Subject: Re: [PATCH v4 13/25] virtio_console: enable VQs early

From: "Michael S. Tsirkin" <[email-masked]>
Date: Mon, 20 Oct 2014 16:14:05 +0300

On Mon, Oct 20, 2014 at 04:10:16PM +0300, Michael S. Tsirkin wrote:
> On Mon, Oct 20, 2014 at 01:07:50PM +0100, Thomas Graf 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 <[email-masked]>
> > > ---
> > >  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) {
> 
> I see Cornelia sent a patch already.
> I'd like to reproduce this though - could you send me
> the command line please?

Nevermind, the trick is to add a port it seems:

-device virtio-serial -chardev socket,path=/tmp/c1,server,nowait,id=foo
-device virtserialport,chardev=foo,name=org.fedoraproject.port.0

works fine without -device virtserialport.

-- 
MST