arch/x86/kvm/pmu_amd.c

   1 /*
   2  * KVM PMU support for AMD
   3  *
   4  * Copyright 2015, Red Hat, Inc. and/or its affiliates.
   5  *
   6  * Author:
   7  *   Wei Huang <wei@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  * Implementation is based on pmu_intel.c file
  13  */
  14 #include <linux/types.h>
  15 #include <linux/kvm_host.h>
  16 #include <linux/perf_event.h>
  17 #include "x86.h"
  18 #include "cpuid.h"
  19 #include "lapic.h"
  20 #include "pmu.h"
  21
  22 enum pmu_type {
  23         PMU_TYPE_COUNTER = 0,
  24         PMU_TYPE_EVNTSEL,
  25 };
  26
  27 enum index {
  28         INDEX_ZERO = 0,
  29         INDEX_ONE,
  30         INDEX_TWO,
  31         INDEX_THREE,
  32         INDEX_FOUR,
  33         INDEX_FIVE,
  34         INDEX_ERROR,
  35 };
  36
  37 /* duplicated from amd_perfmon_event_map, K7 and above should work. */
  38 static struct kvm_event_hw_type_mapping amd_event_mapping[] = {
  39         [0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES },
  40         [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS },
  41         [2] = { 0x7d, 0x07, PERF_COUNT_HW_CACHE_REFERENCES },
  42         [3] = { 0x7e, 0x07, PERF_COUNT_HW_CACHE_MISSES },
  43         [4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS },
  44         [5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES },
  45         [6] = { 0xd0, 0x00, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND },
  46         [7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND },
  47 };
  48
  49 static unsigned int get_msr_base(struct kvm_pmu *pmu, enum pmu_type type)
  50 {
  51         struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
  52
  53         if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
  54                 if (type == PMU_TYPE_COUNTER)
  55                         return MSR_F15H_PERF_CTR;
  56                 else
  57                         return MSR_F15H_PERF_CTL;
  58         } else {
  59                 if (type == PMU_TYPE_COUNTER)
  60                         return MSR_K7_PERFCTR0;
  61                 else
  62                         return MSR_K7_EVNTSEL0;
  63         }
  64 }
  65
  66 static enum index msr_to_index(u32 msr)
  67 {
  68         switch (msr) {
  69         case MSR_F15H_PERF_CTL0:
  70         case MSR_F15H_PERF_CTR0:
  71         case MSR_K7_EVNTSEL0:
  72         case MSR_K7_PERFCTR0:
  73                 return INDEX_ZERO;
  74         case MSR_F15H_PERF_CTL1:
  75         case MSR_F15H_PERF_CTR1:
  76         case MSR_K7_EVNTSEL1:
  77         case MSR_K7_PERFCTR1:
  78                 return INDEX_ONE;
  79         case MSR_F15H_PERF_CTL2:
  80         case MSR_F15H_PERF_CTR2:
  81         case MSR_K7_EVNTSEL2:
  82         case MSR_K7_PERFCTR2:
  83                 return INDEX_TWO;
  84         case MSR_F15H_PERF_CTL3:
  85         case MSR_F15H_PERF_CTR3:
  86         case MSR_K7_EVNTSEL3:
  87         case MSR_K7_PERFCTR3:
  88                 return INDEX_THREE;
  89         case MSR_F15H_PERF_CTL4:
  90         case MSR_F15H_PERF_CTR4:
  91                 return INDEX_FOUR;
  92         case MSR_F15H_PERF_CTL5:
  93         case MSR_F15H_PERF_CTR5:
  94                 return INDEX_FIVE;
  95         default:
  96                 return INDEX_ERROR;
  97         }
  98 }
  99
 100 static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr,
 101                                              enum pmu_type type)
 102 {
 103         switch (msr) {
 104         case MSR_F15H_PERF_CTL0:
 105         case MSR_F15H_PERF_CTL1:
 106         case MSR_F15H_PERF_CTL2:
 107         case MSR_F15H_PERF_CTL3:
 108         case MSR_F15H_PERF_CTL4:
 109         case MSR_F15H_PERF_CTL5:
 110         case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3:
 111                 if (type != PMU_TYPE_EVNTSEL)
 112                         return NULL;
 113                 break;
 114         case MSR_F15H_PERF_CTR0:
 115         case MSR_F15H_PERF_CTR1:
 116         case MSR_F15H_PERF_CTR2:
 117         case MSR_F15H_PERF_CTR3:
 118         case MSR_F15H_PERF_CTR4:
 119         case MSR_F15H_PERF_CTR5:
 120         case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3:
 121                 if (type != PMU_TYPE_COUNTER)
 122                         return NULL;
 123                 break;
 124         default:
 125                 return NULL;
 126         }
 127
 128         return &pmu->gp_counters[msr_to_index(msr)];
 129 }
 130
 131 static unsigned amd_find_arch_event(struct kvm_pmu *pmu,
 132                                     u8 event_select,
 133                                     u8 unit_mask)
 134 {
 135         int i;
 136
 137         for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++)
 138                 if (amd_event_mapping[i].eventsel == event_select
 139                     && amd_event_mapping[i].unit_mask == unit_mask)
 140                         break;
 141
 142         if (i == ARRAY_SIZE(amd_event_mapping))
 143                 return PERF_COUNT_HW_MAX;
 144
 145         return amd_event_mapping[i].event_type;
 146 }
 147
 148 /* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */
 149 static unsigned amd_find_fixed_event(int idx)
 150 {
 151         return PERF_COUNT_HW_MAX;
 152 }
 153
 154 /* check if a PMC is enabled by comparing it against global_ctrl bits. Because
 155  * AMD CPU doesn't have global_ctrl MSR, all PMCs are enabled (return TRUE).
 156  */
 157 static bool amd_pmc_is_enabled(struct kvm_pmc *pmc)
 158 {
 159         return true;
 160 }
 161
 162 static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx)
 163 {
 164         unsigned int base = get_msr_base(pmu, PMU_TYPE_COUNTER);
 165         struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu);
 166
 167         if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) {
 168                 /*
 169                  * The idx is contiguous. The MSRs are not. The counter MSRs
 170                  * are interleaved with the event select MSRs.
 171                  */
 172                 pmc_idx *= 2;
 173         }
 174
 175         return get_gp_pmc_amd(pmu, base + pmc_idx, PMU_TYPE_COUNTER);
 176 }
 177
 178 /* returns 0 if idx's corresponding MSR exists; otherwise returns 1. */
 179 static int amd_is_valid_msr_idx(struct kvm_vcpu *vcpu, unsigned idx)
 180 {
 181         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 182
 183         idx &= ~(3u << 30);
 184
 185         return (idx >= pmu->nr_arch_gp_counters);
 186 }
 187
 188 /* idx is the ECX register of RDPMC instruction */
 189 static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, unsigned idx)
 190 {
 191         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 192         struct kvm_pmc *counters;
 193
 194         idx &= ~(3u << 30);
 195         if (idx >= pmu->nr_arch_gp_counters)
 196                 return NULL;
 197         counters = pmu->gp_counters;
 198
 199         return &counters[idx];
 200 }
 201
 202 static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr)
 203 {
 204         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 205         int ret = false;
 206
 207         ret = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER) ||
 208                 get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
 209
 210         return ret;
 211 }
 212
 213 static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data)
 214 {
 215         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 216         struct kvm_pmc *pmc;
 217
 218         /* MSR_PERFCTRn */
 219         pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
 220         if (pmc) {
 221                 *data = pmc_read_counter(pmc);
 222                 return 0;
 223         }
 224         /* MSR_EVNTSELn */
 225         pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
 226         if (pmc) {
 227                 *data = pmc->eventsel;
 228                 return 0;
 229         }
 230
 231         return 1;
 232 }
 233
 234 static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info)
 235 {
 236         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 237         struct kvm_pmc *pmc;
 238         u32 msr = msr_info->index;
 239         u64 data = msr_info->data;
 240
 241         /* MSR_PERFCTRn */
 242         pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER);
 243         if (pmc) {
 244                 pmc->counter += data - pmc_read_counter(pmc);
 245                 return 0;
 246         }
 247         /* MSR_EVNTSELn */
 248         pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL);
 249         if (pmc) {
 250                 if (data == pmc->eventsel)
 251                         return 0;
 252                 if (!(data & pmu->reserved_bits)) {
 253                         reprogram_gp_counter(pmc, data);
 254                         return 0;
 255                 }
 256         }
 257
 258         return 1;
 259 }
 260
 261 static void amd_pmu_refresh(struct kvm_vcpu *vcpu)
 262 {
 263         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 264
 265         if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE))
 266                 pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS_CORE;
 267         else
 268                 pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS;
 269
 270         pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1;
 271         pmu->reserved_bits = 0xffffffff00200000ull;
 272         /* not applicable to AMD; but clean them to prevent any fall out */
 273         pmu->counter_bitmask[KVM_PMC_FIXED] = 0;
 274         pmu->nr_arch_fixed_counters = 0;
 275         pmu->version = 0;
 276         pmu->global_status = 0;
 277 }
 278
 279 static void amd_pmu_init(struct kvm_vcpu *vcpu)
 280 {
 281         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 282         int i;
 283
 284         BUILD_BUG_ON(AMD64_NUM_COUNTERS_CORE > INTEL_PMC_MAX_GENERIC);
 285
 286         for (i = 0; i < AMD64_NUM_COUNTERS_CORE ; i++) {
 287                 pmu->gp_counters[i].type = KVM_PMC_GP;
 288                 pmu->gp_counters[i].vcpu = vcpu;
 289                 pmu->gp_counters[i].idx = i;
 290         }
 291 }
 292
 293 static void amd_pmu_reset(struct kvm_vcpu *vcpu)
 294 {
 295         struct kvm_pmu *pmu = vcpu_to_pmu(vcpu);
 296         int i;
 297
 298         for (i = 0; i < AMD64_NUM_COUNTERS_CORE; i++) {
 299                 struct kvm_pmc *pmc = &pmu->gp_counters[i];
 300
 301                 pmc_stop_counter(pmc);
 302                 pmc->counter = pmc->eventsel = 0;
 303         }
 304 }
 305
 306 struct kvm_pmu_ops amd_pmu_ops = {
 307         .find_arch_event = amd_find_arch_event,
 308         .find_fixed_event = amd_find_fixed_event,
 309         .pmc_is_enabled = amd_pmc_is_enabled,
 310         .pmc_idx_to_pmc = amd_pmc_idx_to_pmc,
 311         .msr_idx_to_pmc = amd_msr_idx_to_pmc,
 312         .is_valid_msr_idx = amd_is_valid_msr_idx,
 313         .is_valid_msr = amd_is_valid_msr,
 314         .get_msr = amd_pmu_get_msr,
 315         .set_msr = amd_pmu_set_msr,
 316         .refresh = amd_pmu_refresh,
 317         .init = amd_pmu_init,
 318         .reset = amd_pmu_reset,
 319 };