Re: [PATCH v3 05/18] KVM: x86/pmu: Drop nr_arch_{gp,fixed}_counters from kvm_pmu

[Yosry Ahmed]

On Fri, Nov 6, 2026 at 4:42 PM Jim Mattson <jmattson@xxxxxxxxxx> wrote:
>
> On Fri, Nov 6, 2026 at 11:34 AM Yosry Ahmed <yosry@xxxxxxxxxx> wrote:
> >
> > > @@ -979,8 +979,6 @@ void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
> > >       kvm_pmu_reset(vcpu);
> > >
> > >       pmu->version = 0;
> > > -     pmu->nr_arch_gp_counters = 0;
> > > -     pmu->nr_arch_fixed_counters = 0;
> > >       pmu->counter_bitmask[KVM_PMC_GP] = 0;
> > >       pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
> > >       /*
> > > @@ -1008,16 +1006,12 @@ void kvm_pmu_refresh(struct kvm_vcpu *vcpu)
> > >        * in the global controls).  Emulate that behavior when refreshing the
> > >        * PMU so that userspace doesn't need to manually set PERF_GLOBAL_CTRL.
> > >        */
> > > -     if (pmu->nr_arch_gp_counters &&
> > > +     if (kvm_gp_pmc_mask(pmu) &&
> > >           (kvm_pmu_has_perf_global_ctrl(pmu) || kvm_vcpu_has_mediated_pmu(vcpu)))
> > > -             pmu->global_ctrl = GENMASK_ULL(pmu->nr_arch_gp_counters - 1, 0);
> > > +             pmu->global_ctrl = kvm_gp_pmc_mask(pmu);
> > >
> > >       if (kvm_vcpu_has_mediated_pmu(vcpu))
> > >               kvm_pmu_call(write_global_ctrl)(pmu->global_ctrl);
> > > -
> > > -     bitmap_set(pmu->pmc_exists, 0, pmu->nr_arch_gp_counters);
> > > -     bitmap_set(pmu->pmc_exists, KVM_FIXED_PMC_BASE_IDX,
> > > -                pmu->nr_arch_fixed_counters);
> >
> > I understand the vendor modules are responsible of initializing this
> > now, but should we clear it before calling into the vendors like other
> > fields above?
>
> pmc_exists is zeroed further up in kvm_pmu_refresh. See patch 02/18.

Duh, sorry I missed this.