Provided by: libibverbs-dev_50.0-2ubuntu0.2_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 transmit‐
ting 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_AT‐
TR_FLAGS_CRYPTO. MKey that was created with MLX5DV_MKEY_INIT_ATTR_FLAGS_CRYPTO must have crypto proper‐
ties 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/decryp‐
tion 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 prop‐
erties 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 sig‐
nature 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_SIGNA‐
TURE_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 new‐
ly 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 (en‐
crypt/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 process‐
ing 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 respec‐
tively. 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 sig‐
nature_crypto_order should have in order to achieve such behavior.
Memory Op1 Op2 Op3 Wire en‐ signature_cryp‐
crypt_on_tx to_order
───────────────────────────────────────────────────────────────────────────────────────────────
A data Encrypt SIG.mem SIG.wire enc(da‐ True Doesn’t matter
on TX = none = none ta)
B data Encrypt SIG.mem SIG.wire enc(da‐ True SIGNATURE_AF‐
On TX = none = SIG ta)+SIG TER_CRYPTO_ON_TX
C data SIG.mem SIG.wire Encrypt enc(da‐ True SIGNATURE_BE‐
= none = SIG on TX ta+SIG) FORE_CRYPTO_ON_TX
D data+SIG SIG.mem SIG.wire Encrypt enc(da‐ True SIGNATURE_BE‐
= SIG = none on TX ta) FORE_CRYPTO_ON_TX
E da‐ SIG.mem SIG.wire Encrypt enc(da‐ True SIGNATURE_BE‐
ta+SIG1 = SIG1 = SIG2 on TX ta+SIG2) FORE_CRYPTO_ON_TX
F enc(da‐ Decrypt SIG.mem SIG.wire data False Doesn’t matter
ta) on TX = none = none
G enc(da‐ Decrypt SIG.mem SIG.wire data+SIG False SIGNATURE_AF‐
ta) on TX = none = SIG TER_CRYPTO_ON_TX
H enc(da‐ Decrypt SIG.mem SIG.wire data False SIGNATURE_AF‐
ta+SIG) on TX = SIG = none TER_CRYPTO_ON_TX
I enc(da‐ Decrypt SIG.mem SIG.wire da‐ False SIGNATURE_AF‐
ta+SIG1) on TX = SIG1 = SIG2 ta+SIG2 TER_CRYPTO_ON_TX
J enc(da‐ SIG.mem SIG.wire Decrypt data False SIGNATURE_BE‐
ta)+SIG = SIG = none on TX FORE_CRYPTO_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 per‐
formed. 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 pro‐
vided 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. signa‐
ture/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/de‐
cryption 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_de‐
stroy_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)