From: Shih-Wei Li <shihwei@xxxxxxxxxxxxxxx> In cases like IPI, we could be queueing an interrupt for a VCPU that is already running and is not about to exit, because the VCPU has entered the VM with the interrupt pending and would not trap on EOI'ing that interrupt. This could result to delays in interrupt deliveries or even loss of interrupts. To guarantee prompt interrupt injection, here we have to try to kick the VCPU. Signed-off-by: Shih-Wei Li <shihwei@xxxxxxxxxxxxxxx> Reviewed-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- virt/kvm/arm/vgic/vgic.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/virt/kvm/arm/vgic/vgic.c b/virt/kvm/arm/vgic/vgic.c index 2893d5ba523a..6440b56ec90e 100644 --- a/virt/kvm/arm/vgic/vgic.c +++ b/virt/kvm/arm/vgic/vgic.c @@ -273,6 +273,18 @@ bool vgic_queue_irq_unlock(struct kvm *kvm, struct vgic_irq *irq) * no more work for us to do. */ spin_unlock(&irq->irq_lock); + + /* + * We have to kick the VCPU here, because we could be + * queueing an edge-triggered interrupt for which we + * get no EOI maintenance interrupt. In that case, + * while the IRQ is already on the VCPU's AP list, the + * VCPU could have EOI'ed the original interrupt and + * won't see this one until it exits for some other + * reason. + */ + if (vcpu) + kvm_vcpu_kick(vcpu); return false; } -- 2.10.1 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
