Re: [Qemu-devel] [PATCH V4 06/19] virtio-ccw: using VIRTIO_NO_VECTOR instead of 0 for invalid virtqueue

[Michael S. Tsirkin]

On Wed, Mar 18, 2015 at 05:34:56PM +0800, Jason Wang wrote:
> There's no need to use vector 0 for invalid virtqueue. So this patch
> changes to use VIRTIO_NO_VECTOR instead.
> 
> Cc: Michael S. Tsirkin <address@hidden>
> Cc: Cornelia Huck <address@hidden>
> CC: Christian Borntraeger <address@hidden>
> Cc: Richard Henderson <address@hidden>
> Cc: Alexander Graf <address@hidden>
> Signed-off-by: Jason Wang <address@hidden>

I don't know what does this actually do.
Cornelia?

> ---
>  hw/s390x/virtio-ccw.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
> index 130535c..c8b87aa 100644
> --- a/hw/s390x/virtio-ccw.c
> +++ b/hw/s390x/virtio-ccw.c
> @@ -281,7 +281,7 @@ static int virtio_ccw_set_vqs(SubchDev *sch, uint64_t 
> addr, uint32_t align,
>  
>      virtio_queue_set_addr(vdev, index, addr);
>      if (!addr) {
> -        virtio_queue_set_vector(vdev, index, 0);
> +        virtio_queue_set_vector(vdev, index, VIRTIO_NO_VECTOR);
>      } else {
>          /* Fail if we don't have a big enough queue. */
>          /* TODO: Add interface to handle vring.num changing */

Right below this, we have
    /* tell notify handler in case of config change */
    vdev->config_vector = VIRTIO_PCI_QUEUE_MAX;

which also does not seem to make sense.

These changes need some testing though.

> -- 
> 2.1.0