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 23 static 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 */ 36 static int fixed_pmc_events[] = {1, 0, 7}; 37 38 static 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. */ 59 static 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 70 static 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 88 static 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. */ 97 static 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 } 103 104 static 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. */ 117 static 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 } 127 128 static struct kvm_pmc *intel_msr_idx_to_pmc(struct kvm_vcpu *vcpu, 129 unsigned idx, u64 *mask) 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 *mask &= pmu->counter_bitmask[fixed ? KVM_PMC_FIXED : KVM_PMC_GP]; 142 143 return &counters[idx]; 144 } 145 146 static bool intel_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) 147 { 148 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 149 int ret; 150 151 switch (msr) { 152 case MSR_CORE_PERF_FIXED_CTR_CTRL: 153 case MSR_CORE_PERF_GLOBAL_STATUS: 154 case MSR_CORE_PERF_GLOBAL_CTRL: 155 case MSR_CORE_PERF_GLOBAL_OVF_CTRL: 156 ret = pmu->version > 1; 157 break; 158 default: 159 ret = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0) || 160 get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0) || 161 get_fixed_pmc(pmu, msr); 162 break; 163 } 164 165 return ret; 166 } 167 168 static int intel_pmu_get_msr(struct kvm_vcpu *vcpu, u32 msr, u64 *data) 169 { 170 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 171 struct kvm_pmc *pmc; 172 173 switch (msr) { 174 case MSR_CORE_PERF_FIXED_CTR_CTRL: 175 *data = pmu->fixed_ctr_ctrl; 176 return 0; 177 case MSR_CORE_PERF_GLOBAL_STATUS: 178 *data = pmu->global_status; 179 return 0; 180 case MSR_CORE_PERF_GLOBAL_CTRL: 181 *data = pmu->global_ctrl; 182 return 0; 183 case MSR_CORE_PERF_GLOBAL_OVF_CTRL: 184 *data = pmu->global_ovf_ctrl; 185 return 0; 186 default: 187 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) { 188 u64 val = pmc_read_counter(pmc); 189 *data = val & pmu->counter_bitmask[KVM_PMC_GP]; 190 return 0; 191 } else if ((pmc = get_fixed_pmc(pmu, msr))) { 192 u64 val = pmc_read_counter(pmc); 193 *data = val & pmu->counter_bitmask[KVM_PMC_FIXED]; 194 return 0; 195 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { 196 *data = pmc->eventsel; 197 return 0; 198 } 199 } 200 201 return 1; 202 } 203 204 static int intel_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 205 { 206 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 207 struct kvm_pmc *pmc; 208 u32 msr = msr_info->index; 209 u64 data = msr_info->data; 210 211 switch (msr) { 212 case MSR_CORE_PERF_FIXED_CTR_CTRL: 213 if (pmu->fixed_ctr_ctrl == data) 214 return 0; 215 if (!(data & 0xfffffffffffff444ull)) { 216 reprogram_fixed_counters(pmu, data); 217 return 0; 218 } 219 break; 220 case MSR_CORE_PERF_GLOBAL_STATUS: 221 if (msr_info->host_initiated) { 222 pmu->global_status = data; 223 return 0; 224 } 225 break; /* RO MSR */ 226 case MSR_CORE_PERF_GLOBAL_CTRL: 227 if (pmu->global_ctrl == data) 228 return 0; 229 if (!(data & pmu->global_ctrl_mask)) { 230 global_ctrl_changed(pmu, data); 231 return 0; 232 } 233 break; 234 case MSR_CORE_PERF_GLOBAL_OVF_CTRL: 235 if (!(data & pmu->global_ovf_ctrl_mask)) { 236 if (!msr_info->host_initiated) 237 pmu->global_status &= ~data; 238 pmu->global_ovf_ctrl = data; 239 return 0; 240 } 241 break; 242 default: 243 if ((pmc = get_gp_pmc(pmu, msr, MSR_IA32_PERFCTR0))) { 244 if (msr_info->host_initiated) 245 pmc->counter = data; 246 else 247 pmc->counter = (s32)data; 248 return 0; 249 } else if ((pmc = get_fixed_pmc(pmu, msr))) { 250 pmc->counter = data; 251 return 0; 252 } else if ((pmc = get_gp_pmc(pmu, msr, MSR_P6_EVNTSEL0))) { 253 if (data == pmc->eventsel) 254 return 0; 255 if (!(data & pmu->reserved_bits)) { 256 reprogram_gp_counter(pmc, data); 257 return 0; 258 } 259 } 260 } 261 262 return 1; 263 } 264 265 static void intel_pmu_refresh(struct kvm_vcpu *vcpu) 266 { 267 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 268 struct kvm_cpuid_entry2 *entry; 269 union cpuid10_eax eax; 270 union cpuid10_edx edx; 271 272 pmu->nr_arch_gp_counters = 0; 273 pmu->nr_arch_fixed_counters = 0; 274 pmu->counter_bitmask[KVM_PMC_GP] = 0; 275 pmu->counter_bitmask[KVM_PMC_FIXED] = 0; 276 pmu->version = 0; 277 pmu->reserved_bits = 0xffffffff00200000ull; 278 279 entry = kvm_find_cpuid_entry(vcpu, 0xa, 0); 280 if (!entry) 281 return; 282 eax.full = entry->eax; 283 edx.full = entry->edx; 284 285 pmu->version = eax.split.version_id; 286 if (!pmu->version) 287 return; 288 289 pmu->nr_arch_gp_counters = min_t(int, eax.split.num_counters, 290 INTEL_PMC_MAX_GENERIC); 291 pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << eax.split.bit_width) - 1; 292 pmu->available_event_types = ~entry->ebx & 293 ((1ull << eax.split.mask_length) - 1); 294 295 if (pmu->version == 1) { 296 pmu->nr_arch_fixed_counters = 0; 297 } else { 298 pmu->nr_arch_fixed_counters = 299 min_t(int, edx.split.num_counters_fixed, 300 INTEL_PMC_MAX_FIXED); 301 pmu->counter_bitmask[KVM_PMC_FIXED] = 302 ((u64)1 << edx.split.bit_width_fixed) - 1; 303 } 304 305 pmu->global_ctrl = ((1ull << pmu->nr_arch_gp_counters) - 1) | 306 (((1ull << pmu->nr_arch_fixed_counters) - 1) << INTEL_PMC_IDX_FIXED); 307 pmu->global_ctrl_mask = ~pmu->global_ctrl; 308 pmu->global_ovf_ctrl_mask = pmu->global_ctrl_mask 309 & ~(MSR_CORE_PERF_GLOBAL_OVF_CTRL_OVF_BUF | 310 MSR_CORE_PERF_GLOBAL_OVF_CTRL_COND_CHGD); 311 if (kvm_x86_ops->pt_supported()) 312 pmu->global_ovf_ctrl_mask &= 313 ~MSR_CORE_PERF_GLOBAL_OVF_CTRL_TRACE_TOPA_PMI; 314 315 entry = kvm_find_cpuid_entry(vcpu, 7, 0); 316 if (entry && 317 (boot_cpu_has(X86_FEATURE_HLE) || boot_cpu_has(X86_FEATURE_RTM)) && 318 (entry->ebx & (X86_FEATURE_HLE|X86_FEATURE_RTM))) 319 pmu->reserved_bits ^= HSW_IN_TX|HSW_IN_TX_CHECKPOINTED; 320 } 321 322 static void intel_pmu_init(struct kvm_vcpu *vcpu) 323 { 324 int i; 325 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 326 327 for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) { 328 pmu->gp_counters[i].type = KVM_PMC_GP; 329 pmu->gp_counters[i].vcpu = vcpu; 330 pmu->gp_counters[i].idx = i; 331 } 332 333 for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) { 334 pmu->fixed_counters[i].type = KVM_PMC_FIXED; 335 pmu->fixed_counters[i].vcpu = vcpu; 336 pmu->fixed_counters[i].idx = i + INTEL_PMC_IDX_FIXED; 337 } 338 } 339 340 static void intel_pmu_reset(struct kvm_vcpu *vcpu) 341 { 342 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 343 int i; 344 345 for (i = 0; i < INTEL_PMC_MAX_GENERIC; i++) { 346 struct kvm_pmc *pmc = &pmu->gp_counters[i]; 347 348 pmc_stop_counter(pmc); 349 pmc->counter = pmc->eventsel = 0; 350 } 351 352 for (i = 0; i < INTEL_PMC_MAX_FIXED; i++) 353 pmc_stop_counter(&pmu->fixed_counters[i]); 354 355 pmu->fixed_ctr_ctrl = pmu->global_ctrl = pmu->global_status = 356 pmu->global_ovf_ctrl = 0; 357 } 358 359 struct kvm_pmu_ops intel_pmu_ops = { 360 .find_arch_event = intel_find_arch_event, 361 .find_fixed_event = intel_find_fixed_event, 362 .pmc_is_enabled = intel_pmc_is_enabled, 363 .pmc_idx_to_pmc = intel_pmc_idx_to_pmc, 364 .msr_idx_to_pmc = intel_msr_idx_to_pmc, 365 .is_valid_msr_idx = intel_is_valid_msr_idx, 366 .is_valid_msr = intel_is_valid_msr, 367 .get_msr = intel_pmu_get_msr, 368 .set_msr = intel_pmu_set_msr, 369 .refresh = intel_pmu_refresh, 370 .init = intel_pmu_init, 371 .reset = intel_pmu_reset, 372 }; 373