i386/cpu: Set and track CPUID_EXT3_CMP_LEG in env->features[FEAT_8000_0001_ECX]

The correct usage is tracking and maintaining features in env->features[]
instead of manually set it in cpu_x86_cpuid().

Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
Link: https://lore.kernel.org/r/20241219110125.1266461-11-xiaoyao.li@intel.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

target/i386/cpu.c

@@ -6953,17 +6953,6 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count,
         *ecx = env->features[FEAT_8000_0001_ECX];
         *edx = env->features[FEAT_8000_0001_EDX];
 
-        /* The Linux kernel checks for the CMPLegacy bit and
-         * discards multiple thread information if it is set.
-         * So don't set it here for Intel to make Linux guests happy.
-         */
-        if (threads_per_pkg > 1) {
-            if (env->cpuid_vendor1 != CPUID_VENDOR_INTEL_1 ||
-                env->cpuid_vendor2 != CPUID_VENDOR_INTEL_2 ||
-                env->cpuid_vendor3 != CPUID_VENDOR_INTEL_3) {
-                *ecx |= 1 << 1;    /* CmpLegacy bit */
-            }
-        }
         if (tcg_enabled() && env->cpuid_vendor1 == CPUID_VENDOR_INTEL_1 &&
             !(env->hflags & HF_LMA_MASK)) {
             *edx &= ~CPUID_EXT2_SYSCALL;
@@ -7530,6 +7519,15 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
 
     if (x86_threads_per_pkg(&env->topo_info) > 1) {
         env->features[FEAT_1_EDX] |= CPUID_HT;
+
+        /*
+         * The Linux kernel checks for the CMPLegacy bit and
+         * discards multiple thread information if it is set.
+         * So don't set it here for Intel to make Linux guests happy.
+         */
+        if (!IS_INTEL_CPU(env)) {
+            env->features[FEAT_8000_0001_ECX] |= CPUID_EXT3_CMP_LEG;
+        }
     }
 
     for (i = 0; i < ARRAY_SIZE(feature_dependencies); i++) {