* [PATCH net] virtio-net: set queues after driver_ok
@ 2023-08-09 3:13 Jason Wang
2023-08-09 6:22 ` Dragos Tatulea
2023-08-09 6:40 ` Michael S. Tsirkin
0 siblings, 2 replies; 6+ messages in thread
From: Jason Wang @ 2023-08-09 3:13 UTC (permalink / raw)
To: mst, jasowang, xuanzhuo
Cc: davem, edumazet, kuba, pabeni, virtualization, netdev,
Dragos Tatulea
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@nvidia.com>
Signed-off-by: Jason Wang <jasowang@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
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH net] virtio-net: set queues after driver_ok
2023-08-09 3:13 [PATCH net] virtio-net: set queues after driver_ok Jason Wang
@ 2023-08-09 6:22 ` Dragos Tatulea
2023-08-09 6:45 ` Jason Wang
2023-08-09 6:40 ` Michael S. Tsirkin
1 sibling, 1 reply; 6+ messages in thread
From: Dragos Tatulea @ 2023-08-09 6:22 UTC (permalink / raw)
To: jasowang@redhat.com, mst@redhat.com, xuanzhuo@linux.alibaba.com
Cc: virtualization@lists.linux-foundation.org, edumazet@google.com,
davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
netdev@vger.kernel.org
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@nvidia.com>
> Signed-off-by: Jason Wang <jasowang@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
Thanks 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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net] virtio-net: set queues after driver_ok
2023-08-09 3:13 [PATCH net] virtio-net: set queues after driver_ok Jason Wang
2023-08-09 6:22 ` Dragos Tatulea
@ 2023-08-09 6:40 ` Michael S. Tsirkin
1 sibling, 0 replies; 6+ messages in thread
From: Michael S. Tsirkin @ 2023-08-09 6:40 UTC (permalink / raw)
To: Jason Wang
Cc: xuanzhuo, davem, edumazet, kuba, pabeni, virtualization, netdev,
Dragos Tatulea
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@nvidia.com>
> Signed-off-by: Jason Wang <jasowang@redhat.com>
Acked-by: Michael S. Tsirkin <mst@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
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net] virtio-net: set queues after driver_ok
2023-08-09 6:22 ` Dragos Tatulea
@ 2023-08-09 6:45 ` Jason Wang
2023-08-09 6:50 ` Michael S. Tsirkin
0 siblings, 1 reply; 6+ messages in thread
From: Jason Wang @ 2023-08-09 6:45 UTC (permalink / raw)
To: Dragos Tatulea
Cc: mst@redhat.com, xuanzhuo@linux.alibaba.com,
virtualization@lists.linux-foundation.org, edumazet@google.com,
davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
netdev@vger.kernel.org
On Wed, Aug 9, 2023 at 2:23 PM Dragos Tatulea <dtatulea@nvidia.com> wrote:
>
> 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@nvidia.com>
> > Signed-off-by: Jason Wang <jasowang@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
>
> Thanks 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?
Yes, rtnl needs to be held for userspace requests to change the number
of queues. So we are serialized in this way.
Thanks
>
> Thanks,
> Dragos
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net] virtio-net: set queues after driver_ok
2023-08-09 6:45 ` Jason Wang
@ 2023-08-09 6:50 ` Michael S. Tsirkin
2023-08-10 3:11 ` Jason Wang
0 siblings, 1 reply; 6+ messages in thread
From: Michael S. Tsirkin @ 2023-08-09 6:50 UTC (permalink / raw)
To: Jason Wang
Cc: Dragos Tatulea, xuanzhuo@linux.alibaba.com,
virtualization@lists.linux-foundation.org, edumazet@google.com,
davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
netdev@vger.kernel.org
On Wed, Aug 09, 2023 at 02:45:17PM +0800, Jason Wang wrote:
> On Wed, Aug 9, 2023 at 2:23 PM Dragos Tatulea <dtatulea@nvidia.com> wrote:
> >
> > 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@nvidia.com>
> > > Signed-off-by: Jason Wang <jasowang@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
> >
> > Thanks 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?
>
> Yes, rtnl needs to be held for userspace requests to change the number
> of queues. So we are serialized in this way.
>
> Thanks
maybe post v2 adding this in the commit log.
> >
> > Thanks,
> > Dragos
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [PATCH net] virtio-net: set queues after driver_ok
2023-08-09 6:50 ` Michael S. Tsirkin
@ 2023-08-10 3:11 ` Jason Wang
0 siblings, 0 replies; 6+ messages in thread
From: Jason Wang @ 2023-08-10 3:11 UTC (permalink / raw)
To: Michael S. Tsirkin
Cc: Dragos Tatulea, xuanzhuo@linux.alibaba.com,
virtualization@lists.linux-foundation.org, edumazet@google.com,
davem@davemloft.net, kuba@kernel.org, pabeni@redhat.com,
netdev@vger.kernel.org
On Wed, Aug 9, 2023 at 2:51 PM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Wed, Aug 09, 2023 at 02:45:17PM +0800, Jason Wang wrote:
> > On Wed, Aug 9, 2023 at 2:23 PM Dragos Tatulea <dtatulea@nvidia.com> wrote:
> > >
> > > 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@nvidia.com>
> > > > Signed-off-by: Jason Wang <jasowang@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
> > >
> > > Thanks 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?
> >
> > Yes, rtnl needs to be held for userspace requests to change the number
> > of queues. So we are serialized in this way.
> >
> > Thanks
>
> maybe post v2 adding this in the commit log.
Ok, v2 will be posted soon.
Thanks
>
>
> > >
> > > Thanks,
> > > Dragos
>
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-08-10 3:11 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2023-08-09 3:13 [PATCH net] virtio-net: set queues after driver_ok Jason Wang
2023-08-09 6:22 ` Dragos Tatulea
2023-08-09 6:45 ` Jason Wang
2023-08-09 6:50 ` Michael S. Tsirkin
2023-08-10 3:11 ` Jason Wang
2023-08-09 6:40 ` Michael S. Tsirkin
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).