Re: [virtio-comment] RE: [PATCH V2 3/6] virtio: dont reset vqs when SUSPEND

[Jason Wang <jasowang@redhat.com>]

On Wed, Nov 22, 2023 at 5:18âAM Michael S. Tsirkin <mst@redhat.com> wrote:
>
> On Tue, Nov 21, 2023 at 03:33:07PM +0800, Jason Wang wrote:
> > > Lingshan claimed that suspending device is for live migration in commit log and in discussion he portray it as some basic facility unrelated to device migration such as debug etc.
> > > Instead of claiming it as some non_device_migration facility does not make sense.
> >
> > It is used for migration for sure.
>
> Well having a generic facility to stop device sounds like a nice thing.
> However the devil is in the detail. A lot of detail here seems very much
> tailored to a very specific implementation in mind.
> So thinking through how it will work e.g. for power management
> would be a good excercise to figure out how it should work in detail.

It might work in the case where there's no PM support in the
transport. E.g for MMIO devices.

Thanks


> Parav did you indicate at some point a virtio specific SUSPEND
> bit can be useful for PM? Could you share how it's better than
> transport level PM and what the requirements are?
> Thanks!
>
> --
> MST
>