arch/x86/kvm/pmu.c - kernel/msm - Gitiles

 /*
  * 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 },
 	[7] = { 0x00, 0x30, PERF_COUNT_HW_REF_CPU_CYCLES },
 };

 /* mapping between fixed pmc index and arch_events array */
 int fixed_pmc_events[] = {1, 0, 7};

 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;

 	if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
 		printk_once("kvm pmu: pin control bit is ignored\n");

 	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 (!(eventsel & (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 & 0xfffffffffffff444ull)) {
 			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);
 	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->nr_arch_fixed_counters = 0;
 	} else {
 		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 = ((1 << pmu->nr_arch_gp_counters) - 1) |
 		(((1ull << pmu->nr_arch_fixed_counters) - 1) << X86_PMC_IDX_FIXED);
 	pmu->global_ctrl_mask = ~pmu->global_ctrl;
 }

 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);
 	}
 }
	/*
	* 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 },
	[7] = { 0x00, 0x30, PERF_COUNT_HW_REF_CPU_CYCLES },
	};

	/* mapping between fixed pmc index and arch_events array */
	int fixed_pmc_events[] = {1, 0, 7};

	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;

	if (eventsel & ARCH_PERFMON_EVENTSEL_PIN_CONTROL)
	printk_once("kvm pmu: pin control bit is ignored\n");

	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 (!(eventsel & (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 & 0xfffffffffffff444ull)) {
	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);
	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->nr_arch_fixed_counters = 0;
	} else {
	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 = ((1 << pmu->nr_arch_gp_counters) - 1) \|
	(((1ull << pmu->nr_arch_fixed_counters) - 1) << X86_PMC_IDX_FIXED);
	pmu->global_ctrl_mask = ~pmu->global_ctrl;
	}

	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);
	}
	}