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 <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(AVX512DQ) | 370 F(AVX512BW) | F(AVX512VL); 371 372 /* cpuid 0xD.1.eax */ 373 const u32 kvm_cpuid_D_1_eax_x86_features = 374 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 375 376 /* cpuid 7.0.ecx*/ 377 const u32 kvm_cpuid_7_0_ecx_x86_features = F(PKU) | 0 /*OSPKE*/; 378 379 /* all calls to cpuid_count() should be made on the same cpu */ 380 get_cpu(); 381 382 r = -E2BIG; 383 384 if (*nent >= maxnent) 385 goto out; 386 387 do_cpuid_1_ent(entry, function, index); 388 ++*nent; 389 390 switch (function) { 391 case 0: 392 entry->eax = min(entry->eax, (u32)0xd); 393 break; 394 case 1: 395 entry->edx &= kvm_cpuid_1_edx_x86_features; 396 cpuid_mask(&entry->edx, CPUID_1_EDX); 397 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 398 cpuid_mask(&entry->ecx, CPUID_1_ECX); 399 /* we support x2apic emulation even if host does not support 400 * it since we emulate x2apic in software */ 401 entry->ecx |= F(X2APIC); 402 break; 403 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 404 * may return different values. This forces us to get_cpu() before 405 * issuing the first command, and also to emulate this annoying behavior 406 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 407 case 2: { 408 int t, times = entry->eax & 0xff; 409 410 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 411 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 412 for (t = 1; t < times; ++t) { 413 if (*nent >= maxnent) 414 goto out; 415 416 do_cpuid_1_ent(&entry[t], function, 0); 417 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 418 ++*nent; 419 } 420 break; 421 } 422 /* function 4 has additional index. */ 423 case 4: { 424 int i, cache_type; 425 426 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 427 /* read more entries until cache_type is zero */ 428 for (i = 1; ; ++i) { 429 if (*nent >= maxnent) 430 goto out; 431 432 cache_type = entry[i - 1].eax & 0x1f; 433 if (!cache_type) 434 break; 435 do_cpuid_1_ent(&entry[i], function, i); 436 entry[i].flags |= 437 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 438 ++*nent; 439 } 440 break; 441 } 442 case 6: /* Thermal management */ 443 entry->eax = 0x4; /* allow ARAT */ 444 entry->ebx = 0; 445 entry->ecx = 0; 446 entry->edx = 0; 447 break; 448 case 7: { 449 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 450 /* Mask ebx against host capability word 9 */ 451 if (index == 0) { 452 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 453 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 454 // TSC_ADJUST is emulated 455 entry->ebx |= F(TSC_ADJUST); 456 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 457 cpuid_mask(&entry->ecx, CPUID_7_ECX); 458 /* PKU is not yet implemented for shadow paging. */ 459 if (!tdp_enabled) 460 entry->ecx &= ~F(PKU); 461 } else { 462 entry->ebx = 0; 463 entry->ecx = 0; 464 } 465 entry->eax = 0; 466 entry->edx = 0; 467 break; 468 } 469 case 9: 470 break; 471 case 0xa: { /* Architectural Performance Monitoring */ 472 struct x86_pmu_capability cap; 473 union cpuid10_eax eax; 474 union cpuid10_edx edx; 475 476 perf_get_x86_pmu_capability(&cap); 477 478 /* 479 * Only support guest architectural pmu on a host 480 * with architectural pmu. 481 */ 482 if (!cap.version) 483 memset(&cap, 0, sizeof(cap)); 484 485 eax.split.version_id = min(cap.version, 2); 486 eax.split.num_counters = cap.num_counters_gp; 487 eax.split.bit_width = cap.bit_width_gp; 488 eax.split.mask_length = cap.events_mask_len; 489 490 edx.split.num_counters_fixed = cap.num_counters_fixed; 491 edx.split.bit_width_fixed = cap.bit_width_fixed; 492 edx.split.reserved = 0; 493 494 entry->eax = eax.full; 495 entry->ebx = cap.events_mask; 496 entry->ecx = 0; 497 entry->edx = edx.full; 498 break; 499 } 500 /* function 0xb has additional index. */ 501 case 0xb: { 502 int i, level_type; 503 504 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 505 /* read more entries until level_type is zero */ 506 for (i = 1; ; ++i) { 507 if (*nent >= maxnent) 508 goto out; 509 510 level_type = entry[i - 1].ecx & 0xff00; 511 if (!level_type) 512 break; 513 do_cpuid_1_ent(&entry[i], function, i); 514 entry[i].flags |= 515 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 516 ++*nent; 517 } 518 break; 519 } 520 case 0xd: { 521 int idx, i; 522 u64 supported = kvm_supported_xcr0(); 523 524 entry->eax &= supported; 525 entry->ebx = xstate_required_size(supported, false); 526 entry->ecx = entry->ebx; 527 entry->edx &= supported >> 32; 528 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 529 if (!supported) 530 break; 531 532 for (idx = 1, i = 1; idx < 64; ++idx) { 533 u64 mask = ((u64)1 << idx); 534 if (*nent >= maxnent) 535 goto out; 536 537 do_cpuid_1_ent(&entry[i], function, idx); 538 if (idx == 1) { 539 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 540 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 541 entry[i].ebx = 0; 542 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 543 entry[i].ebx = 544 xstate_required_size(supported, 545 true); 546 } else { 547 if (entry[i].eax == 0 || !(supported & mask)) 548 continue; 549 if (WARN_ON_ONCE(entry[i].ecx & 1)) 550 continue; 551 } 552 entry[i].ecx = 0; 553 entry[i].edx = 0; 554 entry[i].flags |= 555 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 556 ++*nent; 557 ++i; 558 } 559 break; 560 } 561 case KVM_CPUID_SIGNATURE: { 562 static const char signature[12] = "KVMKVMKVM\0\0"; 563 const u32 *sigptr = (const u32 *)signature; 564 entry->eax = KVM_CPUID_FEATURES; 565 entry->ebx = sigptr[0]; 566 entry->ecx = sigptr[1]; 567 entry->edx = sigptr[2]; 568 break; 569 } 570 case KVM_CPUID_FEATURES: 571 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 572 (1 << KVM_FEATURE_NOP_IO_DELAY) | 573 (1 << KVM_FEATURE_CLOCKSOURCE2) | 574 (1 << KVM_FEATURE_ASYNC_PF) | 575 (1 << KVM_FEATURE_PV_EOI) | 576 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 577 (1 << KVM_FEATURE_PV_UNHALT); 578 579 if (sched_info_on()) 580 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 581 582 entry->ebx = 0; 583 entry->ecx = 0; 584 entry->edx = 0; 585 break; 586 case 0x80000000: 587 entry->eax = min(entry->eax, 0x8000001a); 588 break; 589 case 0x80000001: 590 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 591 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 592 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 593 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 594 break; 595 case 0x80000007: /* Advanced power management */ 596 /* invariant TSC is CPUID.80000007H:EDX[8] */ 597 entry->edx &= (1 << 8); 598 /* mask against host */ 599 entry->edx &= boot_cpu_data.x86_power; 600 entry->eax = entry->ebx = entry->ecx = 0; 601 break; 602 case 0x80000008: { 603 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 604 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 605 unsigned phys_as = entry->eax & 0xff; 606 607 if (!g_phys_as) 608 g_phys_as = phys_as; 609 entry->eax = g_phys_as | (virt_as << 8); 610 entry->ebx = entry->edx = 0; 611 break; 612 } 613 case 0x80000019: 614 entry->ecx = entry->edx = 0; 615 break; 616 case 0x8000001a: 617 break; 618 case 0x8000001d: 619 break; 620 /*Add support for Centaur's CPUID instruction*/ 621 case 0xC0000000: 622 /*Just support up to 0xC0000004 now*/ 623 entry->eax = min(entry->eax, 0xC0000004); 624 break; 625 case 0xC0000001: 626 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 627 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 628 break; 629 case 3: /* Processor serial number */ 630 case 5: /* MONITOR/MWAIT */ 631 case 0xC0000002: 632 case 0xC0000003: 633 case 0xC0000004: 634 default: 635 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 636 break; 637 } 638 639 kvm_x86_ops->set_supported_cpuid(function, entry); 640 641 r = 0; 642 643 out: 644 put_cpu(); 645 646 return r; 647 } 648 649 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 650 u32 idx, int *nent, int maxnent, unsigned int type) 651 { 652 if (type == KVM_GET_EMULATED_CPUID) 653 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 654 655 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 656 } 657 658 #undef F 659 660 struct kvm_cpuid_param { 661 u32 func; 662 u32 idx; 663 bool has_leaf_count; 664 bool (*qualifier)(const struct kvm_cpuid_param *param); 665 }; 666 667 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 668 { 669 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 670 } 671 672 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 673 __u32 num_entries, unsigned int ioctl_type) 674 { 675 int i; 676 __u32 pad[3]; 677 678 if (ioctl_type != KVM_GET_EMULATED_CPUID) 679 return false; 680 681 /* 682 * We want to make sure that ->padding is being passed clean from 683 * userspace in case we want to use it for something in the future. 684 * 685 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 686 * have to give ourselves satisfied only with the emulated side. /me 687 * sheds a tear. 688 */ 689 for (i = 0; i < num_entries; i++) { 690 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 691 return true; 692 693 if (pad[0] || pad[1] || pad[2]) 694 return true; 695 } 696 return false; 697 } 698 699 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 700 struct kvm_cpuid_entry2 __user *entries, 701 unsigned int type) 702 { 703 struct kvm_cpuid_entry2 *cpuid_entries; 704 int limit, nent = 0, r = -E2BIG, i; 705 u32 func; 706 static const struct kvm_cpuid_param param[] = { 707 { .func = 0, .has_leaf_count = true }, 708 { .func = 0x80000000, .has_leaf_count = true }, 709 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 710 { .func = KVM_CPUID_SIGNATURE }, 711 { .func = KVM_CPUID_FEATURES }, 712 }; 713 714 if (cpuid->nent < 1) 715 goto out; 716 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 717 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 718 719 if (sanity_check_entries(entries, cpuid->nent, type)) 720 return -EINVAL; 721 722 r = -ENOMEM; 723 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 724 if (!cpuid_entries) 725 goto out; 726 727 r = 0; 728 for (i = 0; i < ARRAY_SIZE(param); i++) { 729 const struct kvm_cpuid_param *ent = ¶m[i]; 730 731 if (ent->qualifier && !ent->qualifier(ent)) 732 continue; 733 734 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 735 &nent, cpuid->nent, type); 736 737 if (r) 738 goto out_free; 739 740 if (!ent->has_leaf_count) 741 continue; 742 743 limit = cpuid_entries[nent - 1].eax; 744 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 745 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 746 &nent, cpuid->nent, type); 747 748 if (r) 749 goto out_free; 750 } 751 752 r = -EFAULT; 753 if (copy_to_user(entries, cpuid_entries, 754 nent * sizeof(struct kvm_cpuid_entry2))) 755 goto out_free; 756 cpuid->nent = nent; 757 r = 0; 758 759 out_free: 760 vfree(cpuid_entries); 761 out: 762 return r; 763 } 764 765 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 766 { 767 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 768 int j, nent = vcpu->arch.cpuid_nent; 769 770 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 771 /* when no next entry is found, the current entry[i] is reselected */ 772 for (j = i + 1; ; j = (j + 1) % nent) { 773 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 774 if (ej->function == e->function) { 775 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 776 return j; 777 } 778 } 779 return 0; /* silence gcc, even though control never reaches here */ 780 } 781 782 /* find an entry with matching function, matching index (if needed), and that 783 * should be read next (if it's stateful) */ 784 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 785 u32 function, u32 index) 786 { 787 if (e->function != function) 788 return 0; 789 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 790 return 0; 791 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 792 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 793 return 0; 794 return 1; 795 } 796 797 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 798 u32 function, u32 index) 799 { 800 int i; 801 struct kvm_cpuid_entry2 *best = NULL; 802 803 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 804 struct kvm_cpuid_entry2 *e; 805 806 e = &vcpu->arch.cpuid_entries[i]; 807 if (is_matching_cpuid_entry(e, function, index)) { 808 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 809 move_to_next_stateful_cpuid_entry(vcpu, i); 810 best = e; 811 break; 812 } 813 } 814 return best; 815 } 816 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 817 818 /* 819 * If no match is found, check whether we exceed the vCPU's limit 820 * and return the content of the highest valid _standard_ leaf instead. 821 * This is to satisfy the CPUID specification. 822 */ 823 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 824 u32 function, u32 index) 825 { 826 struct kvm_cpuid_entry2 *maxlevel; 827 828 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 829 if (!maxlevel || maxlevel->eax >= function) 830 return NULL; 831 if (function & 0x80000000) { 832 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 833 if (!maxlevel) 834 return NULL; 835 } 836 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 837 } 838 839 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 840 { 841 u32 function = *eax, index = *ecx; 842 struct kvm_cpuid_entry2 *best; 843 844 best = kvm_find_cpuid_entry(vcpu, function, index); 845 846 if (!best) 847 best = check_cpuid_limit(vcpu, function, index); 848 849 /* 850 * Perfmon not yet supported for L2 guest. 851 */ 852 if (is_guest_mode(vcpu) && function == 0xa) 853 best = NULL; 854 855 if (best) { 856 *eax = best->eax; 857 *ebx = best->ebx; 858 *ecx = best->ecx; 859 *edx = best->edx; 860 } else 861 *eax = *ebx = *ecx = *edx = 0; 862 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 863 } 864 EXPORT_SYMBOL_GPL(kvm_cpuid); 865 866 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 867 { 868 u32 function, eax, ebx, ecx, edx; 869 870 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 871 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 872 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 873 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 874 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 875 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 876 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 877 kvm_x86_ops->skip_emulated_instruction(vcpu); 878 } 879 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 880