diff options
Diffstat (limited to 'arch/arm64/kvm/pmu-emul.c')
| -rw-r--r-- | arch/arm64/kvm/pmu-emul.c | 869 |
1 files changed, 869 insertions, 0 deletions
diff --git a/arch/arm64/kvm/pmu-emul.c b/arch/arm64/kvm/pmu-emul.c new file mode 100644 index 000000000000..f0d0312c0a55 --- /dev/null +++ b/arch/arm64/kvm/pmu-emul.c @@ -0,0 +1,869 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2015 Linaro Ltd. + * Author: Shannon Zhao <shannon.zhao@linaro.org> + */ + +#include <linux/cpu.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/perf_event.h> +#include <linux/perf/arm_pmu.h> +#include <linux/uaccess.h> +#include <asm/kvm_emulate.h> +#include <kvm/arm_pmu.h> +#include <kvm/arm_vgic.h> + +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx); +static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx); +static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc); + +#define PERF_ATTR_CFG1_KVM_PMU_CHAINED 0x1 + +/** + * kvm_pmu_idx_is_64bit - determine if select_idx is a 64bit counter + * @vcpu: The vcpu pointer + * @select_idx: The counter index + */ +static bool kvm_pmu_idx_is_64bit(struct kvm_vcpu *vcpu, u64 select_idx) +{ + return (select_idx == ARMV8_PMU_CYCLE_IDX && + __vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_LC); +} + +static struct kvm_vcpu *kvm_pmc_to_vcpu(struct kvm_pmc *pmc) +{ + struct kvm_pmu *pmu; + struct kvm_vcpu_arch *vcpu_arch; + + pmc -= pmc->idx; + pmu = container_of(pmc, struct kvm_pmu, pmc[0]); + vcpu_arch = container_of(pmu, struct kvm_vcpu_arch, pmu); + return container_of(vcpu_arch, struct kvm_vcpu, arch); +} + +/** + * kvm_pmu_pmc_is_chained - determine if the pmc is chained + * @pmc: The PMU counter pointer + */ +static bool kvm_pmu_pmc_is_chained(struct kvm_pmc *pmc) +{ + struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc); + + return test_bit(pmc->idx >> 1, vcpu->arch.pmu.chained); +} + +/** + * kvm_pmu_idx_is_high_counter - determine if select_idx is a high/low counter + * @select_idx: The counter index + */ +static bool kvm_pmu_idx_is_high_counter(u64 select_idx) +{ + return select_idx & 0x1; +} + +/** + * kvm_pmu_get_canonical_pmc - obtain the canonical pmc + * @pmc: The PMU counter pointer + * + * When a pair of PMCs are chained together we use the low counter (canonical) + * to hold the underlying perf event. + */ +static struct kvm_pmc *kvm_pmu_get_canonical_pmc(struct kvm_pmc *pmc) +{ + if (kvm_pmu_pmc_is_chained(pmc) && + kvm_pmu_idx_is_high_counter(pmc->idx)) + return pmc - 1; + + return pmc; +} +static struct kvm_pmc *kvm_pmu_get_alternate_pmc(struct kvm_pmc *pmc) +{ + if (kvm_pmu_idx_is_high_counter(pmc->idx)) + return pmc - 1; + else + return pmc + 1; +} + +/** + * kvm_pmu_idx_has_chain_evtype - determine if the event type is chain + * @vcpu: The vcpu pointer + * @select_idx: The counter index + */ +static bool kvm_pmu_idx_has_chain_evtype(struct kvm_vcpu *vcpu, u64 select_idx) +{ + u64 eventsel, reg; + + select_idx |= 0x1; + + if (select_idx == ARMV8_PMU_CYCLE_IDX) + return false; + + reg = PMEVTYPER0_EL0 + select_idx; + eventsel = __vcpu_sys_reg(vcpu, reg) & ARMV8_PMU_EVTYPE_EVENT; + + return eventsel == ARMV8_PMUV3_PERFCTR_CHAIN; +} + +/** + * kvm_pmu_get_pair_counter_value - get PMU counter value + * @vcpu: The vcpu pointer + * @pmc: The PMU counter pointer + */ +static u64 kvm_pmu_get_pair_counter_value(struct kvm_vcpu *vcpu, + struct kvm_pmc *pmc) +{ + u64 counter, counter_high, reg, enabled, running; + + if (kvm_pmu_pmc_is_chained(pmc)) { + pmc = kvm_pmu_get_canonical_pmc(pmc); + reg = PMEVCNTR0_EL0 + pmc->idx; + + counter = __vcpu_sys_reg(vcpu, reg); + counter_high = __vcpu_sys_reg(vcpu, reg + 1); + + counter = lower_32_bits(counter) | (counter_high << 32); + } else { + reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx; + counter = __vcpu_sys_reg(vcpu, reg); + } + + /* + * The real counter value is equal to the value of counter register plus + * the value perf event counts. + */ + if (pmc->perf_event) + counter += perf_event_read_value(pmc->perf_event, &enabled, + &running); + + return counter; +} + +/** + * kvm_pmu_get_counter_value - get PMU counter value + * @vcpu: The vcpu pointer + * @select_idx: The counter index + */ +u64 kvm_pmu_get_counter_value(struct kvm_vcpu *vcpu, u64 select_idx) +{ + u64 counter; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc = &pmu->pmc[select_idx]; + + counter = kvm_pmu_get_pair_counter_value(vcpu, pmc); + + if (kvm_pmu_pmc_is_chained(pmc) && + kvm_pmu_idx_is_high_counter(select_idx)) + counter = upper_32_bits(counter); + else if (select_idx != ARMV8_PMU_CYCLE_IDX) + counter = lower_32_bits(counter); + + return counter; +} + +/** + * kvm_pmu_set_counter_value - set PMU counter value + * @vcpu: The vcpu pointer + * @select_idx: The counter index + * @val: The counter value + */ +void kvm_pmu_set_counter_value(struct kvm_vcpu *vcpu, u64 select_idx, u64 val) +{ + u64 reg; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_idx; + __vcpu_sys_reg(vcpu, reg) += (s64)val - kvm_pmu_get_counter_value(vcpu, select_idx); + + /* Recreate the perf event to reflect the updated sample_period */ + kvm_pmu_create_perf_event(vcpu, select_idx); +} + +/** + * kvm_pmu_release_perf_event - remove the perf event + * @pmc: The PMU counter pointer + */ +static void kvm_pmu_release_perf_event(struct kvm_pmc *pmc) +{ + pmc = kvm_pmu_get_canonical_pmc(pmc); + if (pmc->perf_event) { + perf_event_disable(pmc->perf_event); + perf_event_release_kernel(pmc->perf_event); + pmc->perf_event = NULL; + } +} + +/** + * kvm_pmu_stop_counter - stop PMU counter + * @pmc: The PMU counter pointer + * + * If this counter has been configured to monitor some event, release it here. + */ +static void kvm_pmu_stop_counter(struct kvm_vcpu *vcpu, struct kvm_pmc *pmc) +{ + u64 counter, reg, val; + + pmc = kvm_pmu_get_canonical_pmc(pmc); + if (!pmc->perf_event) + return; + + counter = kvm_pmu_get_pair_counter_value(vcpu, pmc); + + if (pmc->idx == ARMV8_PMU_CYCLE_IDX) { + reg = PMCCNTR_EL0; + val = counter; + } else { + reg = PMEVCNTR0_EL0 + pmc->idx; + val = lower_32_bits(counter); + } + + __vcpu_sys_reg(vcpu, reg) = val; + + if (kvm_pmu_pmc_is_chained(pmc)) + __vcpu_sys_reg(vcpu, reg + 1) = upper_32_bits(counter); + + kvm_pmu_release_perf_event(pmc); +} + +/** + * kvm_pmu_vcpu_init - assign pmu counter idx for cpu + * @vcpu: The vcpu pointer + * + */ +void kvm_pmu_vcpu_init(struct kvm_vcpu *vcpu) +{ + int i; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + + for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) + pmu->pmc[i].idx = i; +} + +/** + * kvm_pmu_vcpu_reset - reset pmu state for cpu + * @vcpu: The vcpu pointer + * + */ +void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) +{ + unsigned long mask = kvm_pmu_valid_counter_mask(vcpu); + struct kvm_pmu *pmu = &vcpu->arch.pmu; + int i; + + for_each_set_bit(i, &mask, 32) + kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]); + + bitmap_zero(vcpu->arch.pmu.chained, ARMV8_PMU_MAX_COUNTER_PAIRS); +} + +/** + * kvm_pmu_vcpu_destroy - free perf event of PMU for cpu + * @vcpu: The vcpu pointer + * + */ +void kvm_pmu_vcpu_destroy(struct kvm_vcpu *vcpu) +{ + int i; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + + for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) + kvm_pmu_release_perf_event(&pmu->pmc[i]); +} + +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_mask - enable selected PMU counters + * @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_mask(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]; + + /* A change in the enable state may affect the chain state */ + kvm_pmu_update_pmc_chained(vcpu, i); + kvm_pmu_create_perf_event(vcpu, i); + + /* At this point, pmc must be the canonical */ + 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_mask - disable selected PMU counters + * @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_mask(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]; + + /* A change in the enable state may affect the chain state */ + kvm_pmu_update_pmc_chained(vcpu, i); + kvm_pmu_create_perf_event(vcpu, i); + + /* At this point, pmc must be the canonical */ + if (pmc->perf_event) + perf_event_disable(pmc->perf_event); + } +} + +static u64 kvm_pmu_overflow_status(struct kvm_vcpu *vcpu) +{ + u64 reg = 0; + + if ((__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E)) { + reg = __vcpu_sys_reg(vcpu, PMOVSSET_EL0); + reg &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); + reg &= __vcpu_sys_reg(vcpu, PMINTENSET_EL1); + reg &= kvm_pmu_valid_counter_mask(vcpu); + } + + return reg; +} + +static void kvm_pmu_update_state(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + bool overflow; + + if (!kvm_arm_pmu_v3_ready(vcpu)) + return; + + overflow = !!kvm_pmu_overflow_status(vcpu); + if (pmu->irq_level == overflow) + return; + + pmu->irq_level = overflow; + + if (likely(irqchip_in_kernel(vcpu->kvm))) { + int ret = kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + pmu->irq_num, overflow, pmu); + WARN_ON(ret); + } +} + +bool kvm_pmu_should_notify_user(struct kvm_vcpu *vcpu) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_sync_regs *sregs = &vcpu->run->s.regs; + bool run_level = sregs->device_irq_level & KVM_ARM_DEV_PMU; + + if (likely(irqchip_in_kernel(vcpu->kvm))) + return false; + + return pmu->irq_level != run_level; +} + +/* + * Reflect the PMU overflow interrupt output level into the kvm_run structure + */ +void kvm_pmu_update_run(struct kvm_vcpu *vcpu) +{ + struct kvm_sync_regs *regs = &vcpu->run->s.regs; + + /* Populate the timer bitmap for user space */ + regs->device_irq_level &= ~KVM_ARM_DEV_PMU; + if (vcpu->arch.pmu.irq_level) + regs->device_irq_level |= KVM_ARM_DEV_PMU; +} + +/** + * kvm_pmu_flush_hwstate - flush pmu state to cpu + * @vcpu: The vcpu pointer + * + * Check if the PMU has overflowed while we were running in the host, and inject + * an interrupt if that was the case. + */ +void kvm_pmu_flush_hwstate(struct kvm_vcpu *vcpu) +{ + kvm_pmu_update_state(vcpu); +} + +/** + * kvm_pmu_sync_hwstate - sync pmu state from cpu + * @vcpu: The vcpu pointer + * + * Check if the PMU has overflowed while we were running in the guest, and + * inject an interrupt if that was the case. + */ +void kvm_pmu_sync_hwstate(struct kvm_vcpu *vcpu) +{ + kvm_pmu_update_state(vcpu); +} + +/** + * When the perf event overflows, set the overflow status and inform the vcpu. + */ +static void kvm_pmu_perf_overflow(struct perf_event *perf_event, + struct perf_sample_data *data, + struct pt_regs *regs) +{ + struct kvm_pmc *pmc = perf_event->overflow_handler_context; + struct arm_pmu *cpu_pmu = to_arm_pmu(perf_event->pmu); + struct kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc); + int idx = pmc->idx; + u64 period; + + cpu_pmu->pmu.stop(perf_event, PERF_EF_UPDATE); + + /* + * Reset the sample period to the architectural limit, + * i.e. the point where the counter overflows. + */ + period = -(local64_read(&perf_event->count)); + + if (!kvm_pmu_idx_is_64bit(vcpu, pmc->idx)) + period &= GENMASK(31, 0); + + local64_set(&perf_event->hw.period_left, 0); + perf_event->attr.sample_period = period; + perf_event->hw.sample_period = period; + + __vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(idx); + + if (kvm_pmu_overflow_status(vcpu)) { + kvm_make_request(KVM_REQ_IRQ_PENDING, vcpu); + kvm_vcpu_kick(vcpu); + } + + cpu_pmu->pmu.start(perf_event, PERF_EF_RELOAD); +} + +/** + * kvm_pmu_software_increment - do software increment + * @vcpu: The vcpu pointer + * @val: the value guest writes to PMSWINC register + */ +void kvm_pmu_software_increment(struct kvm_vcpu *vcpu, u64 val) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + int i; + + if (!(__vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E)) + return; + + /* Weed out disabled counters */ + val &= __vcpu_sys_reg(vcpu, PMCNTENSET_EL0); + + for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) { + u64 type, reg; + + if (!(val & BIT(i))) + continue; + + /* PMSWINC only applies to ... SW_INC! */ + type = __vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i); + type &= ARMV8_PMU_EVTYPE_EVENT; + if (type != ARMV8_PMUV3_PERFCTR_SW_INCR) + continue; + + /* increment this even SW_INC counter */ + reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1; + reg = lower_32_bits(reg); + __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg; + + if (reg) /* no overflow on the low part */ + continue; + + if (kvm_pmu_pmc_is_chained(&pmu->pmc[i])) { + /* increment the high counter */ + reg = __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i + 1) + 1; + reg = lower_32_bits(reg); + __vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i + 1) = reg; + if (!reg) /* mark overflow on the high counter */ + __vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i + 1); + } else { + /* mark overflow on low counter */ + __vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= BIT(i); + } + } +} + +/** + * 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) +{ + unsigned long mask = kvm_pmu_valid_counter_mask(vcpu); + int i; + + if (val & ARMV8_PMU_PMCR_E) { + kvm_pmu_enable_counter_mask(vcpu, + __vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & mask); + } else { + kvm_pmu_disable_counter_mask(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_each_set_bit(i, &mask, 32) + kvm_pmu_set_counter_value(vcpu, i, 0); + } +} + +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) && + (__vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & BIT(select_idx)); +} + +/** + * kvm_pmu_create_perf_event - create a perf event for a counter + * @vcpu: The vcpu pointer + * @select_idx: The number of selected counter + */ +static void kvm_pmu_create_perf_event(struct kvm_vcpu *vcpu, u64 select_idx) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc; + struct perf_event *event; + struct perf_event_attr attr; + u64 eventsel, counter, reg, data; + + /* + * For chained counters the event type and filtering attributes are + * obtained from the low/even counter. We also use this counter to + * determine if the event is enabled/disabled. + */ + pmc = kvm_pmu_get_canonical_pmc(&pmu->pmc[select_idx]); + + reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + pmc->idx; + data = __vcpu_sys_reg(vcpu, reg); + + kvm_pmu_stop_counter(vcpu, pmc); + eventsel = data & ARMV8_PMU_EVTYPE_EVENT; + + /* Software increment event does't need to be backed by a perf event */ + if (eventsel == ARMV8_PMUV3_PERFCTR_SW_INCR && + pmc->idx != ARMV8_PMU_CYCLE_IDX) + return; + + memset(&attr, 0, sizeof(struct perf_event_attr)); + attr.type = PERF_TYPE_RAW; + attr.size = sizeof(attr); + attr.pinned = 1; + attr.disabled = !kvm_pmu_counter_is_enabled(vcpu, pmc->idx); + attr.exclude_user = data & ARMV8_PMU_EXCLUDE_EL0 ? 1 : 0; + attr.exclude_kernel = data & ARMV8_PMU_EXCLUDE_EL1 ? 1 : 0; + attr.exclude_hv = 1; /* Don't count EL2 events */ + attr.exclude_host = 1; /* Don't count host events */ + attr.config = (pmc->idx == ARMV8_PMU_CYCLE_IDX) ? + ARMV8_PMUV3_PERFCTR_CPU_CYCLES : eventsel; + + counter = kvm_pmu_get_pair_counter_value(vcpu, pmc); + + if (kvm_pmu_pmc_is_chained(pmc)) { + /** + * The initial sample period (overflow count) of an event. For + * chained counters we only support overflow interrupts on the + * high counter. + */ + attr.sample_period = (-counter) & GENMASK(63, 0); + attr.config1 |= PERF_ATTR_CFG1_KVM_PMU_CHAINED; + + event = perf_event_create_kernel_counter(&attr, -1, current, + kvm_pmu_perf_overflow, + pmc + 1); + } else { + /* The initial sample period (overflow count) of an event. */ + if (kvm_pmu_idx_is_64bit(vcpu, pmc->idx)) + attr.sample_period = (-counter) & GENMASK(63, 0); + else + attr.sample_period = (-counter) & GENMASK(31, 0); + + event = perf_event_create_kernel_counter(&attr, -1, current, + kvm_pmu_perf_overflow, pmc); + } + + if (IS_ERR(event)) { + pr_err_once("kvm: pmu event creation failed %ld\n", + PTR_ERR(event)); + return; + } + + pmc->perf_event = event; +} + +/** + * kvm_pmu_update_pmc_chained - update chained bitmap + * @vcpu: The vcpu pointer + * @select_idx: The number of selected counter + * + * Update the chained bitmap based on the event type written in the + * typer register and the enable state of the odd register. + */ +static void kvm_pmu_update_pmc_chained(struct kvm_vcpu *vcpu, u64 select_idx) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc = &pmu->pmc[select_idx], *canonical_pmc; + bool new_state, old_state; + + old_state = kvm_pmu_pmc_is_chained(pmc); + new_state = kvm_pmu_idx_has_chain_evtype(vcpu, pmc->idx) && + kvm_pmu_counter_is_enabled(vcpu, pmc->idx | 0x1); + + if (old_state == new_state) + return; + + canonical_pmc = kvm_pmu_get_canonical_pmc(pmc); + kvm_pmu_stop_counter(vcpu, canonical_pmc); + if (new_state) { + /* + * During promotion from !chained to chained we must ensure + * the adjacent counter is stopped and its event destroyed + */ + kvm_pmu_stop_counter(vcpu, kvm_pmu_get_alternate_pmc(pmc)); + set_bit(pmc->idx >> 1, vcpu->arch.pmu.chained); + return; + } + clear_bit(pmc->idx >> 1, vcpu->arch.pmu.chained); +} + +/** + * 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 + * @select_idx: The number of selected counter + * + * When OS accesses PMXEVTYPER_EL0, that means it wants to set a PMC to count an + * event with given hardware event number. Here we call perf_event API to + * emulate this action and create a kernel perf event for it. + */ +void kvm_pmu_set_counter_event_type(struct kvm_vcpu *vcpu, u64 data, + u64 select_idx) +{ + u64 reg, event_type = data & ARMV8_PMU_EVTYPE_MASK; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCFILTR_EL0 : PMEVTYPER0_EL0 + select_idx; + + __vcpu_sys_reg(vcpu, reg) = event_type; + + kvm_pmu_update_pmc_chained(vcpu, select_idx); + kvm_pmu_create_perf_event(vcpu, select_idx); +} + +bool kvm_arm_support_pmu_v3(void) +{ + /* + * Check if HW_PERF_EVENTS are supported by checking the number of + * hardware performance counters. This could ensure the presence of + * a physical PMU and CONFIG_PERF_EVENT is selected. + */ + return (perf_num_counters() > 0); +} + +int kvm_arm_pmu_v3_enable(struct kvm_vcpu *vcpu) +{ + if (!vcpu->arch.pmu.created) + return 0; + + /* + * A valid interrupt configuration for the PMU is either to have a + * properly configured interrupt number and using an in-kernel + * irqchip, or to not have an in-kernel GIC and not set an IRQ. + */ + if (irqchip_in_kernel(vcpu->kvm)) { + int irq = vcpu->arch.pmu.irq_num; + if (!kvm_arm_pmu_irq_initialized(vcpu)) + return -EINVAL; + + /* + * If we are using an in-kernel vgic, at this point we know + * the vgic will be initialized, so we can check the PMU irq + * number against the dimensions of the vgic and make sure + * it's valid. + */ + if (!irq_is_ppi(irq) && !vgic_valid_spi(vcpu->kvm, irq)) + return -EINVAL; + } else if (kvm_arm_pmu_irq_initialized(vcpu)) { + return -EINVAL; + } + + kvm_pmu_vcpu_reset(vcpu); + vcpu->arch.pmu.ready = true; + + return 0; +} + +static int kvm_arm_pmu_v3_init(struct kvm_vcpu *vcpu) +{ + if (!kvm_arm_support_pmu_v3()) + return -ENODEV; + + if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) + return -ENXIO; + + if (vcpu->arch.pmu.created) + return -EBUSY; + + if (irqchip_in_kernel(vcpu->kvm)) { + int ret; + + /* + * If using the PMU with an in-kernel virtual GIC + * implementation, we require the GIC to be already + * initialized when initializing the PMU. + */ + if (!vgic_initialized(vcpu->kvm)) + return -ENODEV; + + if (!kvm_arm_pmu_irq_initialized(vcpu)) + return -ENXIO; + + ret = kvm_vgic_set_owner(vcpu, vcpu->arch.pmu.irq_num, + &vcpu->arch.pmu); + if (ret) + return ret; + } + + vcpu->arch.pmu.created = true; + return 0; +} + +/* + * For one VM the interrupt type must be same for each vcpu. + * As a PPI, the interrupt number is the same for all vcpus, + * while as an SPI it must be a separate number per vcpu. + */ +static bool pmu_irq_is_valid(struct kvm *kvm, int irq) +{ + int i; + struct kvm_vcpu *vcpu; + + kvm_for_each_vcpu(i, vcpu, kvm) { + if (!kvm_arm_pmu_irq_initialized(vcpu)) + continue; + + if (irq_is_ppi(irq)) { + if (vcpu->arch.pmu.irq_num != irq) + return false; + } else { + if (vcpu->arch.pmu.irq_num == irq) + return false; + } + } + + return true; +} + +int kvm_arm_pmu_v3_set_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) +{ + switch (attr->attr) { + case KVM_ARM_VCPU_PMU_V3_IRQ: { + int __user *uaddr = (int __user *)(long)attr->addr; + int irq; + + if (!irqchip_in_kernel(vcpu->kvm)) + return -EINVAL; + + if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) + return -ENODEV; + + if (get_user(irq, uaddr)) + return -EFAULT; + + /* The PMU overflow interrupt can be a PPI or a valid SPI. */ + if (!(irq_is_ppi(irq) || irq_is_spi(irq))) + return -EINVAL; + + if (!pmu_irq_is_valid(vcpu->kvm, irq)) + return -EINVAL; + + if (kvm_arm_pmu_irq_initialized(vcpu)) + return -EBUSY; + + kvm_debug("Set kvm ARM PMU irq: %d\n", irq); + vcpu->arch.pmu.irq_num = irq; + return 0; + } + case KVM_ARM_VCPU_PMU_V3_INIT: + return kvm_arm_pmu_v3_init(vcpu); + } + + return -ENXIO; +} + +int kvm_arm_pmu_v3_get_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) +{ + switch (attr->attr) { + case KVM_ARM_VCPU_PMU_V3_IRQ: { + int __user *uaddr = (int __user *)(long)attr->addr; + int irq; + + if (!irqchip_in_kernel(vcpu->kvm)) + return -EINVAL; + + if (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) + return -ENODEV; + + if (!kvm_arm_pmu_irq_initialized(vcpu)) + return -ENXIO; + + irq = vcpu->arch.pmu.irq_num; + return put_user(irq, uaddr); + } + } + + return -ENXIO; +} + +int kvm_arm_pmu_v3_has_attr(struct kvm_vcpu *vcpu, struct kvm_device_attr *attr) +{ + switch (attr->attr) { + case KVM_ARM_VCPU_PMU_V3_IRQ: + case KVM_ARM_VCPU_PMU_V3_INIT: + if (kvm_arm_support_pmu_v3() && + test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) + return 0; + } + + return -ENXIO; +} |