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>

3 files changed, 34 insertions, 0 deletions

diff --git a/arch/x86/kvm/irq.c b/arch/x86/kvm/irq.c
index 0d9e55275af1..90911958d853 100644
--- a/arch/x86/kvm/irq.c
+++ b/arch/x86/kvm/irq.c
@@ -111,3 +111,25 @@ void kvm_set_irq(struct kvm *kvm, int irq, int level)
         kvm_ioapic_set_irq(kvm->arch.vioapic, irq, level);
         kvm_pic_set_irq(pic_irqchip(kvm), irq, level);
 }
+
+void kvm_notify_acked_irq(struct kvm *kvm, unsigned gsi)
+{
+        struct kvm_irq_ack_notifier *kian;
+        struct hlist_node *n;
+
+        hlist_for_each_entry(kian, n, &kvm->arch.irq_ack_notifier_list, link)
+                if (kian->gsi == gsi)
+                        kian->irq_acked(kian);
+}
+
+void kvm_register_irq_ack_notifier(struct kvm *kvm,
+                                   struct kvm_irq_ack_notifier *kian)
+{
+        hlist_add_head(&kian->link, &kvm->arch.irq_ack_notifier_list);
+}
+
+void kvm_unregister_irq_ack_notifier(struct kvm *kvm,
+                                     struct kvm_irq_ack_notifier *kian)
+{
+        hlist_del(&kian->link);
+}
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 07ff2aef0c13..95fe718e3abc 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -83,6 +83,11 @@ static inline int irqchip_in_kernel(struct kvm *kvm)
 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);
diff --git a/include/asm-x86/kvm_host.h b/include/asm-x86/kvm_host.h
index 83afa10c77f5..d451928fc841 100644
--- a/include/asm-x86/kvm_host.h
+++ b/include/asm-x86/kvm_host.h
@@ -321,6 +321,12 @@ struct kvm_mem_alias {
         gfn_t target_gfn;
 };
 
+struct kvm_irq_ack_notifier {
+        struct hlist_node link;
+        unsigned gsi;
+        void (*irq_acked)(struct kvm_irq_ack_notifier *kian);
+};
+
 struct kvm_arch{
         int naliases;
         struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS];
@@ -336,6 +342,7 @@ struct kvm_arch{
         struct kvm_pic *vpic;
         struct kvm_ioapic *vioapic;
         struct kvm_pit *vpit;
+        struct hlist_head irq_ack_notifier_list;
 
         int round_robin_prev_vcpu;
         unsigned int tss_addr;