KVM: Add irq ack notifier list

This can be used by kvm subsystems that are interested in when
interrupts are acked, for example time drift compensation.

Signed-off-by: Avi Kivity <avi@qumranet.com>
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 07ff2ae..95fe718 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -83,6 +83,11 @@
 void kvm_pic_reset(struct kvm_kpic_state *s);
 
 void kvm_set_irq(struct kvm *kvm, int irq, int level);
+void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi);
+void kvm_register_irq_ack_notifier(struct kvm *kvm,
+				   struct kvm_irq_ack_notifier *kian);
+void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
+				     struct kvm_irq_ack_notifier *kian);
 
 void kvm_timer_intr_post(struct kvm_vcpu *vcpu, int vec);
 void kvm_inject_pending_timer_irqs(struct kvm_vcpu *vcpu);