[PATCH v6 18/21] KVM: ARM64: Add PMU overflow interrupt routing
From: Shannon Zhao <hidden>
Date: 2015-12-08 12:47:37
Also in:
kvm, kvmarm
Subsystem:
arm port, kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Russell King, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Shannon Zhao <redacted> When calling perf_event_create_kernel_counter to create perf_event, assign a overflow handler. Then when perf event overflows, call kvm_vcpu_kick() to sync the interrupt. Signed-off-by: Shannon Zhao <redacted> --- arch/arm/kvm/arm.c | 2 ++ include/kvm/arm_pmu.h | 2 ++ virt/kvm/arm/pmu.c | 52 ++++++++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 55 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index e06fd29..cd696ef 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c@@ -28,6 +28,7 @@ #include <linux/sched.h> #include <linux/kvm.h> #include <trace/events/kvm.h> +#include <kvm/arm_pmu.h> #define CREATE_TRACE_POINTS #include "trace.h"
@@ -569,6 +570,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) * non-preemptible context. */ preempt_disable(); + kvm_pmu_flush_hwstate(vcpu); kvm_timer_flush_hwstate(vcpu); kvm_vgic_flush_hwstate(vcpu);
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index a131f76..c4041008 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h@@ -38,6 +38,7 @@ struct kvm_pmu { }; #ifdef CONFIG_KVM_ARM_PMU +void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu); u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx); void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u32 val); void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u32 val, bool all_enable);
@@ -48,6 +49,7 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data, u32 select_idx); void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u32 val); #else +void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) {} u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx) { return 0;
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 9b9c706..ff182d6 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c@@ -21,6 +21,7 @@ #include <linux/perf_event.h> #include <asm/kvm_emulate.h> #include <kvm/arm_pmu.h> +#include <kvm/arm_vgic.h> /** * kvm_pmu_get_counter_value - get PMU counter value
@@ -90,6 +91,54 @@ static void kvm_pmu_stop_counter(struct kvm_pmc *pmc) } /** + * kvm_pmu_flush_hwstate - flush pmu state to cpu + * @vcpu: The vcpu pointer + * + * Inject virtual PMU IRQ if IRQ is pending for this cpu. + */ +void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + u32 overflow; + + if (pmu->irq_num == -1) + return; + + if (!vcpu_mode_is_32bit(vcpu)) { + if (!(vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMCR_E)) + return; + + overflow = vcpu_sys_reg(vcpu, PMCNTENSET_EL0) + & vcpu_sys_reg(vcpu, PMINTENSET_EL1) + & vcpu_sys_reg(vcpu, PMOVSSET_EL0); + } else { + if (!(vcpu_cp15(vcpu, c9_PMCR) & ARMV8_PMCR_E)) + return; + + overflow = vcpu_cp15(vcpu, c9_PMCNTENSET) + & vcpu_cp15(vcpu, c9_PMINTENSET) + & vcpu_cp15(vcpu, c9_PMOVSSET); + } + + kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, pmu->irq_num, + overflow ? 1 : 0); +} + +/** + * When perf event overflows, call kvm_pmu_overflow_set to set overflow status. + */ +static void kvm_pmu_perf_overflow(struct perf_event *perf_event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct kvm_pmc *pmc = perf_event->overflow_handler_context; + struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc); + int idx = pmc->idx; + + kvm_pmu_overflow_set(vcpu, BIT(idx)); +} + +/** * kvm_pmu_enable_counter - enable selected PMU counter * @vcpu: The vcpu pointer * @val: the value guest writes to PMCNTENSET register
@@ -341,7 +390,8 @@ void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data, /* The initial sample period (overflow count) of an event. */ attr.sample_period = (-counter) & pmc->bitmask; - event = perf_event_create_kernel_counter(&attr, -1, current, NULL, pmc); + event = perf_event_create_kernel_counter(&attr, -1, current, + kvm_pmu_perf_overflow, pmc); if (IS_ERR(event)) { printk_once("kvm: pmu event creation failed %ld\n", PTR_ERR(event));
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2.0.4