On 11/10/2023 09:16, Oliver Upton wrote: > Prevent the guest from setting the NSH bit, which enables event counting > while the PE is in EL2. kvm_pmu_create_perf_event() never wired up the > bit, nor does it make any sense in the context of a guest without NV. > > While at it, build the event type mask using explicit field definitions > instead of relying on ARMV8_PMU_EVTYPE_MASK. KVM probably should've been > doing this in the first place, as it avoids changes to the > aforementioned mask affecting sysreg emulation. > > Signed-off-by: Oliver Upton <oliver.upton@xxxxxxxxx> > --- > arch/arm64/kvm/pmu-emul.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c > index 0666212c0c15..087764435390 100644 > --- a/arch/arm64/kvm/pmu-emul.c > +++ b/arch/arm64/kvm/pmu-emul.c > @@ -663,8 +663,7 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, > if (!kvm_vcpu_has_pmu(vcpu)) > return; > > - mask = ARMV8_PMU_EVTYPE_MASK; ARMV8_PMU_EVTYPE_MASK is still used in access_pmu_evtyper() and reset_pmevtyper(), although it's not really an issue if you can't set the bits in the first place. But it probably makes sense to use the same mask everywhere. > - mask &= ~ARMV8_PMU_EVTYPE_EVENT; > + mask = ARMV8_PMU_EXCLUDE_EL1 | ARMV8_PMU_EXCLUDE_EL0; > mask |= kvm_pmu_event_mask(vcpu->kvm); > > reg = counter_index_to_evtreg(pmc->idx);
