On Tue, Jul 25, 2023 at 3:53 PM Michael S. Tsirkin [off-list ref] wrote:

On Tue, Jul 25, 2023 at 03:20:49AM -0400, Jason Wang wrote:

quoted

A race were found where set_channels could be called after registering
but before virtnet_set_queues() in virtnet_probe(). Fixing this by
moving the virtnet_set_queues() before netdevice registering. While at
it, use _virtnet_set_queues() to avoid holding rtnl as the device is
not even registered at that time.

Fixes: a220871be66f ("virtio-net: correctly enable multiqueue")
Signed-off-by: Jason Wang <jasowang@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

stable material I guess?

Yes it is.

Thanks

quoted

---
 drivers/net/virtio_net.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0db14f6b87d3..1270c8d23463 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c

@@ -4219,6 +4219,8 @@ static int virtnet_probe(struct virtio_device *vdev)
      if (vi->has_rss || vi->has_rss_hash_report)
              virtnet_init_default_rss(vi);

+     _virtnet_set_queues(vi, vi->curr_queue_pairs);
+
      /* serialize netdev register + virtio_device_ready() with ndo_open() */
      rtnl_lock();

@@ -4257,8 +4259,6 @@ static int virtnet_probe(struct virtio_device *vdev)
              goto free_unregister_netdev;
      }

-     virtnet_set_queues(vi, vi->curr_queue_pairs);
-
      /* Assume link up if device can't report link status,
         otherwise get link status from config. */
      netif_carrier_off(dev);
--

2.39.3