vhost: correctly check the iova range when waking virtqueue

BugLink: https://bugs.launchpad.net/bugs/1835972
[ Upstream commit 2d66f997f0545c8f7fc5cf0b49af1decb35170e7 ]

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>
Reviewed-by: Peter Xu <peterx@redhat.com>
Tested-by: Peter Xu <peterx@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 746cf40070590351f0bb4106dcd6b4ab7e5a76e8..17ffdeba25229731dc04c10fdcb0451de0b2e6fe 100644 (file)
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -961,7 +961,7 @@ 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);