arm64: KVM: Add access handler for event counter register

These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which
is mapped to PMEVCNTRn.

The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.

When reading these registers, return the sum of register value and the
value perf event counts.

Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

1 files changed, 11 insertions, 0 deletions

diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 8157fe5bcbb0..bcb769805839 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h
@@ -23,6 +23,8 @@
 #include <linux/perf_event.h>
 #include <asm/perf_event.h>
 
+#define ARMV8_PMU_CYCLE_IDX		(ARMV8_PMU_MAX_COUNTERS - 1)
+
 struct kvm_pmc {
 	u8 idx;	/* index into the pmu->pmc array */
 	struct perf_event *perf_event;
@@ -36,11 +38,20 @@ struct kvm_pmu {
 };
 
 #define kvm_arm_pmu_v3_ready(v)		((v)->arch.pmu.ready)
+u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx);
+void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val);
 #else
 struct kvm_pmu {
 };
 
 #define kvm_arm_pmu_v3_ready(v)		(false)
+static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu,
+					    u64 select_idx)
+{
+	return 0;
+}
+static inline void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu,
+					     u64 select_idx, u64 val) {}
 #endif
 
 #endif