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| author | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-13 15:00:22 +0000 | 
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2012-01-13 15:00:22 +0000 | 
| commit | 4de3a8e101150feaefa1139611a50ff37467f33e (patch) | |
| tree | daada742542518b02d7db7c5d32e715eaa5f166d /arch/x86/kvm/pmu.c | |
| parent | 294064f58953f9964e5945424b09c51800330a83 (diff) | |
| parent | 099469502f62fbe0d7e4f0b83a2f22538367f734 (diff) | |
| download | olio-linux-3.10-4de3a8e101150feaefa1139611a50ff37467f33e.tar.xz olio-linux-3.10-4de3a8e101150feaefa1139611a50ff37467f33e.zip  | |
Merge branch 'master' into fixes
Diffstat (limited to 'arch/x86/kvm/pmu.c')
| -rw-r--r-- | arch/x86/kvm/pmu.c | 533 | 
1 files changed, 533 insertions, 0 deletions
diff --git a/arch/x86/kvm/pmu.c b/arch/x86/kvm/pmu.c new file mode 100644 index 00000000000..7aad5446f39 --- /dev/null +++ b/arch/x86/kvm/pmu.c @@ -0,0 +1,533 @@ +/* + * Kernel-based Virtual Machine -- Performane Monitoring Unit support + * + * Copyright 2011 Red Hat, Inc. and/or its affiliates. + * + * Authors: + *   Avi Kivity   <avi@redhat.com> + *   Gleb Natapov <gleb@redhat.com> + * + * This work is licensed under the terms of the GNU GPL, version 2.  See + * the COPYING file in the top-level directory. + * + */ + +#include <linux/types.h> +#include <linux/kvm_host.h> +#include <linux/perf_event.h> +#include "x86.h" +#include "cpuid.h" +#include "lapic.h" + +static struct kvm_arch_event_perf_mapping { +	u8 eventsel; +	u8 unit_mask; +	unsigned event_type; +	bool inexact; +} arch_events[] = { +	/* Index must match CPUID 0x0A.EBX bit vector */ +	[0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES }, +	[1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS }, +	[2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES  }, +	[3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES }, +	[4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES }, +	[5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS }, +	[6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES }, +}; + +/* mapping between fixed pmc index and arch_events array */ +int fixed_pmc_events[] = {1, 0, 2}; + +static bool pmc_is_gp(struct kvm_pmc *pmc) +{ +	return pmc->type == KVM_PMC_GP; +} + +static inline u64 pmc_bitmask(struct kvm_pmc *pmc) +{ +	struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu; + +	return pmu->counter_bitmask[pmc->type]; +} + +static inline bool pmc_enabled(struct kvm_pmc *pmc) +{ +	struct kvm_pmu *pmu = &pmc->vcpu->arch.pmu; +	return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl); +} + +static inline struct kvm_pmc *get_gp_pmc(struct kvm_pmu *pmu, u32 msr, +					 u32 base) +{ +	if (msr >= base && msr < base + pmu->nr_arch_gp_counters) +		return &pmu->gp_counters[msr - base]; +	return NULL; +} + +static inline struct kvm_pmc *get_fixed_pmc(struct kvm_pmu *pmu, u32 msr) +{ +	int base = MSR_CORE_PERF_FIXED_CTR0; +	if (msr >= base && msr < base + pmu->nr_arch_fixed_counters) +		return &pmu->fixed_counters[msr - base]; +	return NULL; +} + +static inline struct kvm_pmc *get_fixed_pmc_idx(struct kvm_pmu *pmu, int idx) +{ +	return get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + idx); +} + +static struct kvm_pmc *global_idx_to_pmc(struct kvm_pmu *pmu, int idx) +{ +	if (idx < X86_PMC_IDX_FIXED) +		return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + idx, MSR_P6_EVNTSEL0); +	else +		return get_fixed_pmc_idx(pmu, idx - X86_PMC_IDX_FIXED); +} + +void kvm_deliver_pmi(struct kvm_vcpu *vcpu) +{ +	if (vcpu->arch.apic) +		kvm_apic_local_deliver(vcpu->arch.apic, APIC_LVTPC); +} + +static void trigger_pmi(struct irq_work *irq_work) +{ +	struct kvm_pmu *pmu = container_of(irq_work, struct kvm_pmu, +			irq_work); +	struct kvm_vcpu *vcpu = container_of(pmu, struct kvm_vcpu, +			arch.pmu); + +	kvm_deliver_pmi(vcpu); +} + +static void kvm_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_pmu *pmu = &pmc->vcpu->arch.pmu; +	__set_bit(pmc->idx, (unsigned long *)&pmu->global_status); +} + +static void kvm_perf_overflow_intr(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_pmu *pmu = &pmc->vcpu->arch.pmu; +	if (!test_and_set_bit(pmc->idx, (unsigned long *)&pmu->reprogram_pmi)) { +		kvm_perf_overflow(perf_event, data, regs); +		kvm_make_request(KVM_REQ_PMU, pmc->vcpu); +		/* +		 * Inject PMI. If vcpu was in a guest mode during NMI PMI +		 * can be ejected on a guest mode re-entry. Otherwise we can't +		 * be sure that vcpu wasn't executing hlt instruction at the +		 * time of vmexit and is not going to re-enter guest mode until, +		 * woken up. So we should wake it, but this is impossible from +		 * NMI context. Do it from irq work instead. +		 */ +		if (!kvm_is_in_guest()) +			irq_work_queue(&pmc->vcpu->arch.pmu.irq_work); +		else +			kvm_make_request(KVM_REQ_PMI, pmc->vcpu); +	} +} + +static u64 read_pmc(struct kvm_pmc *pmc) +{ +	u64 counter, enabled, running; + +	counter = pmc->counter; + +	if (pmc->perf_event) +		counter += perf_event_read_value(pmc->perf_event, +						 &enabled, &running); + +	/* FIXME: Scaling needed? */ + +	return counter & pmc_bitmask(pmc); +} + +static void stop_counter(struct kvm_pmc *pmc) +{ +	if (pmc->perf_event) { +		pmc->counter = read_pmc(pmc); +		perf_event_release_kernel(pmc->perf_event); +		pmc->perf_event = NULL; +	} +} + +static void reprogram_counter(struct kvm_pmc *pmc, u32 type, +		unsigned config, bool exclude_user, bool exclude_kernel, +		bool intr) +{ +	struct perf_event *event; +	struct perf_event_attr attr = { +		.type = type, +		.size = sizeof(attr), +		.pinned = true, +		.exclude_idle = true, +		.exclude_host = 1, +		.exclude_user = exclude_user, +		.exclude_kernel = exclude_kernel, +		.config = config, +	}; + +	attr.sample_period = (-pmc->counter) & pmc_bitmask(pmc); + +	event = perf_event_create_kernel_counter(&attr, -1, current, +						 intr ? kvm_perf_overflow_intr : +						 kvm_perf_overflow, pmc); +	if (IS_ERR(event)) { +		printk_once("kvm: pmu event creation failed %ld\n", +				PTR_ERR(event)); +		return; +	} + +	pmc->perf_event = event; +	clear_bit(pmc->idx, (unsigned long*)&pmc->vcpu->arch.pmu.reprogram_pmi); +} + +static unsigned find_arch_event(struct kvm_pmu *pmu, u8 event_select, +		u8 unit_mask) +{ +	int i; + +	for (i = 0; i < ARRAY_SIZE(arch_events); i++) +		if (arch_events[i].eventsel == event_select +				&& arch_events[i].unit_mask == unit_mask +				&& (pmu->available_event_types & (1 << i))) +			break; + +	if (i == ARRAY_SIZE(arch_events)) +		return PERF_COUNT_HW_MAX; + +	return arch_events[i].event_type; +} + +static void reprogram_gp_counter(struct kvm_pmc *pmc, u64 eventsel) +{ +	unsigned config, type = PERF_TYPE_RAW; +	u8 event_select, unit_mask; + +	pmc->eventsel = eventsel; + +	stop_counter(pmc); + +	if (!(eventsel & ARCH_PERFMON_EVENTSEL_ENABLE) || !pmc_enabled(pmc)) +		return; + +	event_select = eventsel & ARCH_PERFMON_EVENTSEL_EVENT; +	unit_mask = (eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; + +	if (!(event_select & (ARCH_PERFMON_EVENTSEL_EDGE | +				ARCH_PERFMON_EVENTSEL_INV | +				ARCH_PERFMON_EVENTSEL_CMASK))) { +		config = find_arch_event(&pmc->vcpu->arch.pmu, event_select, +				unit_mask); +		if (config != PERF_COUNT_HW_MAX) +			type = PERF_TYPE_HARDWARE; +	} + +	if (type == PERF_TYPE_RAW) +		config = eventsel & X86_RAW_EVENT_MASK; + +	reprogram_counter(pmc, type, config, +			!(eventsel & ARCH_PERFMON_EVENTSEL_USR), +			!(eventsel & ARCH_PERFMON_EVENTSEL_OS), +			eventsel & ARCH_PERFMON_EVENTSEL_INT); +} + +static void reprogram_fixed_counter(struct kvm_pmc *pmc, u8 en_pmi, int idx) +{ +	unsigned en = en_pmi & 0x3; +	bool pmi = en_pmi & 0x8; + +	stop_counter(pmc); + +	if (!en || !pmc_enabled(pmc)) +		return; + +	reprogram_counter(pmc, PERF_TYPE_HARDWARE, +			arch_events[fixed_pmc_events[idx]].event_type, +			!(en & 0x2), /* exclude user */ +			!(en & 0x1), /* exclude kernel */ +			pmi); +} + +static inline u8 fixed_en_pmi(u64 ctrl, int idx) +{ +	return (ctrl >> (idx * 4)) & 0xf; +} + +static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data) +{ +	int i; + +	for (i = 0; i < pmu->nr_arch_fixed_counters; i++) { +		u8 en_pmi = fixed_en_pmi(data, i); +		struct kvm_pmc *pmc = get_fixed_pmc_idx(pmu, i); + +		if (fixed_en_pmi(pmu->fixed_ctr_ctrl, i) == en_pmi) +			continue; + +		reprogram_fixed_counter(pmc, en_pmi, i); +	} + +	pmu->fixed_ctr_ctrl = data; +} + +static void reprogram_idx(struct kvm_pmu *pmu, int idx) +{ +	struct kvm_pmc *pmc = global_idx_to_pmc(pmu, idx); + +	if (!pmc) +		return; + +	if (pmc_is_gp(pmc)) +		reprogram_gp_counter(pmc, pmc->eventsel); +	else { +		int fidx = idx - X86_PMC_IDX_FIXED; +		reprogram_fixed_counter(pmc, +				fixed_en_pmi(pmu->fixed_ctr_ctrl, fidx), fidx); +	} +} + +static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data) +{ +	int bit; +	u64 diff = pmu->global_ctrl ^ data; + +	pmu->global_ctrl = data; + +	for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX) +		reprogram_idx(pmu, bit); +} + +bool kvm_pmu_msr(struct kvm_vcpu *vcpu, u32 msr) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	int ret; + +	switch (msr) { +	case MSR_CORE_PERF_FIXED_CTR_CTRL: +	case MSR_CORE_PERF_GLOBAL_STATUS: +	case MSR_CORE_PERF_GLOBAL_CTRL: +	case MSR_CORE_PERF_GLOBAL_OVF_CTRL: +		ret = pmu->version > 1; +		break; +	default: +		ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) +			|| get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) +			|| get_fixed_pmc(pmu, msr); +		break; +	} +	return ret; +} + +int kvm_pmu_get_msr(struct kvm_vcpu *vcpu, u32 index, u64 *data) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	struct kvm_pmc *pmc; + +	switch (index) { +	case MSR_CORE_PERF_FIXED_CTR_CTRL: +		*data = pmu->fixed_ctr_ctrl; +		return 0; +	case MSR_CORE_PERF_GLOBAL_STATUS: +		*data = pmu->global_status; +		return 0; +	case MSR_CORE_PERF_GLOBAL_CTRL: +		*data = pmu->global_ctrl; +		return 0; +	case MSR_CORE_PERF_GLOBAL_OVF_CTRL: +		*data = pmu->global_ovf_ctrl; +		return 0; +	default: +		if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) || +				(pmc = get_fixed_pmc(pmu, index))) { +			*data = read_pmc(pmc); +			return 0; +		} else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) { +			*data = pmc->eventsel; +			return 0; +		} +	} +	return 1; +} + +int kvm_pmu_set_msr(struct kvm_vcpu *vcpu, u32 index, u64 data) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	struct kvm_pmc *pmc; + +	switch (index) { +	case MSR_CORE_PERF_FIXED_CTR_CTRL: +		if (pmu->fixed_ctr_ctrl == data) +			return 0; +		if (!(data & 0xfffffffffffff444)) { +			reprogram_fixed_counters(pmu, data); +			return 0; +		} +		break; +	case MSR_CORE_PERF_GLOBAL_STATUS: +		break; /* RO MSR */ +	case MSR_CORE_PERF_GLOBAL_CTRL: +		if (pmu->global_ctrl == data) +			return 0; +		if (!(data & pmu->global_ctrl_mask)) { +			global_ctrl_changed(pmu, data); +			return 0; +		} +		break; +	case MSR_CORE_PERF_GLOBAL_OVF_CTRL: +		if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) { +			pmu->global_status &= ~data; +			pmu->global_ovf_ctrl = data; +			return 0; +		} +		break; +	default: +		if ((pmc = get_gp_pmc(pmu, index, MSR_IA32_PERFCTR0)) || +				(pmc = get_fixed_pmc(pmu, index))) { +			data = (s64)(s32)data; +			pmc->counter += data - read_pmc(pmc); +			return 0; +		} else if ((pmc = get_gp_pmc(pmu, index, MSR_P6_EVNTSEL0))) { +			if (data == pmc->eventsel) +				return 0; +			if (!(data & 0xffffffff00200000ull)) { +				reprogram_gp_counter(pmc, data); +				return 0; +			} +		} +	} +	return 1; +} + +int kvm_pmu_read_pmc(struct kvm_vcpu *vcpu, unsigned pmc, u64 *data) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	bool fast_mode = pmc & (1u << 31); +	bool fixed = pmc & (1u << 30); +	struct kvm_pmc *counters; +	u64 ctr; + +	pmc &= (3u << 30) - 1; +	if (!fixed && pmc >= pmu->nr_arch_gp_counters) +		return 1; +	if (fixed && pmc >= pmu->nr_arch_fixed_counters) +		return 1; +	counters = fixed ? pmu->fixed_counters : pmu->gp_counters; +	ctr = read_pmc(&counters[pmc]); +	if (fast_mode) +		ctr = (u32)ctr; +	*data = ctr; + +	return 0; +} + +void kvm_pmu_cpuid_update(struct kvm_vcpu *vcpu) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	struct kvm_cpuid_entry2 *entry; +	unsigned bitmap_len; + +	pmu->nr_arch_gp_counters = 0; +	pmu->nr_arch_fixed_counters = 0; +	pmu->counter_bitmask[KVM_PMC_GP] = 0; +	pmu->counter_bitmask[KVM_PMC_FIXED] = 0; +	pmu->version = 0; + +	entry = kvm_find_cpuid_entry(vcpu, 0xa, 0); +	if (!entry) +		return; + +	pmu->version = entry->eax & 0xff; +	if (!pmu->version) +		return; + +	pmu->nr_arch_gp_counters = min((int)(entry->eax >> 8) & 0xff, +			X86_PMC_MAX_GENERIC); +	pmu->counter_bitmask[KVM_PMC_GP] = +		((u64)1 << ((entry->eax >> 16) & 0xff)) - 1; +	bitmap_len = (entry->eax >> 24) & 0xff; +	pmu->available_event_types = ~entry->ebx & ((1ull << bitmap_len) - 1); + +	if (pmu->version == 1) { +		pmu->global_ctrl = (1 << pmu->nr_arch_gp_counters) - 1; +		return; +	} + +	pmu->nr_arch_fixed_counters = min((int)(entry->edx & 0x1f), +			X86_PMC_MAX_FIXED); +	pmu->counter_bitmask[KVM_PMC_FIXED] = +		((u64)1 << ((entry->edx >> 5) & 0xff)) - 1; +	pmu->global_ctrl_mask = ~(((1 << pmu->nr_arch_gp_counters) - 1) +			| (((1ull << pmu->nr_arch_fixed_counters) - 1) +				<< X86_PMC_IDX_FIXED)); +} + +void kvm_pmu_init(struct kvm_vcpu *vcpu) +{ +	int i; +	struct kvm_pmu *pmu = &vcpu->arch.pmu; + +	memset(pmu, 0, sizeof(*pmu)); +	for (i = 0; i < X86_PMC_MAX_GENERIC; i++) { +		pmu->gp_counters[i].type = KVM_PMC_GP; +		pmu->gp_counters[i].vcpu = vcpu; +		pmu->gp_counters[i].idx = i; +	} +	for (i = 0; i < X86_PMC_MAX_FIXED; i++) { +		pmu->fixed_counters[i].type = KVM_PMC_FIXED; +		pmu->fixed_counters[i].vcpu = vcpu; +		pmu->fixed_counters[i].idx = i + X86_PMC_IDX_FIXED; +	} +	init_irq_work(&pmu->irq_work, trigger_pmi); +	kvm_pmu_cpuid_update(vcpu); +} + +void kvm_pmu_reset(struct kvm_vcpu *vcpu) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	int i; + +	irq_work_sync(&pmu->irq_work); +	for (i = 0; i < X86_PMC_MAX_GENERIC; i++) { +		struct kvm_pmc *pmc = &pmu->gp_counters[i]; +		stop_counter(pmc); +		pmc->counter = pmc->eventsel = 0; +	} + +	for (i = 0; i < X86_PMC_MAX_FIXED; i++) +		stop_counter(&pmu->fixed_counters[i]); + +	pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = +		pmu->global_ovf_ctrl = 0; +} + +void kvm_pmu_destroy(struct kvm_vcpu *vcpu) +{ +	kvm_pmu_reset(vcpu); +} + +void kvm_handle_pmu_event(struct kvm_vcpu *vcpu) +{ +	struct kvm_pmu *pmu = &vcpu->arch.pmu; +	u64 bitmask; +	int bit; + +	bitmask = pmu->reprogram_pmi; + +	for_each_set_bit(bit, (unsigned long *)&bitmask, X86_PMC_IDX_MAX) { +		struct kvm_pmc *pmc = global_idx_to_pmc(pmu, bit); + +		if (unlikely(!pmc || !pmc->perf_event)) { +			clear_bit(bit, (unsigned long *)&pmu->reprogram_pmi); +			continue; +		} + +		reprogram_idx(pmu, bit); +	} +}  |