[PATCH net] virtio-net: set queues after driver_ok

[PATCH net] virtio-net: set queues after driver_ok

[Jason Wang]

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

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[PATCH net] virtio-net: set queues after driver_ok

[Jason Wang]

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

Re: [PATCH net] virtio-net: set queues after driver_ok

[Dragos Tatulea via Virtualization]

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
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Re: [PATCH net] virtio-net: set queues after driver_ok

[Dragos Tatulea]

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

Re: [PATCH net] virtio-net: set queues after driver_ok

[Jason Wang]

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

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Re: [PATCH net] virtio-net: set queues after driver_ok

[Jason Wang]

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

Re: [PATCH net] virtio-net: set queues after driver_ok

[Michael S. Tsirkin]

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

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Re: [PATCH net] virtio-net: set queues after driver_ok

[Michael S. Tsirkin]

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

Re: [PATCH net] virtio-net: set queues after driver_ok

[Jason Wang]

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
>

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Re: [PATCH net] virtio-net: set queues after driver_ok

[Jason Wang]

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
>

Re: [PATCH net] virtio-net: set queues after driver_ok

[Michael S. Tsirkin]

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

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Re: [PATCH net] virtio-net: set queues after driver_ok

[Michael S. Tsirkin]

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