port>]/<target-iqn>/<lun>"

           Example (without authentication):

                   qemu -cdrom iscsi://192.0.2.1/iqn.2001-04.com.example/2 \
                   --drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1

           Example (CHAP username/password via URL):

                   qemu --drive file=iscsi://user%password@192.0.2.1/iqn.2001-04.com.example/1

           Example (CHAP username/password via environment variables):

                   LIBISCSI_CHAP_USERNAME="user" \
                   LIBISCSI_CHAP_PASSWORD="password" \
                   qemu --drive file=iscsi://192.0.2.1/iqn.2001-04.com.example/1

           iSCSI support is an optional feature of QEMU and only available when compiled and
           linked against libiscsi.

       NBD QEMU supports NBD (Network Block Devices) both using TCP protocol as well as Unix
           Domain Sockets.

           Syntax for specifying a NBD device using TCP
           "nbd:<server-ip>:<port>[:exportname=<export>]"

           Syntax for specifying a NBD device using Unix Domain Sockets
           "nbd:unix:<domain-socket>[:exportname=<export>]"

           Example for TCP

                   qemu --drive file=nbd:192.0.2.1:30000

           Example for Unix Domain Sockets

                   qemu --drive file=nbd:unix:/tmp/nbd-socket

       Sheepdog
           Sheepdog is a distributed storage system for QEMU.  QEMU supports using either local
           sheepdog devices or remote networked devices.

           Syntax for specifying a sheepdog device

               "sheepdog:<vdiname>"

               "sheepdog:<vdiname>:<snapid>"

               "sheepdog:<vdiname>:<tag>"

               "sheepdog:<host>:<port>:<vdiname>"

               "sheepdog:<host>:<port>:<vdiname>:<snapid>"

               "sheepdog:<host>:<port>:<vdiname>:<tag>"

           Example

                   qemu --drive file=sheepdog:192.0.2.1:30000:MyVirtualMachine

           See also <http://http://www.osrg.net/sheepdog/>.

       Bluetooth(R) options:

       -bt hci[...]
           Defines the function of the corresponding Bluetooth HCI.  -bt options are matched with
           the HCIs present in the chosen machine type.  For example when emulating a machine
           with only one HCI built into it, only the first "-bt hci[...]" option is valid and
           defines the HCI's logic.  The Transport Layer is decided by the machine type.
           Currently the machines "n800" and "n810" have one HCI and all other machines have
           none.

           The following three types are recognized:

           -bt hci,null
               (default) The corresponding Bluetooth HCI assumes no internal logic and will not
               respond to any HCI commands or emit events.

           -bt hci,host[:id]
               ("bluez" only) The corresponding HCI passes commands / events to / from the
               physical HCI identified by the name id (default: "hci0") on the computer running
               QEMU.  Only available on "bluez" capable systems like Linux.

           -bt hci[,vlan=n]
               Add a virtual, standard HCI that will participate in the Bluetooth scatternet n
               (default 0).  Similarly to -net VLANs, devices inside a bluetooth network n can
               only communicate with other devices in the same network (scatternet).

       -bt vhci[,vlan=n]
           (Linux-host only) Create a HCI in scatternet n (default 0) attached to the host
           bluetooth stack instead of to the emulated target.  This allows the host and target
           machines to participate in a common scatternet and communicate.  Requires the Linux
           "vhci" driver installed.  Can be used as following:

                   qemu [...OPTIONS...] -bt hci,vlan=5 -bt vhci,vlan=5

       -bt device:dev[,vlan=n]
           Emulate a bluetooth device dev and place it in network n (default 0).  QEMU can only
           emulate one type of bluetooth devices currently:

           keyboard
               Virtual wireless keyboard implementing the HIDP bluetooth profile.

       Linux/Multiboot boot specific:

       When using these options, you can use a given Linux or Multiboot kernel without installing
       it in the disk image. It can be useful for easier testing of various kernels.

       -kernel bzImage
           Use bzImage as kernel image. The kernel can be either a Linux kernel or in multiboot
           format.

       -append cmdline
           Use cmdline as kernel command line

       -initrd file
           Use file as initial ram disk.

       -initrd "file1 arg=foo,file2"
           This syntax is only available with multiboot.

           Use file1 and file2 as modules and pass arg=foo as parameter to the first module.

       Debug/Expert options:

       -serial dev
           Redirect the virtual serial port to host character device dev. The default device is
           "vc" in graphical mode and "stdio" in non graphical mode.

           This option can be used several times to simulate up to 4 serial ports.

           Use "-serial none" to disable all serial ports.

           Available character devices are:

           vc[:WxH]
               Virtual console. Optionally, a width and height can be given in pixel with

                       vc:800x600

               It is also possible to specify width or height in characters:

                       vc:80Cx24C

           pty [Linux only] Pseudo TTY (a new PTY is automatically allocated)

           none
               No device is allocated.

           null
               void device

           /dev/XXX
               [Linux only] Use host tty, e.g. /dev/ttyS0. The host serial port parameters are
               set according to the emulated ones.

           /dev/parportN
               [Linux only, parallel port only] Use host parallel port N. Currently SPP and EPP
               parallel port features can be used.

           file:filename
               Write output to filename. No character can be read.

           stdio
               [Unix only] standard input/output

           pipe:filename
               name pipe filename

           COMn
               [Windows only] Use host serial port n

           udp:[remote_host]:remote_port[@[src_ip]:src_port]
               This implements UDP Net Console.  When remote_host or src_ip are not specified
               they default to 0.0.0.0.  When not using a specified src_port a random port is
               automatically chosen.

               If you just want a simple readonly console you can use "netcat" or "nc", by
               starting qemu with: "-serial udp::4555" and nc as: "nc -u -l -p 4555". Any time
               qemu writes something to that port it will appear in the netconsole session.

               If you plan to send characters back via netconsole or you want to stop and start
               qemu a lot of times, you should have qemu use the same source port each time by
               using something like "-serial udp::4555@4556" to qemu. Another approach is to use
               a patched version of netcat which can listen to a TCP port and send and receive
               characters via udp.  If you have a patched version of netcat which activates
               telnet remote echo and single char transfer, then you can use the following
               options to step up a netcat redirector to allow telnet on port 5555 to access the
               qemu port.

               "Qemu Options:"
                   -serial udp::4555@4556

               "netcat options:"
                   -u -P 4555 -L 0.0.0.0:4556 -t -p 5555 -I -T

               "telnet options:"
                   localhost 5555

           tcp:[host]:port[,server][,nowait][,nodelay]
               The TCP Net Console has two modes of operation.  It can send the serial I/O to a
               location or wait for a connection from a location.  By default the TCP Net Console
               is sent to host at the port.  If you use the server option QEMU will wait for a
               client socket application to connect to the port before continuing, unless the
               "nowait" option was specified.  The "nodelay" option disables the Nagle buffering
               algorithm.  If host is omitted, 0.0.0.0 is assumed. Only one TCP connection at a
               time is accepted. You can use "telnet" to connect to the corresponding character
               device.

               "Example to send tcp console to 192.168.0.2 port 4444"
                   -serial tcp:192.168.0.2:4444

               "Example to listen and wait on port 4444 for connection"
                   -serial tcp::4444,server

               "Example to not wait and listen on ip 192.168.0.100 port 4444"
                   -serial tcp:192.168.0.100:4444,server,nowait

           telnet:host:port[,server][,nowait][,nodelay]
               The telnet protocol is used instead of raw tcp sockets.  The options work the same
               as if you had specified "-serial tcp".  The difference is that the port acts like
               a telnet server or client using telnet option negotiation.  This will also allow
               you to send the MAGIC_SYSRQ sequence if you use a telnet that supports sending the
               break sequence.  Typically in unix telnet you do it with Control-] and then type
               "send break" followed by pressing the enter key.

           unix:path[,server][,nowait]
               A unix domain socket is used instead of a tcp socket.  The option works the same
               as if you had specified "-serial tcp" except the unix domain socket path is used
               for connections.

           mon:dev_string
               This is a special option to allow the monitor to be multiplexed onto another
               serial port.  The monitor is accessed with key sequence of Control-a and then
               pressing c. See monitor access pcsys_keys in the -nographic section for more keys.
               dev_string should be any one of the serial devices specified above.  An example to
               multiplex the monitor onto a telnet server listening on port 4444 would be:

               "-serial mon:telnet::4444,server,nowait"
           braille
               Braille device.  This will use BrlAPI to display the braille output on a real or
               fake device.

           msmouse
               Three button serial mouse. Configure the guest to use Microsoft protocol.

       -parallel dev
           Redirect the virtual parallel port to host device dev (same devices as the serial
           port). On Linux hosts, /dev/parportN can be used to use hardware devices connected on
           the corresponding host parallel port.

           This option can be used several times to simulate up to 3 parallel ports.

           Use "-parallel none" to disable all parallel ports.

       -monitor dev
           Redirect the monitor to host device dev (same devices as the serial port).  The
           default device is "vc" in graphical mode and "stdio" in non graphical mode.

       -qmp dev
           Like -monitor but opens in 'control' mode.

       -mon chardev=[name][,mode=readline|control][,default]
           Setup monitor on chardev name.

       -debugcon dev
           Redirect the debug console to host device dev (same devices as the serial port).  The
           debug console is an I/O port which is typically port 0xe9; writing to that I/O port
           sends output to this device.  The default device is "vc" in graphical mode and "stdio"
           in non graphical mode.

       -pidfile file
           Store the QEMU process PID in file. It is useful if you launch QEMU from a script.

       -singlestep
           Run the emulation in single step mode.

       -S  Do not start CPU at startup (you must type 'c' in the monitor).

       -gdb dev
           Wait for gdb connection on device dev. Typical connections will likely be TCP-based,
           but also UDP, pseudo TTY, or even stdio are reasonable use case. The latter is
           allowing to start qemu from within gdb and establish the connection via a pipe:

                   (gdb) target remote | exec qemu -gdb stdio ...

       -s  Shorthand for -gdb tcp::1234, i.e. open a gdbserver on TCP port 1234.

       -d  Output log in /tmp/qemu.log

       -D  Output log in logfile instead of /tmp/qemu.log

       -hdachs c,h,s,[,t]
           Force hard disk 0 physical geometry (1 <= c <= 16383, 1 <= h <= 16, 1 <= s <= 63) and
           optionally force the BIOS translation mode (t=none, lba or auto). Usually QEMU can
           guess all those parameters. This option is useful for old MS-DOS disk images.

       -L  path
           Set the directory for the BIOS, VGA BIOS and keymaps.

       -bios file
           Set the filename for the BIOS.

       -enable-kvm
           Enable KVM full virtualization support. This option is only available if KVM support
           is enabled when compiling.

       -xen-domid id
           Specify xen guest domain id (XEN only).

       -xen-create
           Create domain using xen hypercalls, bypassing xend.  Warning: should not be used when
           xend is in use (XEN only).

       -xen-attach
           Attach to existing xen domain.  xend will use this when starting qemu (XEN only).

       -no-reboot
           Exit instead of rebooting.

       -no-shutdown
           Don't exit QEMU on guest shutdown, but instead only stop the emulation.  This allows
           for instance switching to monitor to commit changes to the disk image.

       -loadvm file
           Start right away with a saved state ("loadvm" in monitor)

       -daemonize
           Daemonize the QEMU process after initialization.  QEMU will not detach from standard
           IO until it is ready to receive connections on any of its devices.  This option is a
           useful way for external programs to launch QEMU without having to cope with
           initialization race conditions.

       -option-rom file
           Load the contents of file as an option ROM.  This option is useful to load things like
           EtherBoot.

       -clock method
           Force the use of the given methods for timer alarm. To see what timers are available
           use -clock ?.

       -rtc [base=utc|localtime|date][,clock=host|vm][,driftfix=none|slew]
           Specify base as "utc" or "localtime" to let the RTC start at the current UTC or local
           time, respectively. "localtime" is required for correct date in MS-DOS or Windows. To
           start at a specific point in time, provide date in the format "2006-06-17T16:01:21" or
           "2006-06-17". The default base is UTC.

           By default the RTC is driven by the host system time. This allows to use the RTC as
           accurate reference clock inside the guest, specifically if the host time is smoothly
           following an accurate external reference clock, e.g. via NTP.  If you want to isolate
           the guest time from the host, even prevent it from progressing during suspension, you
           can set clock to "vm" instead.

           Enable driftfix (i386 targets only) if you experience time drift problems,
           specifically with Windows' ACPI HAL. This option will try to figure out how many timer
           interrupts were not processed by the Windows guest and will re-inject them.

       -icount [N|auto]
           Enable virtual instruction counter.  The virtual cpu will execute one instruction
           every 2^N ns of virtual time.  If "auto" is specified then the virtual cpu speed will
           be automatically adjusted to keep virtual time within a few seconds of real time.

           Note that while this option can give deterministic behavior, it does not provide cycle
           accurate emulation.  Modern CPUs contain superscalar out of order cores with complex
           cache hierarchies.  The number of instructions executed often has little or no
           correlation with actual performance.

       -watchdog model
           Create a virtual hardware watchdog device.  Once enabled (by a guest action), the
           watchdog must be periodically polled by an agent inside the guest or else the guest
           will be restarted.

           The model is the model of hardware watchdog to emulate.  Choices for model are:
           "ib700" (iBASE 700) which is a very simple ISA watchdog with a single timer, or
           "i6300esb" (Intel 6300ESB I/O controller hub) which is a much more featureful PCI-
           based dual-timer watchdog.  Choose a model for which your guest has drivers.

           Use "-watchdog ?" to list available hardware models.  Only one watchdog can be enabled
           for a guest.

       -watchdog-action action
           The action controls what QEMU will do when the watchdog timer expires.  The default is
           "reset" (forcefully reset the guest).  Other possible actions are: "shutdown" (attempt
           to gracefully shutdown the guest), "poweroff" (forcefully poweroff the guest), "pause"
           (pause the guest), "debug" (print a debug message and continue), or "none" (do
           nothing).

           Note that the "shutdown" action requires that the guest responds to ACPI signals,
           which it may not be able to do in the sort of situations where the watchdog would have
           expired, and thus "-watchdog-action shutdown" is not recommended for production use.

           Examples:

           "-watchdog i6300esb -watchdog-action pause"
           "-watchdog ib700"
       -echr numeric_ascii_value
           Change the escape character used for switching to the monitor when using monitor and
           serial sharing.  The default is 0x01 when using the "-nographic" option.  0x01 is
           equal to pressing "Control-a".  You can select a different character from the ascii
           control keys where 1 through 26 map to Control-a through Control-z.  For instance you
           could use the either of the following to change the escape character to Control-t.

           "-echr 0x14"
           "-echr 20"
       -virtioconsole c
           Set virtio console.

           This option is maintained for backward compatibility.

           Please use "-device virtconsole" for the new way of invocation.

       -show-cursor
           Show cursor.

       -tb-size n
           Set TB size.

       -incoming port
           Prepare for incoming migration, listen on port.

       -nodefaults
           Don't create default devices.

       -chroot dir
           Immediately before starting guest execution, chroot to the specified directory.
           Especially useful in combination with -runas.

       -runas user
           Immediately before starting guest execution, drop root privileges, switching to the
           specified user.

       -prom-env variable=value
           Set OpenBIOS nvram variable to given value (PPC, SPARC only).

       -semihosting
           Semihosting mode (ARM, M68K, Xtensa only).

       -old-param
           Old param mode (ARM only).

       -readconfig file
           Read device configuration from file.

       -writeconfig file
           Write device configuration to file.

       -nodefconfig
           Normally QEMU loads a configuration file from sysconfdir/qemu.conf and
           sysconfdir/target-ARCH.conf on startup.  The "-nodefconfig" option will prevent QEMU
           from loading these configuration files at startup.

       -trace [events=file][,file=file]
           Specify tracing options.

           events=file
               Immediately enable events listed in file.  The file must contain one event name
               (as listed in the trace-events file) per line.  This option is only available if
               QEMU has been compiled with either simple or stderr tracing backend.

           file=file
               Log output traces to file.

               This option is only available if QEMU has been compiled with the simple tracing
               backend.

       During the graphical emulation, you can use special key combinations to change modes. The
       default key mappings are shown below, but if you use "-alt-grab" then the modifier is
       Ctrl-Alt-Shift (instead of Ctrl-Alt) and if you use "-ctrl-grab" then the modifier is the
       right Ctrl key (instead of Ctrl-Alt):

       Ctrl-Alt-f
           Toggle full screen

       Ctrl-Alt-+
           Enlarge the screen

       Ctrl-Alt--
           Shrink the screen

       Ctrl-Alt-u
           Restore the screen's un-scaled dimensions

       Ctrl-Alt-n
           Switch to virtual console 'n'. Standard console mappings are:

           1   Target system display

           2   Monitor

           3   Serial port

       Ctrl-Alt
           Toggle mouse and keyboard grab.

       In the virtual consoles, you can use Ctrl-Up, Ctrl-Down, Ctrl-PageUp and Ctrl-PageDown to
       move in the back log.

       During emulation, if you are using the -nographic option, use Ctrl-a h to get terminal
       commands:

       Ctrl-a h
       Ctrl-a ?
           Print this help

       Ctrl-a x
           Exit emulator

       Ctrl-a s
           Save disk data back to file (if -snapshot)

       Ctrl-a t
           Toggle console timestamps

       Ctrl-a b
           Send break (magic sysrq in Linux)

       Ctrl-a c
           Switch between console and monitor

       Ctrl-a Ctrl-a
           Send Ctrl-a

       The following options are specific to the PowerPC emulation:

       -g WxH[xDEPTH]
           Set the initial VGA graphic mode. The default is 800x600x15.

       -prom-env string
           Set OpenBIOS variables in NVRAM, for example:

                   qemu-system-ppc -prom-env 'auto-boot?=false' \
                    -prom-env 'boot-device=hd:2,\yaboot' \
                    -prom-env 'boot-args=conf=hd:2,\yaboot.conf'

           These variables are not used by Open Hack'Ware.

       The following options are specific to the Sparc32 emulation:

       -g WxHx[xDEPTH]
           Set the initial TCX graphic mode. The default is 1024x768x8, currently the only other
           possible mode is 1024x768x24.

       -prom-env string
           Set OpenBIOS variables in NVRAM, for example:

                   qemu-system-sparc -prom-env 'auto-boot?=false' \
                    -prom-env 'boot-device=sd(0,2,0):d' -prom-env 'boot-args=linux single'

       -M [SS-4|SS-5|SS-10|SS-20|SS-600MP|LX|Voyager|SPARCClassic]
       [|SPARCbook|SS-2|SS-1000|SS-2000]
           Set the emulated machine type. Default is SS-5.

       The following options are specific to the Sparc64 emulation:

       -prom-env string
           Set OpenBIOS variables in NVRAM, for example:

                   qemu-system-sparc64 -prom-env 'auto-boot?=false'

       -M [sun4u|sun4v|Niagara]
           Set the emulated machine type. The default is sun4u.

SEE ALSO

       The HTML documentation of QEMU for more precise information and Linux user mode emulator
       invocation.

AUTHOR

       Fabrice Bellard

                                            2012-04-12                                    QEMU(1)