linux/arch/x86/kvm/vmx/pmu_intel.c
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   1/*
   2 * KVM PMU support for Intel CPUs
   3 *
   4 * Copyright 2011 Red Hat, Inc. and/or its affiliates.
   5 *
   6 * Authors:
   7 *   Avi Kivity   <avi@redhat.com>
   8 *   Gleb Natapov <gleb@redhat.com>
   9 *
  10 * This work is licensed under the terms of the GNU GPL, version 2.  See
  11 * the COPYING file in the top-level directory.
  12 *
  13 */
  14#include <linux/types.h>
  15#include <linux/kvm_host.h>
  16#include <linux/perf_event.h>
  17#include <asm/perf_event.h>
  18#include "x86.h"
  19#include "cpuid.h"
  20#include "lapic.h"
  21#include "pmu.h"
  22
  23static struct kvm_event_hw_type_mapping intel_arch_events[] = {
  24        /* Index must match CPUID 0x0A.EBX bit vector */
  25        [0] = { 0x3c, 0x00, PERF_COUNT_HW_CPU_CYCLES },
  26        [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
  27        [2] = { 0x3c, 0x01, PERF_COUNT_HW_BUS_CYCLES  },
  28        [3] = { 0x2e, 0x4f, PERF_COUNT_HW_CACHE_REFERENCES },
  29        [4] = { 0x2e, 0x41, PERF_COUNT_HW_CACHE_MISSES },
  30        [5] = { 0xc4, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
  31        [6] = { 0xc5, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
  32        [7] = { 0x00, 0x30, PERF_COUNT_HW_REF_CPU_CYCLES },
  33};
  34
  35/* mapping between fixed pmc index and intel_arch_events array */
  36static int fixed_pmc_events[] = {1, 0, 7};
  37
  38static void reprogram_fixed_counters(struct kvm_pmu *pmu, u64 data)
  39{
  40        int i;
  41
  42        for (i = 0; i < pmu->nr_arch_fixed_counters; i++) {
  43                u8 new_ctrl = fixed_ctrl_field(data, i);
  44                u8 old_ctrl = fixed_ctrl_field(pmu->fixed_ctr_ctrl, i);
  45                struct kvm_pmc *pmc;
  46
  47                pmc = get_fixed_pmc(pmu, MSR_CORE_PERF_FIXED_CTR0 + i);
  48
  49                if (old_ctrl == new_ctrl)
  50                        continue;
  51
  52                reprogram_fixed_counter(pmc, new_ctrl, i);
  53        }
  54
  55        pmu->fixed_ctr_ctrl = data;
  56}
  57
  58/* function is called when global control register has been updated. */
  59static void global_ctrl_changed(struct kvm_pmu *pmu, u64 data)
  60{
  61        int bit;
  62        u64 diff = pmu->global_ctrl ^ data;
  63
  64        pmu->global_ctrl = data;
  65
  66        for_each_set_bit(bit, (unsigned long *)&diff, X86_PMC_IDX_MAX)
  67                reprogram_counter(pmu, bit);
  68}
  69
  70static unsigned intel_find_arch_event(struct kvm_pmu *pmu,
  71                                      u8 event_select,
  72                                      u8 unit_mask)
  73{
  74        int i;
  75
  76        for (i = 0; i < ARRAY_SIZE(intel_arch_events); i++)
  77                if (intel_arch_events[i].eventsel == event_select
  78                    && intel_arch_events[i].unit_mask == unit_mask
  79                    && (pmu->available_event_types & (1 << i)))
  80                        break;
  81
  82        if (i == ARRAY_SIZE(intel_arch_events))
  83                return PERF_COUNT_HW_MAX;
  84
  85        return intel_arch_events[i].event_type;
  86}
  87
  88static unsigned intel_find_fixed_event(int idx)
  89{
  90        if (idx >= ARRAY_SIZE(fixed_pmc_events))
  91                return PERF_COUNT_HW_MAX;
  92
  93        return intel_arch_events[fixed_pmc_events[idx]].event_type;
  94}
  95
  96/* check if a PMC is enabled by comparing it with globl_ctrl bits. */
  97static bool intel_pmc_is_enabled(struct kvm_pmc *pmc)
  98{
  99        struct kvm_pmu *pmu = pmc_to_pmu(pmc);
 100
 101        return test_bit(pmc->idx, (unsigned long *)&pmu->global_ctrl);
 102}
 103
 104static struct kvm_pmc *intel_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
 105{
 106        if (pmc_idx < INTEL_PMC_IDX_FIXED)
 107                return get_gp_pmc(pmu, MSR_P6_EVNTSEL0 + pmc_idx,
 108                                  MSR_P6_EVNTSEL0);
 109        else {
 110                u32 idx = pmc_idx - INTEL_PMC_IDX_FIXED;
 111
 112                return get_fixed_pmc(pmu, idx + MSR_CORE_PERF_FIXED_CTR0);
 113        }
 114}
 115
 116/* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
 117static int intel_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
 118{
 119        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 120        bool fixed = idx & (1u << 30);
 121
 122        idx &= ~(3u << 30);
 123
 124        return (!fixed && idx >= pmu->nr_arch_gp_counters) ||
 125                (fixed && idx >= pmu->nr_arch_fixed_counters);
 126}
 127
 128static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu,
 129                                            unsigned idx)
 130{
 131        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 132        bool fixed = idx & (1u << 30);
 133        struct kvm_pmc *counters;
 134
 135        idx &= ~(3u << 30);
 136        if (!fixed && idx >= pmu->nr_arch_gp_counters)
 137                return NULL;
 138        if (fixed && idx >= pmu->nr_arch_fixed_counters)
 139                return NULL;
 140        counters = fixed ? pmu->fixed_counters : pmu->gp_counters;
 141
 142        return &counters[idx];
 143}
 144
 145static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 146{
 147        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 148        int ret;
 149
 150        switch (msr) {
 151        case MSR_CORE_PERF_FIXED_CTR_CTRL:
 152        case MSR_CORE_PERF_GLOBAL_STATUS:
 153        case MSR_CORE_PERF_GLOBAL_CTRL:
 154        case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 155                ret = pmu->version > 1;
 156                break;
 157        default:
 158                ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) ||
 159                        get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) ||
 160                        get_fixed_pmc(pmu, msr);
 161                break;
 162        }
 163
 164        return ret;
 165}
 166
 167static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
 168{
 169        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 170        struct kvm_pmc *pmc;
 171
 172        switch (msr) {
 173        case MSR_CORE_PERF_FIXED_CTR_CTRL:
 174                *data = pmu->fixed_ctr_ctrl;
 175                return 0;
 176        case MSR_CORE_PERF_GLOBAL_STATUS:
 177                *data = pmu->global_status;
 178                return 0;
 179        case MSR_CORE_PERF_GLOBAL_CTRL:
 180                *data = pmu->global_ctrl;
 181                return 0;
 182        case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 183                *data = pmu->global_ovf_ctrl;
 184                return 0;
 185        default:
 186                if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 187                    (pmc = get_fixed_pmc(pmu, msr))) {
 188                        *data = pmc_read_counter(pmc);
 189                        return 0;
 190                } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 191                        *data = pmc->eventsel;
 192                        return 0;
 193                }
 194        }
 195
 196        return 1;
 197}
 198
 199static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 200{
 201        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 202        struct kvm_pmc *pmc;
 203        u32 msr = msr_info->index;
 204        u64 data = msr_info->data;
 205
 206        switch (msr) {
 207        case MSR_CORE_PERF_FIXED_CTR_CTRL:
 208                if (pmu->fixed_ctr_ctrl == data)
 209                        return 0;
 210                if (!(data & 0xfffffffffffff444ull)) {
 211                        reprogram_fixed_counters(pmu, data);
 212                        return 0;
 213                }
 214                break;
 215        case MSR_CORE_PERF_GLOBAL_STATUS:
 216                if (msr_info->host_initiated) {
 217                        pmu->global_status = data;
 218                        return 0;
 219                }
 220                break; /* RO MSR */
 221        case MSR_CORE_PERF_GLOBAL_CTRL:
 222                if (pmu->global_ctrl == data)
 223                        return 0;
 224                if (!(data & pmu->global_ctrl_mask)) {
 225                        global_ctrl_changed(pmu, data);
 226                        return 0;
 227                }
 228                break;
 229        case MSR_CORE_PERF_GLOBAL_OVF_CTRL:
 230                if (!(data & (pmu->global_ctrl_mask & ~(3ull<<62)))) {
 231                        if (!msr_info->host_initiated)
 232                                pmu->global_status &= ~data;
 233                        pmu->global_ovf_ctrl = data;
 234                        return 0;
 235                }
 236                break;
 237        default:
 238                if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0)) ||
 239                    (pmc = get_fixed_pmc(pmu, msr))) {
 240                        if (!msr_info->host_initiated)
 241                                data = (s64)(s32)data;
 242                        pmc->counter += data - pmc_read_counter(pmc);
 243                        return 0;
 244                } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) {
 245                        if (data == pmc->eventsel)
 246                                return 0;
 247                        if (!(data & pmu->reserved_bits)) {
 248                                reprogram_gp_counter(pmc, data);
 249                                return 0;
 250                        }
 251                }
 252        }
 253
 254        return 1;
 255}
 256
 257static void intel_pmu_refresh(struct kvm_vcpu *vcpu)
 258{
 259        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 260        struct kvm_cpuid_entry2 *entry;
 261        union cpuid10_eax eax;
 262        union cpuid10_edx edx;
 263
 264        pmu->nr_arch_gp_counters = 0;
 265        pmu->nr_arch_fixed_counters = 0;
 266        pmu->counter_bitmask[KVM_PMC_GP] = 0;
 267        pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
 268        pmu->version = 0;
 269        pmu->reserved_bits = 0xffffffff00200000ull;
 270
 271        entry = kvm_find_cpuid_entry(vcpu, 0xa, 0);
 272        if (!entry)
 273                return;
 274        eax.full = entry->eax;
 275        edx.full = entry->edx;
 276
 277        pmu->version = eax.split.version_id;
 278        if (!pmu->version)
 279                return;
 280
 281        pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters,
 282                                        INTEL_PMC_MAX_GENERIC);
 283        pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1;
 284        pmu->available_event_types = ~entry->ebx &
 285                                        ((1ull << eax.split.mask_length) - 1);
 286
 287        if (pmu->version == 1) {
 288                pmu->nr_arch_fixed_counters = 0;
 289        } else {
 290                pmu->nr_arch_fixed_counters =
 291                        min_t(int, edx.split.num_counters_fixed,
 292                                INTEL_PMC_MAX_FIXED);
 293                pmu->counter_bitmask[KVM_PMC_FIXED] =
 294                        ((u64)1 << edx.split.bit_width_fixed) - 1;
 295        }
 296
 297        pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) |
 298                (((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED);
 299        pmu->global_ctrl_mask = ~pmu->global_ctrl;
 300
 301        entry = kvm_find_cpuid_entry(vcpu, 7, 0);
 302        if (entry &&
 303            (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) &&
 304            (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM)))
 305                pmu->reserved_bits ^= HSW_IN_TX|HSW_IN_TX_CHECKPOINTED;
 306}
 307
 308static void intel_pmu_init(struct kvm_vcpu *vcpu)
 309{
 310        int i;
 311        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 312
 313        for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 314                pmu->gp_counters[i].type = KVM_PMC_GP;
 315                pmu->gp_counters[i].vcpu = vcpu;
 316                pmu->gp_counters[i].idx = i;
 317        }
 318
 319        for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) {
 320                pmu->fixed_counters[i].type = KVM_PMC_FIXED;
 321                pmu->fixed_counters[i].vcpu = vcpu;
 322                pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED;
 323        }
 324}
 325
 326static void intel_pmu_reset(struct kvm_vcpu *vcpu)
 327{
 328        struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 329        int i;
 330
 331        for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) {
 332                struct kvm_pmc *pmc = &pmu->gp_counters[i];
 333
 334                pmc_stop_counter(pmc);
 335                pmc->counter = pmc->eventsel = 0;
 336        }
 337
 338        for (i = 0; i < INTEL_PMC_MAX_FIXED; i++)
 339                pmc_stop_counter(&pmu->fixed_counters[i]);
 340
 341        pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status =
 342                pmu->global_ovf_ctrl = 0;
 343}
 344
 345struct kvm_pmu_ops intel_pmu_ops = {
 346        .find_arch_event = intel_find_arch_event,
 347        .find_fixed_event = intel_find_fixed_event,
 348        .pmc_is_enabled = intel_pmc_is_enabled,
 349        .pmc_idx_to_pmc = intel_pmc_idx_to_pmc,
 350        .msr_idx_to_pmc = intel_msr_idx_to_pmc,
 351        .is_valid_msr_idx = intel_is_valid_msr_idx,
 352        .is_valid_msr = intel_is_valid_msr,
 353        .get_msr = intel_pmu_get_msr,
 354        .set_msr = intel_pmu_set_msr,
 355        .refresh = intel_pmu_refresh,
 356        .init = intel_pmu_init,
 357        .reset = intel_pmu_reset,
 358};
 359