vhost: correctly check the iova range when waking virtqueue

[ Upstream commit 2d66f99 ]

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: 6b1e6cc ("vhost: new device IOTLB API")
Reported-by: Peter Xu <[email protected]>
Signed-off-by: Jason Wang <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Tested-by: Peter Xu <[email protected]>
Acked-by: Michael S. Tsirkin <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: jasowang

drivers/vhost/vhost.c

@@ -960,7 +960,7 @@ 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);