2 files changed, 20 insertions, 0 deletions

diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index f01392f51e86..a2edfd177faf 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -100,6 +100,19 @@ static int ioapic_service(struct kvm_ioapic *ioapic, unsigned int idx)
         return injected;
 }
 
+static void update_handled_vectors(struct kvm_ioapic *ioapic)
+{
+        DECLARE_BITMAP(handled_vectors, 256);
+        int i;
+
+        memset(handled_vectors, 0, sizeof(handled_vectors));
+        for (i = 0; i < IOAPIC_NUM_PINS; ++i)
+                __set_bit(ioapic->redirtbl[i].fields.vector, handled_vectors);
+        memcpy(ioapic->handled_vectors, handled_vectors,
+               sizeof(handled_vectors));
+        smp_wmb();
+}
+
 static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
 {
         unsigned index;
@@ -134,6 +147,7 @@ static void ioapic_write_indirect(struct kvm_ioapic *ioapic, u32 val)
                         e->bits |= (u32) val;
                         e->fields.remote_irr = 0;
                 }
+                update_handled_vectors(ioapic);
                 mask_after = e->fields.mask;
                 if (mask_before != mask_after)
                         kvm_fire_mask_notifiers(ioapic->kvm, index, mask_after);
@@ -241,6 +255,9 @@ void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
 {
         struct kvm_ioapic *ioapic = kvm->arch.vioapic;
 
+        smp_rmb();
+        if (!test_bit(vector, ioapic->handled_vectors))
+                return;
         mutex_lock(&ioapic->lock);
         __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
         mutex_unlock(&ioapic->lock);
@@ -352,6 +369,7 @@ void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
         ioapic->ioregsel = 0;
         ioapic->irr = 0;
         ioapic->id = 0;
+        update_handled_vectors(ioapic);
 }
 
 static const struct kvm_io_device_ops ioapic_mmio_ops = {
@@ -401,6 +419,7 @@ int kvm_set_ioapic(struct kvm *kvm, struct kvm_ioapic_state *state)
 
         mutex_lock(&ioapic->lock);
         memcpy(ioapic, state, sizeof(struct kvm_ioapic_state));
+        update_handled_vectors(ioapic);
         mutex_unlock(&ioapic->lock);
         return 0;
 }
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 419c43b667ab..a505ce9054f3 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -46,6 +46,7 @@ struct kvm_ioapic {
         struct kvm *kvm;
         void (*ack_notifier)(void *opaque, int irq);
         struct mutex lock;
+        DECLARE_BITMAP(handled_vectors, 256);
 };
 
 #ifdef DEBUG