From 5421db1be3b11c5e469cce3760d5c8a013a90f2c Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Wed, 14 Apr 2021 14:44:05 +0100 Subject: [PATCH] KVM: arm64: Divorce the perf code from oprofile helpers KVM/arm64 is the sole user of perf_num_counters(), and really could do without it. Stop using the obsolete API by relying on the existing probing code. Signed-off-by: Marc Zyngier Acked-by: Will Deacon Link: https://lore.kernel.org/r/20210414134409.1266357-2-maz@kernel.org --- arch/arm64/kvm/perf.c | 7 +------ arch/arm64/kvm/pmu-emul.c | 2 +- include/kvm/arm_pmu.h | 4 ++++ 3 files changed, 6 insertions(+), 7 deletions(-) diff --git a/arch/arm64/kvm/perf.c b/arch/arm64/kvm/perf.c index 739164324afedb..b8b398670ef277 100644 --- a/arch/arm64/kvm/perf.c +++ b/arch/arm64/kvm/perf.c @@ -50,12 +50,7 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = { int kvm_perf_init(void) { - /* - * Check if HW_PERF_EVENTS are supported by checking the number of - * hardware performance counters. This could ensure the presence of - * a physical PMU and CONFIG_PERF_EVENT is selected. - */ - if (IS_ENABLED(CONFIG_ARM_PMU) && perf_num_counters() > 0) + if (kvm_pmu_probe_pmuver() != 0xf) static_branch_enable(&kvm_arm_pmu_available); return perf_register_guest_info_callbacks(&kvm_guest_cbs); diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c index e32c6e139a09d3..fd167d4f42157a 100644 --- a/arch/arm64/kvm/pmu-emul.c +++ b/arch/arm64/kvm/pmu-emul.c @@ -739,7 +739,7 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, kvm_pmu_create_perf_event(vcpu, select_idx); } -static int kvm_pmu_probe_pmuver(void) +int kvm_pmu_probe_pmuver(void) { struct perf_event_attr attr = { }; struct perf_event *event; diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 6fd3cda608e4a6..864b9997efb20d 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -61,6 +61,7 @@ int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr); int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu); +int kvm_pmu_probe_pmuver(void); #else struct kvm_pmu { }; @@ -116,6 +117,9 @@ static inline u64 kvm_pmu_get_pmceid(struct kvm_vcpu *vcpu, bool pmceid1) { return 0; } + +static inline int kvm_pmu_probe_pmuver(void) { return 0xf; } + #endif #endif