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author | Shannon Zhao <shannon.zhao@linaro.org> | 2015-09-08 12:26:13 +0800 |
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committer | Marc Zyngier <marc.zyngier@arm.com> | 2016-02-29 18:34:20 +0000 |
commit | 96b0eebcc6a14e3bdb9ff0e7176fbfc225bdde94 (patch) | |
tree | afd6c0fcecda21c73164e7fee6c9bef65ee50e16 /virt | |
parent | 051ff581ce70e822729e9474941f3c206cbf7436 (diff) | |
download | linux-stable-96b0eebcc6a14e3bdb9ff0e7176fbfc225bdde94.tar.gz linux-stable-96b0eebcc6a14e3bdb9ff0e7176fbfc225bdde94.tar.bz2 linux-stable-96b0eebcc6a14e3bdb9ff0e7176fbfc225bdde94.zip |
arm64: KVM: Add access handler for PMCNTENSET and PMCNTENCLR register
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 <shannon.zhao@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'virt')
-rw-r--r-- | virt/kvm/arm/pmu.c | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c index cd74e6367cd6..f8dc17430813 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); + } +} |