5.4-stable review patch. If anyone has any objections, please let me know.
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From: Jason Wang jasowang@redhat.com
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@nvidia.com Acked-by: Michael S. Tsirkin mst@redhat.com Signed-off-by: Jason Wang jasowang@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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);