arm64: KVM: Add access handler for PMSWINC register
Add access handler which emulates writing and reading PMSWINC
register and add support for creating software increment event.
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>
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 0232861..9fc775e 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -180,6 +180,36 @@
kvm_vcpu_kick(vcpu);
}
+/**
+ * kvm_pmu_software_increment - do software increment
+ * @vcpu: The vcpu pointer
+ * @val: the value guest writes to PMSWINC register
+ */
+void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val)
+{
+ int i;
+ u64 type, enable, reg;
+
+ if (val == 0)
+ return;
+
+ enable = vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
+ for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) {
+ if (!(val & BIT(i)))
+ continue;
+ type = vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i)
+ & ARMV8_PMU_EVTYPE_EVENT;
+ if ((type == ARMV8_PMU_EVTYPE_EVENT_SW_INCR)
+ && (enable & BIT(i))) {
+ reg = vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1;
+ reg = lower_32_bits(reg);
+ vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg;
+ if (!reg)
+ kvm_pmu_overflow_set(vcpu, BIT(i));
+ }
+ }
+}
+
static bool kvm_pmu_counter_is_enabled(struct kvm_vcpu *vcpu, u64 select_idx)
{
return (vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) &&
@@ -208,6 +238,10 @@
kvm_pmu_stop_counter(vcpu, pmc);
eventsel = data & ARMV8_PMU_EVTYPE_EVENT;
+ /* Software increment event does't need to be backed by a perf event */
+ if (eventsel == ARMV8_PMU_EVTYPE_EVENT_SW_INCR)
+ return;
+
memset(&attr, 0, sizeof(struct perf_event_attr));
attr.type = PERF_TYPE_RAW;
attr.size = sizeof(attr);