On Mon, 2020-05-04 at 15:46 +0700, Suravee Suthikulpanit wrote: > Paolo / Maxim, > > On 5/2/20 11:42 PM, Paolo Bonzini wrote: > > On 02/05/20 15:58, Maxim Levitsky wrote: > > > The AVIC is disabled by svm_toggle_avic_for_irq_window, which calls > > > kvm_request_apicv_update, which broadcasts the KVM_REQ_APICV_UPDATE vcpu request, > > > however it doesn't broadcast it to CPU on which now we are running, which seems OK, > > > because the code that handles that broadcast runs on each VCPU entry, thus > > > when this CPU will enter guest mode it will notice and disable the AVIC. > > > > > > However later in svm_enable_vintr, there is test 'WARN_ON(kvm_vcpu_apicv_active(&svm->vcpu));' > > > which is still true on current CPU because of the above. > > > > Good point! We can just remove the WARN_ON I think. Can you send a patch? > > Instead, as an alternative to remove the WARN_ON(), would it be better to just explicitly > calling kvm_vcpu_update_apicv(vcpu) to update the apicv_active flag right after > kvm_request_apicv_update()? > > Thanks, > Suravee > This should work IMHO, other that the fact kvm_vcpu_update_apicv will be called again, when this vcpu is entered since the KVM_REQ_APICV_UPDATE will still be pending on it. It shoudn't be a problem, and we can even add a check to do nothing when it is called while avic is already in target enable state. Best regards, Maxim Levitsky
