Re: [PATCH v12 3/3] KVM: s390: resetting the Topology-Change-Report

[Pierre Morel]

On 7/13/22 11:01, Janosch Frank wrote:
> On 7/12/22 13:17, Pierre Morel wrote:
> > On 7/12/22 10:47, Janis Schoetterl-Glausch wrote:
> > > On 7/12/22 09:24, Pierre Morel wrote:
> > > >

...

> > kernel.
> >
> > In userland we check any wrong selector before the instruction goes back
> > to the guest.
>
> I opt for passing the lower selectors down for QEMU to handle.

OK

> > > But that's only relevant if STSI can be extended without a 
> > > capability, which is why I asked about that.
> >
> > Logicaly any change, extension, in the architecture should be signaled
> > by a facility bit or something.
> >
> > > > Even testing the facility or PV in the kernel is for my opinion 
> > > > arguable in the case we do not do any treatment in the kernel.
>
> That's actually a good point.
>
> New instruction interceptions for PV will need to be enabled by KVM via 
> a switch somewhere since the UV can't rely on the fact that KVM will 
> correctly handle it without an enablement.
>
>
> So please remove the pv check

OK

>

...

> > > > > >     +static int kvm_s390_set_topology(struct kvm *kvm, struct 
> > > > > > kvm_device_attr *attr)
> > > > >
> > > > > kvm_s390_set_topology_changed maybe?
> > > > > kvm_s390_get_topology_changed below then.
>
> kvm_s390_set_topology_change_indication
>
> It's long but it's rarely used.
> Maybe shorten topology to "topo"

OK
I use
kvm_s390_get_topo_change_indication()


Thanks.

Regards,
Pierre

--
Pierre Morel
IBM Lab Boeblingen