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/module.h> 17 #include <linux/vmalloc.h> 18 #include <linux/uaccess.h> 19 #include <asm/fpu/internal.h> /* For use_eager_fpu. Ugh! */ 20 #include <asm/user.h> 21 #include <asm/fpu/xstate.h> 22 #include "cpuid.h" 23 #include "lapic.h" 24 #include "mmu.h" 25 #include "trace.h" 26 #include "pmu.h" 27 28 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 29 { 30 int feature_bit = 0; 31 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 32 33 xstate_bv &= XFEATURE_MASK_EXTEND; 34 while (xstate_bv) { 35 if (xstate_bv & 0x1) { 36 u32 eax, ebx, ecx, edx, offset; 37 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 38 offset = compacted ? ret : ebx; 39 ret = max(ret, offset + eax); 40 } 41 42 xstate_bv >>= 1; 43 feature_bit++; 44 } 45 46 return ret; 47 } 48 49 bool kvm_mpx_supported(void) 50 { 51 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) 52 && kvm_x86_ops->mpx_supported()); 53 } 54 EXPORT_SYMBOL_GPL(kvm_mpx_supported); 55 56 u64 kvm_supported_xcr0(void) 57 { 58 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 59 60 if (!kvm_mpx_supported()) 61 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); 62 63 return xcr0; 64 } 65 66 #define F(x) bit(X86_FEATURE_##x) 67 68 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 69 { 70 struct kvm_cpuid_entry2 *best; 71 struct kvm_lapic *apic = vcpu->arch.apic; 72 73 best = kvm_find_cpuid_entry(vcpu, 1, 0); 74 if (!best) 75 return 0; 76 77 /* Update OSXSAVE bit */ 78 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) { 79 best->ecx &= ~F(OSXSAVE); 80 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 81 best->ecx |= F(OSXSAVE); 82 } 83 84 if (apic) { 85 if (best->ecx & F(TSC_DEADLINE_TIMER)) 86 apic->lapic_timer.timer_mode_mask = 3 << 17; 87 else 88 apic->lapic_timer.timer_mode_mask = 1 << 17; 89 } 90 91 best = kvm_find_cpuid_entry(vcpu, 7, 0); 92 if (best) { 93 /* Update OSPKE bit */ 94 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) { 95 best->ecx &= ~F(OSPKE); 96 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) 97 best->ecx |= F(OSPKE); 98 } 99 } 100 101 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 102 if (!best) { 103 vcpu->arch.guest_supported_xcr0 = 0; 104 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 105 } else { 106 vcpu->arch.guest_supported_xcr0 = 107 (best->eax | ((u64)best->edx << 32)) & 108 kvm_supported_xcr0(); 109 vcpu->arch.guest_xstate_size = best->ebx = 110 xstate_required_size(vcpu->arch.xcr0, false); 111 } 112 113 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 114 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 115 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 116 117 if (use_eager_fpu()) 118 kvm_x86_ops->fpu_activate(vcpu); 119 120 /* 121 * The existing code assumes virtual address is 48-bit in the canonical 122 * address checks; exit if it is ever changed. 123 */ 124 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 125 if (best && ((best->eax & 0xff00) >> 8) != 48 && 126 ((best->eax & 0xff00) >> 8) != 0) 127 return -EINVAL; 128 129 /* Update physical-address width */ 130 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 131 132 kvm_pmu_refresh(vcpu); 133 return 0; 134 } 135 136 static int is_efer_nx(void) 137 { 138 unsigned long long efer = 0; 139 140 rdmsrl_safe(MSR_EFER, &efer); 141 return efer & EFER_NX; 142 } 143 144 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 145 { 146 int i; 147 struct kvm_cpuid_entry2 *e, *entry; 148 149 entry = NULL; 150 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 151 e = &vcpu->arch.cpuid_entries[i]; 152 if (e->function == 0x80000001) { 153 entry = e; 154 break; 155 } 156 } 157 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 158 entry->edx &= ~F(NX); 159 printk(KERN_INFO "kvm: guest NX capability removed\n"); 160 } 161 } 162 163 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 164 { 165 struct kvm_cpuid_entry2 *best; 166 167 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 168 if (!best || best->eax < 0x80000008) 169 goto not_found; 170 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 171 if (best) 172 return best->eax & 0xff; 173 not_found: 174 return 36; 175 } 176 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 177 178 /* when an old userspace process fills a new kernel module */ 179 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 180 struct kvm_cpuid *cpuid, 181 struct kvm_cpuid_entry __user *entries) 182 { 183 int r, i; 184 struct kvm_cpuid_entry *cpuid_entries = NULL; 185 186 r = -E2BIG; 187 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 188 goto out; 189 r = -ENOMEM; 190 if (cpuid->nent) { 191 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * 192 cpuid->nent); 193 if (!cpuid_entries) 194 goto out; 195 r = -EFAULT; 196 if (copy_from_user(cpuid_entries, entries, 197 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 198 goto out; 199 } 200 for (i = 0; i < cpuid->nent; i++) { 201 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 202 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 203 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 204 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 205 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 206 vcpu->arch.cpuid_entries[i].index = 0; 207 vcpu->arch.cpuid_entries[i].flags = 0; 208 vcpu->arch.cpuid_entries[i].padding[0] = 0; 209 vcpu->arch.cpuid_entries[i].padding[1] = 0; 210 vcpu->arch.cpuid_entries[i].padding[2] = 0; 211 } 212 vcpu->arch.cpuid_nent = cpuid->nent; 213 cpuid_fix_nx_cap(vcpu); 214 kvm_apic_set_version(vcpu); 215 kvm_x86_ops->cpuid_update(vcpu); 216 r = kvm_update_cpuid(vcpu); 217 218 out: 219 vfree(cpuid_entries); 220 return r; 221 } 222 223 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 224 struct kvm_cpuid2 *cpuid, 225 struct kvm_cpuid_entry2 __user *entries) 226 { 227 int r; 228 229 r = -E2BIG; 230 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 231 goto out; 232 r = -EFAULT; 233 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 234 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 235 goto out; 236 vcpu->arch.cpuid_nent = cpuid->nent; 237 kvm_apic_set_version(vcpu); 238 kvm_x86_ops->cpuid_update(vcpu); 239 r = kvm_update_cpuid(vcpu); 240 out: 241 return r; 242 } 243 244 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 245 struct kvm_cpuid2 *cpuid, 246 struct kvm_cpuid_entry2 __user *entries) 247 { 248 int r; 249 250 r = -E2BIG; 251 if (cpuid->nent < vcpu->arch.cpuid_nent) 252 goto out; 253 r = -EFAULT; 254 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 255 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 256 goto out; 257 return 0; 258 259 out: 260 cpuid->nent = vcpu->arch.cpuid_nent; 261 return r; 262 } 263 264 static void cpuid_mask(u32 *word, int wordnum) 265 { 266 *word &= boot_cpu_data.x86_capability[wordnum]; 267 } 268 269 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 270 u32 index) 271 { 272 entry->function = function; 273 entry->index = index; 274 cpuid_count(entry->function, entry->index, 275 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 276 entry->flags = 0; 277 } 278 279 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 280 u32 func, u32 index, int *nent, int maxnent) 281 { 282 switch (func) { 283 case 0: 284 entry->eax = 1; /* only one leaf currently */ 285 ++*nent; 286 break; 287 case 1: 288 entry->ecx = F(MOVBE); 289 ++*nent; 290 break; 291 default: 292 break; 293 } 294 295 entry->function = func; 296 entry->index = index; 297 298 return 0; 299 } 300 301 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 302 u32 index, int *nent, int maxnent) 303 { 304 int r; 305 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 306 #ifdef CONFIG_X86_64 307 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 308 ? F(GBPAGES) : 0; 309 unsigned f_lm = F(LM); 310 #else 311 unsigned f_gbpages = 0; 312 unsigned f_lm = 0; 313 #endif 314 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 315 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 316 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 317 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 318 319 /* cpuid 1.edx */ 320 const u32 kvm_cpuid_1_edx_x86_features = 321 F(FPU) | F(VME) | F(DE) | F(PSE) | 322 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 323 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 324 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 325 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 326 0 /* Reserved, DS, ACPI */ | F(MMX) | 327 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 328 0 /* HTT, TM, Reserved, PBE */; 329 /* cpuid 0x80000001.edx */ 330 const u32 kvm_cpuid_8000_0001_edx_x86_features = 331 F(FPU) | F(VME) | F(DE) | F(PSE) | 332 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 333 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 334 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 335 F(PAT) | F(PSE36) | 0 /* Reserved */ | 336 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 337 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 338 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 339 /* cpuid 1.ecx */ 340 const u32 kvm_cpuid_1_ecx_x86_features = 341 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 342 * but *not* advertised to guests via CPUID ! */ 343 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 344 0 /* DS-CPL, VMX, SMX, EST */ | 345 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 346 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 347 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 348 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 349 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 350 F(F16C) | F(RDRAND); 351 /* cpuid 0x80000001.ecx */ 352 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 353 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 354 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 355 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 356 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 357 358 /* cpuid 0xC0000001.edx */ 359 const u32 kvm_cpuid_C000_0001_edx_x86_features = 360 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 361 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 362 F(PMM) | F(PMM_EN); 363 364 /* cpuid 7.0.ebx */ 365 const u32 kvm_cpuid_7_0_ebx_x86_features = 366 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 367 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 368 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) | 369 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(PCOMMIT); 370 371 /* cpuid 0xD.1.eax */ 372 const u32 kvm_cpuid_D_1_eax_x86_features = 373 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 374 375 /* cpuid 7.0.ecx*/ 376 const u32 kvm_cpuid_7_0_ecx_x86_features = F(PKU) | 0 /*OSPKE*/; 377 378 /* all calls to cpuid_count() should be made on the same cpu */ 379 get_cpu(); 380 381 r = -E2BIG; 382 383 if (*nent >= maxnent) 384 goto out; 385 386 do_cpuid_1_ent(entry, function, index); 387 ++*nent; 388 389 switch (function) { 390 case 0: 391 entry->eax = min(entry->eax, (u32)0xd); 392 break; 393 case 1: 394 entry->edx &= kvm_cpuid_1_edx_x86_features; 395 cpuid_mask(&entry->edx, CPUID_1_EDX); 396 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 397 cpuid_mask(&entry->ecx, CPUID_1_ECX); 398 /* we support x2apic emulation even if host does not support 399 * it since we emulate x2apic in software */ 400 entry->ecx |= F(X2APIC); 401 break; 402 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 403 * may return different values. This forces us to get_cpu() before 404 * issuing the first command, and also to emulate this annoying behavior 405 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 406 case 2: { 407 int t, times = entry->eax & 0xff; 408 409 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 410 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 411 for (t = 1; t < times; ++t) { 412 if (*nent >= maxnent) 413 goto out; 414 415 do_cpuid_1_ent(&entry[t], function, 0); 416 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 417 ++*nent; 418 } 419 break; 420 } 421 /* function 4 has additional index. */ 422 case 4: { 423 int i, cache_type; 424 425 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 426 /* read more entries until cache_type is zero */ 427 for (i = 1; ; ++i) { 428 if (*nent >= maxnent) 429 goto out; 430 431 cache_type = entry[i - 1].eax & 0x1f; 432 if (!cache_type) 433 break; 434 do_cpuid_1_ent(&entry[i], function, i); 435 entry[i].flags |= 436 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 437 ++*nent; 438 } 439 break; 440 } 441 case 6: /* Thermal management */ 442 entry->eax = 0x4; /* allow ARAT */ 443 entry->ebx = 0; 444 entry->ecx = 0; 445 entry->edx = 0; 446 break; 447 case 7: { 448 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 449 /* Mask ebx against host capability word 9 */ 450 if (index == 0) { 451 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 452 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 453 // TSC_ADJUST is emulated 454 entry->ebx |= F(TSC_ADJUST); 455 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 456 cpuid_mask(&entry->ecx, CPUID_7_ECX); 457 /* PKU is not yet implemented for shadow paging. */ 458 if (!tdp_enabled) 459 entry->ecx &= ~F(PKU); 460 } else { 461 entry->ebx = 0; 462 entry->ecx = 0; 463 } 464 entry->eax = 0; 465 entry->edx = 0; 466 break; 467 } 468 case 9: 469 break; 470 case 0xa: { /* Architectural Performance Monitoring */ 471 struct x86_pmu_capability cap; 472 union cpuid10_eax eax; 473 union cpuid10_edx edx; 474 475 perf_get_x86_pmu_capability(&cap); 476 477 /* 478 * Only support guest architectural pmu on a host 479 * with architectural pmu. 480 */ 481 if (!cap.version) 482 memset(&cap, 0, sizeof(cap)); 483 484 eax.split.version_id = min(cap.version, 2); 485 eax.split.num_counters = cap.num_counters_gp; 486 eax.split.bit_width = cap.bit_width_gp; 487 eax.split.mask_length = cap.events_mask_len; 488 489 edx.split.num_counters_fixed = cap.num_counters_fixed; 490 edx.split.bit_width_fixed = cap.bit_width_fixed; 491 edx.split.reserved = 0; 492 493 entry->eax = eax.full; 494 entry->ebx = cap.events_mask; 495 entry->ecx = 0; 496 entry->edx = edx.full; 497 break; 498 } 499 /* function 0xb has additional index. */ 500 case 0xb: { 501 int i, level_type; 502 503 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 504 /* read more entries until level_type is zero */ 505 for (i = 1; ; ++i) { 506 if (*nent >= maxnent) 507 goto out; 508 509 level_type = entry[i - 1].ecx & 0xff00; 510 if (!level_type) 511 break; 512 do_cpuid_1_ent(&entry[i], function, i); 513 entry[i].flags |= 514 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 515 ++*nent; 516 } 517 break; 518 } 519 case 0xd: { 520 int idx, i; 521 u64 supported = kvm_supported_xcr0(); 522 523 entry->eax &= supported; 524 entry->ebx = xstate_required_size(supported, false); 525 entry->ecx = entry->ebx; 526 entry->edx &= supported >> 32; 527 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 528 if (!supported) 529 break; 530 531 for (idx = 1, i = 1; idx < 64; ++idx) { 532 u64 mask = ((u64)1 << idx); 533 if (*nent >= maxnent) 534 goto out; 535 536 do_cpuid_1_ent(&entry[i], function, idx); 537 if (idx == 1) { 538 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 539 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 540 entry[i].ebx = 0; 541 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 542 entry[i].ebx = 543 xstate_required_size(supported, 544 true); 545 } else { 546 if (entry[i].eax == 0 || !(supported & mask)) 547 continue; 548 if (WARN_ON_ONCE(entry[i].ecx & 1)) 549 continue; 550 } 551 entry[i].ecx = 0; 552 entry[i].edx = 0; 553 entry[i].flags |= 554 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 555 ++*nent; 556 ++i; 557 } 558 break; 559 } 560 case KVM_CPUID_SIGNATURE: { 561 static const char signature[12] = "KVMKVMKVM\0\0"; 562 const u32 *sigptr = (const u32 *)signature; 563 entry->eax = KVM_CPUID_FEATURES; 564 entry->ebx = sigptr[0]; 565 entry->ecx = sigptr[1]; 566 entry->edx = sigptr[2]; 567 break; 568 } 569 case KVM_CPUID_FEATURES: 570 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 571 (1 << KVM_FEATURE_NOP_IO_DELAY) | 572 (1 << KVM_FEATURE_CLOCKSOURCE2) | 573 (1 << KVM_FEATURE_ASYNC_PF) | 574 (1 << KVM_FEATURE_PV_EOI) | 575 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 576 (1 << KVM_FEATURE_PV_UNHALT); 577 578 if (sched_info_on()) 579 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 580 581 entry->ebx = 0; 582 entry->ecx = 0; 583 entry->edx = 0; 584 break; 585 case 0x80000000: 586 entry->eax = min(entry->eax, 0x8000001a); 587 break; 588 case 0x80000001: 589 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 590 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 591 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 592 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 593 break; 594 case 0x80000007: /* Advanced power management */ 595 /* invariant TSC is CPUID.80000007H:EDX[8] */ 596 entry->edx &= (1 << 8); 597 /* mask against host */ 598 entry->edx &= boot_cpu_data.x86_power; 599 entry->eax = entry->ebx = entry->ecx = 0; 600 break; 601 case 0x80000008: { 602 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 603 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 604 unsigned phys_as = entry->eax & 0xff; 605 606 if (!g_phys_as) 607 g_phys_as = phys_as; 608 entry->eax = g_phys_as | (virt_as << 8); 609 entry->ebx = entry->edx = 0; 610 break; 611 } 612 case 0x80000019: 613 entry->ecx = entry->edx = 0; 614 break; 615 case 0x8000001a: 616 break; 617 case 0x8000001d: 618 break; 619 /*Add support for Centaur's CPUID instruction*/ 620 case 0xC0000000: 621 /*Just support up to 0xC0000004 now*/ 622 entry->eax = min(entry->eax, 0xC0000004); 623 break; 624 case 0xC0000001: 625 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 626 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 627 break; 628 case 3: /* Processor serial number */ 629 case 5: /* MONITOR/MWAIT */ 630 case 0xC0000002: 631 case 0xC0000003: 632 case 0xC0000004: 633 default: 634 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 635 break; 636 } 637 638 kvm_x86_ops->set_supported_cpuid(function, entry); 639 640 r = 0; 641 642 out: 643 put_cpu(); 644 645 return r; 646 } 647 648 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 649 u32 idx, int *nent, int maxnent, unsigned int type) 650 { 651 if (type == KVM_GET_EMULATED_CPUID) 652 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 653 654 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 655 } 656 657 #undef F 658 659 struct kvm_cpuid_param { 660 u32 func; 661 u32 idx; 662 bool has_leaf_count; 663 bool (*qualifier)(const struct kvm_cpuid_param *param); 664 }; 665 666 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 667 { 668 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 669 } 670 671 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 672 __u32 num_entries, unsigned int ioctl_type) 673 { 674 int i; 675 __u32 pad[3]; 676 677 if (ioctl_type != KVM_GET_EMULATED_CPUID) 678 return false; 679 680 /* 681 * We want to make sure that ->padding is being passed clean from 682 * userspace in case we want to use it for something in the future. 683 * 684 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 685 * have to give ourselves satisfied only with the emulated side. /me 686 * sheds a tear. 687 */ 688 for (i = 0; i < num_entries; i++) { 689 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 690 return true; 691 692 if (pad[0] || pad[1] || pad[2]) 693 return true; 694 } 695 return false; 696 } 697 698 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 699 struct kvm_cpuid_entry2 __user *entries, 700 unsigned int type) 701 { 702 struct kvm_cpuid_entry2 *cpuid_entries; 703 int limit, nent = 0, r = -E2BIG, i; 704 u32 func; 705 static const struct kvm_cpuid_param param[] = { 706 { .func = 0, .has_leaf_count = true }, 707 { .func = 0x80000000, .has_leaf_count = true }, 708 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 709 { .func = KVM_CPUID_SIGNATURE }, 710 { .func = KVM_CPUID_FEATURES }, 711 }; 712 713 if (cpuid->nent < 1) 714 goto out; 715 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 716 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 717 718 if (sanity_check_entries(entries, cpuid->nent, type)) 719 return -EINVAL; 720 721 r = -ENOMEM; 722 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 723 if (!cpuid_entries) 724 goto out; 725 726 r = 0; 727 for (i = 0; i < ARRAY_SIZE(param); i++) { 728 const struct kvm_cpuid_param *ent = ¶m[i]; 729 730 if (ent->qualifier && !ent->qualifier(ent)) 731 continue; 732 733 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 734 &nent, cpuid->nent, type); 735 736 if (r) 737 goto out_free; 738 739 if (!ent->has_leaf_count) 740 continue; 741 742 limit = cpuid_entries[nent - 1].eax; 743 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 744 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 745 &nent, cpuid->nent, type); 746 747 if (r) 748 goto out_free; 749 } 750 751 r = -EFAULT; 752 if (copy_to_user(entries, cpuid_entries, 753 nent * sizeof(struct kvm_cpuid_entry2))) 754 goto out_free; 755 cpuid->nent = nent; 756 r = 0; 757 758 out_free: 759 vfree(cpuid_entries); 760 out: 761 return r; 762 } 763 764 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 765 { 766 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 767 int j, nent = vcpu->arch.cpuid_nent; 768 769 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 770 /* when no next entry is found, the current entry[i] is reselected */ 771 for (j = i + 1; ; j = (j + 1) % nent) { 772 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 773 if (ej->function == e->function) { 774 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 775 return j; 776 } 777 } 778 return 0; /* silence gcc, even though control never reaches here */ 779 } 780 781 /* find an entry with matching function, matching index (if needed), and that 782 * should be read next (if it's stateful) */ 783 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 784 u32 function, u32 index) 785 { 786 if (e->function != function) 787 return 0; 788 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 789 return 0; 790 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 791 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 792 return 0; 793 return 1; 794 } 795 796 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 797 u32 function, u32 index) 798 { 799 int i; 800 struct kvm_cpuid_entry2 *best = NULL; 801 802 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 803 struct kvm_cpuid_entry2 *e; 804 805 e = &vcpu->arch.cpuid_entries[i]; 806 if (is_matching_cpuid_entry(e, function, index)) { 807 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 808 move_to_next_stateful_cpuid_entry(vcpu, i); 809 best = e; 810 break; 811 } 812 } 813 return best; 814 } 815 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 816 817 /* 818 * If no match is found, check whether we exceed the vCPU's limit 819 * and return the content of the highest valid _standard_ leaf instead. 820 * This is to satisfy the CPUID specification. 821 */ 822 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 823 u32 function, u32 index) 824 { 825 struct kvm_cpuid_entry2 *maxlevel; 826 827 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 828 if (!maxlevel || maxlevel->eax >= function) 829 return NULL; 830 if (function & 0x80000000) { 831 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 832 if (!maxlevel) 833 return NULL; 834 } 835 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 836 } 837 838 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 839 { 840 u32 function = *eax, index = *ecx; 841 struct kvm_cpuid_entry2 *best; 842 843 best = kvm_find_cpuid_entry(vcpu, function, index); 844 845 if (!best) 846 best = check_cpuid_limit(vcpu, function, index); 847 848 /* 849 * Perfmon not yet supported for L2 guest. 850 */ 851 if (is_guest_mode(vcpu) && function == 0xa) 852 best = NULL; 853 854 if (best) { 855 *eax = best->eax; 856 *ebx = best->ebx; 857 *ecx = best->ecx; 858 *edx = best->edx; 859 } else 860 *eax = *ebx = *ecx = *edx = 0; 861 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 862 } 863 EXPORT_SYMBOL_GPL(kvm_cpuid); 864 865 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 866 { 867 u32 function, eax, ebx, ecx, edx; 868 869 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 870 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 871 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 872 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 873 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 874 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 875 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 876 kvm_x86_ops->skip_emulated_instruction(vcpu); 877 } 878 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 879