5.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Jason Wang <jasowang@xxxxxxxxxx>
commit 51b813176f098ff61bd2833f627f5319ead098a5 upstream.
Commit 25266128fe16 ("virtio-net: fix race between set queues and
probe") tries to fix the race between set queues and probe by calling
_virtnet_set_queues() before DRIVER_OK is set. This violates virtio
spec. Fixing this by setting queues after virtio_device_ready().
Note that rtnl needs to be held for userspace requests to change the
number of queues. So we are serialized in this way.
Fixes: 25266128fe16 ("virtio-net: fix race between set queues and probe")
Reported-by: Dragos Tatulea <dtatulea@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/virtio_net.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3265,8 +3265,6 @@ static int virtnet_probe(struct virtio_d
}
}
- _virtnet_set_queues(vi, vi->curr_queue_pairs);
-
/* serialize netdev register + virtio_device_ready() with ndo_open() */
rtnl_lock();
@@ -3279,6 +3277,8 @@ static int virtnet_probe(struct virtio_d
virtio_device_ready(vdev);
+ _virtnet_set_queues(vi, vi->curr_queue_pairs);
+
rtnl_unlock();
err = virtnet_cpu_notif_add(vi);
