Patchwork [v4,2/4] arm64: KVM: add accessors to track guest/host only counters

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Submitter Andrew Murray
Date Dec. 4, 2018, 2:58 p.m.
Message ID <1543935500-23207-3-git-send-email-andrew.murray@arm.com>
Download mbox | patch
Permalink /patch/672061/
State New
Headers show

Comments

Andrew Murray - Dec. 4, 2018, 2:58 p.m.
In order to effeciently enable/disable guest/host only 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.

Signed-off-by: Andrew Murray <andrew.murray@arm.com>
---
 arch/arm64/include/asm/kvm_host.h | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

Patch

diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 1550192..800c87b 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h
@@ -203,6 +203,8 @@  struct kvm_cpu_context {
 	};
 
 	struct kvm_vcpu *__hyp_running_vcpu;
+	u32 events_host;
+	u32 events_guest;
 };
 
 typedef struct kvm_cpu_context kvm_cpu_context_t;
@@ -467,11 +469,33 @@  void kvm_arch_vcpu_load_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_ctxsync_fp(struct kvm_vcpu *vcpu);
 void kvm_arch_vcpu_put_fp(struct kvm_vcpu *vcpu);
 
+#define KVM_PMU_EVENTS_HOST	1
+#define KVM_PMU_EVENTS_GUEST	2
+
 #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);
 }
+static inline void kvm_set_pmu_events(u32 set, int flags)
+{
+	kvm_cpu_context_t *ctx = this_cpu_ptr(&kvm_host_cpu_state);
+
+	if (flags & KVM_PMU_EVENTS_HOST)
+		ctx->events_host |= set;
+	if (flags & KVM_PMU_EVENTS_GUEST)
+		ctx->events_guest |= set;
+}
+static inline void kvm_clr_pmu_events(u32 clr)
+{
+	kvm_cpu_context_t *ctx = this_cpu_ptr(&kvm_host_cpu_state);
+
+	ctx->events_host &= ~clr;
+	ctx->events_guest &= ~clr;
+}
+#else
+static inline void kvm_set_pmu_events(u32 set, int flags) {}
+static inline void kvm_clr_pmu_events(u32 clr) {}
 #endif
 
 static inline void kvm_arm_vhe_guest_enter(void)