Re: [PATCH v9 00/10] s390x: CPU Topology

[Pierre Morel]

On 9/12/22 16:38, Janis Schoetterl-Glausch wrote:
> I found this version much easier to understand than the previous one.
>
> You could consider splitting up the series into two.
> One that introduces support for STSI, PTF, migration, etc.
> And a second one that adds support for the maximum-MNist facility and
> drawers and books.

I agree, sending the first part as supporting only sockets already is an 
enhancement that could be proposed on its own.

> This would also make bisecting a bit nicer because it moves the feature
> enablement closer to the commits adding the support.
>
> Right now, with this series, the topology is static and cannot change.

If we ignore changes on hotplug, yes we consider the topology fixed and 
that the vCPU does not migrate.

> Most of the value of making the topology visible to the guest is for it
> to mirror reality, and a static topology is a hindrance for that.
> I'm completely fine with having a static topology as a stepping stone
> to a dynamic one.
> However I think we should have a rough plan or maybe even a prototype
> for how we turn a static into a dynamic topology before we merge this
> series in order to avoid designing us into a corner.
> What do you think?

Yes, we can discuss this internally before moving there.

Thanks,
Pierre

--
Pierre Morel
IBM Lab Boeblingen