>>From: Shannon Zhao<shannon.zhao@xxxxxxxxxx>
>>
>>When calling perf_event_create_kernel_counter to create perf_event,
>>assign a overflow handler. Then when the perf event overflows, set the
>>corresponding bit of guest PMOVSSET register. If this counter is enabled
>>and its interrupt is enabled as well, kick the vcpu to sync the
>>interrupt.
>>
>>On VM entry, if there is counter overflowed, inject the interrupt with
>>the level set to 1. Otherwise, inject the interrupt with the level set
>>to 0.
>>
>>Signed-off-by: Shannon Zhao<shannon.zhao@xxxxxxxxxx>
>>Reviewed-by: Marc Zyngier<marc.zyngier@xxxxxxx>
>>Reviewed-by: Andrew Jones<drjones@xxxxxxxxxx>
>>---
>> arch/arm/kvm/arm.c | 2 ++
>> include/kvm/arm_pmu.h | 3 +++
>> virt/kvm/arm/pmu.c | 51 ++++++++++++++++++++++++++++++++++++++++++++++++++-
>> 3 files changed, 55 insertions(+), 1 deletion(-)
>>
>>diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
>>index dda1959..f54264c 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"
>>@@ -577,6 +578,7 @@ 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 8bc92d1..0aed4d4 100644
>>--- a/include/kvm/arm_pmu.h
>>+++ b/include/kvm/arm_pmu.h
>>@@ -35,6 +35,7 @@ struct kvm_pmu {
>> int irq_num;
>> struct kvm_pmc pmc[ARMV8_PMU_MAX_COUNTERS];
>> bool ready;
>>+ bool irq_level;
>> };
>>
>> #define kvm_arm_pmu_v3_ready(v) ((v)->arch.pmu.ready)
>>@@ -44,6 +45,7 @@ u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu);
>> void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val);
>> void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val);
>> void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val);
>>+void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu);
>> void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val);
>> void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val);
>> void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data,
>>@@ -67,6 +69,7 @@ static inline u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
>> static inline void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val) {}
>> static inline void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val) {}
>> static inline void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) {}
>>+static inline void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) {}
>> static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {}
>> static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {}
>> static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu,
>>diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
>>index cda869c..1cd4214 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
>>@@ -181,6 +182,53 @@ void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val)
>> }
>>
>> /**
>>+ * 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;
>>+ bool overflow;
>>+
>>+ if (!kvm_arm_pmu_v3_ready(vcpu))
>>+ return;
>>+
>>+ overflow = !!kvm_pmu_overflow_status(vcpu);
>>+ if (pmu->irq_level != overflow) {
>>+ pmu->irq_level = overflow;
>>+ kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id,
>>+ pmu->irq_num, overflow);
>>+ }
