From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
When calling perf_event_create_kernel_counter to create perf_event,
assign a overflow handler. Then when perf event overflows, set
irq_pending and call kvm_vcpu_kick() to sync the interrupt.
Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
---
arch/arm/kvm/arm.c | 4 +++
include/kvm/arm_pmu.h | 4 +++
virt/kvm/arm/pmu.c | 76 ++++++++++++++++++++++++++++++++++++++++++++++++++-
3 files changed, 83 insertions(+), 1 deletion(-)
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 78b2869..9c0fec4 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"
@@ -551,6 +552,7 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
if (ret <= 0 || need_new_vmid_gen(vcpu->kvm)) {
local_irq_enable();
+ kvm_pmu_sync_hwstate(vcpu);
kvm_vgic_sync_hwstate(vcpu);
preempt_enable();
kvm_timer_sync_hwstate(vcpu);
@@ -598,6 +600,8 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run)
kvm_guest_exit();
trace_kvm_exit(kvm_vcpu_trap_get_class(vcpu), *vcpu_pc(vcpu));
+ kvm_pmu_post_sync_hwstate(vcpu);
+
kvm_vgic_sync_hwstate(vcpu);
preempt_enable();
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index acd025a..5e7f943 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -39,6 +39,8 @@ struct kvm_pmu {
};
#ifdef CONFIG_KVM_ARM_PMU
+void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu);
+void kvm_pmu_post_sync_hwstate(struct kvm_vcpu *vcpu);
unsigned long 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);
@@ -49,6 +51,8 @@ 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_sync_hwstate(struct kvm_vcpu *vcpu) {}
+void kvm_pmu_post_sync_hwstate(struct kvm_vcpu *vcpu) {}
unsigned long 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 11d1bfb..6d48d9a 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
@@ -69,6 +70,78 @@ static void kvm_pmu_stop_counter(struct kvm_pmc *pmc)
}
/**
+ * kvm_pmu_sync_hwstate - sync pmu state for cpu
+ * @vcpu: The vcpu pointer
+ *
+ * Inject virtual PMU IRQ if IRQ is pending for this cpu.
+ */
+void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ u32 overflow;
+
+ if (!vcpu_mode_is_32bit(vcpu))
+ overflow = vcpu_sys_reg(vcpu, PMOVSSET_EL0);
+ else
+ overflow = vcpu_cp15(vcpu, c9_PMOVSSET);
+
+ if ((pmu->irq_pending || overflow != 0) && (pmu->irq_num != -1))
+ kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, pmu->irq_num, 1);
+
+ pmu->irq_pending = false;
+}
+
+/**
+ * kvm_pmu_post_sync_hwstate - post sync pmu state for cpu
+ * @vcpu: The vcpu pointer
+ *
+ * Inject virtual PMU IRQ if IRQ is pending for this cpu when back from guest.
+ */
+void kvm_pmu_post_sync_hwstate(struct kvm_vcpu *vcpu)
+{
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+
+ if (pmu->irq_pending && (pmu->irq_num != -1))
+ kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, pmu->irq_num, 1);
+
+ pmu->irq_pending = false;
+}
+
+/**
+ * When perf event overflows, set irq_pending and call kvm_vcpu_kick() to inject
+ * the interrupt.
+ */
+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 = pmc->vcpu;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ int idx = pmc->idx;
+
+ if (!vcpu_mode_is_32bit(vcpu)) {
+ if ((vcpu_sys_reg(vcpu, PMINTENSET_EL1) >> idx) & 0x1) {
+ __set_bit(idx,
+ (unsigned long *)&vcpu_sys_reg(vcpu, PMOVSSET_EL0));
+ __set_bit(idx,
+ (unsigned long *)&vcpu_sys_reg(vcpu, PMOVSCLR_EL0));
+ pmu->irq_pending = true;
+ kvm_vcpu_kick(vcpu);
+ }
+ } else {
+ if ((vcpu_cp15(vcpu, c9_PMINTENSET) >> idx) & 0x1) {
+ __set_bit(idx,
+ (unsigned long *)&vcpu_cp15(vcpu, c9_PMOVSSET));
+ __set_bit(idx,
+ (unsigned long *)&vcpu_cp15(vcpu, c9_PMOVSCLR));
+ pmu->irq_pending = true;
+ kvm_vcpu_kick(vcpu);
+ }
+ }
+}
+
+/**
* kvm_pmu_enable_counter - enable selected PMU counter
* @vcpu: The vcpu pointer
* @val: the value guest writes to PMCNTENSET register
@@ -293,7 +366,8 @@ 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));
--
2.0.4
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