Virtualization - Oct 2021 - [RFC PATCH v4 11/20] vhost: Route host->guest notification through shadow virtqueue

? 2021/10/14 ??11:58, Eugenio Perez Martin ??:
> On Wed, Oct 13, 2021 at 5:49 AM Jason Wang <jasowang at redhat.com>
wrote:
>>
>> ? 2021/10/1 ??3:05, Eugenio P?rez ??:
>>> 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.

That's fine, but need to doc that method 3 is something that is done in 
the patch.

Thanks

>
>>> Signed-off-by: Eugenio P?rez<eperezma at redhat.com>