KVM can return the host microcode revision as a feature MSR. Use it as the default value for -cpu host.
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> Message-Id: <1579544504-3616-4-git-send-email-pbonz...@redhat.com> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com> --- target/i386/cpu.c | 4 ++++ target/i386/kvm.c | 5 +++++ 2 files changed, 9 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 790254e..ffe5de0 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6416,6 +6416,10 @@ static void x86_cpu_realizefn(DeviceState *dev, Error **errp) &cpu->mwait.ecx, &cpu->mwait.edx); env->features[FEAT_1_ECX] |= CPUID_EXT_MONITOR; } + if (kvm_enabled() && cpu->ucode_rev == 0) { + cpu->ucode_rev = kvm_arch_get_supported_msr_feature(kvm_state, + MSR_IA32_UCODE_REV); + } } if (cpu->ucode_rev == 0) { diff --git a/target/i386/kvm.c b/target/i386/kvm.c index f6dd6b7..1b67090 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -2696,6 +2696,11 @@ static void kvm_init_msrs(X86CPU *cpu) env->features[FEAT_CORE_CAPABILITY]); } + if (kvm_arch_get_supported_msr_feature(kvm_state, + MSR_IA32_UCODE_REV)) { + kvm_msr_entry_add(cpu, MSR_IA32_UCODE_REV, cpu->ucode_rev); + } + /* * Older kernels do not include VMX MSRs in KVM_GET_MSR_INDEX_LIST, but * all kernels with MSR features should have them. -- 1.8.3.1