Re: [RFC 0/3] aio-posix: call ->poll_end() when removing AioHandler

[Paolo Bonzini <pbonzini@redhat.com>]

On Mon, Dec 18, 2023 at 1:41 PM Fiona Ebner <f.ebner@proxmox.com> wrote:
> I think it's because of nested drains, because when additionally
> checking that the drain count is zero and only executing the loop then,
> that issue doesn't seem to manifest

But isn't virtio_scsi_drained_end only run if bus->drain_count == 0?

    if (bus->drain_count-- == 1) {
        trace_scsi_bus_drained_end(bus, sdev);
        if (bus->info->drained_end) {
            bus->info->drained_end(bus);
        }
    }

Paolo

>
> > diff --git a/hw/scsi/virtio-scsi.c b/hw/scsi/virtio-scsi.c
> > index 9c751bf296..d22c586b38 100644
> > --- a/hw/scsi/virtio-scsi.c
> > +++ b/hw/scsi/virtio-scsi.c
> > @@ -1164,9 +1164,13 @@ static void virtio_scsi_drained_end(SCSIBus *bus)
> >          return;
> >      }
> >
> > -    for (uint32_t i = 0; i < total_queues; i++) {
> > -        VirtQueue *vq = virtio_get_queue(vdev, i);
> > -        virtio_queue_aio_attach_host_notifier(vq, s->ctx);
> > +    if (s->bus.drain_count == 0) {
> > +        for (uint32_t i = 0; i < total_queues; i++) {
> > +            VirtQueue *vq = virtio_get_queue(vdev, i);
> > +            virtio_queue_set_notification(vq, 1);
> > +            virtio_queue_notify(vdev, i);
> > +            virtio_queue_aio_attach_host_notifier(vq, s->ctx);
> > +        }
> >      }
> >  }
> >
>
> Best Regards,
> Fiona
>