kvm: don't try to register to KVM_FAST_MMIO_BUS for non mmio eventfd

We only want zero length mmio eventfd to be registered on KVM_FAST_MMIO_BUS. So check this explicitly when arg->len is zero to make sure this. Cc: [email protected] Cc: Gleb Natapov <[email protected]> Cc: Paolo Bonzini <[email protected]> Signed-off-by: Jason Wang <[email protected]> Reviewed-by: Cornelia Huck <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
iegor · Sep 15, 2015 · 8453fec · 8453fec
1 parent 81523aa
commit 8453fec
Showing 1 changed file with 2 additions and 2 deletions.
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
@@ -846,7 +846,7 @@ kvm_assign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 	/* When length is ignored, MMIO is also put on a separate bus, for
 	 * faster lookups.
 	 */
-	if (!args->len && !(args->flags & KVM_IOEVENTFD_FLAG_PIO)) {
+	if (!args->len && bus_idx == KVM_MMIO_BUS) {
 		ret = kvm_io_bus_register_dev(kvm, KVM_FAST_MMIO_BUS,
 					      p->addr, 0, &p->dev);
 		if (ret < 0)
@@ -901,7 +901,7 @@ kvm_deassign_ioeventfd(struct kvm *kvm, struct kvm_ioeventfd *args)
 			continue;
 
 		kvm_io_bus_unregister_dev(kvm, bus_idx, &p->dev);
-		if (!p->length) {
+		if (!p->length && p->bus_idx == KVM_MMIO_BUS) {
 			kvm_io_bus_unregister_dev(kvm, KVM_FAST_MMIO_BUS,
 						  &p->dev);
 		}