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