vhost: correctly check the iova range when waking virtqueue

We don't wakeup the virtqueue if the first byte of pending iova range
is the last byte of the range we just got updated. This will lead a
virtqueue to wait for IOTLB updating forever. Fixing by correct the
check and wake up the virtqueue in this case.

Fixes: 6b1e6cc7 ("vhost: new device IOTLB API")
Reported-by: NPeter Xu <peterx@redhat.com>
Signed-off-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NPeter Xu <peterx@redhat.com>
Tested-by: NPeter Xu <peterx@redhat.com>
Acked-by: NMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/vhost/vhost.c

@@ -952,7 +952,7 @@ static void vhost_iotlb_notify_vq(struct vhost_dev *d,
 	list_for_each_entry_safe(node, n, &d->pending_list, node) {
 		struct vhost_iotlb_msg *vq_msg = &node->msg.iotlb;
 		if (msg->iova <= vq_msg->iova &&
-		    msg->iova + msg->size - 1 > vq_msg->iova &&
+		    msg->iova + msg->size - 1 >= vq_msg->iova &&
 		    vq_msg->type == VHOST_IOTLB_MISS) {
 			vhost_poll_queue(&node->vq->poll);
 			list_del(&node->node);