Re: [PATCH v7 07/10] virtio-mmio: add support for configure interrupt

[Cindy Lu <lulu@redhat.com>]

On Thu, Jun 3, 2021 at 2:36 PM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2021/6/2 上午11:47, Cindy Lu 写道:
> > Add configure interrupt support for virtio-mmio bus. This
> > interrupt will working while backend is vhost-vdpa
> >
> > Signed-off-by: Cindy Lu <lulu@redhat.com>
> > ---
> >   hw/virtio/virtio-mmio.c | 26 ++++++++++++++++++++++++++
> >   1 file changed, 26 insertions(+)
> >
> > diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
> > index 13772d52bb..423267d51c 100644
> > --- a/hw/virtio/virtio-mmio.c
> > +++ b/hw/virtio/virtio-mmio.c
> > @@ -670,7 +670,26 @@ static int virtio_mmio_set_guest_notifier(DeviceState *d, int n, bool assign,
> >
> >       return 0;
> >   }
> > +static int virtio_mmio_set_config_notifier(DeviceState *d, bool assign)
> > +{
> > +    VirtIOMMIOProxy *proxy = VIRTIO_MMIO(d);
> > +    VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> > +    VirtioDeviceClass *vdc = VIRTIO_DEVICE_GET_CLASS(vdev);
> >
> > +    EventNotifier *notifier = virtio_get_config_notifier(vdev);
> > +    int r = 0;
> > +    if (assign) {
> > +        r = event_notifier_init(notifier, 0);
>
>
> The return value is ignored.
>
will add the check here
>
> > +        virtio_set_notifier_fd_handler(vdev, -1, true, false);
>
>
> You'd better use the macro you introduced in patch 1 here?
>
sorry, Seems I missed this, I will correct this
>
> > +    } else {
> > +        virtio_set_notifier_fd_handler(vdev, -1, false, false);
> > +        event_notifier_cleanup(notifier);
> > +    }
> > +    if (vdc->guest_notifier_mask && vdev->use_guest_notifier_mask) {
> > +        vdc->guest_notifier_mask(vdev, -1, !assign);
> > +    }
> > +    return r;
> > +}
> >   static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
> >                                              bool assign)
> >   {
> > @@ -692,8 +711,15 @@ static int virtio_mmio_set_guest_notifiers(DeviceState *d, int nvqs,
> >               goto assign_error;
> >           }
> >       }
> > +    r = virtio_mmio_set_config_notifier(d, assign);
> > +    if (r < 0) {
> > +        goto config_assign_error;
> > +    }
> >
> >       return 0;
> > +config_assign_error:
> > +    assert(assign);
> > +    r = virtio_mmio_set_config_notifier(d, false);
>
>
> This looks wired. We only have a single configure interrupt, so assign
> fails should mean unassigned?
>
> Thanks
>
sure Will correct this
> >
> >   assign_error:
> >       /* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
>