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(). Fixes: 25266128fe16 ("virtio-net: fix race between set queues and probe") Reported-by: Dragos Tatulea <dtatulea at nvidia.com> Signed-off-by: Jason Wang <jasowang at redhat.com> --- The patch is needed for -stable. --- 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 1270c8d23463..ff03921e46df 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -4219,8 +4219,6 @@ 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(); @@ -4233,6 +4231,8 @@ static int virtnet_probe(struct virtio_device *vdev) virtio_device_ready(vdev); + _virtnet_set_queues(vi, vi->curr_queue_pairs); + /* a random MAC address has been assigned, notify the device. * We don't fail probe if VIRTIO_NET_F_CTRL_MAC_ADDR is not there * because many devices work fine without getting MAC explicitly -- 2.39.3
On Tue, 2023-08-08 at 23:13 -0400, Jason Wang wrote:> 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(). > > Fixes: 25266128fe16 ("virtio-net: fix race between set queues and probe") > Reported-by: Dragos Tatulea <dtatulea at nvidia.com> > Signed-off-by: Jason Wang <jasowang at redhat.com> > --- > The patch is needed for -stable. > --- > ?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 1270c8d23463..ff03921e46df 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -4219,8 +4219,6 @@ 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(); > ? > @@ -4233,6 +4231,8 @@ static int virtnet_probe(struct virtio_device *vdev) > ? > ????????virtio_device_ready(vdev); > ? > +???????_virtnet_set_queues(vi, vi->curr_queue_pairs); > + > ????????/* a random MAC address has been assigned, notify the device. > ???????? * We don't fail probe if VIRTIO_NET_F_CTRL_MAC_ADDR is not there > ???????? * because many devices work fine without getting MAC explicitlyThanks for the quick fix. Doesn't this fix though bring back the original race that was fixed in commit 25266128fe16 ("virtio-net: fix race between set queues and probe")? Or is being under the same rntl_lock session as register_netdev enough to avoid the race? Thanks, Dragos
Michael S. Tsirkin
2023-Aug-09 06:40 UTC
[PATCH net] virtio-net: set queues after driver_ok
On Tue, Aug 08, 2023 at 11:13:29PM -0400, Jason Wang wrote:> 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(). > > Fixes: 25266128fe16 ("virtio-net: fix race between set queues and probe") > Reported-by: Dragos Tatulea <dtatulea at nvidia.com> > Signed-off-by: Jason Wang <jasowang at redhat.com>Acked-by: Michael S. Tsirkin <mst at redhat.com>> --- > The patch is needed for -stable. > --- > 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 1270c8d23463..ff03921e46df 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -4219,8 +4219,6 @@ 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(); > > @@ -4233,6 +4231,8 @@ static int virtnet_probe(struct virtio_device *vdev) > > virtio_device_ready(vdev); > > + _virtnet_set_queues(vi, vi->curr_queue_pairs); > + > /* a random MAC address has been assigned, notify the device. > * We don't fail probe if VIRTIO_NET_F_CTRL_MAC_ADDR is not there > * because many devices work fine without getting MAC explicitly > -- > 2.39.3