[libvirt] [RFC 4/5] target-i386: Introduce X86CPU.filtered_features field
This field will contain the feature bits that were filtered out because
of missing host support.
Signed-off-by: Eduardo Habkost <ehabkost(a)redhat.com>
---
target-i386/cpu-qom.h | 3 +++
target-i386/cpu.c | 9 ++++++---
2 files changed, 9 insertions(+), 3 deletions(-)
diff --git a/target-i386/cpu-qom.h b/target-i386/cpu-qom.h
index 08f9eb6..159378f 100644
--- a/target-i386/cpu-qom.h
+++ b/target-i386/cpu-qom.h
@@ -65,6 +65,9 @@ typedef struct X86CPU {
/*< public >*/
CPUX86State env;
+
+ /* Features that were filtered out because of missing host capabilities */
+ uint32_t filtered_features[FEATURE_WORDS];
} X86CPU;
static inline X86CPU *x86_env_get_cpu(CPUX86State *env)
diff --git a/target-i386/cpu.c b/target-i386/cpu.c
index 3f4bcfd..64e5570 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -1641,9 +1641,12 @@ static void filter_features_for_kvm(X86CPU *cpu)
for (w = 0; w < FEATURE_WORDS; w++) {
FeatureWordInfo *wi = &feature_word_info[w];
- env->features[w] &= kvm_arch_get_supported_cpuid(s, wi->cpuid_eax,
- wi->cpuid_ecx,
- wi->cpuid_reg);
+ uint32_t host_feat = kvm_arch_get_supported_cpuid(s, wi->cpuid_eax,
+ wi->cpuid_ecx,
+ wi->cpuid_reg);
+ uint32_t requested_features = env->features[w];
+ env->features[w] &= host_feat;
+ cpu->filtered_features[w] = requested_features & ~env->features[w];
}
}
#endif
--
1.8.1.4