kvm: Simplify invtsc check

Instead of searching the table we have just built, we can check
the env->features field directly.
Reviewed-by: NMarcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>
Message-Id: <20170108173234.25721-2-ehabkost@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

target/i386/kvm.c

@@ -963,8 +963,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
         has_msr_mcg_ext_ctl = has_msr_feature_control = true;
     }
 
-    c = cpuid_find_entry(&cpuid_data.cpuid, 0x80000007, 0);
-    if (c && (c->edx & 1<<8) && invtsc_mig_blocker == NULL) {
+    if ((env->features[FEAT_8000_0007_EDX] & CPUID_APM_INVTSC) &&
+        invtsc_mig_blocker == NULL) {
         /* for migration */
         error_setg(&invtsc_mig_blocker,
                    "State blocked by non-migratable CPU device"