The microcode version should be set just once, since it is essentially a CPU feature; so do it on vCPU creation rather than reset. Userspace can tie the fix to the availability of MSR_IA32_UCODE_REV in the list of emulated MSRs. Reported-by: Alex Williamson <alex.williamson@xxxxxxxxxx> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx> --- arch/x86/kvm/svm.c | 2 +- arch/x86/kvm/vmx/vmx.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a7e63b613837..280f6d024e84 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -2185,7 +2185,6 @@ static void svm_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) u32 dummy; u32 eax = 1; - vcpu->arch.microcode_version = 0x01000065; svm->spec_ctrl = 0; svm->virt_spec_ctrl = 0; @@ -2276,6 +2275,7 @@ static int svm_create_vcpu(struct kvm_vcpu *vcpu) init_vmcb(svm); svm_init_osvw(vcpu); + vcpu->arch.microcode_version = 0x01000065; return 0; diff --git a/arch/x86/kvm/vmx/vmx.c b/arch/x86/kvm/vmx/vmx.c index 9a6664886f2e..d625b4b0e7b4 100644 --- a/arch/x86/kvm/vmx/vmx.c +++ b/arch/x86/kvm/vmx/vmx.c @@ -4238,7 +4238,6 @@ static void vmx_vcpu_reset(struct kvm_vcpu *vcpu, bool init_event) vmx->msr_ia32_umwait_control = 0; - vcpu->arch.microcode_version = 0x100000000ULL; vmx->vcpu.arch.regs[VCPU_REGS_RDX] = get_rdx_init_val(); vmx->hv_deadline_tsc = -1; kvm_set_cr8(vcpu, 0); @@ -6763,6 +6762,7 @@ static int vmx_create_vcpu(struct kvm_vcpu *vcpu) vmx->nested.posted_intr_nv = -1; vmx->nested.current_vmptr = -1ull; + vcpu->arch.microcode_version = 0x100000000ULL; vmx->msr_ia32_feature_control_valid_bits = FEAT_CTL_LOCKED; /* -- 1.8.3.1