Re: [PATCH v5 4/6] vhost-vdpa: add support for configure interrupt

[Cindy Lu]

On Fri, Apr 9, 2021 at 3:24 PM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2021/4/8 下午5:38, Cindy Lu 写道:
> > Add support for configure interrupt. Set the notifier's fd to
> > the kernel driver when vdpa start. also set -1 while vdpa stop.
> > then the kernel will release the related resource
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >   hw/virtio/vhost-vdpa.c | 26 +++++++++++++++++++++++++-
> >   1 file changed, 25 insertions(+), 1 deletion(-)
> >
> > diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
> > index 9ba2a2bed4..7825366f64 100644
> > --- a/hw/virtio/vhost-vdpa.c
> > +++ b/hw/virtio/vhost-vdpa.c
> > @@ -467,11 +467,33 @@ static int vhost_vdpa_get_config(struct vhost_dev 
> > *dev, uint8_t *config,
> >       }
> >       return ret;
> >    }
> > -
>
>
> Let's keep this blank line.
>
>
sure will fix this
> > +static void vhost_vdpa_config_notify_start(struct vhost_dev *dev,
> > +                                struct VirtIODevice *vdev, bool start)
> > +{
> > +    int fd = 0;
> > +    int r = 0;
> > +    if (!(dev->features & (0x1ULL << VIRTIO_NET_F_STATUS))) {
> > +        return;
> > +    }
> > +    if (start) {
> > +        fd = event_notifier_get_fd(&vdev->config_notifier);
> > +        r = dev->vhost_ops->vhost_set_config_call(dev, &fd);
>
>
> So you introduce a general vhost ops but it's call by devic specific
> code (vhost-vdpa).
>
> Any reason that we don't do that in vhost_dev_start/vhost_dev_stop?
>
> Thanks
>
sure, will move this part to dev_start/stop
>
> > +        if (!r) {
> > +            vdev->use_config_notifier = true;
> > +            event_notifier_set(&vdev->config_notifier);
> > +        }
> > +    } else {
> > +        fd = -1;
> > +        vdev->use_config_notifier = false;
> > +        r = dev->vhost_ops->vhost_set_config_call(dev, &fd);
> > +    }
> > +    return;
> > +}
> >   static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
> >   {
> >       struct vhost_vdpa *v = dev->opaque;
> >       trace_vhost_vdpa_dev_start(dev, started);
> > +    VirtIODevice *vdev = dev->vdev;
> >       if (started) {
> >           uint8_t status = 0;
> >           memory_listener_register(&v->listener, &address_space_memory);
> > @@ -479,8 +501,10 @@ static int vhost_vdpa_dev_start(struct vhost_dev *dev, 
> > bool started)
> >           vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
> >           vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
> >
> > +        vhost_vdpa_config_notify_start(dev, vdev, true);
> >           return !(status & VIRTIO_CONFIG_S_DRIVER_OK);
> >       } else {
> > +        vhost_vdpa_config_notify_start(dev, vdev, false);
> >           vhost_vdpa_reset_device(dev);
> >           vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
> >                                      VIRTIO_CONFIG_S_DRIVER);
>