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authorShannon Zhao <shannon.zhao@linaro.org>2015-09-08 12:26:13 +0800
committerMarc Zyngier <marc.zyngier@arm.com>2016-02-29 18:34:20 +0000
commit96b0eebcc6a14e3bdb9ff0e7176fbfc225bdde94 (patch)
treeafd6c0fcecda21c73164e7fee6c9bef65ee50e16 /virt/kvm
parent051ff581ce70e822729e9474941f3c206cbf7436 (diff)
downloadlinux-96b0eebcc6a14e3bdb9ff0e7176fbfc225bdde94.tar.gz
arm64: KVM: Add access handler for PMCNTENSET and PMCNTENCLR register
Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use reset_unknown for its reset handler. Add a handler to emulate writing PMCNTENSET or PMCNTENCLR register. When writing to PMCNTENSET, call perf_event_enable to enable the perf event. When writing to PMCNTENCLR, call perf_event_disable to disable the perf event. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt/kvm')
-rw-r--r--virt/kvm/arm/pmu.c66
1 files changed, 66 insertions, 0 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index cd74e6367cd6..f8dc17430813 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -61,3 +61,69 @@ void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val)
? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx;
vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx);
}
+
+u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu)
+{
+ u64 val = vcpu_sys_reg(vcpu, PMCR_EL0) >> ARMV8_PMU_PMCR_N_SHIFT;
+
+ val &= ARMV8_PMU_PMCR_N_MASK;
+ if (val == 0)
+ return BIT(ARMV8_PMU_CYCLE_IDX);
+ else
+ return GENMASK(val - 1, 0) | BIT(ARMV8_PMU_CYCLE_IDX);
+}
+
+/**
+ * kvm_pmu_enable_counter - enable selected PMU counter
+ * @vcpu: The vcpu pointer
+ * @val: the value guest writes to PMCNTENSET register
+ *
+ * Call perf_event_enable to start counting the perf event
+ */
+void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ if (!(vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E) || !val)
+ return;
+
+ for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
+ if (!(val & BIT(i)))
+ continue;
+
+ pmc = &pmu->pmc[i];
+ if (pmc->perf_event) {
+ perf_event_enable(pmc->perf_event);
+ if (pmc->perf_event->state != PERF_EVENT_STATE_ACTIVE)
+ kvm_debug("fail to enable perf event\n");
+ }
+ }
+}
+
+/**
+ * kvm_pmu_disable_counter - disable selected PMU counter
+ * @vcpu: The vcpu pointer
+ * @val: the value guest writes to PMCNTENCLR register
+ *
+ * Call perf_event_disable to stop counting the perf event
+ */
+void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ if (!val)
+ return;
+
+ for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) {
+ if (!(val & BIT(i)))
+ continue;
+
+ pmc = &pmu->pmc[i];
+ if (pmc->perf_event)
+ perf_event_disable(pmc->perf_event);
+ }
+}