Paolo, On 1/30/19 11:22 PM, Paolo Bonzini wrote: > On 29/01/19 09:09, Suthikulpanit, Suravee wrote: >> The function svm_refresh_apicv_exec_ctrl() always returning prematurely >> as kvm_vcpu_apicv_active() always return false when calling from >> the function arch/x86/kvm/x86.c:kvm_vcpu_deactivate_apicv(). >> This is because the apicv_active is set to false just before calling >> refresh_apicv_exec_ctrl(). >> >> Also, we need to mark VMCB_AVIC bit as dirty instead of VMCB_INTR. >> >> So, fix svm_refresh_apicv_exec_ctrl() to properly deactivate AVIC. >> >> Fixes: 67034bb9dd5e ('KVM: SVM: Add irqchip_split() checks before enabling AVIC') > > Having the lapic_in_kernel check in your code is a bit ugly - the caller > should check it. And actually, even though it doesn't check it right > now, svm_refresh_apicv_exec_ctrl is only reachable if lapic_in_kernel > returns true; see the KVM_CAP_HYPERV_SYNIC case of > kvm_vcpu_ioctl_enable_cap. > > What about this simpler patch: > > diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c > index 01b66bbcdd7a..74ceda470eae 100644 > --- a/arch/x86/kvm/svm.c > +++ b/arch/x86/kvm/svm.c > @@ -5122,11 +5122,11 @@ static void svm_refresh_apicv_exec_ctrl( > struct vcpu_svm *svm = to_svm(vcpu); > struct vmcb *vmcb = svm->vmcb; > > - if (!kvm_vcpu_apicv_active(&svm->vcpu)) > - return; > - > - vmcb->control.int_ctl &= ~AVIC_ENABLE_MASK; > - mark_dirty(vmcb, VMCB_INTR); > + if (kvm_vcpu_apicv_active(vcpu)) > + vmcb->control.int_ctl |= AVIC_ENABLE_MASK; > + else > + vmcb->control.int_ctl &= ~AVIC_ENABLE_MASK; > + mark_dirty(vmcb, VMCB_AVIC); > } > > static void svm_load_eoi_exitmap(struct kvm_vcpu *vcpu, u64 > *eoi_exit_bitmap) > > ? > > Thanks, > > Paolo > Yes, this would work. This patch is actually a precursor of a patch series that I am working on to allow AVIC enabling/disabling during run-time. I will send out a series for RFC soon. Thanks, Suravee