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authorMarc Zyngier <maz@kernel.org>2021-03-05 18:52:50 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2021-03-06 04:18:40 -0500
commit6b5b368fccd7109b052e45af8ba1464c8d140a49 (patch)
tree25ee8f56e285fc586d63e53f0b78396f8c0ddd0b /include/kvm
parentc4b000c3928d4f20acef79dccf3a65ae3795e0b0 (diff)
downloadlwn-6b5b368fccd7109b052e45af8ba1464c8d140a49.tar.gz
lwn-6b5b368fccd7109b052e45af8ba1464c8d140a49.zip
KVM: arm64: Turn kvm_arm_support_pmu_v3() into a static key
We currently find out about the presence of a HW PMU (or the handling of that PMU by perf, which amounts to the same thing) in a fairly roundabout way, by checking the number of counters available to perf. That's good enough for now, but we will soon need to find about about that on paths where perf is out of reach (in the world switch). Instead, let's turn kvm_arm_support_pmu_v3() into a static key. Signed-off-by: Marc Zyngier <maz@kernel.org> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Link: https://lore.kernel.org/r/20210209114844.3278746-2-maz@kernel.org Message-Id: <20210305185254.3730990-5-maz@kernel.org> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'include/kvm')
-rw-r--r--include/kvm/arm_pmu.h9
1 files changed, 7 insertions, 2 deletions
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 8dcb3e1477bc..6fd3cda608e4 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -13,6 +13,13 @@
#define ARMV8_PMU_CYCLE_IDX (ARMV8_PMU_MAX_COUNTERS - 1)
#define ARMV8_PMU_MAX_COUNTER_PAIRS ((ARMV8_PMU_MAX_COUNTERS + 1) >> 1)
+DECLARE_STATIC_KEY_FALSE(kvm_arm_pmu_available);
+
+static __always_inline bool kvm_arm_support_pmu_v3(void)
+{
+ return static_branch_likely(&kvm_arm_pmu_available);
+}
+
#ifdef CONFIG_HW_PERF_EVENTS
struct kvm_pmc {
@@ -47,7 +54,6 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);
void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);
void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
u64 select_idx);
-bool kvm_arm_support_pmu_v3(void);
int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr);
int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu,
@@ -87,7 +93,6 @@ static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}
static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}
static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
u64 data, u64 select_idx) {}
-static inline bool kvm_arm_support_pmu_v3(void) { return false; }
static inline int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu,
struct kvm_device_attr *attr)
{