1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * KVM PMU support for AMD 4 * 5 * Copyright 2015, Red Hat, Inc. and/or its affiliates. 6 * 7 * Author: 8 * Wei Huang <wei@redhat.com> 9 * 10 * Implementation is based on pmu_intel.c file 11 */ 12 #include <linux/types.h> 13 #include <linux/kvm_host.h> 14 #include <linux/perf_event.h> 15 #include "x86.h" 16 #include "cpuid.h" 17 #include "lapic.h" 18 #include "pmu.h" 19 #include "svm.h" 20 21 enum pmu_type { 22 PMU_TYPE_COUNTER = 0, 23 PMU_TYPE_EVNTSEL, 24 }; 25 26 enum index { 27 INDEX_ZERO = 0, 28 INDEX_ONE, 29 INDEX_TWO, 30 INDEX_THREE, 31 INDEX_FOUR, 32 INDEX_FIVE, 33 INDEX_ERROR, 34 }; 35 36 /* duplicated from amd_perfmon_event_map, K7 and above should work. */ 37 static struct kvm_event_hw_type_mapping amd_event_mapping[] = { 38 [0] = { 0x76, 0x00, PERF_COUNT_HW_CPU_CYCLES }, 39 [1] = { 0xc0, 0x00, PERF_COUNT_HW_INSTRUCTIONS }, 40 [2] = { 0x7d, 0x07, PERF_COUNT_HW_CACHE_REFERENCES }, 41 [3] = { 0x7e, 0x07, PERF_COUNT_HW_CACHE_MISSES }, 42 [4] = { 0xc2, 0x00, PERF_COUNT_HW_BRANCH_INSTRUCTIONS }, 43 [5] = { 0xc3, 0x00, PERF_COUNT_HW_BRANCH_MISSES }, 44 [6] = { 0xd0, 0x00, PERF_COUNT_HW_STALLED_CYCLES_FRONTEND }, 45 [7] = { 0xd1, 0x00, PERF_COUNT_HW_STALLED_CYCLES_BACKEND }, 46 }; 47 48 static unsigned int get_msr_base(struct kvm_pmu *pmu, enum pmu_type type) 49 { 50 struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); 51 52 if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) { 53 if (type == PMU_TYPE_COUNTER) 54 return MSR_F15H_PERF_CTR; 55 else 56 return MSR_F15H_PERF_CTL; 57 } else { 58 if (type == PMU_TYPE_COUNTER) 59 return MSR_K7_PERFCTR0; 60 else 61 return MSR_K7_EVNTSEL0; 62 } 63 } 64 65 static enum index msr_to_index(u32 msr) 66 { 67 switch (msr) { 68 case MSR_F15H_PERF_CTL0: 69 case MSR_F15H_PERF_CTR0: 70 case MSR_K7_EVNTSEL0: 71 case MSR_K7_PERFCTR0: 72 return INDEX_ZERO; 73 case MSR_F15H_PERF_CTL1: 74 case MSR_F15H_PERF_CTR1: 75 case MSR_K7_EVNTSEL1: 76 case MSR_K7_PERFCTR1: 77 return INDEX_ONE; 78 case MSR_F15H_PERF_CTL2: 79 case MSR_F15H_PERF_CTR2: 80 case MSR_K7_EVNTSEL2: 81 case MSR_K7_PERFCTR2: 82 return INDEX_TWO; 83 case MSR_F15H_PERF_CTL3: 84 case MSR_F15H_PERF_CTR3: 85 case MSR_K7_EVNTSEL3: 86 case MSR_K7_PERFCTR3: 87 return INDEX_THREE; 88 case MSR_F15H_PERF_CTL4: 89 case MSR_F15H_PERF_CTR4: 90 return INDEX_FOUR; 91 case MSR_F15H_PERF_CTL5: 92 case MSR_F15H_PERF_CTR5: 93 return INDEX_FIVE; 94 default: 95 return INDEX_ERROR; 96 } 97 } 98 99 static inline struct kvm_pmc *get_gp_pmc_amd(struct kvm_pmu *pmu, u32 msr, 100 enum pmu_type type) 101 { 102 struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); 103 104 if (!enable_pmu) 105 return NULL; 106 107 switch (msr) { 108 case MSR_F15H_PERF_CTL0: 109 case MSR_F15H_PERF_CTL1: 110 case MSR_F15H_PERF_CTL2: 111 case MSR_F15H_PERF_CTL3: 112 case MSR_F15H_PERF_CTL4: 113 case MSR_F15H_PERF_CTL5: 114 if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) 115 return NULL; 116 fallthrough; 117 case MSR_K7_EVNTSEL0 ... MSR_K7_EVNTSEL3: 118 if (type != PMU_TYPE_EVNTSEL) 119 return NULL; 120 break; 121 case MSR_F15H_PERF_CTR0: 122 case MSR_F15H_PERF_CTR1: 123 case MSR_F15H_PERF_CTR2: 124 case MSR_F15H_PERF_CTR3: 125 case MSR_F15H_PERF_CTR4: 126 case MSR_F15H_PERF_CTR5: 127 if (!guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) 128 return NULL; 129 fallthrough; 130 case MSR_K7_PERFCTR0 ... MSR_K7_PERFCTR3: 131 if (type != PMU_TYPE_COUNTER) 132 return NULL; 133 break; 134 default: 135 return NULL; 136 } 137 138 return &pmu->gp_counters[msr_to_index(msr)]; 139 } 140 141 static unsigned int amd_pmc_perf_hw_id(struct kvm_pmc *pmc) 142 { 143 u8 event_select = pmc->eventsel & ARCH_PERFMON_EVENTSEL_EVENT; 144 u8 unit_mask = (pmc->eventsel & ARCH_PERFMON_EVENTSEL_UMASK) >> 8; 145 int i; 146 147 /* return PERF_COUNT_HW_MAX as AMD doesn't have fixed events */ 148 if (WARN_ON(pmc_is_fixed(pmc))) 149 return PERF_COUNT_HW_MAX; 150 151 for (i = 0; i < ARRAY_SIZE(amd_event_mapping); i++) 152 if (amd_event_mapping[i].eventsel == event_select 153 && amd_event_mapping[i].unit_mask == unit_mask) 154 break; 155 156 if (i == ARRAY_SIZE(amd_event_mapping)) 157 return PERF_COUNT_HW_MAX; 158 159 return amd_event_mapping[i].event_type; 160 } 161 162 /* check if a PMC is enabled by comparing it against global_ctrl bits. Because 163 * AMD CPU doesn't have global_ctrl MSR, all PMCs are enabled (return TRUE). 164 */ 165 static bool amd_pmc_is_enabled(struct kvm_pmc *pmc) 166 { 167 return true; 168 } 169 170 static struct kvm_pmc *amd_pmc_idx_to_pmc(struct kvm_pmu *pmu, int pmc_idx) 171 { 172 unsigned int base = get_msr_base(pmu, PMU_TYPE_COUNTER); 173 struct kvm_vcpu *vcpu = pmu_to_vcpu(pmu); 174 175 if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) { 176 /* 177 * The idx is contiguous. The MSRs are not. The counter MSRs 178 * are interleaved with the event select MSRs. 179 */ 180 pmc_idx *= 2; 181 } 182 183 return get_gp_pmc_amd(pmu, base + pmc_idx, PMU_TYPE_COUNTER); 184 } 185 186 static bool amd_is_valid_rdpmc_ecx(struct kvm_vcpu *vcpu, unsigned int idx) 187 { 188 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 189 190 idx &= ~(3u << 30); 191 192 return idx < pmu->nr_arch_gp_counters; 193 } 194 195 /* idx is the ECX register of RDPMC instruction */ 196 static struct kvm_pmc *amd_rdpmc_ecx_to_pmc(struct kvm_vcpu *vcpu, 197 unsigned int idx, u64 *mask) 198 { 199 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 200 struct kvm_pmc *counters; 201 202 idx &= ~(3u << 30); 203 if (idx >= pmu->nr_arch_gp_counters) 204 return NULL; 205 counters = pmu->gp_counters; 206 207 return &counters[idx]; 208 } 209 210 static bool amd_is_valid_msr(struct kvm_vcpu *vcpu, u32 msr) 211 { 212 /* All MSRs refer to exactly one PMC, so msr_idx_to_pmc is enough. */ 213 return false; 214 } 215 216 static struct kvm_pmc *amd_msr_idx_to_pmc(struct kvm_vcpu *vcpu, u32 msr) 217 { 218 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 219 struct kvm_pmc *pmc; 220 221 pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER); 222 pmc = pmc ? pmc : get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL); 223 224 return pmc; 225 } 226 227 static int amd_pmu_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 228 { 229 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 230 struct kvm_pmc *pmc; 231 u32 msr = msr_info->index; 232 233 /* MSR_PERFCTRn */ 234 pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER); 235 if (pmc) { 236 msr_info->data = pmc_read_counter(pmc); 237 return 0; 238 } 239 /* MSR_EVNTSELn */ 240 pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL); 241 if (pmc) { 242 msr_info->data = pmc->eventsel; 243 return 0; 244 } 245 246 return 1; 247 } 248 249 static int amd_pmu_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) 250 { 251 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 252 struct kvm_pmc *pmc; 253 u32 msr = msr_info->index; 254 u64 data = msr_info->data; 255 256 /* MSR_PERFCTRn */ 257 pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_COUNTER); 258 if (pmc) { 259 pmc->counter += data - pmc_read_counter(pmc); 260 return 0; 261 } 262 /* MSR_EVNTSELn */ 263 pmc = get_gp_pmc_amd(pmu, msr, PMU_TYPE_EVNTSEL); 264 if (pmc) { 265 if (data == pmc->eventsel) 266 return 0; 267 if (!(data & pmu->reserved_bits)) { 268 reprogram_gp_counter(pmc, data); 269 return 0; 270 } 271 } 272 273 return 1; 274 } 275 276 static void amd_pmu_refresh(struct kvm_vcpu *vcpu) 277 { 278 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 279 280 if (guest_cpuid_has(vcpu, X86_FEATURE_PERFCTR_CORE)) 281 pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS_CORE; 282 else 283 pmu->nr_arch_gp_counters = AMD64_NUM_COUNTERS; 284 285 pmu->counter_bitmask[KVM_PMC_GP] = ((u64)1 << 48) - 1; 286 pmu->reserved_bits = 0xfffffff000280000ull; 287 pmu->version = 1; 288 /* not applicable to AMD; but clean them to prevent any fall out */ 289 pmu->counter_bitmask[KVM_PMC_FIXED] = 0; 290 pmu->nr_arch_fixed_counters = 0; 291 pmu->global_status = 0; 292 bitmap_set(pmu->all_valid_pmc_idx, 0, pmu->nr_arch_gp_counters); 293 } 294 295 static void amd_pmu_init(struct kvm_vcpu *vcpu) 296 { 297 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 298 int i; 299 300 BUILD_BUG_ON(AMD64_NUM_COUNTERS_CORE > INTEL_PMC_MAX_GENERIC); 301 302 for (i = 0; i < AMD64_NUM_COUNTERS_CORE ; i++) { 303 pmu->gp_counters[i].type = KVM_PMC_GP; 304 pmu->gp_counters[i].vcpu = vcpu; 305 pmu->gp_counters[i].idx = i; 306 pmu->gp_counters[i].current_config = 0; 307 } 308 } 309 310 static void amd_pmu_reset(struct kvm_vcpu *vcpu) 311 { 312 struct kvm_pmu *pmu = vcpu_to_pmu(vcpu); 313 int i; 314 315 for (i = 0; i < AMD64_NUM_COUNTERS_CORE; i++) { 316 struct kvm_pmc *pmc = &pmu->gp_counters[i]; 317 318 pmc_stop_counter(pmc); 319 pmc->counter = pmc->eventsel = 0; 320 } 321 } 322 323 struct kvm_pmu_ops amd_pmu_ops = { 324 .pmc_perf_hw_id = amd_pmc_perf_hw_id, 325 .pmc_is_enabled = amd_pmc_is_enabled, 326 .pmc_idx_to_pmc = amd_pmc_idx_to_pmc, 327 .rdpmc_ecx_to_pmc = amd_rdpmc_ecx_to_pmc, 328 .msr_idx_to_pmc = amd_msr_idx_to_pmc, 329 .is_valid_rdpmc_ecx = amd_is_valid_rdpmc_ecx, 330 .is_valid_msr = amd_is_valid_msr, 331 .get_msr = amd_pmu_get_msr, 332 .set_msr = amd_pmu_set_msr, 333 .refresh = amd_pmu_refresh, 334 .init = amd_pmu_init, 335 .reset = amd_pmu_reset, 336 }; 337