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SubjectRe: [PATCH] svm: Fix AVIC incomplete IPI emulation
Date
Oren,

On 3/11/19 6:38 PM, Suthikulpanit, Suravee wrote:
> However, looking a bit more closely, I notice the logic in svm_deliver_avic_intr()
> should also have been changed from kvm_vcpu_wake_up() to kvm_vcpu_kick()
> since the latter will result in clearing the IRR bit for the IPI vector
> when trying to send IPI as part of the following call path.
>
> vcpu_enter_guest()
> |-- inject_pending_event()
> |-- kvm_cpu_get_interrupt()
> |-- kvm_get_apic_interrupt()
> |-- apic_clear_irr()
> |-- apic_set_isr()
> |-- apic_update_ppr() ....
>
> Please see the patch below.
>
> Not sure if this would address the problem you are seeing.
>
> Thanks,
> Suravee
>
> diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
> index 24dfa6a93711..d2841c3dbc04 100644
> --- a/arch/x86/kvm/svm.c
> +++ b/arch/x86/kvm/svm.c
> @@ -5219,11 +5256,13 @@ static void svm_deliver_avic_intr(struct kvm_vcpu *vcpu, int vec)
> kvm_lapic_set_irr(vec, vcpu->arch.apic);
> smp_mb__after_atomic();
>
> - if (avic_vcpu_is_running(vcpu))
> + if (avic_vcpu_is_running(vcpu)) {
> wrmsrl(SVM_AVIC_DOORBELL,
> kvm_cpu_get_apicid(vcpu->cpu));
> - else
> - kvm_vcpu_wake_up(vcpu);
> + } else {
> + kvm_make_request(KVM_REQ_EVENT, vcpu);
> + kvm_vcpu_kick(vcpu);
> + }
> }
>
> static void svm_ir_list_del(struct vcpu_svm *svm, struct amd_iommu_pi_data *pi)

Please ignore the part mentioned above. The current implementation should already be fine.

Suravee
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