Re: [PATCH crypto] x86/aesni: don't require alignment of data

[Ard Biesheuvel <ardb@kernel.org>]

On Tue, 21 Dec 2021 at 16:06, Jakub Kicinski <kuba@kernel.org> wrote:
>
> x86 AES-NI routines can deal with unaligned data. Crypto context
> (key, iv etc.) have to be aligned but we take care of that separately
> by copying it onto the stack. We were feeding unaligned data into
> crypto routines up until commit 83c83e658863 ("crypto: aesni -
> refactor scatterlist processing") switched to use the full
> skcipher API which uses cra_alignmask to decide data alignment.
>
> This fixes 21% performance regression in kTLS.
>
> Tested by booting with CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y
> (and running thru various kTLS packets).
>
> CC: stable@vger.kernel.org # 5.15+
> Fixes: 83c83e658863 ("crypto: aesni - refactor scatterlist processing")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Acked-by: Ard Biesheuvel <ardb@kernel.org>

> ---
> CC: herbert@gondor.apana.org.au
> CC: x86@kernel.org
> CC: ardb@kernel.org
> CC: linux-crypto@vger.kernel.org
> ---
>  arch/x86/crypto/aesni-intel_glue.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
> index e09f4672dd38..41901ba9d3a2 100644
> --- a/arch/x86/crypto/aesni-intel_glue.c
> +++ b/arch/x86/crypto/aesni-intel_glue.c
> @@ -1107,7 +1107,7 @@ static struct aead_alg aesni_aeads[] = { {
>                 .cra_flags              = CRYPTO_ALG_INTERNAL,
>                 .cra_blocksize          = 1,
>                 .cra_ctxsize            = sizeof(struct aesni_rfc4106_gcm_ctx),
> -               .cra_alignmask          = AESNI_ALIGN - 1,
> +               .cra_alignmask          = 0,
>                 .cra_module             = THIS_MODULE,
>         },
>  }, {
> @@ -1124,7 +1124,7 @@ static struct aead_alg aesni_aeads[] = { {
>                 .cra_flags              = CRYPTO_ALG_INTERNAL,
>                 .cra_blocksize          = 1,
>                 .cra_ctxsize            = sizeof(struct generic_gcmaes_ctx),
> -               .cra_alignmask          = AESNI_ALIGN - 1,
> +               .cra_alignmask          = 0,
>                 .cra_module             = THIS_MODULE,
>         },
>  } };
> --
> 2.31.1
>