From: Shannon Zhao <[email protected]> According to ARMv8 spec, when writing 1 to PMCR.E, all counters are enabled by PMCNTENSET, while writing 0 to PMCR.E, all counters are disabled. When writing 1 to PMCR.P, reset all event counters, not including PMCCNTR, to zero. When writing 1 to PMCR.C, reset PMCCNTR to zero.
Signed-off-by: Shannon Zhao <[email protected]> Reviewed-by: Marc Zyngier <[email protected]> Signed-off-by: Marc Zyngier <[email protected]> --- arch/arm64/include/asm/kvm_perf_event.h | 4 +++- arch/arm64/kvm/sys_regs.c | 1 + include/kvm/arm_pmu.h | 2 ++ virt/kvm/arm/pmu.c | 34 +++++++++++++++++++++++++++++++++ 4 files changed, 40 insertions(+), 1 deletion(-) diff --git a/arch/arm64/include/asm/kvm_perf_event.h b/arch/arm64/include/asm/kvm_perf_event.h index 62fa60f..6d080c0 100644 --- a/arch/arm64/include/asm/kvm_perf_event.h +++ b/arch/arm64/include/asm/kvm_perf_event.h @@ -29,9 +29,11 @@ #define ARMV8_PMU_PMCR_D (1 << 3) /* CCNT counts every 64th cpu cycle */ #define ARMV8_PMU_PMCR_X (1 << 4) /* Export to ETM */ #define ARMV8_PMU_PMCR_DP (1 << 5) /* Disable CCNT if non-invasive debug*/ +/* Determines which bit of PMCCNTR_EL0 generates an overflow */ +#define ARMV8_PMU_PMCR_LC (1 << 6) #define ARMV8_PMU_PMCR_N_SHIFT 11 /* Number of counters supported */ #define ARMV8_PMU_PMCR_N_MASK 0x1f -#define ARMV8_PMU_PMCR_MASK 0x3f /* Mask for writable bits */ +#define ARMV8_PMU_PMCR_MASK 0x7f /* Mask for writable bits */ /* * PMOVSR: counters overflow flag status reg diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c index 10e5379..12f36ef 100644 --- a/arch/arm64/kvm/sys_regs.c +++ b/arch/arm64/kvm/sys_regs.c @@ -467,6 +467,7 @@ static bool access_pmcr(struct kvm_vcpu *vcpu, struct sys_reg_params *p, val &= ~ARMV8_PMU_PMCR_MASK; val |= p->regval & ARMV8_PMU_PMCR_MASK; vcpu_sys_reg(vcpu, PMCR_EL0) = val; + kvm_pmu_handle_pmcr(vcpu, val); } else { /* PMCR.P & PMCR.C are RAZ */ val = vcpu_sys_reg(vcpu, PMCR_EL0) diff --git a/include/kvm/arm_pmu.h b/include/kvm/arm_pmu.h index 348c4c9..8bc92d1 100644 --- a/include/kvm/arm_pmu.h +++ b/include/kvm/arm_pmu.h @@ -45,6 +45,7 @@ void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u64 val); void kvm_pmu_enable_counter(struct kvm_vcpu *vcpu, u64 val); void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val); void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val); +void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val); void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, u64 select_idx); #else @@ -67,6 +68,7 @@ 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) {} static inline void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) {} static inline void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) {} +static inline void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) {} static inline void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, u64 select_idx) {} #endif diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index 9fc775e..cda869c 100644 --- a/virt/kvm/arm/pmu.c +++ b/virt/kvm/arm/pmu.c @@ -210,6 +210,40 @@ void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) } } +/** + * kvm_pmu_handle_pmcr - handle PMCR register + * @vcpu: The vcpu pointer + * @val: the value guest writes to PMCR register + */ +void kvm_pmu_handle_pmcr(struct kvm_vcpu *vcpu, u64 val) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc; + u64 mask; + int i; + + mask = kvm_pmu_valid_counter_mask(vcpu); + if (val & ARMV8_PMU_PMCR_E) { + kvm_pmu_enable_counter(vcpu, + vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask); + } else { + kvm_pmu_disable_counter(vcpu, mask); + } + + if (val & ARMV8_PMU_PMCR_C) + kvm_pmu_set_counter_value(vcpu, ARMV8_PMU_CYCLE_IDX, 0); + + if (val & ARMV8_PMU_PMCR_P) { + for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) + kvm_pmu_set_counter_value(vcpu, i, 0); + } + + if (val & ARMV8_PMU_PMCR_LC) { + pmc = &pmu->pmc[ARMV8_PMU_CYCLE_IDX]; + pmc->bitmask = 0xffffffffffffffffUL; + } +} + 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) && -- 2.1.4 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
