[v1,2/3] target/i386: Add a new CPU feature word for CPUID.7.1.ECX

Commit Message

Xin Li (Intel) Jan. 3, 2025, 8:48 a.m. UTC

The immediate form of MSR access instructions will use this new CPU
feature word.

Signed-off-by: Xin Li (Intel) <[e-mail]>
---
 target/i386/cpu.c | 23 ++++++++++++++++++++++-
 target/i386/cpu.h |  1 +
 2 files changed, 23 insertions(+), 1 deletion(-)

Patch

diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 8a1223acb3..2fb05879c3 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -894,6 +894,7 @@  void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1,
 
 #define TCG_7_1_EAX_FEATURES (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | \
           CPUID_7_1_EAX_FSRC | CPUID_7_1_EAX_CMPCCXADD)
+#define TCG_7_1_ECX_FEATURES 0
 #define TCG_7_1_EDX_FEATURES 0
 #define TCG_7_2_EDX_FEATURES 0
 #define TCG_APM_FEATURES 0
@@ -1133,6 +1134,25 @@  FeatureWordInfo feature_word_info[FEATURE_WORDS] = {
         },
         .tcg_features = TCG_7_1_EAX_FEATURES,
     },
+    [FEAT_7_1_ECX] = {
+        .type = CPUID_FEATURE_WORD,
+        .feat_names = {
+            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, NULL,
+            NULL, NULL, NULL, NULL,
+        },
+        .cpuid = {
+            .eax = 7,
+            .needs_ecx = true, .ecx = 1,
+            .reg = R_ECX,
+        },
+        .tcg_features = TCG_7_1_ECX_FEATURES,
+    },
     [FEAT_7_1_EDX] = {
         .type = CPUID_FEATURE_WORD,
         .feat_names = {
@@ -6659,9 +6679,9 @@  void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
             *edx = env->features[FEAT_7_0_EDX]; /* Feature flags */
         } else if (count == 1) {
             *eax = env->features[FEAT_7_1_EAX];
+            *ecx = env->features[FEAT_7_1_ECX];
             *edx = env->features[FEAT_7_1_EDX];
             *ebx = 0;
-            *ecx = 0;
         } else if (count == 2) {
             *edx = env->features[FEAT_7_2_EDX];
             *eax = 0;
@@ -7563,6 +7583,7 @@  void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
         x86_cpu_adjust_feat_level(cpu, FEAT_6_EAX);
         x86_cpu_adjust_feat_level(cpu, FEAT_7_0_ECX);
         x86_cpu_adjust_feat_level(cpu, FEAT_7_1_EAX);
+        x86_cpu_adjust_feat_level(cpu, FEAT_7_1_ECX);
         x86_cpu_adjust_feat_level(cpu, FEAT_7_1_EDX);
         x86_cpu_adjust_feat_level(cpu, FEAT_7_2_EDX);
         x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_EDX);
diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index dbd8f1ffc7..d23fa96549 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -667,6 +667,7 @@  typedef enum FeatureWord {
     FEAT_7_1_EDX,       /* CPUID[EAX=7,ECX=1].EDX */
     FEAT_7_2_EDX,       /* CPUID[EAX=7,ECX=2].EDX */
     FEAT_24_0_EBX,      /* CPUID[EAX=0x24,ECX=0].EBX */
+    FEAT_7_1_ECX,       /* CPUID[EAX=7,ECX=1].ECX */
     FEATURE_WORDS,
 } FeatureWord;