[PATCH 1/2] KVM: arm64: PMU: Introduce pmu_v3_is_supported() helper

[Reiji Watanabe <reijiw@google.com>]

Introduce pmu_v3_is_supported() helper to check if the given
PMUVer supports PMUv3, and use it instead of open coding it.

Signed-off-by: Reiji Watanabe <reijiw@google.com>
---
 arch/arm64/kvm/pmu-emul.c | 3 +--
 arch/arm64/kvm/sys_regs.c | 2 +-
 include/kvm/arm_pmu.h     | 8 ++++++++
 3 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c
index 491ca7eb2a4c..5d2903f52a5f 100644
--- a/arch/arm64/kvm/pmu-emul.c
+++ b/arch/arm64/kvm/pmu-emul.c
@@ -672,8 +672,7 @@ void kvm_host_pmu_init(struct arm_pmu *pmu)
 {
 	struct arm_pmu_entry *entry;
 
-	if (pmu->pmuver == ID_AA64DFR0_EL1_PMUVer_NI ||
-	    pmu->pmuver == ID_AA64DFR0_EL1_PMUVer_IMP_DEF)
+	if (!pmu_v3_is_supported(pmu->pmuver))
 		return;
 
 	mutex_lock(&arm_pmus_lock);
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 753aa7418149..9200b18127f6 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -1408,7 +1408,7 @@ static int set_id_aa64dfr0_el1(struct kvm_vcpu *vcpu,
 	if ((pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF && pmuver > host_pmuver))
 		return -EINVAL;
 
-	valid_pmu = (pmuver != 0 && pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF);
+	valid_pmu = pmu_v3_is_supported(pmuver);
 
 	/* Make sure view register and PMU support do match */
 	if (kvm_vcpu_has_pmu(vcpu) != valid_pmu)
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 1a6a695ca67a..eef17de966da 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -12,6 +12,14 @@
 
 #define ARMV8_PMU_CYCLE_IDX		(ARMV8_PMU_MAX_COUNTERS - 1)
 
+static inline bool pmu_v3_is_supported(int pmuver)
+{
+	WARN_ON_ONCE(pmuver & ~GENMASK_ULL(ARM64_FEATURE_FIELD_BITS - 1, 0));
+
+	return (pmuver != ID_AA64DFR0_EL1_PMUVer_NI) &&
+	       (pmuver != ID_AA64DFR0_EL1_PMUVer_IMP_DEF);
+}
+
 #ifdef CONFIG_HW_PERF_EVENTS
 
 struct kvm_pmc {
-- 
2.41.0.162.gfafddb0af9-goog