i386/cpu: Expose AVX_VNNI instruction to guest

Expose AVX (VEX-encoded) versions of the Vector Neural Network
Instructions to guest.

The bit definition:
CPUID.(EAX=7,ECX=1):EAX[bit 4] AVX_VNNI

The following instructions are available when this feature is
present in the guest.
  1. VPDPBUS: Multiply and Add Unsigned and Signed Bytes
  2. VPDPBUSDS: Multiply and Add Unsigned and Signed Bytes with Saturation
  3. VPDPWSSD: Multiply and Add Signed Word Integers
  4. VPDPWSSDS: Multiply and Add Signed Integers with Saturation

As for the kvm related code, please reference Linux commit id 1085a6b585d7.

The release document ref below link:
https://software.intel.com/content/www/us/en/develop/download/\
intel-architecture-instruction-set-extensions-programming-reference.html

Signed-off-by: Yang Zhong <yang.zhong@intel.com>
Message-Id: <20210407015609.22936-1-yang.zhong@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Yang Zhong 2021-04-07 09:56:09 +08:00 committed by Paolo Bonzini
parent cfa1f4bcee
commit c1826ea6a0
2 changed files with 4 additions and 2 deletions

View File

@ -940,7 +940,7 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
.type = CPUID_FEATURE_WORD,
.feat_names = {
NULL, NULL, NULL, NULL,
NULL, "avx512-bf16", NULL, NULL,
"avx-vnni", "avx512-bf16", NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
NULL, NULL, NULL, NULL,
@ -3194,7 +3194,7 @@ static X86CPUDefinition builtin_x86_defs[] = {
MSR_ARCH_CAP_SKIP_L1DFL_VMENTRY | MSR_ARCH_CAP_MDS_NO |
MSR_ARCH_CAP_PSCHANGE_MC_NO | MSR_ARCH_CAP_TAA_NO,
.features[FEAT_7_1_EAX] =
CPUID_7_1_EAX_AVX512_BF16,
CPUID_7_1_EAX_AVX_VNNI | CPUID_7_1_EAX_AVX512_BF16,
/*
* Missing: XSAVES (not supported by some Linux versions,
* including v4.1 to v4.12).

View File

@ -817,6 +817,8 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS];
/* Speculative Store Bypass Disable */
#define CPUID_7_0_EDX_SPEC_CTRL_SSBD (1U << 31)
/* AVX VNNI Instruction */
#define CPUID_7_1_EAX_AVX_VNNI (1U << 4)
/* AVX512 BFloat16 Instruction */
#define CPUID_7_1_EAX_AVX512_BF16 (1U << 5)