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/user.h> 20 #include <asm/xsave.h> 21 #include "cpuid.h" 22 #include "lapic.h" 23 #include "mmu.h" 24 #include "trace.h" 25 26 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 27 { 28 int feature_bit = 0; 29 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 30 31 xstate_bv &= XSTATE_EXTEND_MASK; 32 while (xstate_bv) { 33 if (xstate_bv & 0x1) { 34 u32 eax, ebx, ecx, edx, offset; 35 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 36 offset = compacted ? ret : ebx; 37 ret = max(ret, offset + eax); 38 } 39 40 xstate_bv >>= 1; 41 feature_bit++; 42 } 43 44 return ret; 45 } 46 47 u64 kvm_supported_xcr0(void) 48 { 49 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 50 51 if (!kvm_x86_ops->mpx_supported()) 52 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR); 53 54 return xcr0; 55 } 56 57 #define F(x) bit(X86_FEATURE_##x) 58 59 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 60 { 61 struct kvm_cpuid_entry2 *best; 62 struct kvm_lapic *apic = vcpu->arch.apic; 63 64 best = kvm_find_cpuid_entry(vcpu, 1, 0); 65 if (!best) 66 return 0; 67 68 /* Update OSXSAVE bit */ 69 if (cpu_has_xsave && best->function == 0x1) { 70 best->ecx &= ~F(OSXSAVE); 71 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 72 best->ecx |= F(OSXSAVE); 73 } 74 75 if (apic) { 76 if (best->ecx & F(TSC_DEADLINE_TIMER)) 77 apic->lapic_timer.timer_mode_mask = 3 << 17; 78 else 79 apic->lapic_timer.timer_mode_mask = 1 << 17; 80 } 81 82 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 83 if (!best) { 84 vcpu->arch.guest_supported_xcr0 = 0; 85 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 86 } else { 87 vcpu->arch.guest_supported_xcr0 = 88 (best->eax | ((u64)best->edx << 32)) & 89 kvm_supported_xcr0(); 90 vcpu->arch.guest_xstate_size = best->ebx = 91 xstate_required_size(vcpu->arch.xcr0, false); 92 } 93 94 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 95 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 96 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 97 98 /* 99 * The existing code assumes virtual address is 48-bit in the canonical 100 * address checks; exit if it is ever changed. 101 */ 102 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 103 if (best && ((best->eax & 0xff00) >> 8) != 48 && 104 ((best->eax & 0xff00) >> 8) != 0) 105 return -EINVAL; 106 107 /* Update physical-address width */ 108 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 109 110 kvm_pmu_cpuid_update(vcpu); 111 return 0; 112 } 113 114 static int is_efer_nx(void) 115 { 116 unsigned long long efer = 0; 117 118 rdmsrl_safe(MSR_EFER, &efer); 119 return efer & EFER_NX; 120 } 121 122 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 123 { 124 int i; 125 struct kvm_cpuid_entry2 *e, *entry; 126 127 entry = NULL; 128 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 129 e = &vcpu->arch.cpuid_entries[i]; 130 if (e->function == 0x80000001) { 131 entry = e; 132 break; 133 } 134 } 135 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 136 entry->edx &= ~F(NX); 137 printk(KERN_INFO "kvm: guest NX capability removed\n"); 138 } 139 } 140 141 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 142 { 143 struct kvm_cpuid_entry2 *best; 144 145 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 146 if (!best || best->eax < 0x80000008) 147 goto not_found; 148 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 149 if (best) 150 return best->eax & 0xff; 151 not_found: 152 return 36; 153 } 154 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 155 156 /* when an old userspace process fills a new kernel module */ 157 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 158 struct kvm_cpuid *cpuid, 159 struct kvm_cpuid_entry __user *entries) 160 { 161 int r, i; 162 struct kvm_cpuid_entry *cpuid_entries; 163 164 r = -E2BIG; 165 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 166 goto out; 167 r = -ENOMEM; 168 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); 169 if (!cpuid_entries) 170 goto out; 171 r = -EFAULT; 172 if (copy_from_user(cpuid_entries, entries, 173 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 174 goto out_free; 175 for (i = 0; i < cpuid->nent; i++) { 176 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 177 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 178 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 179 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 180 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 181 vcpu->arch.cpuid_entries[i].index = 0; 182 vcpu->arch.cpuid_entries[i].flags = 0; 183 vcpu->arch.cpuid_entries[i].padding[0] = 0; 184 vcpu->arch.cpuid_entries[i].padding[1] = 0; 185 vcpu->arch.cpuid_entries[i].padding[2] = 0; 186 } 187 vcpu->arch.cpuid_nent = cpuid->nent; 188 cpuid_fix_nx_cap(vcpu); 189 kvm_apic_set_version(vcpu); 190 kvm_x86_ops->cpuid_update(vcpu); 191 r = kvm_update_cpuid(vcpu); 192 193 out_free: 194 vfree(cpuid_entries); 195 out: 196 return r; 197 } 198 199 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 200 struct kvm_cpuid2 *cpuid, 201 struct kvm_cpuid_entry2 __user *entries) 202 { 203 int r; 204 205 r = -E2BIG; 206 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 207 goto out; 208 r = -EFAULT; 209 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 210 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 211 goto out; 212 vcpu->arch.cpuid_nent = cpuid->nent; 213 kvm_apic_set_version(vcpu); 214 kvm_x86_ops->cpuid_update(vcpu); 215 r = kvm_update_cpuid(vcpu); 216 out: 217 return r; 218 } 219 220 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 221 struct kvm_cpuid2 *cpuid, 222 struct kvm_cpuid_entry2 __user *entries) 223 { 224 int r; 225 226 r = -E2BIG; 227 if (cpuid->nent < vcpu->arch.cpuid_nent) 228 goto out; 229 r = -EFAULT; 230 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 231 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 232 goto out; 233 return 0; 234 235 out: 236 cpuid->nent = vcpu->arch.cpuid_nent; 237 return r; 238 } 239 240 static void cpuid_mask(u32 *word, int wordnum) 241 { 242 *word &= boot_cpu_data.x86_capability[wordnum]; 243 } 244 245 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 246 u32 index) 247 { 248 entry->function = function; 249 entry->index = index; 250 cpuid_count(entry->function, entry->index, 251 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 252 entry->flags = 0; 253 } 254 255 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 256 u32 func, u32 index, int *nent, int maxnent) 257 { 258 switch (func) { 259 case 0: 260 entry->eax = 1; /* only one leaf currently */ 261 ++*nent; 262 break; 263 case 1: 264 entry->ecx = F(MOVBE); 265 ++*nent; 266 break; 267 default: 268 break; 269 } 270 271 entry->function = func; 272 entry->index = index; 273 274 return 0; 275 } 276 277 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 278 u32 index, int *nent, int maxnent) 279 { 280 int r; 281 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 282 #ifdef CONFIG_X86_64 283 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 284 ? F(GBPAGES) : 0; 285 unsigned f_lm = F(LM); 286 #else 287 unsigned f_gbpages = 0; 288 unsigned f_lm = 0; 289 #endif 290 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 291 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 292 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0; 293 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 294 295 /* cpuid 1.edx */ 296 const u32 kvm_supported_word0_x86_features = 297 F(FPU) | F(VME) | F(DE) | F(PSE) | 298 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 299 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 300 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 301 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 302 0 /* Reserved, DS, ACPI */ | F(MMX) | 303 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 304 0 /* HTT, TM, Reserved, PBE */; 305 /* cpuid 0x80000001.edx */ 306 const u32 kvm_supported_word1_x86_features = 307 F(FPU) | F(VME) | F(DE) | F(PSE) | 308 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 309 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 310 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 311 F(PAT) | F(PSE36) | 0 /* Reserved */ | 312 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 313 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 314 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 315 /* cpuid 1.ecx */ 316 const u32 kvm_supported_word4_x86_features = 317 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 318 * but *not* advertised to guests via CPUID ! */ 319 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 320 0 /* DS-CPL, VMX, SMX, EST */ | 321 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 322 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 323 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 324 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 325 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 326 F(F16C) | F(RDRAND); 327 /* cpuid 0x80000001.ecx */ 328 const u32 kvm_supported_word6_x86_features = 329 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 330 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 331 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 332 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 333 334 /* cpuid 0xC0000001.edx */ 335 const u32 kvm_supported_word5_x86_features = 336 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 337 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 338 F(PMM) | F(PMM_EN); 339 340 /* cpuid 7.0.ebx */ 341 const u32 kvm_supported_word9_x86_features = 342 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 343 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 344 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) | 345 F(AVX512CD); 346 347 /* cpuid 0xD.1.eax */ 348 const u32 kvm_supported_word10_x86_features = 349 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 350 351 /* all calls to cpuid_count() should be made on the same cpu */ 352 get_cpu(); 353 354 r = -E2BIG; 355 356 if (*nent >= maxnent) 357 goto out; 358 359 do_cpuid_1_ent(entry, function, index); 360 ++*nent; 361 362 switch (function) { 363 case 0: 364 entry->eax = min(entry->eax, (u32)0xd); 365 break; 366 case 1: 367 entry->edx &= kvm_supported_word0_x86_features; 368 cpuid_mask(&entry->edx, 0); 369 entry->ecx &= kvm_supported_word4_x86_features; 370 cpuid_mask(&entry->ecx, 4); 371 /* we support x2apic emulation even if host does not support 372 * it since we emulate x2apic in software */ 373 entry->ecx |= F(X2APIC); 374 break; 375 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 376 * may return different values. This forces us to get_cpu() before 377 * issuing the first command, and also to emulate this annoying behavior 378 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 379 case 2: { 380 int t, times = entry->eax & 0xff; 381 382 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 383 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 384 for (t = 1; t < times; ++t) { 385 if (*nent >= maxnent) 386 goto out; 387 388 do_cpuid_1_ent(&entry[t], function, 0); 389 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 390 ++*nent; 391 } 392 break; 393 } 394 /* function 4 has additional index. */ 395 case 4: { 396 int i, cache_type; 397 398 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 399 /* read more entries until cache_type is zero */ 400 for (i = 1; ; ++i) { 401 if (*nent >= maxnent) 402 goto out; 403 404 cache_type = entry[i - 1].eax & 0x1f; 405 if (!cache_type) 406 break; 407 do_cpuid_1_ent(&entry[i], function, i); 408 entry[i].flags |= 409 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 410 ++*nent; 411 } 412 break; 413 } 414 case 7: { 415 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 416 /* Mask ebx against host capability word 9 */ 417 if (index == 0) { 418 entry->ebx &= kvm_supported_word9_x86_features; 419 cpuid_mask(&entry->ebx, 9); 420 // TSC_ADJUST is emulated 421 entry->ebx |= F(TSC_ADJUST); 422 } else 423 entry->ebx = 0; 424 entry->eax = 0; 425 entry->ecx = 0; 426 entry->edx = 0; 427 break; 428 } 429 case 9: 430 break; 431 case 0xa: { /* Architectural Performance Monitoring */ 432 struct x86_pmu_capability cap; 433 union cpuid10_eax eax; 434 union cpuid10_edx edx; 435 436 perf_get_x86_pmu_capability(&cap); 437 438 /* 439 * Only support guest architectural pmu on a host 440 * with architectural pmu. 441 */ 442 if (!cap.version) 443 memset(&cap, 0, sizeof(cap)); 444 445 eax.split.version_id = min(cap.version, 2); 446 eax.split.num_counters = cap.num_counters_gp; 447 eax.split.bit_width = cap.bit_width_gp; 448 eax.split.mask_length = cap.events_mask_len; 449 450 edx.split.num_counters_fixed = cap.num_counters_fixed; 451 edx.split.bit_width_fixed = cap.bit_width_fixed; 452 edx.split.reserved = 0; 453 454 entry->eax = eax.full; 455 entry->ebx = cap.events_mask; 456 entry->ecx = 0; 457 entry->edx = edx.full; 458 break; 459 } 460 /* function 0xb has additional index. */ 461 case 0xb: { 462 int i, level_type; 463 464 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 465 /* read more entries until level_type is zero */ 466 for (i = 1; ; ++i) { 467 if (*nent >= maxnent) 468 goto out; 469 470 level_type = entry[i - 1].ecx & 0xff00; 471 if (!level_type) 472 break; 473 do_cpuid_1_ent(&entry[i], function, i); 474 entry[i].flags |= 475 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 476 ++*nent; 477 } 478 break; 479 } 480 case 0xd: { 481 int idx, i; 482 u64 supported = kvm_supported_xcr0(); 483 484 entry->eax &= supported; 485 entry->ebx = xstate_required_size(supported, false); 486 entry->ecx = entry->ebx; 487 entry->edx &= supported >> 32; 488 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 489 if (!supported) 490 break; 491 492 for (idx = 1, i = 1; idx < 64; ++idx) { 493 u64 mask = ((u64)1 << idx); 494 if (*nent >= maxnent) 495 goto out; 496 497 do_cpuid_1_ent(&entry[i], function, idx); 498 if (idx == 1) { 499 entry[i].eax &= kvm_supported_word10_x86_features; 500 entry[i].ebx = 0; 501 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 502 entry[i].ebx = 503 xstate_required_size(supported, 504 true); 505 } else { 506 if (entry[i].eax == 0 || !(supported & mask)) 507 continue; 508 if (WARN_ON_ONCE(entry[i].ecx & 1)) 509 continue; 510 } 511 entry[i].ecx = 0; 512 entry[i].edx = 0; 513 entry[i].flags |= 514 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 515 ++*nent; 516 ++i; 517 } 518 break; 519 } 520 case KVM_CPUID_SIGNATURE: { 521 static const char signature[12] = "KVMKVMKVM\0\0"; 522 const u32 *sigptr = (const u32 *)signature; 523 entry->eax = KVM_CPUID_FEATURES; 524 entry->ebx = sigptr[0]; 525 entry->ecx = sigptr[1]; 526 entry->edx = sigptr[2]; 527 break; 528 } 529 case KVM_CPUID_FEATURES: 530 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 531 (1 << KVM_FEATURE_NOP_IO_DELAY) | 532 (1 << KVM_FEATURE_CLOCKSOURCE2) | 533 (1 << KVM_FEATURE_ASYNC_PF) | 534 (1 << KVM_FEATURE_PV_EOI) | 535 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 536 (1 << KVM_FEATURE_PV_UNHALT); 537 538 if (sched_info_on()) 539 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 540 541 entry->ebx = 0; 542 entry->ecx = 0; 543 entry->edx = 0; 544 break; 545 case 0x80000000: 546 entry->eax = min(entry->eax, 0x8000001a); 547 break; 548 case 0x80000001: 549 entry->edx &= kvm_supported_word1_x86_features; 550 cpuid_mask(&entry->edx, 1); 551 entry->ecx &= kvm_supported_word6_x86_features; 552 cpuid_mask(&entry->ecx, 6); 553 break; 554 case 0x80000007: /* Advanced power management */ 555 /* invariant TSC is CPUID.80000007H:EDX[8] */ 556 entry->edx &= (1 << 8); 557 /* mask against host */ 558 entry->edx &= boot_cpu_data.x86_power; 559 entry->eax = entry->ebx = entry->ecx = 0; 560 break; 561 case 0x80000008: { 562 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 563 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 564 unsigned phys_as = entry->eax & 0xff; 565 566 if (!g_phys_as) 567 g_phys_as = phys_as; 568 entry->eax = g_phys_as | (virt_as << 8); 569 entry->ebx = entry->edx = 0; 570 break; 571 } 572 case 0x80000019: 573 entry->ecx = entry->edx = 0; 574 break; 575 case 0x8000001a: 576 break; 577 case 0x8000001d: 578 break; 579 /*Add support for Centaur's CPUID instruction*/ 580 case 0xC0000000: 581 /*Just support up to 0xC0000004 now*/ 582 entry->eax = min(entry->eax, 0xC0000004); 583 break; 584 case 0xC0000001: 585 entry->edx &= kvm_supported_word5_x86_features; 586 cpuid_mask(&entry->edx, 5); 587 break; 588 case 3: /* Processor serial number */ 589 case 5: /* MONITOR/MWAIT */ 590 case 6: /* Thermal management */ 591 case 0xC0000002: 592 case 0xC0000003: 593 case 0xC0000004: 594 default: 595 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 596 break; 597 } 598 599 kvm_x86_ops->set_supported_cpuid(function, entry); 600 601 r = 0; 602 603 out: 604 put_cpu(); 605 606 return r; 607 } 608 609 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 610 u32 idx, int *nent, int maxnent, unsigned int type) 611 { 612 if (type == KVM_GET_EMULATED_CPUID) 613 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 614 615 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 616 } 617 618 #undef F 619 620 struct kvm_cpuid_param { 621 u32 func; 622 u32 idx; 623 bool has_leaf_count; 624 bool (*qualifier)(const struct kvm_cpuid_param *param); 625 }; 626 627 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 628 { 629 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 630 } 631 632 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 633 __u32 num_entries, unsigned int ioctl_type) 634 { 635 int i; 636 __u32 pad[3]; 637 638 if (ioctl_type != KVM_GET_EMULATED_CPUID) 639 return false; 640 641 /* 642 * We want to make sure that ->padding is being passed clean from 643 * userspace in case we want to use it for something in the future. 644 * 645 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 646 * have to give ourselves satisfied only with the emulated side. /me 647 * sheds a tear. 648 */ 649 for (i = 0; i < num_entries; i++) { 650 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 651 return true; 652 653 if (pad[0] || pad[1] || pad[2]) 654 return true; 655 } 656 return false; 657 } 658 659 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 660 struct kvm_cpuid_entry2 __user *entries, 661 unsigned int type) 662 { 663 struct kvm_cpuid_entry2 *cpuid_entries; 664 int limit, nent = 0, r = -E2BIG, i; 665 u32 func; 666 static const struct kvm_cpuid_param param[] = { 667 { .func = 0, .has_leaf_count = true }, 668 { .func = 0x80000000, .has_leaf_count = true }, 669 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 670 { .func = KVM_CPUID_SIGNATURE }, 671 { .func = KVM_CPUID_FEATURES }, 672 }; 673 674 if (cpuid->nent < 1) 675 goto out; 676 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 677 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 678 679 if (sanity_check_entries(entries, cpuid->nent, type)) 680 return -EINVAL; 681 682 r = -ENOMEM; 683 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 684 if (!cpuid_entries) 685 goto out; 686 687 r = 0; 688 for (i = 0; i < ARRAY_SIZE(param); i++) { 689 const struct kvm_cpuid_param *ent = ¶m[i]; 690 691 if (ent->qualifier && !ent->qualifier(ent)) 692 continue; 693 694 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 695 &nent, cpuid->nent, type); 696 697 if (r) 698 goto out_free; 699 700 if (!ent->has_leaf_count) 701 continue; 702 703 limit = cpuid_entries[nent - 1].eax; 704 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 705 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 706 &nent, cpuid->nent, type); 707 708 if (r) 709 goto out_free; 710 } 711 712 r = -EFAULT; 713 if (copy_to_user(entries, cpuid_entries, 714 nent * sizeof(struct kvm_cpuid_entry2))) 715 goto out_free; 716 cpuid->nent = nent; 717 r = 0; 718 719 out_free: 720 vfree(cpuid_entries); 721 out: 722 return r; 723 } 724 725 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 726 { 727 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 728 int j, nent = vcpu->arch.cpuid_nent; 729 730 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 731 /* when no next entry is found, the current entry[i] is reselected */ 732 for (j = i + 1; ; j = (j + 1) % nent) { 733 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 734 if (ej->function == e->function) { 735 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 736 return j; 737 } 738 } 739 return 0; /* silence gcc, even though control never reaches here */ 740 } 741 742 /* find an entry with matching function, matching index (if needed), and that 743 * should be read next (if it's stateful) */ 744 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 745 u32 function, u32 index) 746 { 747 if (e->function != function) 748 return 0; 749 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 750 return 0; 751 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 752 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 753 return 0; 754 return 1; 755 } 756 757 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 758 u32 function, u32 index) 759 { 760 int i; 761 struct kvm_cpuid_entry2 *best = NULL; 762 763 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 764 struct kvm_cpuid_entry2 *e; 765 766 e = &vcpu->arch.cpuid_entries[i]; 767 if (is_matching_cpuid_entry(e, function, index)) { 768 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 769 move_to_next_stateful_cpuid_entry(vcpu, i); 770 best = e; 771 break; 772 } 773 } 774 return best; 775 } 776 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 777 778 /* 779 * If no match is found, check whether we exceed the vCPU's limit 780 * and return the content of the highest valid _standard_ leaf instead. 781 * This is to satisfy the CPUID specification. 782 */ 783 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 784 u32 function, u32 index) 785 { 786 struct kvm_cpuid_entry2 *maxlevel; 787 788 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 789 if (!maxlevel || maxlevel->eax >= function) 790 return NULL; 791 if (function & 0x80000000) { 792 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 793 if (!maxlevel) 794 return NULL; 795 } 796 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 797 } 798 799 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 800 { 801 u32 function = *eax, index = *ecx; 802 struct kvm_cpuid_entry2 *best; 803 804 best = kvm_find_cpuid_entry(vcpu, function, index); 805 806 if (!best) 807 best = check_cpuid_limit(vcpu, function, index); 808 809 /* 810 * Perfmon not yet supported for L2 guest. 811 */ 812 if (is_guest_mode(vcpu) && function == 0xa) 813 best = NULL; 814 815 if (best) { 816 *eax = best->eax; 817 *ebx = best->ebx; 818 *ecx = best->ecx; 819 *edx = best->edx; 820 } else 821 *eax = *ebx = *ecx = *edx = 0; 822 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 823 } 824 EXPORT_SYMBOL_GPL(kvm_cpuid); 825 826 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 827 { 828 u32 function, eax, ebx, ecx, edx; 829 830 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 831 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 832 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 833 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 834 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 835 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 836 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 837 kvm_x86_ops->skip_emulated_instruction(vcpu); 838 } 839 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 840