On Thu, Jun 9, 2016 at 9:25 AM, Paolo Bonzini <pbonz...@redhat.com> wrote:
> On 09/06/2016 09:35, Stefan Hajnoczi wrote:
>>
>> if (s->dataplane) {
>> virtio_blk_data_plane_stop(s->dataplane);
>> }
>>
>> virtio_save(vdev, f);
>> }
>>
>> We reach the situation I described where BDS AioContext changes but
>> mirror_run() is still in the IOThread AioContext.
>
> Why is the virtio_blk_data_plane_stop necessary? It used to sync
> between vring and virtio state, but that's not required anymore---and we
> know that the virtqueues are quiescent at this point...
I agree. It doesn't seem necessary anymore unless I'm missing a race
condition with ioeventfd.
It was introduced so that the savevm command (without live migration!) works:
commit 10a06fd65f667a972848ebbbcac11bdba931b544
Author: Pavel Butsykin <pbutsy...@virtuozzo.com>
Date: Mon Oct 26 14:42:57 2015 +0300
virtio: sync the dataplane vring state to the virtqueue before virtio_save
We can remove it now.
Stefan
