[PATCH v2 4/6] crypto: x86/aes-xts - wire up VAES + AVX2 implementation

Eric Biggers
2024-03-29T08:06:01Z

From: Eric Biggers <ebiggers@google.com>

Add an AES-XTS implementation "xts-aes-vaes-avx2" for x86_64 CPUs with
the VAES, VPCLMULQDQ, and AVX2 extensions, but not AVX512 or AVX10.
This implementation uses ymm registers to operate on two AES blocks at a
time. The assembly code is instantiated using a macro so that most of
the source code is shared with other implementations.

This is the optimal implementation on AMD Zen 3. It should also be the
optimal implementation on Intel Alder Lake, which similarly supports
VAES but not AVX512. Comparing to xts-aes-aesni-avx on Zen 3,
xts-aes-vaes-avx2 provides 70% higher AES-256-XTS decryption throughput
with 4096-byte messages, or 23% higher with 512-byte messages.

A large improvement is also seen with CPUs that do support AVX512 (e.g.,
98% higher AES-256-XTS decryption throughput on Ice Lake with 4096-byte
messages), though the following patches add AVX512 optimized
implementations to get a bit more performance on those CPUs.

Signed-off-by: Eric Biggers <ebiggers@google.com>
---
arch/x86/crypto/aes-xts-avx-x86_64.S | 11 +++++++++++
arch/x86/crypto/aesni-intel_glue.c | 20 ++++++++++++++++++++
2 files changed, 31 insertions(+)

diff --git a/arch/x86/crypto/aes-xts-avx-x86_64.S b/arch/x86/crypto/aes-xts-avx-x86_64.S
index 32e26f562cf0..43706213dfca 100644
--- a/arch/x86/crypto/aes-xts-avx-x86_64.S
+++ b/arch/x86/crypto/aes-xts-avx-x86_64.S
@@ -805,5 +805,16 @@ SYM_TYPED_FUNC_START(aes_xts_encrypt_aesni_avx)
_aes_xts_crypt 1
SYM_FUNC_END(aes_xts_encrypt_aesni_avx)
SYM_TYPED_FUNC_START(aes_xts_decrypt_aesni_avx)
_aes_xts_crypt 0
SYM_FUNC_END(aes_xts_decrypt_aesni_avx)
+
+#if defined(CONFIG_AS_VAES) && defined(CONFIG_AS_VPCLMULQDQ)
+.set VL, 32
+.set USE_AVX10, 0
+SYM_TYPED_FUNC_START(aes_xts_encrypt_vaes_avx2)
+ _aes_xts_crypt 1
+SYM_FUNC_END(aes_xts_encrypt_vaes_avx2)
+SYM_TYPED_FUNC_START(aes_xts_decrypt_vaes_avx2)
+ _aes_xts_crypt 0
+SYM_FUNC_END(aes_xts_decrypt_vaes_avx2)
+#endif /* CONFIG_AS_VAES && CONFIG_AS_VPCLMULQDQ */
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c
index 10e283721a85..4cc15c7207f3 100644
--- a/arch/x86/crypto/aesni-intel_glue.c
+++ b/arch/x86/crypto/aesni-intel_glue.c
@@ -1295,10 +1295,13 @@ static struct skcipher_alg aes_xts_alg_##suffix = { \
}; \
\
static struct simd_skcipher_alg *aes_xts_simdalg_##suffix

DEFINE_XTS_ALG(aesni_avx, "xts-aes-aesni-avx", 500);
+#if defined(CONFIG_AS_VAES) && defined(CONFIG_AS_VPCLMULQDQ)
+DEFINE_XTS_ALG(vaes_avx2, "xts-aes-vaes-avx2", 600);
+#endif

static int __init register_xts_algs(void)
{
int err;

@@ -1306,18 +1309,35 @@ static int __init register_xts_algs(void)
return 0;
err = simd_register_skciphers_compat(&aes_xts_alg_aesni_avx, 1,
&aes_xts_simdalg_aesni_avx);
if (err)
return err;
+#if defined(CONFIG_AS_VAES) && defined(CONFIG_AS_VPCLMULQDQ)
+ if (!boot_cpu_has(X86_FEATURE_AVX2) ||
+ !boot_cpu_has(X86_FEATURE_VAES) ||
+ !boot_cpu_has(X86_FEATURE_VPCLMULQDQ) ||
+ !boot_cpu_has(X86_FEATURE_PCLMULQDQ) ||
+ !cpu_has_xfeatures(XFEATURE_MASK_SSE | XFEATURE_MASK_YMM, NULL))
+ return 0;
+ err = simd_register_skciphers_compat(&aes_xts_alg_vaes_avx2, 1,
+ &aes_xts_simdalg_vaes_avx2);
+ if (err)
+ return err;
+#endif /* CONFIG_AS_VAES && CONFIG_AS_VPCLMULQDQ */
return 0;
}

static void unregister_xts_algs(void)
{
if (aes_xts_simdalg_aesni_avx)
simd_unregister_skciphers(&aes_xts_alg_aesni_avx, 1,
&aes_xts_simdalg_aesni_avx);
+#if defined(CONFIG_AS_VAES) && defined(CONFIG_AS_VPCLMULQDQ)
+ if (aes_xts_simdalg_vaes_avx2)
+ simd_unregister_skciphers(&aes_xts_alg_vaes_avx2, 1,
+ &aes_xts_simdalg_vaes_avx2);
+#endif
}
#else /* CONFIG_X86_64 */
static int __init register_xts_algs(void)
{
return 0;
--
2.44.0