- 根目录:
- arch
- x86
- kvm
- pmu.c
/*
* Kernel-based Virtual Machine -- Performance 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 < INTEL_PMC_IDX_FIXED)
return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + idx, MSR_P6_EVNTSEL0);
else
return get_fixed_pmc_idx(pmu, idx - INTEL_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 - INTEL_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, struct msr_data *msr_info)
{
struct kvm_pmu *pmu = &vcpu->arch.pmu;
struct kvm_pmc *pmc;
u32 index = msr_info->index;
u64 data = msr_info->data;
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:
if (msr_info->host_initiated) {
pmu->global_status = data;
return 0;
}
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)))) {
if (!msr_info->host_initiated)
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))) {
if (!msr_info->host_initiated)
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,
INTEL_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),
INTEL_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) << INTEL_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 < INTEL_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 < INTEL_PMC_MAX_FIXED; i++) {
pmu->fixed_counters[i].type = KVM_PMC_FIXED;
pmu->fixed_counters[i].vcpu = vcpu;
pmu->fixed_counters[i].idx = i + INTEL_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 < INTEL_PMC_MAX_GENERIC; i++) {
struct kvm_pmc *pmc = &pmu->gp_counters[i];
stop_counter(pmc);
pmc->counter = pmc->eventsel = 0;
}
for (i = 0; i < INTEL_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);
}
}