Hi I created this kernel module that stress-tests the crypto API: https://people.redhat.com/~mpatocka/benchmarks/qat/tools/module-multithreaded.c It shows that QAT underperforms significantly compared to AES-NI (for large requests it is 10 times slower; for small requests it is even worse) - see the second table in this document: https://people.redhat.com/~mpatocka/benchmarks/qat/kernel-module.txt QAT has higher priority than AES-NI, so the kernel prefers it (it is not used for dm-crypt because it has the flag "CRYPTO_ALG_ALLOCATES_MEMORY", but it is preferred over AES-NI in other cases). AES-NI has priority 300 or 400, unaccelerated AES has 100, so I suggest to lower the priority of QAT from 4001 to 201. Signed-off-by: Mikulas Patocka <mpatocka@xxxxxxxxxx> --- drivers/crypto/intel/qat/qat_common/qat_algs.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) Index: linux-2.6/drivers/crypto/intel/qat/qat_common/qat_algs.c =================================================================== --- linux-2.6.orig/drivers/crypto/intel/qat/qat_common/qat_algs.c +++ linux-2.6/drivers/crypto/intel/qat/qat_common/qat_algs.c @@ -1277,7 +1277,7 @@ static struct aead_alg qat_aeads[] = { { .base = { .cra_name = "authenc(hmac(sha1),cbc(aes))", .cra_driver_name = "qat_aes_cbc_hmac_sha1", - .cra_priority = 4001, + .cra_priority = 201, .cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct qat_alg_aead_ctx), @@ -1294,7 +1294,7 @@ static struct aead_alg qat_aeads[] = { { .base = { .cra_name = "authenc(hmac(sha256),cbc(aes))", .cra_driver_name = "qat_aes_cbc_hmac_sha256", - .cra_priority = 4001, + .cra_priority = 201, .cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct qat_alg_aead_ctx), @@ -1311,7 +1311,7 @@ static struct aead_alg qat_aeads[] = { { .base = { .cra_name = "authenc(hmac(sha512),cbc(aes))", .cra_driver_name = "qat_aes_cbc_hmac_sha512", - .cra_priority = 4001, + .cra_priority = 201, .cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY, .cra_blocksize = AES_BLOCK_SIZE, .cra_ctxsize = sizeof(struct qat_alg_aead_ctx), @@ -1329,7 +1329,7 @@ static struct aead_alg qat_aeads[] = { { static struct skcipher_alg qat_skciphers[] = { { .base.cra_name = "cbc(aes)", .base.cra_driver_name = "qat_aes_cbc", - .base.cra_priority = 4001, + .base.cra_priority = 201, .base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY, .base.cra_blocksize = AES_BLOCK_SIZE, .base.cra_ctxsize = sizeof(struct qat_alg_skcipher_ctx), @@ -1347,7 +1347,7 @@ static struct skcipher_alg qat_skciphers }, { .base.cra_name = "ctr(aes)", .base.cra_driver_name = "qat_aes_ctr", - .base.cra_priority = 4001, + .base.cra_priority = 201, .base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_ALLOCATES_MEMORY, .base.cra_blocksize = 1, .base.cra_ctxsize = sizeof(struct qat_alg_skcipher_ctx), @@ -1365,7 +1365,7 @@ static struct skcipher_alg qat_skciphers }, { .base.cra_name = "xts(aes)", .base.cra_driver_name = "qat_aes_xts", - .base.cra_priority = 4001, + .base.cra_priority = 201, .base.cra_flags = CRYPTO_ALG_ASYNC | CRYPTO_ALG_NEED_FALLBACK | CRYPTO_ALG_ALLOCATES_MEMORY, .base.cra_blocksize = AES_BLOCK_SIZE,