From: Shannon Zhao <shannon.zhao@xxxxxxxxxx>
Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a new case 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@xxxxxxxxxx>
---
arch/arm64/kvm/sys_regs.c | 39 +++++++++++++++++++++++++++++++++++----
include/kvm/arm_pmu.h | 4 ++++
virt/kvm/arm/pmu.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 86 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index 2304937..a780cb5 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -577,6 +577,21 @@ static bool access_pmu_regs(struct kvm_vcpu *vcpu,
vcpu_sys_reg(vcpu, r->reg) = p->regval;
break;
}
+ case PMCNTENSET_EL0: {
+ val = p->regval;
+ if (r->Op2 == 1) {
+ /* accessing PMCNTENSET_EL0 */
+ kvm_pmu_enable_counter(vcpu, val,
+ vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMCR_E);
+ vcpu_sys_reg(vcpu, r->reg) |= val;
+ } else {
+
+ /* accessing PMCNTENCLR_EL0 */
+ kvm_pmu_disable_counter(vcpu, val);
+ vcpu_sys_reg(vcpu, r->reg) &= ~val;
+ }
+ break;
+ }
case PMCR_EL0: {
/* Only update writeable bits of PMCR */
val = vcpu_sys_reg(vcpu, r->reg);
@@ -817,10 +832,10 @@ static const struct sys_reg_desc sys_reg_descs[] = {
access_pmu_regs, reset_pmcr, PMCR_EL0, },
/* PMCNTENSET_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001),
- trap_raz_wi },
+ access_pmu_regs, reset_unknown, PMCNTENSET_EL0 },
/* PMCNTENCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010),
- trap_raz_wi },
+ access_pmu_regs, reset_unknown, PMCNTENSET_EL0 },
/* PMOVSCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011),
trap_raz_wi },
@@ -1137,6 +1152,20 @@ static bool access_pmu_cp15_regs(struct kvm_vcpu *vcpu,
vcpu_cp15(vcpu, r->reg) = p->regval;
break;
}
+ case c9_PMCNTENSET: {
+ val = p->regval;
+ if (r->Op2 == 1) {
+ /* accessing c9_PMCNTENSET */
+ kvm_pmu_enable_counter(vcpu, val,
+ vcpu_cp15(vcpu, c9_PMCR) & ARMV8_PMCR_E);
+ vcpu_cp15(vcpu, r->reg) |= val;
+ } else {
+ /* accessing c9_PMCNTENCLR */
+ kvm_pmu_disable_counter(vcpu, val);
+ vcpu_cp15(vcpu, r->reg) &= ~val;
+ }
+ break;
+ }
case c9_PMCR: {
/* Only update writeable bits of PMCR */
val = vcpu_cp15(vcpu, r->reg);
@@ -1220,8 +1249,10 @@ static const struct sys_reg_desc cp15_regs[] = {
/* PMU */
{ Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmu_cp15_regs,
NULL, c9_PMCR },
- { Op1( 0), CRn( 9), CRm(12), Op2( 1), trap_raz_wi },
- { Op1( 0), CRn( 9), CRm(12), Op2( 2), trap_raz_wi },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 1), access_pmu_cp15_regs,
+ NULL, c9_PMCNTENSET },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 2), access_pmu_cp15_regs,
+ NULL, c9_PMCNTENSET },
{ Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmu_cp15_regs,
NULL, c9_PMSELR },
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index 36bde48..e731656 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
u64 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);
void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data,
u32 select_idx);
#else
@@ -46,6 +48,8 @@ u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_idx)
{
return 0;
}
+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) {}
void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data,
u32 select_idx) {}
#endif
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index 15babf1..45586d2 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -90,6 +90,53 @@ static void kvm_pmu_stop_counter(struct kvm_pmc *pmc)
}
/**
+ * kvm_pmu_enable_counter - enable selected PMU counter
+ * @vcpu: The vcpu pointer
+ * @val: the value guest writes to PMCNTENSET register
+ * @all_enable: the value of PMCR.E
+ *
+ * Call perf_event_enable to start counting the perf event
+ */
+void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u32 val, bool all_enable)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ if (!all_enable)
+ return;
+
+ for_each_set_bit(i, (const unsigned long *)&val, ARMV8_MAX_COUNTERS) {
+ 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, u32 val)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ for_each_set_bit(i, (const unsigned long *)&val, ARMV8_MAX_COUNTERS) {
+ pmc = &pmu->pmc[i];
+ if (pmc->perf_event)
+ perf_event_disable(pmc->perf_event);
+ }
+}
+
+/**
* kvm_pmu_set_counter_event_type - set selected counter to monitor some event
* @vcpu: The vcpu pointer
* @data: The data guest writes to PMXEVTYPER_EL0
--
2.0.4
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