[PATCH v13 07/20] KVM: ARM64: Add access handler for PMCNTENSET and PMCNTENCLR register
From: Shannon Zhao <hidden>
Date: 2016-02-24 05:08:27
Also in:
kvm, kvmarm
Subsystem:
arm64 port (aarch64 architecture), kernel virtual machine (kvm), kernel virtual machine for arm64 (kvm/arm64), the rest · Maintainers:
Catalin Marinas, Will Deacon, Paolo Bonzini, Marc Zyngier, Oliver Upton, Linus Torvalds
From: Shannon Zhao <redacted> 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 <redacted> --- arch/arm64/include/asm/kvm_host.h | 1 + arch/arm64/kvm/sys_regs.c | 35 ++++++++++++++++++--- include/kvm/arm_pmu.h | 9 ++++++ virt/kvm/arm/pmu.c | 66 +++++++++++++++++++++++++++++++++++++++ 4 files changed, 107 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h
index 627f01e..e6910db 100644
--- a/arch/arm64/include/asm/kvm_host.h
+++ b/arch/arm64/include/asm/kvm_host.h@@ -121,6 +121,7 @@ enum vcpu_sysreg { PMEVCNTR0_EL0, /* Event Counter Register (0-30) */ PMEVCNTR30_EL0 = PMEVCNTR0_EL0 + 30, PMCCNTR_EL0, /* Cycle Counter Register */ + PMCNTENSET_EL0, /* Count Enable Set Register */ /* 32bit specific registers. Keep them at the end of the range */ DACR32_EL2, /* Domain Access Control Register */
diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c
index ff3214b..d4b6ae3 100644
--- a/arch/arm64/kvm/sys_regs.c
+++ b/arch/arm64/kvm/sys_regs.c@@ -563,6 +563,33 @@ static bool access_pmu_evcntr(struct kvm_vcpu *vcpu, return true; } +static bool access_pmcnten(struct kvm_vcpu *vcpu, struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 val, mask; + + if (!kvm_arm_pmu_v3_ready(vcpu)) + return trap_raz_wi(vcpu, p, r); + + mask = kvm_pmu_valid_counter_mask(vcpu); + if (p->is_write) { + val = p->regval & mask; + if (r->Op2 & 0x1) { + /* accessing PMCNTENSET_EL0 */ + vcpu_sys_reg(vcpu, PMCNTENSET_EL0) |= val; + kvm_pmu_enable_counter(vcpu, val); + } else { + /* accessing PMCNTENCLR_EL0 */ + vcpu_sys_reg(vcpu, PMCNTENSET_EL0) &= ~val; + kvm_pmu_disable_counter(vcpu, val); + } + } else { + p->regval = vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask; + } + + return true; +} + /* Silly macro to expand the DBG{BCR,BVR,WVR,WCR}n_EL1 registers in one go */ #define DBG_BCR_BVR_WCR_WVR_EL1(n) \ /* DBGBVRn_EL1 */ \
@@ -757,10 +784,10 @@ static const struct sys_reg_desc sys_reg_descs[] = { access_pmcr, reset_pmcr, }, /* PMCNTENSET_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b001), - trap_raz_wi }, + access_pmcnten, reset_unknown, PMCNTENSET_EL0 }, /* PMCNTENCLR_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b010), - trap_raz_wi }, + access_pmcnten, NULL, PMCNTENSET_EL0 }, /* PMOVSCLR_EL0 */ { Op0(0b11), Op1(0b011), CRn(0b1001), CRm(0b1100), Op2(0b011), trap_raz_wi },
@@ -1057,8 +1084,8 @@ static const struct sys_reg_desc cp15_regs[] = { /* PMU */ { Op1( 0), CRn( 9), CRm(12), Op2( 0), access_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_pmcnten }, + { Op1( 0), CRn( 9), CRm(12), Op2( 2), access_pmcnten }, { Op1( 0), CRn( 9), CRm(12), Op2( 3), trap_raz_wi }, { Op1( 0), CRn( 9), CRm(12), Op2( 5), access_pmselr }, { Op1( 0), CRn( 9), CRm(12), Op2( 6), access_pmceid },
diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h
index bcb7698..b70058e 100644
--- a/include/kvm/arm_pmu.h
+++ b/include/kvm/arm_pmu.h@@ -40,6 +40,9 @@ 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); +u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu); +void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val); +void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val); #else struct kvm_pmu { };
@@ -52,6 +55,12 @@ static inline u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, } static inline void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) {} +static inline u64 kvm_pmu_valid_counter_mask(struct kvm_vcpu *vcpu) +{ + return 0; +} +static inline void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val) {} +static inline void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val) {} #endif #endif
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
index cd74e63..f8dc174 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); + } +}
--
2.0.4