critical_features_mask =
CPUID_CMOV | CPUID_CX8 |
CPUID_FXSR | CPUID_MMX | CPUID_SSE |
- CPUID_SSE2;
+ CPUID_SSE2 | CPUID_SEP;
if (!is_cpuid_supported()) {
features = 0;
} else {
cpuid(1, eax, ebx, ecx, edx);
features = edx;
}
+#ifdef __x86_64__
+ /* NOTE: on x86_64 CPUs, SYSENTER is not supported in
+ compatibility mode, so in order to have the best performances
+ it is better not to use it */
+ features &= ~CPUID_SEP;
+#endif
env->cpuid_features = (env->cpuid_features & ~critical_features_mask) |
(features & critical_features_mask);
/* XXX: we could update more of the target CPUID state so that the