[PATCH 1/5] KVM: arm64: Divorce the perf code from oprofile helpers
From: Marc Zyngier <maz@kernel.org>
Date: 2021-04-14 13:44:27
Also in:
kvm, kvmarm, linux-s390, linux-sh, lkml
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Marc Zyngier, Oliver Upton, Linus Torvalds
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 <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 739164324afe..b8b398670ef2 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 e32c6e139a09..fd167d4f4215 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 6fd3cda608e4..864b9997efb2 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
--
2.29.2
_______________________________________________
linux-arm-kernel mailing list
linux-arm-kernel@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-arm-kernel