[PATCH v4 17/21] KVM: ARM64: Add helper to handle PMCR register bits
Christopher Covington
cov at codeaurora.org
Mon Nov 2 13:20:40 PST 2015
On 10/30/2015 02:21 AM, Shannon Zhao wrote:
> From: Shannon Zhao <shannon.zhao at linaro.org>
>
> 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.
> diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c
> index ae21089..11d1bfb 100644
> --- a/virt/kvm/arm/pmu.c
> +++ b/virt/kvm/arm/pmu.c
> @@ -121,6 +121,56 @@ void kvm_pmu_disable_counter(struct kvm_vcpu *vcpu, u32 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, u32 val)
> +{
> + struct kvm_pmu *pmu = &vcpu->arch.pmu;
> + struct kvm_pmc *pmc;
> + u32 enable;
> + int i;
> +
> + if (val & ARMV8_PMCR_E) {
> + if (!vcpu_mode_is_32bit(vcpu))
> + enable = vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
> + else
> + enable = vcpu_cp15(vcpu, c9_PMCNTENSET);
> +
> + kvm_pmu_enable_counter(vcpu, enable, true);
> + } else
> + kvm_pmu_disable_counter(vcpu, 0xffffffffUL);
Nit: If using braces on one side of if-else, please use them on the other.
(Search for "braces in both branches" in Documentation/CodingStyle.)
> +
> + if (val & ARMV8_PMCR_C) {
> + pmc = &pmu->pmc[ARMV8_MAX_COUNTERS - 1];
> + if (pmc->perf_event)
> + local64_set(&pmc->perf_event->count, 0);
> + if (!vcpu_mode_is_32bit(vcpu))
> + vcpu_sys_reg(vcpu, PMCCNTR_EL0) = 0;
> + else
> + vcpu_cp15(vcpu, c9_PMCCNTR) = 0;
> + }
> +
> + if (val & ARMV8_PMCR_P) {
> + for (i = 0; i < ARMV8_MAX_COUNTERS - 1; i++) {
> + pmc = &pmu->pmc[i];
> + if (pmc->perf_event)
> + local64_set(&pmc->perf_event->count, 0);
> + if (!vcpu_mode_is_32bit(vcpu))
> + vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = 0;
> + else
> + vcpu_cp15(vcpu, c14_PMEVCNTR0 + i) = 0;
> + }
> + }
> +
> + if (val & ARMV8_PMCR_LC) {
> + pmc = &pmu->pmc[ARMV8_MAX_COUNTERS - 1];
> + pmc->bitmask = 0xffffffffffffffffUL;
> + }
> +}
> +
> +/**
> * kvm_pmu_overflow_clear - clear PMU overflow interrupt
> * @vcpu: The vcpu pointer
> * @val: the value guest writes to PMOVSCLR register
>
--
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