diff options
Diffstat (limited to 'virt/kvm/arm/pmu.c')
| -rw-r--r-- | virt/kvm/arm/pmu.c | 529 |
1 files changed, 529 insertions, 0 deletions
diff --git a/virt/kvm/arm/pmu.c b/virt/kvm/arm/pmu.c new file mode 100644 index 000000000000..b5754c6c5508 --- /dev/null +++ b/virt/kvm/arm/pmu.c @@ -0,0 +1,529 @@ +/* + * Copyright (C) 2015 Linaro Ltd. + * Author: Shannon Zhao <shannon.zhao@linaro.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ + +#include <linux/cpu.h> +#include <linux/kvm.h> +#include <linux/kvm_host.h> +#include <linux/perf_event.h> +#include <linux/uaccess.h> +#include <asm/kvm_emulate.h> +#include <kvm/arm_pmu.h> +#include <kvm/arm_vgic.h> + +/** + * 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, reg, enabled, running; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc = &pmu->pmc[select_idx]; + + reg = (select_idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + select_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 & pmc->bitmask; +} + +/** + * 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); +} + +/** + * 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; + + if (pmc->perf_event) { + counter = kvm_pmu_get_counter_value(vcpu, pmc->idx); + reg = (pmc->idx == ARMV8_PMU_CYCLE_IDX) + ? PMCCNTR_EL0 : PMEVCNTR0_EL0 + pmc->idx; + vcpu_sys_reg(vcpu, reg) = counter; + perf_event_disable(pmc->perf_event); + perf_event_release_kernel(pmc->perf_event); + pmc->perf_event = NULL; + } +} + +/** + * kvm_pmu_vcpu_reset - reset pmu state for cpu + * @vcpu: The vcpu pointer + * + */ +void kvm_pmu_vcpu_reset(struct kvm_vcpu *vcpu) +{ + int i; + struct kvm_pmu *pmu = &vcpu->arch.pmu; + + for (i = 0; i < ARMV8_PMU_MAX_COUNTERS; i++) { + kvm_pmu_stop_counter(vcpu, &pmu->pmc[i]); + pmu->pmc[i].idx = i; + pmu->pmc[i].bitmask = 0xffffffffUL; + } +} + +/** + * 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++) { + struct kvm_pmc *pmc = &pmu->pmc[i]; + + if (pmc->perf_event) { + perf_event_disable(pmc->perf_event); + perf_event_release_kernel(pmc->perf_event); + pmc->perf_event = NULL; + } + } +} + +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); + } +} + +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; +} + +/** + * kvm_pmu_overflow_set - set PMU overflow interrupt + * @vcpu: The vcpu pointer + * @val: the value guest writes to PMOVSSET register + */ +void kvm_pmu_overflow_set(struct kvm_vcpu *vcpu, u64 val) +{ + u64 reg; + + if (val == 0) + return; + + vcpu_sys_reg(vcpu, PMOVSSET_EL0) |= val; + reg = kvm_pmu_overflow_status(vcpu); + if (reg != 0) + kvm_vcpu_kick(vcpu); +} + +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) { + pmu->irq_level = overflow; + kvm_vgic_inject_irq(vcpu->kvm, vcpu->vcpu_id, + pmu->irq_num, overflow); + } +} + +/** + * 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); +} + +static inline 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); +} + +/** + * When perf event overflows, call kvm_pmu_overflow_set to set overflow status. + */ +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 kvm_vcpu *vcpu = kvm_pmc_to_vcpu(pmc); + int idx = pmc->idx; + + kvm_pmu_overflow_set(vcpu, BIT(idx)); +} + +/** + * 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) +{ + int i; + u64 type, enable, reg; + + if (val == 0) + return; + + enable = vcpu_sys_reg(vcpu, PMCNTENSET_EL0); + for (i = 0; i < ARMV8_PMU_CYCLE_IDX; i++) { + if (!(val & BIT(i))) + continue; + type = vcpu_sys_reg(vcpu, PMEVTYPER0_EL0 + i) + & ARMV8_PMU_EVTYPE_EVENT; + if ((type == ARMV8_PMU_EVTYPE_EVENT_SW_INCR) + && (enable & BIT(i))) { + reg = vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) + 1; + reg = lower_32_bits(reg); + vcpu_sys_reg(vcpu, PMEVCNTR0_EL0 + i) = reg; + if (!reg) + kvm_pmu_overflow_set(vcpu, 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) +{ + 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) && + (vcpu_sys_reg(vcpu, PMCNTENSET_EL0) & BIT(select_idx)); +} + +/** + * 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) +{ + struct kvm_pmu *pmu = &vcpu->arch.pmu; + struct kvm_pmc *pmc = &pmu->pmc[select_idx]; + struct perf_event *event; + struct perf_event_attr attr; + u64 eventsel, counter; + + 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_PMU_EVTYPE_EVENT_SW_INCR) + 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, select_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 = eventsel; + + counter = kvm_pmu_get_counter_value(vcpu, select_idx); + /* The initial sample period (overflow count) of an event. */ + attr.sample_period = (-counter) & pmc->bitmask; + + 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; +} + +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); +} + +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) || + !kvm_arm_pmu_irq_initialized(vcpu)) + return -ENXIO; + + if (kvm_arm_pmu_v3_ready(vcpu)) + return -EBUSY; + + kvm_pmu_vcpu_reset(vcpu); + vcpu->arch.pmu.ready = true; + + return 0; +} + +static bool irq_is_valid(struct kvm *kvm, int irq, bool is_ppi) +{ + int i; + struct kvm_vcpu *vcpu; + + kvm_for_each_vcpu(i, vcpu, kvm) { + if (!kvm_arm_pmu_irq_initialized(vcpu)) + continue; + + if (is_ppi) { + 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 (!test_bit(KVM_ARM_VCPU_PMU_V3, vcpu->arch.features)) + return -ENODEV; + + if (get_user(irq, uaddr)) + return -EFAULT; + + /* + * The PMU overflow interrupt could be a PPI or SPI, but 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. + */ + if (irq < VGIC_NR_SGIS || irq >= vcpu->kvm->arch.vgic.nr_irqs || + !irq_is_valid(vcpu->kvm, irq, irq < VGIC_NR_PRIVATE_IRQS)) + 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 (!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; +} |