Re: [PATCH] virtio_console: move early VQ enablement

Josh Boyer
2014-10-20T17:09:14Z

On Mon, Oct 20, 2014 at 10:05 AM, Michael S. Tsirkin <mst@redhat.com> wrote:
> On Mon, Oct 20, 2014 at 03:58:49PM +0200, Cornelia Huck wrote:
>> Commit f5866db6 (virtio_console: enable VQs early) tried to make
>> sure that DRIVER_OK was set when virtio_console started using its
>> virtqueues. Doing this in add_port(), however, means that we try
>> to set DRIVER_OK again when when a port is dynamically added after
>> the probe function is done.
>>
>> Let's move virtio_device_ready() to the probe function just before
>> trying to use the virtqueues instead. This is fine as nothing can
>> fail inbetween.
>>
>> Reported-by: Thomas Graf <tgraf@suug.ch>
>> Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
>> Signed-off-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>
> Thanks!
>
> Acked-by: Michael S. Tsirkin <mst@redhat.com>
> Tested-by: Michael S. Tsirkin <mst@redhat.com>

This fixed my KVM guest boot issue with 3.18-rc1. Thanks for such a quick fix.

Tested-by: Josh Boyer <jwboyer@fedoraproject.org>

josh

>> ---
>> drivers/char/virtio_console.c | 4 ++--
>> 1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> 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;
>>
>> --
>> 1.8.5.5
> --
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at http://www.tux.org/lkml/