2018-02-09 2:12 GMT+08:00 Eduardo Habkost <ehabkost@xxxxxxxxxx>: > On Thu, Feb 08, 2018 at 05:44:20PM +0800, Wanpeng Li wrote: >> From: Wanpeng Li <wanpengli@xxxxxxxxxxx> >> >> Add PV_DEDICATED hint cpuid feature bit. >> > [...] >> diff --git a/target/i386/cpu.c b/target/i386/cpu.c >> index d70954b..cf48931 100644 >> --- a/target/i386/cpu.c >> +++ b/target/i386/cpu.c >> @@ -4076,6 +4076,9 @@ static int x86_cpu_filter_features(X86CPU *cpu) >> x86_cpu_get_supported_feature_word(w, false); >> uint32_t requested_features = env->features[w]; >> env->features[w] &= host_feat; >> + if (cpu->pv_dedicated && (w == FEAT_KVM)) { >> + env->features[w] |= CPUID_PV_DEDICATED; >> + } > > Why do this trick here instead of just adding "pv-dedicated" to > feature_word_info[FEAT_KVM].feat_names? Actually this hint doesn't depend on KVM, just qemu command-line gives a hint and then guest kernel can recognize it. Is there a nicer proposal in qemu? Paolo? Regards, Wanpeng Li