From: Andrew Murray andrew.murray@arm.com
mainline inclusion from mainline-v5.2-rc1 commit eb41238cf19fda694e3a99c1f4f58bd88479a5ee category: feature feature: Support perf event modifiers :G and :H
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In order to effeciently switch events_{guest,host} perf counters at guest entry/exit we add bitfields to kvm_cpu_context for guest and host events as well as accessors for updating them.
A function is also provided which allows the PMU driver to determine if a counter should start counting when it is enabled. With exclude_host, we may only start counting when entering the guest.
Signed-off-by: Andrew Murray andrew.murray@arm.com Signed-off-by: Marc Zyngier marc.zyngier@arm.com Signed-off-by: Zenghui Yu yuzenghui@huawei.com Reviewed-by: Hailiang Zhang zhang.zhanghailiang@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com --- arch/arm64/include/asm/kvm_host.h | 17 +++++++++++++++ arch/arm64/kvm/Makefile | 2 +- arch/arm64/kvm/pmu.c | 45 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 63 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/kvm/pmu.c
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index d9d4a848..b4ec4a8 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -209,8 +209,14 @@ struct kvm_cpu_context { struct kvm_vcpu *__hyp_running_vcpu; };
+struct kvm_pmu_events { + u32 events_host; + u32 events_guest; +}; + struct kvm_host_data { struct kvm_cpu_context host_ctxt; + struct kvm_pmu_events pmu_events; };
typedef struct kvm_host_data kvm_host_data_t; @@ -486,11 +492,22 @@ static inline void __cpu_init_stage2(void) {} void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu); void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);
+static inline bool kvm_pmu_counter_deferred(struct perf_event_attr *attr) +{ + return attr->exclude_host; +} + #ifdef CONFIG_KVM /* Avoid conflicts with core headers if CONFIG_KVM=n */ static inline int kvm_arch_vcpu_run_pid_change(struct kvm_vcpu *vcpu) { return kvm_arch_vcpu_run_map_fp(vcpu); } + +void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr); +void kvm_clr_pmu_events(u32 clr); +#else +static inline void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) {} +static inline void kvm_clr_pmu_events(u32 clr) {} #endif
static inline void kvm_arm_vhe_guest_enter(void) diff --git a/arch/arm64/kvm/Makefile b/arch/arm64/kvm/Makefile index 0f2a135..f34cb49 100644 --- a/arch/arm64/kvm/Makefile +++ b/arch/arm64/kvm/Makefile @@ -19,7 +19,7 @@ kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/psci.o $(KVM)/arm/perf.o kvm-$(CONFIG_KVM_ARM_HOST) += inject_fault.o regmap.o va_layout.o kvm-$(CONFIG_KVM_ARM_HOST) += hyp.o hyp-init.o handle_exit.o kvm-$(CONFIG_KVM_ARM_HOST) += guest.o debug.o reset.o sys_regs.o sys_regs_generic_v8.o -kvm-$(CONFIG_KVM_ARM_HOST) += vgic-sys-reg-v3.o fpsimd.o +kvm-$(CONFIG_KVM_ARM_HOST) += vgic-sys-reg-v3.o fpsimd.o pmu.o kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/aarch32.o
kvm-$(CONFIG_KVM_ARM_HOST) += $(KVM)/arm/vgic/vgic.o diff --git a/arch/arm64/kvm/pmu.c b/arch/arm64/kvm/pmu.c new file mode 100644 index 00000000..5414b13 --- /dev/null +++ b/arch/arm64/kvm/pmu.c @@ -0,0 +1,45 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2019 Arm Limited + * Author: Andrew Murray Andrew.Murray@arm.com + */ +#include <linux/kvm_host.h> +#include <linux/perf_event.h> + +/* + * Given the exclude_{host,guest} attributes, determine if we are going + * to need to switch counters at guest entry/exit. + */ +static bool kvm_pmu_switch_needed(struct perf_event_attr *attr) +{ + /* Only switch if attributes are different */ + return (attr->exclude_host != attr->exclude_guest); +} + +/* + * Add events to track that we may want to switch at guest entry/exit + * time. + */ +void kvm_set_pmu_events(u32 set, struct perf_event_attr *attr) +{ + struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data); + + if (!kvm_pmu_switch_needed(attr)) + return; + + if (!attr->exclude_host) + ctx->pmu_events.events_host |= set; + if (!attr->exclude_guest) + ctx->pmu_events.events_guest |= set; +} + +/* + * Stop tracking events + */ +void kvm_clr_pmu_events(u32 clr) +{ + struct kvm_host_data *ctx = this_cpu_ptr(&kvm_host_data); + + ctx->pmu_events.events_host &= ~clr; + ctx->pmu_events.events_guest &= ~clr; +}