pmu_intel.c
/*
* KVM PMU support for Intel CPUs
*
* 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 <asm/perf_event.h>
#include "x86.h"
#include "cpuid.h"
#include "lapic.h"
#include "pmu.h"
static struct kvm_event_hw_type_mapping intel_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 intel_arch_events array */
static int fixed_pmc_events[] = {1, 0, 7};
static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
{
int i;
for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
u8 new_ctrl = fixed_ctrl_field(data, i);
u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
struct kvm_pmc *pmc;
pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
if (old_ctrl == new_ctrl)
continue;
reprogram_fixed_counter(pmc, new_ctrl, i);
}
pmu->fixed_ctr_ctrl = data;
}
/* function is called when global control register has been updated. */
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_counter(pmu, bit);
}
static unsigned intel_find_arch_event(struct kvm_pmu *pmu,
u8 event_select,
u8 unit_mask)
{
int i;
for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++)
if (intel_arch_events[i].eventsel == event_select
&& intel_arch_events[i].unit_mask == unit_mask
&& (pmu->available_event_types & (1 << i)))
break;
if (i == ARRAY_SIZE(intel_arch_events))
return PERF_COUNT_HW_MAX;
return intel_arch_events[i].event_type;
}
static unsigned intel_find_fixed_event(int idx)
{
if (idx >= ARRAY_SIZE(fixed_pmc_events))
return PERF_COUNT_HW_MAX;
return intel_arch_events[fixed_pmc_events[idx]].event_type;
}
/* check if a PMC is enabled by comparing it with globl_ctrl bits. */
static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
{
struct kvm_pmu *pmu = pmc_to_pmu(pmc);
return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
}
static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
{
if (pmc_idx < INTEL_PMC_IDX_FIXED)
return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
MSR_P6_EVNTSEL0);
else {
u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
}
}
/* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
bool fixed = idx & (1u << 30);
idx &= ~(3u << 30);
return (!fixed && idx >= pmu->nr_arch_gp_counters) ||
(fixed && idx >= pmu->nr_arch_fixed_counters);
}
static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
unsigned idx)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
bool fixed = idx & (1u << 30);
struct kvm_pmc *counters;
idx &= ~(3u << 30);
if (!fixed && idx >= pmu->nr_arch_gp_counters)
return NULL;
if (fixed && idx >= pmu->nr_arch_fixed_counters)
return NULL;
counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
return &counters[idx];
}
static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
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;
}
static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
switch (msr) {
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, msr, MSR_IA32_PERFCTR0)) ||
(pmc = get_fixed_pmc(pmu, msr))) {
*data = pmc_read_counter(pmc);
return 0;
} else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
*data = pmc->eventsel;
return 0;
}
}
return 1;
}
static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_pmc *pmc;
u32 msr = msr_info->index;
u64 data = msr_info->data;
switch (msr) {
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, msr, MSR_IA32_PERFCTR0)) ||
(pmc = get_fixed_pmc(pmu, msr))) {
if (!msr_info->host_initiated)
data = (s64)(s32)data;
pmc->counter += data - pmc_read_counter(pmc);
return 0;
} else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
if (data == pmc->eventsel)
return 0;
if (!(data & pmu->reserved_bits)) {
reprogram_gp_counter(pmc, data);
return 0;
}
}
}
return 1;
}
static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
struct kvm_cpuid_entry2 *entry;
union cpuid10_eax eax;
union cpuid10_edx edx;
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;
pmu->reserved_bits = 0xffffffff00200000ull;
entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
if (!entry)
return;
eax.full = entry->eax;
edx.full = entry->edx;
pmu->version = eax.split.version_id;
if (!pmu->version)
return;
pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
INTEL_PMC_MAX_GENERIC);
pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1;
pmu->available_event_types = ~entry->ebx &
((1ull << eax.split.mask_length) - 1);
if (pmu->version == 1) {
pmu->nr_arch_fixed_counters = 0;
} else {
pmu->nr_arch_fixed_counters =
min_t(int, edx.split.num_counters_fixed,
INTEL_PMC_MAX_FIXED);
pmu->counter_bitmask[KVM_PMC_FIXED] =
((u64)1 << edx.split.bit_width_fixed) - 1;
}
pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) |
(((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
pmu->global_ctrl_mask = ~pmu->global_ctrl;
entry = kvm_find_cpuid_entry(vcpu, 7, 0);
if (entry &&
(boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
(entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
pmu->reserved_bits ^= HSW_IN_TX|HSW_IN_TX_CHECKPOINTED;
}
static void intel_pmu_init(struct kvm_vcpu *vcpu)
{
int i;
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
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;
}
}
static void intel_pmu_reset(struct kvm_vcpu *vcpu)
{
struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
int i;
for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
struct kvm_pmc *pmc = &pmu->gp_counters[i];
pmc_stop_counter(pmc);
pmc->counter = pmc->eventsel = 0;
}
for (i = 0; i < INTEL_PMC_MAX_FIXED; i++)
pmc_stop_counter(&pmu->fixed_counters[i]);
pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status =
pmu->global_ovf_ctrl = 0;
}
struct kvm_pmu_ops intel_pmu_ops = {
.find_arch_event = intel_find_arch_event,
.find_fixed_event = intel_find_fixed_event,
.pmc_is_enabled = intel_pmc_is_enabled,
.pmc_idx_to_pmc = intel_pmc_idx_to_pmc,
.msr_idx_to_pmc = intel_msr_idx_to_pmc,
.is_valid_msr_idx = intel_is_valid_msr_idx,
.is_valid_msr = intel_is_valid_msr,
.get_msr = intel_pmu_get_msr,
.set_msr = intel_pmu_set_msr,
.refresh = intel_pmu_refresh,
.init = intel_pmu_init,
.reset = intel_pmu_reset,
};