Re: [PATCH] vdpa: stop all svq on device deletion

[Laurent Vivier]

Hi,

this patch fixes a QEMU crash, could it be merged?

Thanks,
Laurent

On 2/9/23 18:00, Eugenio Pérez wrote:
> Not stopping them leave the device in a bad state when virtio-net
> fronted device is unplugged with device_del monitor command.
>
> This is not triggable in regular poweroff or qemu forces shutdown
> because cleanup is called right after vhost_vdpa_dev_start(false).  But
> devices hot unplug does not call vdpa device cleanups.  This lead to all
> the vhost_vdpa devices without stop the SVQ but the last.
>
> Fix it and clean the code, making it symmetric with
> vhost_vdpa_svqs_start.
>
> Fixes: dff4426fa656 ("vhost: Add Shadow VirtQueue kick forwarding capabilities")
> Reported-by: Lei Yang <leiyang@redhat.com>
> Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
> ---
>   hw/virtio/vhost-vdpa.c | 17 ++---------------
>   1 file changed, 2 insertions(+), 15 deletions(-)
>
> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> index 542e003101..df3a1e92ac 100644
> --- a/hw/virtio/vhost-vdpa.c
> +++ b/hw/virtio/vhost-vdpa.c
> @@ -689,26 +689,11 @@ static int vhost_vdpa_get_device_id(struct vhost_dev *dev,
>       return ret;
>   }
>   
> -static void vhost_vdpa_reset_svq(struct vhost_vdpa *v)
> -{
> -    if (!v->shadow_vqs_enabled) {
> -        return;
> -    }
> -
> -    for (unsigned i = 0; i < v->shadow_vqs->len; ++i) {
> -        VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i);
> -        vhost_svq_stop(svq);
> -    }
> -}
> -
>   static int vhost_vdpa_reset_device(struct vhost_dev *dev)
>   {
> -    struct vhost_vdpa *v = dev->opaque;
>       int ret;
>       uint8_t status = 0;
>   
> -    vhost_vdpa_reset_svq(v);
> -
>       ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
>       trace_vhost_vdpa_reset_device(dev, status);
>       return ret;
> @@ -1100,6 +1085,8 @@ static void vhost_vdpa_svqs_stop(struct vhost_dev *dev)
>   
>       for (unsigned i = 0; i < v->shadow_vqs->len; ++i) {
>           VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i);
> +
> +        vhost_svq_stop(svq);
>           vhost_vdpa_svq_unmap_rings(dev, svq);
>   
>           event_notifier_cleanup(&svq->hdev_kick);