| Message ID | 20141020144223.5655dcbc.cornelia.huck@de.ibm.com |
|---|---|
| State | Not Applicable, archived |
| Delegated to: | David Miller |
| Headers | show |
On 10/20/14 at 02:42pm, Cornelia Huck wrote: > On Mon, 20 Oct 2014 13:07:50 +0100 > Thomas Graf <tgraf@suug.ch> wrote: > > > On 10/13/14 at 10:50am, Michael S. Tsirkin wrote: > > > virtio spec requires drivers to set DRIVER_OK before using VQs. > > > This is set automatically after probe returns, virtio console violated this > > > rule by adding inbufs, which causes the VQ to be used directly within > > > probe. > > > > > > To fix, call virtio_device_ready before using VQs. > > > > > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > > --- > > > drivers/char/virtio_console.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > > > index b585b47..6ebe8f6 100644 > > > --- a/drivers/char/virtio_console.c > > > +++ b/drivers/char/virtio_console.c > > > @@ -1449,6 +1449,8 @@ static int add_port(struct ports_device *portdev, u32 id) > > > spin_lock_init(&port->outvq_lock); > > > init_waitqueue_head(&port->waitqueue); > > > > > > + virtio_device_ready(portdev->vdev); > > > + > > > /* Fill the in_vq with buffers so the host can send us data. */ > > > nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); > > > if (!nr_added_bufs) { > > > > Seems like probe and add_port() now both set VIRTIO_CONFIG_S_DRIVER_OK > > I think we need to set this in the probe function instead, otherwise we > fail for multiqueue (which also wants to use the control queue early). > > Completely untested patch below; I can send this with proper s-o-b if > it helps. virtio_dev_probe() already sets DRIVER_OK if ->probe() returned without an error. I assume Michael added it to add_port() because probing doesn't always occur first. Can we just remove the BUG_ON()? -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Mon, Oct 20, 2014 at 02:42:23PM +0200, Cornelia Huck wrote: > On Mon, 20 Oct 2014 13:07:50 +0100 > Thomas Graf <tgraf@suug.ch> wrote: > > > On 10/13/14 at 10:50am, Michael S. Tsirkin wrote: > > > virtio spec requires drivers to set DRIVER_OK before using VQs. > > > This is set automatically after probe returns, virtio console violated this > > > rule by adding inbufs, which causes the VQ to be used directly within > > > probe. > > > > > > To fix, call virtio_device_ready before using VQs. > > > > > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > > --- > > > drivers/char/virtio_console.c | 2 ++ > > > 1 file changed, 2 insertions(+) > > > > > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > > > index b585b47..6ebe8f6 100644 > > > --- a/drivers/char/virtio_console.c > > > +++ b/drivers/char/virtio_console.c > > > @@ -1449,6 +1449,8 @@ static int add_port(struct ports_device *portdev, u32 id) > > > spin_lock_init(&port->outvq_lock); > > > init_waitqueue_head(&port->waitqueue); > > > > > > + virtio_device_ready(portdev->vdev); > > > + > > > /* Fill the in_vq with buffers so the host can send us data. */ > > > nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); > > > if (!nr_added_bufs) { > > > > Seems like probe and add_port() now both set VIRTIO_CONFIG_S_DRIVER_OK > > I think we need to set this in the probe function instead, otherwise we > fail for multiqueue (which also wants to use the control queue early). > > Completely untested patch below; I can send this with proper s-o-b if > it helps. > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > index bfa6400..cf7a561 100644 > --- a/drivers/char/virtio_console.c > +++ b/drivers/char/virtio_console.c > @@ -1449,8 +1449,6 @@ static int add_port(struct ports_device *portdev, u32 id) > spin_lock_init(&port->outvq_lock); > init_waitqueue_head(&port->waitqueue); > > - virtio_device_ready(portdev->vdev); > - > /* Fill the in_vq with buffers so the host can send us data. */ > nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); > if (!nr_added_bufs) { > @@ -2026,6 +2024,8 @@ static int virtcons_probe(struct virtio_device *vdev) > spin_lock_init(&portdev->ports_lock); > INIT_LIST_HEAD(&portdev->ports); > > + virtio_device_ready(portdev->vdev); > + > if (multiport) { > unsigned int nr_added_bufs; > I wanted to set DRIVER_OK as late as possible, to both reduce the chance it can fail after DRIVER_OK and to reduce the risk of introducing a regression since old qemu might only start sending interrupts after DRIVER_OK is set. So I wanted everything completely initialized before DRIVER_OK. You patch makes sense to me since nothing can fail, and we won't get interrupts before we add inbufs. Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Testig will report shortly, pls send with sob line.
On Mon, Oct 20, 2014 at 04:35:55PM +0300, Michael S. Tsirkin wrote: > On Mon, Oct 20, 2014 at 02:42:23PM +0200, Cornelia Huck wrote: > > On Mon, 20 Oct 2014 13:07:50 +0100 > > Thomas Graf <tgraf@suug.ch> wrote: > > > > > On 10/13/14 at 10:50am, Michael S. Tsirkin wrote: > > > > virtio spec requires drivers to set DRIVER_OK before using VQs. > > > > This is set automatically after probe returns, virtio console violated this > > > > rule by adding inbufs, which causes the VQ to be used directly within > > > > probe. > > > > > > > > To fix, call virtio_device_ready before using VQs. > > > > > > > > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > > > > --- > > > > drivers/char/virtio_console.c | 2 ++ > > > > 1 file changed, 2 insertions(+) > > > > > > > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > > > > index b585b47..6ebe8f6 100644 > > > > --- a/drivers/char/virtio_console.c > > > > +++ b/drivers/char/virtio_console.c > > > > @@ -1449,6 +1449,8 @@ static int add_port(struct ports_device *portdev, u32 id) > > > > spin_lock_init(&port->outvq_lock); > > > > init_waitqueue_head(&port->waitqueue); > > > > > > > > + virtio_device_ready(portdev->vdev); > > > > + > > > > /* Fill the in_vq with buffers so the host can send us data. */ > > > > nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); > > > > if (!nr_added_bufs) { > > > > > > Seems like probe and add_port() now both set VIRTIO_CONFIG_S_DRIVER_OK > > > > I think we need to set this in the probe function instead, otherwise we > > fail for multiqueue (which also wants to use the control queue early). > > > > Completely untested patch below; I can send this with proper s-o-b if > > it helps. > > > > diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c > > index bfa6400..cf7a561 100644 > > --- a/drivers/char/virtio_console.c > > +++ b/drivers/char/virtio_console.c > > @@ -1449,8 +1449,6 @@ static int add_port(struct ports_device *portdev, u32 id) > > spin_lock_init(&port->outvq_lock); > > init_waitqueue_head(&port->waitqueue); > > > > - virtio_device_ready(portdev->vdev); > > - > > /* Fill the in_vq with buffers so the host can send us data. */ > > nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); > > if (!nr_added_bufs) { > > @@ -2026,6 +2024,8 @@ static int virtcons_probe(struct virtio_device *vdev) > > spin_lock_init(&portdev->ports_lock); > > INIT_LIST_HEAD(&portdev->ports); > > > > + virtio_device_ready(portdev->vdev); > > + > > if (multiport) { > > unsigned int nr_added_bufs; > > > > I wanted to set DRIVER_OK as late as possible, to both reduce > the chance it can fail after DRIVER_OK and to reduce the risk of > introducing a regression since old qemu might only start sending > interrupts after DRIVER_OK is set. > > So I wanted everything completely initialized before DRIVER_OK. > > You patch makes sense to me since nothing can fail, > and we won't get interrupts before we add inbufs. > > Reviewed-by: Michael S. Tsirkin <mst@redhat.com> > > Testig will report shortly, pls send with sob line. Sure enough, this helps: Tested-by: Michael S. Tsirkin <mst@redhat.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Pls repost as a top-level patch. > -- > MST -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 10/20/14 at 05:04pm, Michael S. Tsirkin wrote: > Sure enough, this helps: > > Tested-by: Michael S. Tsirkin <mst@redhat.com> > Acked-by: Michael S. Tsirkin <mst@redhat.com> > > Pls repost as a top-level patch. Thanks for fixing this so promptly. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/char/virtio_console.c b/drivers/char/virtio_console.c index bfa6400..cf7a561 100644 --- a/drivers/char/virtio_console.c +++ b/drivers/char/virtio_console.c @@ -1449,8 +1449,6 @@ static int add_port(struct ports_device *portdev, u32 id) spin_lock_init(&port->outvq_lock); init_waitqueue_head(&port->waitqueue); - virtio_device_ready(portdev->vdev); - /* Fill the in_vq with buffers so the host can send us data. */ nr_added_bufs = fill_queue(port->in_vq, &port->inbuf_lock); if (!nr_added_bufs) { @@ -2026,6 +2024,8 @@ static int virtcons_probe(struct virtio_device *vdev) spin_lock_init(&portdev->ports_lock); INIT_LIST_HEAD(&portdev->ports); + virtio_device_ready(portdev->vdev); + if (multiport) { unsigned int nr_added_bufs;