Re: [RFC PATCH v4 11/20] vhost: Route host->guest notification through shadow virtqueue

[Eugenio Perez Martin]

On Wed, Oct 13, 2021 at 5:49 AM Jason Wang <jasowang@redhat.com> wrote:
>
>
> 在 2021/10/1 下午3:05, Eugenio Pérez 写道:
> > This will make qemu aware of the device used buffers, allowing it to
> > write the guest memory with its contents if needed.
> >
> > Since the use of vhost_virtqueue_start can unmasks and discard call
> > events, vhost_virtqueue_start should be modified in one of these ways:
> > * Split in two: One of them uses all logic to start a queue with no
> >    side effects for the guest, and another one tha actually assumes that
> >    the guest has just started the device. Vdpa should use just the
> >    former.
> > * Actually store and check if the guest notifier is masked, and do it
> >    conditionally.
> > * Left as it is, and duplicate all the logic in vhost-vdpa.
>
>
> Btw, the log looks not clear. I guess this patch goes for method 3. If
> yes, we need explain it and why.
>
> Thanks
>

Sorry about being unclear. This commit log (and code) just exposes the
problem and the solutions I came up with but does nothing to solve it.
I'm actually going for method 3 for the next series but I'm open to
doing it differently.

>
> >
> > Signed-off-by: Eugenio Pérez<eperezma@redhat.com>
>