Re: [PATCH 3/3] KVM: arm64: Disable host PMU counters for protected guests

[Fuad Tabba]

On Tue, 27 Oct 2026 at 09:32, Marc Zyngier <maz@xxxxxxxxxx> wrote:
[...]
> > -     if (pmuv3_implemented(pmuver))
> > +     if (pmuv3_implemented(pmuver)) {
> >               *host_data_ptr(nr_event_counters) = FIELD_GET(ARMV8_PMU_PMCR_N,
> >                                                             read_sysreg(pmcr_el0));
> > +             host_data_set_flag(HAS_PMUV3);
>
> Honestly, I don't think we need to work out which CPUs have PMUv3 and
> which don't. I'd be perfectly happy to disable KVM on asymmetric
> systems, simply because they don't exist.

Ack. I'll drop the per-CPU flag on the respin, gate on
system_supports_pmuv3(), and refuse KVM on asymmetric systems.

/fuad