1 /* 2 * Kernel-based Virtual Machine driver for Linux 3 * cpuid support routines 4 * 5 * derived from arch/x86/kvm/x86.c 6 * 7 * Copyright 2011 Red Hat, Inc. and/or its affiliates. 8 * Copyright IBM Corporation, 2008 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 15 #include <linux/kvm_host.h> 16 #include <linux/export.h> 17 #include <linux/vmalloc.h> 18 #include <linux/uaccess.h> 19 #include <linux/sched/stat.h> 20 21 #include <asm/processor.h> 22 #include <asm/user.h> 23 #include <asm/fpu/xstate.h> 24 #include "cpuid.h" 25 #include "lapic.h" 26 #include "mmu.h" 27 #include "trace.h" 28 #include "pmu.h" 29 30 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 31 { 32 int feature_bit = 0; 33 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 34 35 xstate_bv &= XFEATURE_MASK_EXTEND; 36 while (xstate_bv) { 37 if (xstate_bv & 0x1) { 38 u32 eax, ebx, ecx, edx, offset; 39 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 40 offset = compacted ? ret : ebx; 41 ret = max(ret, offset + eax); 42 } 43 44 xstate_bv >>= 1; 45 feature_bit++; 46 } 47 48 return ret; 49 } 50 51 bool kvm_mpx_supported(void) 52 { 53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) 54 && kvm_x86_ops->mpx_supported()); 55 } 56 EXPORT_SYMBOL_GPL(kvm_mpx_supported); 57 58 u64 kvm_supported_xcr0(void) 59 { 60 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 61 62 if (!kvm_mpx_supported()) 63 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); 64 65 return xcr0; 66 } 67 68 #define F(x) bit(X86_FEATURE_##x) 69 70 /* For scattered features from cpufeatures.h; we currently expose none */ 71 #define KF(x) bit(KVM_CPUID_BIT_##x) 72 73 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 74 { 75 struct kvm_cpuid_entry2 *best; 76 struct kvm_lapic *apic = vcpu->arch.apic; 77 78 best = kvm_find_cpuid_entry(vcpu, 1, 0); 79 if (!best) 80 return 0; 81 82 /* Update OSXSAVE bit */ 83 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) { 84 best->ecx &= ~F(OSXSAVE); 85 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 86 best->ecx |= F(OSXSAVE); 87 } 88 89 best->edx &= ~F(APIC); 90 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE) 91 best->edx |= F(APIC); 92 93 if (apic) { 94 if (best->ecx & F(TSC_DEADLINE_TIMER)) 95 apic->lapic_timer.timer_mode_mask = 3 << 17; 96 else 97 apic->lapic_timer.timer_mode_mask = 1 << 17; 98 } 99 100 best = kvm_find_cpuid_entry(vcpu, 7, 0); 101 if (best) { 102 /* Update OSPKE bit */ 103 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) { 104 best->ecx &= ~F(OSPKE); 105 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) 106 best->ecx |= F(OSPKE); 107 } 108 } 109 110 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 111 if (!best) { 112 vcpu->arch.guest_supported_xcr0 = 0; 113 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 114 } else { 115 vcpu->arch.guest_supported_xcr0 = 116 (best->eax | ((u64)best->edx << 32)) & 117 kvm_supported_xcr0(); 118 vcpu->arch.guest_xstate_size = best->ebx = 119 xstate_required_size(vcpu->arch.xcr0, false); 120 } 121 122 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 123 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 124 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 125 126 /* 127 * The existing code assumes virtual address is 48-bit or 57-bit in the 128 * canonical address checks; exit if it is ever changed. 129 */ 130 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 131 if (best) { 132 int vaddr_bits = (best->eax & 0xff00) >> 8; 133 134 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) 135 return -EINVAL; 136 } 137 138 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0); 139 if (kvm_hlt_in_guest(vcpu->kvm) && best && 140 (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) 141 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); 142 143 /* Update physical-address width */ 144 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 145 kvm_mmu_reset_context(vcpu); 146 147 kvm_pmu_refresh(vcpu); 148 return 0; 149 } 150 151 static int is_efer_nx(void) 152 { 153 unsigned long long efer = 0; 154 155 rdmsrl_safe(MSR_EFER, &efer); 156 return efer & EFER_NX; 157 } 158 159 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 160 { 161 int i; 162 struct kvm_cpuid_entry2 *e, *entry; 163 164 entry = NULL; 165 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 166 e = &vcpu->arch.cpuid_entries[i]; 167 if (e->function == 0x80000001) { 168 entry = e; 169 break; 170 } 171 } 172 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 173 entry->edx &= ~F(NX); 174 printk(KERN_INFO "kvm: guest NX capability removed\n"); 175 } 176 } 177 178 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 179 { 180 struct kvm_cpuid_entry2 *best; 181 182 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 183 if (!best || best->eax < 0x80000008) 184 goto not_found; 185 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 186 if (best) 187 return best->eax & 0xff; 188 not_found: 189 return 36; 190 } 191 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 192 193 /* when an old userspace process fills a new kernel module */ 194 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 195 struct kvm_cpuid *cpuid, 196 struct kvm_cpuid_entry __user *entries) 197 { 198 int r, i; 199 struct kvm_cpuid_entry *cpuid_entries = NULL; 200 201 r = -E2BIG; 202 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 203 goto out; 204 r = -ENOMEM; 205 if (cpuid->nent) { 206 cpuid_entries = 207 vmalloc(array_size(sizeof(struct kvm_cpuid_entry), 208 cpuid->nent)); 209 if (!cpuid_entries) 210 goto out; 211 r = -EFAULT; 212 if (copy_from_user(cpuid_entries, entries, 213 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 214 goto out; 215 } 216 for (i = 0; i < cpuid->nent; i++) { 217 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 218 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 219 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 220 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 221 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 222 vcpu->arch.cpuid_entries[i].index = 0; 223 vcpu->arch.cpuid_entries[i].flags = 0; 224 vcpu->arch.cpuid_entries[i].padding[0] = 0; 225 vcpu->arch.cpuid_entries[i].padding[1] = 0; 226 vcpu->arch.cpuid_entries[i].padding[2] = 0; 227 } 228 vcpu->arch.cpuid_nent = cpuid->nent; 229 cpuid_fix_nx_cap(vcpu); 230 kvm_apic_set_version(vcpu); 231 kvm_x86_ops->cpuid_update(vcpu); 232 r = kvm_update_cpuid(vcpu); 233 234 out: 235 vfree(cpuid_entries); 236 return r; 237 } 238 239 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 240 struct kvm_cpuid2 *cpuid, 241 struct kvm_cpuid_entry2 __user *entries) 242 { 243 int r; 244 245 r = -E2BIG; 246 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 247 goto out; 248 r = -EFAULT; 249 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 250 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 251 goto out; 252 vcpu->arch.cpuid_nent = cpuid->nent; 253 kvm_apic_set_version(vcpu); 254 kvm_x86_ops->cpuid_update(vcpu); 255 r = kvm_update_cpuid(vcpu); 256 out: 257 return r; 258 } 259 260 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 261 struct kvm_cpuid2 *cpuid, 262 struct kvm_cpuid_entry2 __user *entries) 263 { 264 int r; 265 266 r = -E2BIG; 267 if (cpuid->nent < vcpu->arch.cpuid_nent) 268 goto out; 269 r = -EFAULT; 270 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 271 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 272 goto out; 273 return 0; 274 275 out: 276 cpuid->nent = vcpu->arch.cpuid_nent; 277 return r; 278 } 279 280 static void cpuid_mask(u32 *word, int wordnum) 281 { 282 *word &= boot_cpu_data.x86_capability[wordnum]; 283 } 284 285 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 286 u32 index) 287 { 288 entry->function = function; 289 entry->index = index; 290 cpuid_count(entry->function, entry->index, 291 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 292 entry->flags = 0; 293 } 294 295 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 296 u32 func, u32 index, int *nent, int maxnent) 297 { 298 switch (func) { 299 case 0: 300 entry->eax = 7; 301 ++*nent; 302 break; 303 case 1: 304 entry->ecx = F(MOVBE); 305 ++*nent; 306 break; 307 case 7: 308 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 309 if (index == 0) 310 entry->ecx = F(RDPID); 311 ++*nent; 312 default: 313 break; 314 } 315 316 entry->function = func; 317 entry->index = index; 318 319 return 0; 320 } 321 322 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 323 u32 index, int *nent, int maxnent) 324 { 325 int r; 326 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 327 #ifdef CONFIG_X86_64 328 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 329 ? F(GBPAGES) : 0; 330 unsigned f_lm = F(LM); 331 #else 332 unsigned f_gbpages = 0; 333 unsigned f_lm = 0; 334 #endif 335 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 336 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 337 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 338 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 339 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0; 340 341 /* cpuid 1.edx */ 342 const u32 kvm_cpuid_1_edx_x86_features = 343 F(FPU) | F(VME) | F(DE) | F(PSE) | 344 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 345 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 346 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 347 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 348 0 /* Reserved, DS, ACPI */ | F(MMX) | 349 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 350 0 /* HTT, TM, Reserved, PBE */; 351 /* cpuid 0x80000001.edx */ 352 const u32 kvm_cpuid_8000_0001_edx_x86_features = 353 F(FPU) | F(VME) | F(DE) | F(PSE) | 354 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 355 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 356 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 357 F(PAT) | F(PSE36) | 0 /* Reserved */ | 358 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 359 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 360 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 361 /* cpuid 1.ecx */ 362 const u32 kvm_cpuid_1_ecx_x86_features = 363 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 364 * but *not* advertised to guests via CPUID ! */ 365 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 366 0 /* DS-CPL, VMX, SMX, EST */ | 367 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 368 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 369 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 370 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 371 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 372 F(F16C) | F(RDRAND); 373 /* cpuid 0x80000001.ecx */ 374 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 375 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 376 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 377 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 378 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 379 F(TOPOEXT) | F(PERFCTR_CORE); 380 381 /* cpuid 0x80000008.ebx */ 382 const u32 kvm_cpuid_8000_0008_ebx_x86_features = 383 F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | 384 F(AMD_SSB_NO); 385 386 /* cpuid 0xC0000001.edx */ 387 const u32 kvm_cpuid_C000_0001_edx_x86_features = 388 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 389 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 390 F(PMM) | F(PMM_EN); 391 392 /* cpuid 7.0.ebx */ 393 const u32 kvm_cpuid_7_0_ebx_x86_features = 394 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 395 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 396 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 397 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 398 F(SHA_NI) | F(AVX512BW) | F(AVX512VL); 399 400 /* cpuid 0xD.1.eax */ 401 const u32 kvm_cpuid_D_1_eax_x86_features = 402 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 403 404 /* cpuid 7.0.ecx*/ 405 const u32 kvm_cpuid_7_0_ecx_x86_features = 406 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | 407 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 408 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | 409 F(CLDEMOTE); 410 411 /* cpuid 7.0.edx*/ 412 const u32 kvm_cpuid_7_0_edx_x86_features = 413 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 414 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); 415 416 /* all calls to cpuid_count() should be made on the same cpu */ 417 get_cpu(); 418 419 r = -E2BIG; 420 421 if (*nent >= maxnent) 422 goto out; 423 424 do_cpuid_1_ent(entry, function, index); 425 ++*nent; 426 427 switch (function) { 428 case 0: 429 entry->eax = min(entry->eax, (u32)0xd); 430 break; 431 case 1: 432 entry->edx &= kvm_cpuid_1_edx_x86_features; 433 cpuid_mask(&entry->edx, CPUID_1_EDX); 434 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 435 cpuid_mask(&entry->ecx, CPUID_1_ECX); 436 /* we support x2apic emulation even if host does not support 437 * it since we emulate x2apic in software */ 438 entry->ecx |= F(X2APIC); 439 break; 440 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 441 * may return different values. This forces us to get_cpu() before 442 * issuing the first command, and also to emulate this annoying behavior 443 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 444 case 2: { 445 int t, times = entry->eax & 0xff; 446 447 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 448 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 449 for (t = 1; t < times; ++t) { 450 if (*nent >= maxnent) 451 goto out; 452 453 do_cpuid_1_ent(&entry[t], function, 0); 454 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 455 ++*nent; 456 } 457 break; 458 } 459 /* function 4 has additional index. */ 460 case 4: { 461 int i, cache_type; 462 463 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 464 /* read more entries until cache_type is zero */ 465 for (i = 1; ; ++i) { 466 if (*nent >= maxnent) 467 goto out; 468 469 cache_type = entry[i - 1].eax & 0x1f; 470 if (!cache_type) 471 break; 472 do_cpuid_1_ent(&entry[i], function, i); 473 entry[i].flags |= 474 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 475 ++*nent; 476 } 477 break; 478 } 479 case 6: /* Thermal management */ 480 entry->eax = 0x4; /* allow ARAT */ 481 entry->ebx = 0; 482 entry->ecx = 0; 483 entry->edx = 0; 484 break; 485 case 7: { 486 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 487 /* Mask ebx against host capability word 9 */ 488 if (index == 0) { 489 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 490 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 491 // TSC_ADJUST is emulated 492 entry->ebx |= F(TSC_ADJUST); 493 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 494 cpuid_mask(&entry->ecx, CPUID_7_ECX); 495 entry->ecx |= f_umip; 496 /* PKU is not yet implemented for shadow paging. */ 497 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 498 entry->ecx &= ~F(PKU); 499 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 500 cpuid_mask(&entry->edx, CPUID_7_EDX); 501 /* 502 * We emulate ARCH_CAPABILITIES in software even 503 * if the host doesn't support it. 504 */ 505 entry->edx |= F(ARCH_CAPABILITIES); 506 } else { 507 entry->ebx = 0; 508 entry->ecx = 0; 509 entry->edx = 0; 510 } 511 entry->eax = 0; 512 break; 513 } 514 case 9: 515 break; 516 case 0xa: { /* Architectural Performance Monitoring */ 517 struct x86_pmu_capability cap; 518 union cpuid10_eax eax; 519 union cpuid10_edx edx; 520 521 perf_get_x86_pmu_capability(&cap); 522 523 /* 524 * Only support guest architectural pmu on a host 525 * with architectural pmu. 526 */ 527 if (!cap.version) 528 memset(&cap, 0, sizeof(cap)); 529 530 eax.split.version_id = min(cap.version, 2); 531 eax.split.num_counters = cap.num_counters_gp; 532 eax.split.bit_width = cap.bit_width_gp; 533 eax.split.mask_length = cap.events_mask_len; 534 535 edx.split.num_counters_fixed = cap.num_counters_fixed; 536 edx.split.bit_width_fixed = cap.bit_width_fixed; 537 edx.split.reserved = 0; 538 539 entry->eax = eax.full; 540 entry->ebx = cap.events_mask; 541 entry->ecx = 0; 542 entry->edx = edx.full; 543 break; 544 } 545 /* function 0xb has additional index. */ 546 case 0xb: { 547 int i, level_type; 548 549 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 550 /* read more entries until level_type is zero */ 551 for (i = 1; ; ++i) { 552 if (*nent >= maxnent) 553 goto out; 554 555 level_type = entry[i - 1].ecx & 0xff00; 556 if (!level_type) 557 break; 558 do_cpuid_1_ent(&entry[i], function, i); 559 entry[i].flags |= 560 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 561 ++*nent; 562 } 563 break; 564 } 565 case 0xd: { 566 int idx, i; 567 u64 supported = kvm_supported_xcr0(); 568 569 entry->eax &= supported; 570 entry->ebx = xstate_required_size(supported, false); 571 entry->ecx = entry->ebx; 572 entry->edx &= supported >> 32; 573 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 574 if (!supported) 575 break; 576 577 for (idx = 1, i = 1; idx < 64; ++idx) { 578 u64 mask = ((u64)1 << idx); 579 if (*nent >= maxnent) 580 goto out; 581 582 do_cpuid_1_ent(&entry[i], function, idx); 583 if (idx == 1) { 584 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 585 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 586 entry[i].ebx = 0; 587 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 588 entry[i].ebx = 589 xstate_required_size(supported, 590 true); 591 } else { 592 if (entry[i].eax == 0 || !(supported & mask)) 593 continue; 594 if (WARN_ON_ONCE(entry[i].ecx & 1)) 595 continue; 596 } 597 entry[i].ecx = 0; 598 entry[i].edx = 0; 599 entry[i].flags |= 600 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 601 ++*nent; 602 ++i; 603 } 604 break; 605 } 606 case KVM_CPUID_SIGNATURE: { 607 static const char signature[12] = "KVMKVMKVM\0\0"; 608 const u32 *sigptr = (const u32 *)signature; 609 entry->eax = KVM_CPUID_FEATURES; 610 entry->ebx = sigptr[0]; 611 entry->ecx = sigptr[1]; 612 entry->edx = sigptr[2]; 613 break; 614 } 615 case KVM_CPUID_FEATURES: 616 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 617 (1 << KVM_FEATURE_NOP_IO_DELAY) | 618 (1 << KVM_FEATURE_CLOCKSOURCE2) | 619 (1 << KVM_FEATURE_ASYNC_PF) | 620 (1 << KVM_FEATURE_PV_EOI) | 621 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 622 (1 << KVM_FEATURE_PV_UNHALT) | 623 (1 << KVM_FEATURE_PV_TLB_FLUSH) | 624 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT); 625 626 if (sched_info_on()) 627 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 628 629 entry->ebx = 0; 630 entry->ecx = 0; 631 entry->edx = 0; 632 break; 633 case 0x80000000: 634 entry->eax = min(entry->eax, 0x8000001f); 635 break; 636 case 0x80000001: 637 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 638 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 639 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 640 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 641 break; 642 case 0x80000007: /* Advanced power management */ 643 /* invariant TSC is CPUID.80000007H:EDX[8] */ 644 entry->edx &= (1 << 8); 645 /* mask against host */ 646 entry->edx &= boot_cpu_data.x86_power; 647 entry->eax = entry->ebx = entry->ecx = 0; 648 break; 649 case 0x80000008: { 650 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 651 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 652 unsigned phys_as = entry->eax & 0xff; 653 654 if (!g_phys_as) 655 g_phys_as = phys_as; 656 entry->eax = g_phys_as | (virt_as << 8); 657 entry->edx = 0; 658 /* 659 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in 660 * hardware cpuid 661 */ 662 if (boot_cpu_has(X86_FEATURE_AMD_IBPB)) 663 entry->ebx |= F(AMD_IBPB); 664 if (boot_cpu_has(X86_FEATURE_AMD_IBRS)) 665 entry->ebx |= F(AMD_IBRS); 666 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD)) 667 entry->ebx |= F(VIRT_SSBD); 668 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; 669 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); 670 /* 671 * The preference is to use SPEC CTRL MSR instead of the 672 * VIRT_SPEC MSR. 673 */ 674 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && 675 !boot_cpu_has(X86_FEATURE_AMD_SSBD)) 676 entry->ebx |= F(VIRT_SSBD); 677 break; 678 } 679 case 0x80000019: 680 entry->ecx = entry->edx = 0; 681 break; 682 case 0x8000001a: 683 break; 684 case 0x8000001d: 685 break; 686 /*Add support for Centaur's CPUID instruction*/ 687 case 0xC0000000: 688 /*Just support up to 0xC0000004 now*/ 689 entry->eax = min(entry->eax, 0xC0000004); 690 break; 691 case 0xC0000001: 692 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 693 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 694 break; 695 case 3: /* Processor serial number */ 696 case 5: /* MONITOR/MWAIT */ 697 case 0xC0000002: 698 case 0xC0000003: 699 case 0xC0000004: 700 default: 701 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 702 break; 703 } 704 705 kvm_x86_ops->set_supported_cpuid(function, entry); 706 707 r = 0; 708 709 out: 710 put_cpu(); 711 712 return r; 713 } 714 715 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 716 u32 idx, int *nent, int maxnent, unsigned int type) 717 { 718 if (type == KVM_GET_EMULATED_CPUID) 719 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 720 721 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 722 } 723 724 #undef F 725 726 struct kvm_cpuid_param { 727 u32 func; 728 u32 idx; 729 bool has_leaf_count; 730 bool (*qualifier)(const struct kvm_cpuid_param *param); 731 }; 732 733 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 734 { 735 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 736 } 737 738 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 739 __u32 num_entries, unsigned int ioctl_type) 740 { 741 int i; 742 __u32 pad[3]; 743 744 if (ioctl_type != KVM_GET_EMULATED_CPUID) 745 return false; 746 747 /* 748 * We want to make sure that ->padding is being passed clean from 749 * userspace in case we want to use it for something in the future. 750 * 751 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 752 * have to give ourselves satisfied only with the emulated side. /me 753 * sheds a tear. 754 */ 755 for (i = 0; i < num_entries; i++) { 756 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 757 return true; 758 759 if (pad[0] || pad[1] || pad[2]) 760 return true; 761 } 762 return false; 763 } 764 765 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 766 struct kvm_cpuid_entry2 __user *entries, 767 unsigned int type) 768 { 769 struct kvm_cpuid_entry2 *cpuid_entries; 770 int limit, nent = 0, r = -E2BIG, i; 771 u32 func; 772 static const struct kvm_cpuid_param param[] = { 773 { .func = 0, .has_leaf_count = true }, 774 { .func = 0x80000000, .has_leaf_count = true }, 775 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 776 { .func = KVM_CPUID_SIGNATURE }, 777 { .func = KVM_CPUID_FEATURES }, 778 }; 779 780 if (cpuid->nent < 1) 781 goto out; 782 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 783 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 784 785 if (sanity_check_entries(entries, cpuid->nent, type)) 786 return -EINVAL; 787 788 r = -ENOMEM; 789 cpuid_entries = vzalloc(array_size(sizeof(struct kvm_cpuid_entry2), 790 cpuid->nent)); 791 if (!cpuid_entries) 792 goto out; 793 794 r = 0; 795 for (i = 0; i < ARRAY_SIZE(param); i++) { 796 const struct kvm_cpuid_param *ent = ¶m[i]; 797 798 if (ent->qualifier && !ent->qualifier(ent)) 799 continue; 800 801 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 802 &nent, cpuid->nent, type); 803 804 if (r) 805 goto out_free; 806 807 if (!ent->has_leaf_count) 808 continue; 809 810 limit = cpuid_entries[nent - 1].eax; 811 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 812 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 813 &nent, cpuid->nent, type); 814 815 if (r) 816 goto out_free; 817 } 818 819 r = -EFAULT; 820 if (copy_to_user(entries, cpuid_entries, 821 nent * sizeof(struct kvm_cpuid_entry2))) 822 goto out_free; 823 cpuid->nent = nent; 824 r = 0; 825 826 out_free: 827 vfree(cpuid_entries); 828 out: 829 return r; 830 } 831 832 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 833 { 834 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 835 struct kvm_cpuid_entry2 *ej; 836 int j = i; 837 int nent = vcpu->arch.cpuid_nent; 838 839 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 840 /* when no next entry is found, the current entry[i] is reselected */ 841 do { 842 j = (j + 1) % nent; 843 ej = &vcpu->arch.cpuid_entries[j]; 844 } while (ej->function != e->function); 845 846 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 847 848 return j; 849 } 850 851 /* find an entry with matching function, matching index (if needed), and that 852 * should be read next (if it's stateful) */ 853 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 854 u32 function, u32 index) 855 { 856 if (e->function != function) 857 return 0; 858 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 859 return 0; 860 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 861 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 862 return 0; 863 return 1; 864 } 865 866 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 867 u32 function, u32 index) 868 { 869 int i; 870 struct kvm_cpuid_entry2 *best = NULL; 871 872 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 873 struct kvm_cpuid_entry2 *e; 874 875 e = &vcpu->arch.cpuid_entries[i]; 876 if (is_matching_cpuid_entry(e, function, index)) { 877 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 878 move_to_next_stateful_cpuid_entry(vcpu, i); 879 best = e; 880 break; 881 } 882 } 883 return best; 884 } 885 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 886 887 /* 888 * If no match is found, check whether we exceed the vCPU's limit 889 * and return the content of the highest valid _standard_ leaf instead. 890 * This is to satisfy the CPUID specification. 891 */ 892 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 893 u32 function, u32 index) 894 { 895 struct kvm_cpuid_entry2 *maxlevel; 896 897 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 898 if (!maxlevel || maxlevel->eax >= function) 899 return NULL; 900 if (function & 0x80000000) { 901 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 902 if (!maxlevel) 903 return NULL; 904 } 905 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 906 } 907 908 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 909 u32 *ecx, u32 *edx, bool check_limit) 910 { 911 u32 function = *eax, index = *ecx; 912 struct kvm_cpuid_entry2 *best; 913 bool entry_found = true; 914 915 best = kvm_find_cpuid_entry(vcpu, function, index); 916 917 if (!best) { 918 entry_found = false; 919 if (!check_limit) 920 goto out; 921 922 best = check_cpuid_limit(vcpu, function, index); 923 } 924 925 out: 926 if (best) { 927 *eax = best->eax; 928 *ebx = best->ebx; 929 *ecx = best->ecx; 930 *edx = best->edx; 931 } else 932 *eax = *ebx = *ecx = *edx = 0; 933 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); 934 return entry_found; 935 } 936 EXPORT_SYMBOL_GPL(kvm_cpuid); 937 938 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 939 { 940 u32 eax, ebx, ecx, edx; 941 942 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 943 return 1; 944 945 eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 946 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 947 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); 948 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 949 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 950 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 951 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 952 return kvm_skip_emulated_instruction(vcpu); 953 } 954 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 955