Provided by: libibverbs-dev_42.0-1_amd64 
NAME
mlx5dv_wr_set_mkey_crypto - Configure a MKey for crypto operation.
SYNOPSIS
#include <infiniband/mlx5dv.h>
static inline void
mlx5dv_wr_set_mkey_crypto(struct mlx5dv_qp_ex *mqp,
const struct mlx5dv_crypto_attr *attr);
DESCRIPTION
Configure a MKey with crypto properties. With this, the device will encrypt/decrypt data
when transmitting data from memory to network and when receiving data from network to
memory.
In order to configure MKey with crypto properties, the MKey should be created with
MLX5DV_MKEY_INIT_ATTR_FLAGS_CRYPTO. MKey that was created with
MLX5DV_MKEY_INIT_ATTR_FLAGS_CRYPTO must have crypto properties configured to it before it
can be used, i.e. this setter must be called before the MKey can be used or else traffic
will fail, generating a CQE with error. A call to this setter on a MKey that already has
crypto properties configured to it will override existing crypto properties.
Configuring crypto properties to a MKey is done by specifying the crypto standard that
should be used and its attributes, and also by providing the Data Encryption Key (DEK) to
be used for the encryption/decryption itself.
The MKey represents a virtually contiguous memory, by configuring a layout to it. The
crypto properties of the MKey describe whether data in this virtually contiguous memory is
encrypted or in plaintext, and whether it should be encrypted/decrypted before
transmitting it or after receiving it. Depending on the actual operation that happens (TX
or RX), the device will do the “right thing” based on the crypto properties configured in
the MKey.
MKeys can be configured with both crypto and signature properties at the same time by
calling both mlx5dv_wr_set_mkey_crypto()(3) and mlx5dv_wr_set_mkey_sig_block()(3). In
this case, both crypto and signature operations will be performed according to the crypto
and signature properties configured in the MKey, and the order of operations will be
determined by the signature_crypto_order property.
Example 1 (corresponds to row F in the table below):
Memory signature domain is not configured, and memory data is encrypted.
Wire signature domain is not configured, and wire data is in plaintext.
encrypt_on_tx is set to false, and because signature is not configured,
signature_crypto_order value doesn’t matter.
A SEND is issued using the MKey as a local key.
Result: device will gather the encrypted data from the MKey (using whatever layout
configured to the MKey to locate the actual memory), decrypt it using the supplied DEK and
transmit the decrypted data to the wire.
Example 1.1:
Same as above, but a RECV is issued with the same MKey, and RX happens.
Result: device will receive the data from the wire, encrypt it using the supplied DEK and
scatter it to the MKey (using whatever layout configured to the MKey to locate the actual
memory).
Example 2 (corresponds to row C in the table below):
Memory signature domain is configured for no signature, and memory data is in plaintext.
Wire signature domain is configured for T10DIF every 512 Bytes block, and wire data
(including the T10DIF) is encrypted.
encrypt_on_tx is set to true and signature_crypto_order is set to be
MLX5DV_SIGNATURE_CRYPTO_ORDER_SIGNATURE_BEFORE_CRYPTO_ON_TX. data_unit_size is set to
MLX5DV_BLOCK_SIZE_520.
The MKey is sent to a remote node that issues a RDMA_READ to this MKey.
Result: device will gather the data from the MKey (using whatever layout configured to the
MKey to locate the actual memory), generate an additional T10DIF field every 512B of data,
encrypt the data and the newly generated T10DIF field using the supplied DEK, and transmit
it to the wire.
Example 2.1:
Same as above, but remote node issues a RDMA_WRITE to this MKey.
Result: device will receive the data from the wire, decrypt the data using the supplied
DEK, validate each T10DIF field against the previous 512B of data, strip the T10DIF field,
and scatter the data alone to the MKey (using whatever layout configured to the MKey to
locate the actual memory).
ARGUMENTS
mqp The QP where an MKey configuration work request was created by
mlx5dv_wr_mkey_configure().
attr Crypto attributes to set for the MKey.
Crypto Attributes
Crypto attributes describe the format (encrypted or plaintext) and layout of the input and
output data in memory and wire domains, the crypto standard that should be used and its
attributes.
struct mlx5dv_crypto_attr {
enum mlx5dv_crypto_standard crypto_standard;
bool encrypt_on_tx;
enum mlx5dv_signature_crypto_order signature_crypto_order;
enum mlx5dv_block_size data_unit_size;
char initial_tweak[16];
struct mlx5dv_dek *dek;
char keytag[8];
uint64_t comp_mask;
};
crypto_standard
The encryption standard that should be used, currently can only be the following
value
MLX5DV_CRYPTO_STANDARD_AES_XTS
The AES-XTS encryption standard defined in IEEE Std 1619-2007.
encrypt_on_tx
If set, memory data will be encrypted during TX and wire data will be decrypted
during RX. If not set, memory data will be decrypted during TX and wire data will
be encrypted during RX.
signature_crypto_order
Controls the order between crypto and signature operations (Please see detailed
table below). Relevant only if signature is configured. Can be one of the
following values
MLX5DV_SIGNATURE_CRYPTO_ORDER_SIGNATURE_AFTER_CRYPTO_ON_TX
During TX, first perform crypto operation (encrypt/decrypt based on
encrypt_on_tx) and then signature operation on memory data. During RX,
first perform signature operation and then crypto operation (encrypt/decrypt
based on encrypt_on_tx) on wire data.
MLX5DV_SIGNATURE_CRYPTO_ORDER_SIGNATURE_BEFORE_CRYPTO_ON_TX
During TX, first perform signature operation and then crypto operation
(encrypt/decrypt based on encrypt_on_tx) on memory data. During RX, first
perform crypto operation (encrypt/decrypt based on encrypt_on_tx) and then
signature operation on wire data.
Table: signature_crypto_order and encrypt_on_tx Meaning.
The table describes the possible data layouts in memory and wire domains, and the
order in which crypto and signature operations are performed according to
signature_crypto_order, encrypt_on_tx and signature configuration.
Memory column represents the data layout in the memory domain.
Wire column represents the data layout in the wire domain.
There are three possible operations that can be performed by the device on the data
when processing it from memory to wire and from wire to memory:
1. Crypto operation.
2. Signature operation in memory domain.
3. Signature operation in wire domain.
Op1, Op2 and Op3 columns represent these operations. On TX, Op1, Op2 and Op3 are
performed on memory data to produce the data layout that is specified in Wire
column. On RX, Op3, Op2 and Op1 are performed on wire data to produce the data
layout specified in Memory column. “SIG.mem” and “SIG.wire” represent the
signature operation that is performed in memory and wire domains respectively.
None means no operation is performed. The exact signature operations are
determined by the signature attributes configured by
mlx5dv_wr_set_mkey_sig_block().
encrypt_on_tx and signature_crypto_order columns represent the values that
encrypt_on_tx and signature_crypto_order should have in order to achieve such
behavior.
Memory Op1 Op2 Op3 Wire encrypt_on_tx signature_crypto_order
────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
A data Encrypt SIG.mem SIG.wire enc(data) True Doesn’t matter
on TX = none = none
B data Encrypt SIG.mem SIG.wire enc(data)+SIG True SIGNATURE_AFTER_CRYPTO_ON_TX
On TX = none = SIG
C data SIG.mem SIG.wire Encrypt enc(data+SIG) True SIGNATURE_BEFORE_CRYPTO_ON_TX
= none = SIG on TX
D data+SIG SIG.mem SIG.wire Encrypt enc(data) True SIGNATURE_BEFORE_CRYPTO_ON_TX
= SIG = none on TX
E data+SIG1 SIG.mem SIG.wire Encrypt enc(data+SIG2) True SIGNATURE_BEFORE_CRYPTO_ON_TX
= SIG1 = SIG2 on TX
F enc(data) Decrypt SIG.mem SIG.wire data False Doesn’t matter
on TX = none = none
G enc(data) Decrypt SIG.mem SIG.wire data+SIG False SIGNATURE_AFTER_CRYPTO_ON_TX
on TX = none = SIG
H enc(data+SIG) Decrypt SIG.mem SIG.wire data False SIGNATURE_AFTER_CRYPTO_ON_TX
on TX = SIG = none
I enc(data+SIG1) Decrypt SIG.mem SIG.wire data+SIG2 False SIGNATURE_AFTER_CRYPTO_ON_TX
on TX = SIG1 = SIG2
J enc(data)+SIG SIG.mem SIG.wire Decrypt data False SIGNATURE_BEFORE_CRYPTO_ON_TX
= SIG = none on TX
Notes:
• “Encrypt on TX” also means “Decrypt on RX”, and “Decrypt on TX” also means
“Encrypt on RX”.
• When signature properties are not configured in the MKey, only crypto operations
will be performed. Thus, signature_crypto_order has no meaning in this case
(rows A and F), and it can be set to either one of its values.
data_unit_size
For storage, this will normally be the storage block size. The tweak is
incremented after each data_unit_size during the encryption. can be one of enum
mlx5dv_block_size.
initial_tweak
A value to be used during encryption of each data unit. Must be supplied in little
endian. This value is incremented by the device for every data unit in the
message. For storage encryption, this will normally be the LBA of the first block
in the message, so that the increments represent the LBAs of the rest of the blocks
in the message.
dek The DEK to be used for the crypto operations. This DEK must be pre-loaded to the
device using mlx5dv_dek_create().
key_tag
A tag that verifies that the correct DEK is being used. key_tag is optional and is
valid only if the DEK was created with has_keytag set to true. If so, it must
match the key tag that was provided when the DEK was created. Supllied in
plaintext.
comp_mask
Reserved for future extension, must be 0 now.
RETURN VALUE
This function does not return a value.
In case of error, user will be notified later when completing the DV WRs chain.
NOTES
MKey must be created with MLX5DV_MKEY_INIT_ATTR_FLAGS_CRYPTO flag.
The last operation posted on the supplied QP should be mlx5dv_wr_mkey_configure(3), or one
of its related setters, and the operation must still be open (no doorbell issued).
In case of ibv_wr_complete() failure or calling to ibv_wr_abort(), the MKey may be left in
an unknown state. The next configuration of it should not assume any previous state of
the MKey, i.e. signature/crypto should be re-configured or reset, as required. For
example, assuming mlx5dv_wr_set_mkey_sig_block() and then ibv_wr_abort() were called, then
on the next configuration of the MKey, if signature is not needed, it should be reset
using MLX5DV_MKEY_CONF_FLAG_RESET_SIG_ATTR.
When configuring a MKey with AES-XTS crypto offload, and using the former for traffic
(send/receive), the amount of data to send/receive must meet one of the following
conditions for successful encryption/decryption process (per AES-XTS spec):
Let’s refer to the amount of data to send/receive as `job_size' 1.job_size %
data_unit_size == 0 2.(job_size % 16 == 0) && (job_size % data_unit_size <= data_unit_size
- 16)
For example: When data_unit_size = 512B: 1. job_size = 512B is valid (1 holds). 2.
job_size = 128B is valid (2 holds). 3. job_size = 47B is invalid (neither 1 nor 2
holds).
When data_unit_size = 520B: 1. job_size = 520B is valid (1 holds). 2. job_size = 496B
is valid (2 holds). 3. job_size = 512B is invalid (neither 1 nor 2 holds).
SEE ALSO
mlx5dv_wr_mkey_configure(3), mlx5dv_wr_set_mkey_sig_block(3), mlx5dv_create_mkey(3),
mlx5dv_destroy_mkey(3), mlx5dv_crypto_login(3), mlx5dv_crypto_login_create(3),
mlx5dv_dek_create(3)
AUTHORS
Oren Duer <oren@nvidia.com>
Avihai Horon <avihaih@nvidia.com>
Maher Sanalla <msanalla@nvidia.com>
mlx5dv_wr_set_mkey_crypto(3)