On Fri, Sep 04, 2020 at 04:54:31PM +0200, Vitaly Kuznetsov wrote: > To make Hyper-V features appear in e.g. QMP query-cpu-model-expansion we > need to expand and set the corresponding CPUID leaves early. Modify > x86_cpu_get_supported_feature_word() to call newly intoduced Hyper-V > specific kvm_hv_get_supported_cpuid() instead of > kvm_arch_get_supported_cpuid(). We can't use kvm_arch_get_supported_cpuid() > as Hyper-V specific CPUID leaves intersect with KVM's. > > Note, early expansion will only happen when KVM supports system wide > KVM_GET_SUPPORTED_HV_CPUID ioctl (KVM_CAP_SYS_HYPERV_CPUID). > > Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com> > --- [...] > +uint32_t kvm_hv_get_supported_cpuid(X86CPU *cpu, enum FeatureWord w) > +{ > + CPUState *cs = CPU(cpu); > + CPUX86State *env = &cpu->env; > + Error *local_err = NULL; > + > + hyperv_expand_features(cs, &local_err);
This makes a function that sounds like it doesn't have any side effect ("get supported cpuid") have an unintended side effect (hyperv_expand_features() will change all CPUID data inside the cpu object). What about making it more similar to kvm_arch_get_supported_cpuid(), and be just a wrapper to get_supported_hv_cpuid()? I would also make sure get_supported_hv_cpuid() doesn't get CPUState as argument, just to be sure it will never touch the CPU object state. > + > + if (local_err) { > + error_report_err(local_err); > + } > + > + return env->features[w]; > +} > + > static Error *hv_passthrough_mig_blocker; > static Error *hv_no_nonarch_cs_mig_blocker; > > diff --git a/target/i386/kvm_i386.h b/target/i386/kvm_i386.h > index 064b8798a26c..2e7da4f39668 100644 > --- a/target/i386/kvm_i386.h > +++ b/target/i386/kvm_i386.h > @@ -48,4 +48,11 @@ bool kvm_has_waitpkg(void); > > bool kvm_hv_vpindex_settable(void); > > +static inline bool hyperv_feature_word(enum FeatureWord w) > +{ > + return w >= FEAT_HYPERV_EAX && w <= FEAT_HV_NESTED_EDX; > +} > + > +uint32_t kvm_hv_get_supported_cpuid(X86CPU *cpu, enum FeatureWord w); > + > #endif > -- > 2.25.4 > -- Eduardo