Re: [PATCH v2 2/2] KVM: arm64: Use MDCR_EL2.HPME to evaluate overflow of hyp counters

[Oliver Upton <oliver.upton@linux.dev>]

On Tue, Nov 19, 2024 at 04:52:30PM -0800, Oliver Upton wrote:
> The 'global enable control' (as it is termed in the architecture) for
> counters reserved by EL2 is MDCR_EL2.HPME. Use that instead of
> PMCR_EL0.E when evaluating the overflow state for hyp counters.
> 
> Change the return value to a bool while at it, which better reflects the
> fact that the overflow state is a shared signal and not a per-counter
> property.

... and the untested garbage award goes to:

> Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index fb79fa689ae5..456102bc0b55 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -276,6 +276,8 @@ void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu)
 
 static u64 kvm_pmu_hyp_counter_mask(struct kvm_vcpu *vcpu)
 {
+	unsigned int hpmn, n;
+
 	if (!vcpu_has_nv(vcpu))
 		return 0;
 
@@ -308,7 +310,6 @@ bool kvm_pmu_counter_is_hyp(struct kvm_vcpu *vcpu, unsigned int idx)
 u64 kvm_pmu_accessible_counter_mask(struct kvm_vcpu *vcpu)
 {
 	u64 mask = kvm_pmu_implemented_counter_mask(vcpu);
-	u64 hpmn;
 
 	if (!vcpu_has_nv(vcpu) || vcpu_is_el2(vcpu))
 		return mask;