[PATCH v2 4/6] target/i386: Add support for AVX-VNNI-INT8 in CPUID enumeration

[Tao Su <tao1.su@linux.intel.com>]

From: Jiaxi Chen <jiaxi.chen@linux.intel.com>

AVX-VNNI-INT8 is a new set of instructions in the latest Intel platform
Sierra Forest, aims for the platform to have superior AI capabilities.
This instruction multiplies the individual bytes of two unsigned or
unsigned source operands, then adds and accumulates the results into the
destination dword element size operand.

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

AVX-VNNI-INT8 is on a new feature bits leaf. Add a CPUID feature word
FEAT_7_1_EDX for this leaf.

Add CPUID definition for AVX-VNNI-INT8.

Signed-off-by: Jiaxi Chen <jiaxi.chen@linux.intel.com>
Signed-off-by: Tao Su <tao1.su@linux.intel.com>
---
 target/i386/cpu.c | 22 +++++++++++++++++++++-
 target/i386/cpu.h |  4 ++++
 2 files changed, 25 insertions(+), 1 deletion(-)

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 9aaa373e97..246d10aa49 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -664,6 +664,7 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
 #define TCG_7_0_EDX_FEATURES CPUID_7_0_EDX_FSRM
 #define TCG_7_1_EAX_FEATURES (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | \
           CPUID_7_1_EAX_FSRC)
+#define TCG_7_1_EDX_FEATURES 0
 #define TCG_APM_FEATURES 0
 #define TCG_6_EAX_FEATURES CPUID_6_EAX_ARAT
 #define TCG_XSAVE_FEATURES (CPUID_XSAVE_XSAVEOPT | CPUID_XSAVE_XGETBV1)
@@ -887,6 +888,25 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         },
         .tcg_features = TCG_7_1_EAX_FEATURES,
     },
+    [FEAT_7_1_EDX] = {
+        .type = CPUID_FEATURE_WORD,
+        .feat_names = {
+            NULL, NULL, NULL, NULL,
+            "avx-vnni-int8", NULL, NULL, NULL,
+            NULL, NULL, NULL, NULL,
+            NULL, NULL, NULL, NULL,
+            NULL, NULL, NULL, NULL,
+            NULL, NULL, NULL, NULL,
+            NULL, NULL, NULL, NULL,
+            NULL, NULL, NULL, NULL,
+        },
+        .cpuid = {
+            .eax = 7,
+            .needs_ecx = true, .ecx = 1,
+            .reg = R_EDX,
+        },
+        .tcg_features = TCG_7_1_EDX_FEATURES,
+    },
     [FEAT_8000_0007_EDX] = {
         .type = CPUID_FEATURE_WORD,
         .feat_names = {
@@ -5516,9 +5536,9 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             }
         } else if (count == 1) {
             *eax = env->features[FEAT_7_1_EAX];
+            *edx = env->features[FEAT_7_1_EDX];
             *ebx = 0;
             *ecx = 0;
-            *edx = 0;
         } else {
             *eax = 0;
             *ebx = 0;
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 8e50617efb..d53b960f23 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -623,6 +623,7 @@ typedef enum FeatureWord {
     FEAT_SGX_12_1_EAX,  /* CPUID[EAX=0x12,ECX=1].EAX (SGX ATTRIBUTES[31:0]) */
     FEAT_XSAVE_XSS_LO,     /* CPUID[EAX=0xd,ECX=1].ECX */
     FEAT_XSAVE_XSS_HI,     /* CPUID[EAX=0xd,ECX=1].EDX */
+    FEAT_7_1_EDX,       /* CPUID[EAX=7,ECX=1].EDX */
     FEATURE_WORDS,
 } FeatureWord;
 
@@ -917,6 +918,9 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
 /* Support for VPMADD52[H,L]UQ */
 #define CPUID_7_1_EAX_AVX_IFMA          (1U << 23)
 
+/* Support for VPDPB[SU,UU,SS]D[,S] */
+#define CPUID_7_1_EDX_AVX_VNNI_INT8     (1U << 4)
+
 /* XFD Extend Feature Disabled */
 #define CPUID_D_1_EAX_XFD               (1U << 4)
 
-- 
2.34.1