Hi Alvaro:
On Thu, Dec 22, 2022 at 2:44 PM Alvaro Karsz <alvaro.karsz@xxxxxxxxxxxxx> wrote:
>
> Hi Jason,
>
> Adding timeout to the cvq is a great idea IMO.
>
> > - /* Spin for a response, the kick causes an ioport write, trapping
> > - * into the hypervisor, so the request should be handled immediately.
> > - */
> > - while (!virtqueue_get_buf(vi->cvq, &tmp) &&
> > - !virtqueue_is_broken(vi->cvq))
> > - cpu_relax();
> > + virtqueue_wait_for_used(vi->cvq, &tmp);
>
> Do you think that we should continue like nothing happened in case of a timeout?
We could, but we should not depend on a device to do this since it's
not reliable. More below.
> Shouldn't we reset the device?
We can't depend on device, there's probably another loop in reset():
E.g in vp_reset() we had:
while (vp_modern_get_status(mdev))
msleep(1);
> What happens if a device completes the control command after timeout?
Maybe we could have a BAD_RING() here in this case (and more check in
vq->broken in this case).
Thanks
>
> Thanks
>
> Alvaro
>
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