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 | 46 +++++++++++++++++++++++++++++++++++++++++----
include/kvm/arm_pmu.h | 4 ++++
virt/kvm/arm/pmu.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 94 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index c38c2de..98da5a2 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c
@@ -501,6 +501,24 @@ static bool access_pmu_regs(struct kvm_vcpu *vcpu,
val);
break;
}
+ case PMCNTENSET_EL0: {
+ val = *vcpu_reg(vcpu, p->Rt);
+ kvm_pmu_enable_counter(vcpu, val);
+ /*Value 1 of PMCNTENSET_EL0 and PMCNTENCLR_EL0 means
+ * corresponding counter enabled */
+ vcpu_sys_reg(vcpu, r->reg) |= val;
+ vcpu_sys_reg(vcpu, PMCNTENCLR_EL0) |= val;
+ break;
+ }
+ case PMCNTENCLR_EL0: {
+ val = *vcpu_reg(vcpu, p->Rt);
+ kvm_pmu_disable_counter(vcpu, val);
+ /*Value 0 of PMCNTENSET_EL0 and PMCNTENCLR_EL0 means
+ * corresponding counter disabled */
+ vcpu_sys_reg(vcpu, r->reg) &= ~val;
+ vcpu_sys_reg(vcpu, PMCNTENSET_EL0) &= ~val;
+ break;
+ }
case PMCR_EL0: {
/* Only update writeable bits of PMCR */
val = vcpu_sys_reg(vcpu, r->reg);
@@ -733,10 +751,10 @@ 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, PMCNTENCLR_EL0 },
/* PMOVSCLR_EL0 */
{ Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011),
trap_raz_wi },
@@ -986,6 +1004,24 @@ static bool access_pmu_cp15_regs(struct kvm_vcpu *vcpu,
val);
break;
}
+ case c9_PMCNTENSET: {
+ val = *vcpu_reg(vcpu, p->Rt);
+ kvm_pmu_enable_counter(vcpu, val);
+ /*Value 1 of PMCNTENSET_EL0 and PMCNTENCLR_EL0 means
+ * corresponding counter enabled */
+ vcpu_cp15(vcpu, r->reg) |= val;
+ vcpu_cp15(vcpu, c9_PMCNTENCLR) |= val;
+ break;
+ }
+ case c9_PMCNTENCLR: {
+ val = *vcpu_reg(vcpu, p->Rt);
+ kvm_pmu_disable_counter(vcpu, val);
+ /*Value 0 of PMCNTENSET_EL0 and PMCNTENCLR_EL0 means
+ * corresponding counter disabled */
+ vcpu_cp15(vcpu, r->reg) &= ~val;
+ vcpu_cp15(vcpu, c9_PMCNTENSET) &= ~val;
+ break;
+ }
case c9_PMCR: {
/* Only update writeable bits of PMCR */
val = vcpu_cp15(vcpu, r->reg);
@@ -1054,8 +1090,10 @@ static const struct sys_reg_desc cp15_regs[] = {
/* PMU */
{ Op1( 0), CRn( 9), CRm(12), Op2( 0), access_pmu_cp15_regs,
reset_pmcr, 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,
+ reset_unknown_cp15, c9_PMCNTENSET },
+ { Op1( 0), CRn( 9), CRm(12), Op2( 2), access_pmu_cp15_regs,
+ reset_unknown_cp15, c9_PMCNTENCLR },
{ Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi },
{ Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmu_cp15_regs,
reset_unknown_cp15, c9_PMSELR },
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index b48cdc6..9b4ee5e 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
unsigned long 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);
void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u32 data,
u32 select_idx);
#else
@@ -46,6 +48,8 @@ unsigned long 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) {}
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 002ec79..46145d1 100644
--- a/virt/kvm/arm/pmu.c
+++ b/virt/kvm/arm/pmu.c
@@ -86,6 +86,54 @@ unsigned long kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u32 select_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, u32 val)
+{
+ int i;
+ struct kvm_pmu *pmu = &vcpu->arch.pmu;
+ struct kvm_pmc *pmc;
+
+ for (i = 0; i < 32; i++) {
+ if ((val >> i) & 0x1) {
+ 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 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 (i = 0; i < 32; i++) {
+ if ((val >> i) & 0x1) {
+ 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
--
2.1.4
--
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