[PATCH net] vhost: correctly check the iova range when waking virtqueue

From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com
Cc: kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
	netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
	peterx@redhat.com
Subject: [PATCH net] vhost: correctly check the iova range when waking virtqueue
Date: Fri, 24 Aug 2018 16:53:13 +0800	[thread overview]
Message-ID: <20180824085313.21798-1-jasowang@redhat.com> (raw)

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: 6b1e6cc7855b ("vhost: new device IOTLB API")
Reported-by: Peter Xu <peterx@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
---
The patch is needed for -stable.
---
 drivers/vhost/vhost.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 96c1d8400822..b13c6b4b2c66 100644
--- a/drivers/vhost/vhost.c
+++ b/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);
-- 
2.17.1

