This allows modifying the bits in "-cpu max"/"-cpu host" depending on
the guest CPU vendor (which, at least by default, is the host vendor in
the case of KVM).

For example, machine check architecture differs between Intel and AMD,
and bits from AMD should be dropped when configuring the guest for
an Intel model.

Cc: Xiaoyao Li <xiaoyao.li@intel.com>
Cc: John Allen <john.allen@amd.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 target/i386/cpu.h         |  3 +--
 target/i386/cpu.c         | 11 +++++------
 target/i386/kvm/kvm-cpu.c |  2 +-
 3 files changed, 7 insertions(+), 9 deletions(-)

diff --git a/target/i386/cpu.h b/target/i386/cpu.h
index 29daf370485..9bea7142bf4 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -666,8 +666,7 @@ typedef enum FeatureWord {
 } FeatureWord;
 
 typedef uint64_t FeatureWordArray[FEATURE_WORDS];
-uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
-                                            bool migratable_only);
+uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w);
 
 /* cpuid_features bits */
 #define CPUID_FP87 (1U << 0)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 4c2e6f3a71e..4364cb0f8e3 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -6035,8 +6035,7 @@ CpuDefinitionInfoList *qmp_query_cpu_definitions(Error **errp)
 
 #endif /* !CONFIG_USER_ONLY */
 
-uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
-                                            bool migratable_only)
+uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w)
 {
     FeatureWordInfo *wi = &feature_word_info[w];
     uint64_t r = 0;
@@ -6078,7 +6077,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w,
         r &= ~unavail;
     }
 #endif
-    if (migratable_only) {
+    if (cpu && cpu->migratable) {
         r &= x86_cpu_get_migratable_flags(w);
     }
     return r;
@@ -7371,7 +7370,7 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp)
              * by the user.
              */
             env->features[w] |=
-                x86_cpu_get_supported_feature_word(w, cpu->migratable) &
+                x86_cpu_get_supported_feature_word(cpu, w) &
                 ~env->user_features[w] &
                 ~feature_word_info[w].no_autoenable_flags;
         }
@@ -7497,7 +7496,7 @@ static void x86_cpu_filter_features(X86CPU *cpu, bool verbose)
 
     for (w = 0; w < FEATURE_WORDS; w++) {
         uint64_t host_feat =
-            x86_cpu_get_supported_feature_word(w, false);
+            x86_cpu_get_supported_feature_word(NULL, w);
         uint64_t requested_features = env->features[w];
         uint64_t unavailable_features = requested_features & ~host_feat;
         mark_unavailable_features(cpu, w, unavailable_features, prefix);
@@ -7617,7 +7616,7 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp)
         env->features[FEAT_PERF_CAPABILITIES] & PERF_CAP_LBR_FMT;
     if (requested_lbr_fmt && kvm_enabled()) {
         uint64_t host_perf_cap =
-            x86_cpu_get_supported_feature_word(FEAT_PERF_CAPABILITIES, false);
+            x86_cpu_get_supported_feature_word(NULL, FEAT_PERF_CAPABILITIES);
         unsigned host_lbr_fmt = host_perf_cap & PERF_CAP_LBR_FMT;
 
         if (!cpu->enable_pmu) {
diff --git a/target/i386/kvm/kvm-cpu.c b/target/i386/kvm/kvm-cpu.c
index d57a68a301e..6bf8dcfc607 100644
--- a/target/i386/kvm/kvm-cpu.c
+++ b/target/i386/kvm/kvm-cpu.c
@@ -143,7 +143,7 @@ static void kvm_cpu_xsave_init(void)
         if (!esa->size) {
             continue;
         }
-        if ((x86_cpu_get_supported_feature_word(esa->feature, false) & esa->bits)
+        if ((x86_cpu_get_supported_feature_word(NULL, esa->feature) & esa->bits)
             != esa->bits) {
             continue;
         }
-- 
2.45.2