Re: [PATCH] ptp: Add vDSO-style vmclock support

From: Daniel P. Berrangé
Date: Thu Jul 25 2024 - 08:01:00 EST


On Thu, Jul 25, 2024 at 12:53:34PM +0100, David Woodhouse wrote:
> On Thu, 2024-07-25 at 12:31 +0100, Daniel P. Berrangé wrote:
> > On Thu, Jul 25, 2024 at 10:56:05AM +0100, David Woodhouse wrote:
> > > Hi Michael, thanks for the review!
> > >
> > > On Thu, 2024-07-25 at 01:48 -0400, Michael S. Tsirkin wrote:
> > > > Do you want to just help complete virtio-rtc then? Would be easier than
> > > > trying to keep two specs in sync.
> > >
> > > The ACPI version is much more lightweight and doesn't take up a
> > > valuable PCI slot#. (I know, you can do virtio without PCI but that's
> > > complex in other ways).
> >
> > In general it shouldn't have to take up a PCI slot, that's just
> > a common default policy. virtio-devices only need a dedicated
> > slot if there's a need to do hotplug/unplug of them. There is a
> > set of core devices for which hotplug doesn't make sense, which
> > could all be put as functions in the same slot. ie virtio-rng,
> > virtio-balloon and virtio-rtc, could all live in one slot.
>
> But if you don't have any virtio devices already, you still need one
> slot to put them in.

Perhaps - it may still be practical to be a function within a slot
shared with non-virtio PCI devices too.

With regards,
Daniel
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