Re: [PATCH v2 1/5] virtio-net: setup vhost_dev and notifiers for cvq only when feature is negotiated

[Jason Wang <jasowang@redhat.com>]

在 2022/4/27 16:30, Si-Wei Liu 写道:
> When the control virtqueue feature is absent or not negotiated,
> vhost_net_start() still tries to set up vhost_dev and install
> vhost notifiers for the control virtqueue, which results in
> erroneous ioctl calls with incorrect queue index sending down
> to driver. Do that only when needed.
>
> Fixes: 22288fe ("virtio-net: vhost control virtqueue support")
> Signed-off-by: Si-Wei Liu <si-wei.liu@oracle.com>


Acked-by: Jason Wang <jasowang@redhat.com>


> ---
>   hw/net/virtio-net.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/hw/net/virtio-net.c b/hw/net/virtio-net.c
> index 1067e72..ffb3475 100644
> --- a/hw/net/virtio-net.c
> +++ b/hw/net/virtio-net.c
> @@ -245,7 +245,8 @@ static void virtio_net_vhost_status(VirtIONet *n, uint8_t status)
>       VirtIODevice *vdev = VIRTIO_DEVICE(n);
>       NetClientState *nc = qemu_get_queue(n->nic);
>       int queue_pairs = n->multiqueue ? n->max_queue_pairs : 1;
> -    int cvq = n->max_ncs - n->max_queue_pairs;
> +    int cvq = virtio_vdev_has_feature(vdev, VIRTIO_NET_F_CTRL_VQ) ?
> +              n->max_ncs - n->max_queue_pairs : 0;
>   
>       if (!get_vhost_net(nc->peer)) {
>           return;