Commit c61fa9d6 authored by Jan Kiszka's avatar Jan Kiszka Committed by Avi Kivity
Browse files

KVM: Avoid needless registrations of IRQ ack notifier for assigned devices 



We only perform work in kvm_assigned_dev_ack_irq if the guest IRQ is of
INTx type. This completely avoids the callback invocation in non-INTx
cases by registering the IRQ ack notifier only for INTx.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarMarcelo Tosatti <mtosatti@redhat.com>
parent 9f9f6b78

virt/kvm/assigned-dev.c

+8 −10
Original line number Diff line number Diff line
@@ -86,12 +86,8 @@ static irqreturn_t kvm_assigned_dev_thread(int irq, void *dev_id) 
/* Ack the irq line for an assigned device */

static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)

{

	struct kvm_assigned_dev_kernel *dev;



	if (kian->gsi == -1)

		return;



	dev = container_of(kian, struct kvm_assigned_dev_kernel,

	struct kvm_assigned_dev_kernel *dev =

		container_of(kian, struct kvm_assigned_dev_kernel,

			     ack_notifier);



	kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
@@ -110,8 +106,9 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian) 
static void deassign_guest_irq(struct kvm *kvm,

			       struct kvm_assigned_dev_kernel *assigned_dev)

{

	kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);

	assigned_dev->ack_notifier.gsi = -1;

	if (assigned_dev->ack_notifier.gsi != -1)

		kvm_unregister_irq_ack_notifier(kvm,

						&assigned_dev->ack_notifier);



	kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,

		    assigned_dev->guest_irq, 0);
@@ -404,6 +401,7 @@ static int assign_guest_irq(struct kvm *kvm, 


	if (!r) {

		dev->irq_requested_type |= guest_irq_type;

		if (dev->ack_notifier.gsi != -1)

			kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);

	} else

		kvm_free_irq_source_id(kvm, dev->irq_source_id);