Since AVIC does not currently work w/ nested virtualization, disable AVIC for the guest if setting CPUID Fn80000001_ECX[SVM] (i.e. indicate support for SVM, which is needed for nested virtualization).
Suggested-by: Alexander Graf <g...@amazon.com> Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpa...@amd.com> --- arch/x86/kvm/svm.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c index a01bc6a..e02ee1a 100644 --- a/arch/x86/kvm/svm.c +++ b/arch/x86/kvm/svm.c @@ -6029,6 +6029,16 @@ static void svm_cpuid_update(struct kvm_vcpu *vcpu) return; guest_cpuid_clear(vcpu, X86_FEATURE_X2APIC); + + /* + * Currently, AVIC does not work with nested virtualization. + * So, we disable AVIC when cpuid for SVM is set in the L1 guest. + */ + if (nested && guest_cpuid_has(vcpu, X86_FEATURE_SVM)) { + vcpu->srcu_idx = srcu_read_lock(&vcpu->kvm->srcu); + kvm_make_apicv_deactivate_request(vcpu, true); + srcu_read_unlock(&vcpu->kvm->srcu, vcpu->srcu_idx); + } } static void svm_set_supported_cpuid(u32 func, struct kvm_cpuid_entry2 *entry) -- 1.8.3.1