diff --git a/include/kvm/virtio.h b/include/kvm/virtio.h
index c6c380d..cd24285 100644
--- a/include/kvm/virtio.h
+++ b/include/kvm/virtio.h
@@ -38,6 +38,8 @@ static inline bool virt_queue__available(struct virt_queue *vq)
 {
 	if (!vq->vring.avail)
 		return 0;
+
+	vring_avail_event(&vq->vring) = vq->last_avail_idx;
 	return vq->vring.avail->idx !=  vq->last_avail_idx;
 }
 
@@ -51,6 +53,11 @@ static inline void *guest_pfn_to_host(struct kvm *kvm, u32 pfn)
 	return guest_flat_to_host(kvm, (unsigned long)pfn << VIRTIO_PCI_QUEUE_ADDR_SHIFT);
 }
 
+static inline int virtio_queue__should_signal(struct virt_queue *vq)
+{
+	return vring_used_event(&vq->vring) <= vq->vring.used->idx;
+}
+
 struct vring_used_elem *virt_queue__set_used_elem(struct virt_queue *queue, u32 head, u32 len);
 
 u16 virt_queue__get_iov(struct virt_queue *queue, struct iovec iov[], u16 *out, u16 *in, struct kvm *kvm);