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, 0xD, 0); 92 if (!best) { 93 vcpu->arch.guest_supported_xcr0 = 0; 94 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 95 } else { 96 vcpu->arch.guest_supported_xcr0 = 97 (best->eax | ((u64)best->edx << 32)) & 98 kvm_supported_xcr0(); 99 vcpu->arch.guest_xstate_size = best->ebx = 100 xstate_required_size(vcpu->arch.xcr0, false); 101 } 102 103 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 104 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 105 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 106 107 if (use_eager_fpu()) 108 kvm_x86_ops->fpu_activate(vcpu); 109 110 /* 111 * The existing code assumes virtual address is 48-bit in the canonical 112 * address checks; exit if it is ever changed. 113 */ 114 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 115 if (best && ((best->eax & 0xff00) >> 8) != 48 && 116 ((best->eax & 0xff00) >> 8) != 0) 117 return -EINVAL; 118 119 /* Update physical-address width */ 120 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 121 122 kvm_pmu_refresh(vcpu); 123 return 0; 124 } 125 126 static int is_efer_nx(void) 127 { 128 unsigned long long efer = 0; 129 130 rdmsrl_safe(MSR_EFER, &efer); 131 return efer & EFER_NX; 132 } 133 134 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 135 { 136 int i; 137 struct kvm_cpuid_entry2 *e, *entry; 138 139 entry = NULL; 140 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 141 e = &vcpu->arch.cpuid_entries[i]; 142 if (e->function == 0x80000001) { 143 entry = e; 144 break; 145 } 146 } 147 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 148 entry->edx &= ~F(NX); 149 printk(KERN_INFO "kvm: guest NX capability removed\n"); 150 } 151 } 152 153 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 154 { 155 struct kvm_cpuid_entry2 *best; 156 157 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 158 if (!best || best->eax < 0x80000008) 159 goto not_found; 160 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 161 if (best) 162 return best->eax & 0xff; 163 not_found: 164 return 36; 165 } 166 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 167 168 /* when an old userspace process fills a new kernel module */ 169 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 170 struct kvm_cpuid *cpuid, 171 struct kvm_cpuid_entry __user *entries) 172 { 173 int r, i; 174 struct kvm_cpuid_entry *cpuid_entries; 175 176 r = -E2BIG; 177 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 178 goto out; 179 r = -ENOMEM; 180 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); 181 if (!cpuid_entries) 182 goto out; 183 r = -EFAULT; 184 if (copy_from_user(cpuid_entries, entries, 185 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 186 goto out_free; 187 for (i = 0; i < cpuid->nent; i++) { 188 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 189 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 190 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 191 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 192 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 193 vcpu->arch.cpuid_entries[i].index = 0; 194 vcpu->arch.cpuid_entries[i].flags = 0; 195 vcpu->arch.cpuid_entries[i].padding[0] = 0; 196 vcpu->arch.cpuid_entries[i].padding[1] = 0; 197 vcpu->arch.cpuid_entries[i].padding[2] = 0; 198 } 199 vcpu->arch.cpuid_nent = cpuid->nent; 200 cpuid_fix_nx_cap(vcpu); 201 kvm_apic_set_version(vcpu); 202 kvm_x86_ops->cpuid_update(vcpu); 203 r = kvm_update_cpuid(vcpu); 204 205 out_free: 206 vfree(cpuid_entries); 207 out: 208 return r; 209 } 210 211 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 212 struct kvm_cpuid2 *cpuid, 213 struct kvm_cpuid_entry2 __user *entries) 214 { 215 int r; 216 217 r = -E2BIG; 218 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 219 goto out; 220 r = -EFAULT; 221 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 222 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 223 goto out; 224 vcpu->arch.cpuid_nent = cpuid->nent; 225 kvm_apic_set_version(vcpu); 226 kvm_x86_ops->cpuid_update(vcpu); 227 r = kvm_update_cpuid(vcpu); 228 out: 229 return r; 230 } 231 232 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 233 struct kvm_cpuid2 *cpuid, 234 struct kvm_cpuid_entry2 __user *entries) 235 { 236 int r; 237 238 r = -E2BIG; 239 if (cpuid->nent < vcpu->arch.cpuid_nent) 240 goto out; 241 r = -EFAULT; 242 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 243 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 244 goto out; 245 return 0; 246 247 out: 248 cpuid->nent = vcpu->arch.cpuid_nent; 249 return r; 250 } 251 252 static void cpuid_mask(u32 *word, int wordnum) 253 { 254 *word &= boot_cpu_data.x86_capability[wordnum]; 255 } 256 257 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 258 u32 index) 259 { 260 entry->function = function; 261 entry->index = index; 262 cpuid_count(entry->function, entry->index, 263 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 264 entry->flags = 0; 265 } 266 267 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 268 u32 func, u32 index, int *nent, int maxnent) 269 { 270 switch (func) { 271 case 0: 272 entry->eax = 1; /* only one leaf currently */ 273 ++*nent; 274 break; 275 case 1: 276 entry->ecx = F(MOVBE); 277 ++*nent; 278 break; 279 default: 280 break; 281 } 282 283 entry->function = func; 284 entry->index = index; 285 286 return 0; 287 } 288 289 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 290 u32 index, int *nent, int maxnent) 291 { 292 int r; 293 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 294 #ifdef CONFIG_X86_64 295 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 296 ? F(GBPAGES) : 0; 297 unsigned f_lm = F(LM); 298 #else 299 unsigned f_gbpages = 0; 300 unsigned f_lm = 0; 301 #endif 302 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 303 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 304 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 305 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 306 307 /* cpuid 1.edx */ 308 const u32 kvm_supported_word0_x86_features = 309 F(FPU) | F(VME) | F(DE) | F(PSE) | 310 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 311 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 312 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 313 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 314 0 /* Reserved, DS, ACPI */ | F(MMX) | 315 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 316 0 /* HTT, TM, Reserved, PBE */; 317 /* cpuid 0x80000001.edx */ 318 const u32 kvm_supported_word1_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(SYSCALL) | 322 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 323 F(PAT) | F(PSE36) | 0 /* Reserved */ | 324 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 325 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 326 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 327 /* cpuid 1.ecx */ 328 const u32 kvm_supported_word4_x86_features = 329 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 330 * but *not* advertised to guests via CPUID ! */ 331 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 332 0 /* DS-CPL, VMX, SMX, EST */ | 333 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 334 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 335 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 336 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 337 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 338 F(F16C) | F(RDRAND); 339 /* cpuid 0x80000001.ecx */ 340 const u32 kvm_supported_word6_x86_features = 341 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 342 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 343 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 344 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 345 346 /* cpuid 0xC0000001.edx */ 347 const u32 kvm_supported_word5_x86_features = 348 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 349 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 350 F(PMM) | F(PMM_EN); 351 352 /* cpuid 7.0.ebx */ 353 const u32 kvm_supported_word9_x86_features = 354 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 355 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 356 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) | 357 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(PCOMMIT); 358 359 /* cpuid 0xD.1.eax */ 360 const u32 kvm_supported_word10_x86_features = 361 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 362 363 /* all calls to cpuid_count() should be made on the same cpu */ 364 get_cpu(); 365 366 r = -E2BIG; 367 368 if (*nent >= maxnent) 369 goto out; 370 371 do_cpuid_1_ent(entry, function, index); 372 ++*nent; 373 374 switch (function) { 375 case 0: 376 entry->eax = min(entry->eax, (u32)0xd); 377 break; 378 case 1: 379 entry->edx &= kvm_supported_word0_x86_features; 380 cpuid_mask(&entry->edx, 0); 381 entry->ecx &= kvm_supported_word4_x86_features; 382 cpuid_mask(&entry->ecx, 4); 383 /* we support x2apic emulation even if host does not support 384 * it since we emulate x2apic in software */ 385 entry->ecx |= F(X2APIC); 386 break; 387 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 388 * may return different values. This forces us to get_cpu() before 389 * issuing the first command, and also to emulate this annoying behavior 390 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 391 case 2: { 392 int t, times = entry->eax & 0xff; 393 394 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 395 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 396 for (t = 1; t < times; ++t) { 397 if (*nent >= maxnent) 398 goto out; 399 400 do_cpuid_1_ent(&entry[t], function, 0); 401 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 402 ++*nent; 403 } 404 break; 405 } 406 /* function 4 has additional index. */ 407 case 4: { 408 int i, cache_type; 409 410 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 411 /* read more entries until cache_type is zero */ 412 for (i = 1; ; ++i) { 413 if (*nent >= maxnent) 414 goto out; 415 416 cache_type = entry[i - 1].eax & 0x1f; 417 if (!cache_type) 418 break; 419 do_cpuid_1_ent(&entry[i], function, i); 420 entry[i].flags |= 421 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 422 ++*nent; 423 } 424 break; 425 } 426 case 6: /* Thermal management */ 427 entry->eax = 0x4; /* allow ARAT */ 428 entry->ebx = 0; 429 entry->ecx = 0; 430 entry->edx = 0; 431 break; 432 case 7: { 433 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 434 /* Mask ebx against host capability word 9 */ 435 if (index == 0) { 436 entry->ebx &= kvm_supported_word9_x86_features; 437 cpuid_mask(&entry->ebx, 9); 438 // TSC_ADJUST is emulated 439 entry->ebx |= F(TSC_ADJUST); 440 } else 441 entry->ebx = 0; 442 entry->eax = 0; 443 entry->ecx = 0; 444 entry->edx = 0; 445 break; 446 } 447 case 9: 448 break; 449 case 0xa: { /* Architectural Performance Monitoring */ 450 struct x86_pmu_capability cap; 451 union cpuid10_eax eax; 452 union cpuid10_edx edx; 453 454 perf_get_x86_pmu_capability(&cap); 455 456 /* 457 * Only support guest architectural pmu on a host 458 * with architectural pmu. 459 */ 460 if (!cap.version) 461 memset(&cap, 0, sizeof(cap)); 462 463 eax.split.version_id = min(cap.version, 2); 464 eax.split.num_counters = cap.num_counters_gp; 465 eax.split.bit_width = cap.bit_width_gp; 466 eax.split.mask_length = cap.events_mask_len; 467 468 edx.split.num_counters_fixed = cap.num_counters_fixed; 469 edx.split.bit_width_fixed = cap.bit_width_fixed; 470 edx.split.reserved = 0; 471 472 entry->eax = eax.full; 473 entry->ebx = cap.events_mask; 474 entry->ecx = 0; 475 entry->edx = edx.full; 476 break; 477 } 478 /* function 0xb has additional index. */ 479 case 0xb: { 480 int i, level_type; 481 482 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 483 /* read more entries until level_type is zero */ 484 for (i = 1; ; ++i) { 485 if (*nent >= maxnent) 486 goto out; 487 488 level_type = entry[i - 1].ecx & 0xff00; 489 if (!level_type) 490 break; 491 do_cpuid_1_ent(&entry[i], function, i); 492 entry[i].flags |= 493 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 494 ++*nent; 495 } 496 break; 497 } 498 case 0xd: { 499 int idx, i; 500 u64 supported = kvm_supported_xcr0(); 501 502 entry->eax &= supported; 503 entry->ebx = xstate_required_size(supported, false); 504 entry->ecx = entry->ebx; 505 entry->edx &= supported >> 32; 506 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 507 if (!supported) 508 break; 509 510 for (idx = 1, i = 1; idx < 64; ++idx) { 511 u64 mask = ((u64)1 << idx); 512 if (*nent >= maxnent) 513 goto out; 514 515 do_cpuid_1_ent(&entry[i], function, idx); 516 if (idx == 1) { 517 entry[i].eax &= kvm_supported_word10_x86_features; 518 entry[i].ebx = 0; 519 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 520 entry[i].ebx = 521 xstate_required_size(supported, 522 true); 523 } else { 524 if (entry[i].eax == 0 || !(supported & mask)) 525 continue; 526 if (WARN_ON_ONCE(entry[i].ecx & 1)) 527 continue; 528 } 529 entry[i].ecx = 0; 530 entry[i].edx = 0; 531 entry[i].flags |= 532 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 533 ++*nent; 534 ++i; 535 } 536 break; 537 } 538 case KVM_CPUID_SIGNATURE: { 539 static const char signature[12] = "KVMKVMKVM\0\0"; 540 const u32 *sigptr = (const u32 *)signature; 541 entry->eax = KVM_CPUID_FEATURES; 542 entry->ebx = sigptr[0]; 543 entry->ecx = sigptr[1]; 544 entry->edx = sigptr[2]; 545 break; 546 } 547 case KVM_CPUID_FEATURES: 548 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 549 (1 << KVM_FEATURE_NOP_IO_DELAY) | 550 (1 << KVM_FEATURE_CLOCKSOURCE2) | 551 (1 << KVM_FEATURE_ASYNC_PF) | 552 (1 << KVM_FEATURE_PV_EOI) | 553 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 554 (1 << KVM_FEATURE_PV_UNHALT); 555 556 if (sched_info_on()) 557 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 558 559 entry->ebx = 0; 560 entry->ecx = 0; 561 entry->edx = 0; 562 break; 563 case 0x80000000: 564 entry->eax = min(entry->eax, 0x8000001a); 565 break; 566 case 0x80000001: 567 entry->edx &= kvm_supported_word1_x86_features; 568 cpuid_mask(&entry->edx, 1); 569 entry->ecx &= kvm_supported_word6_x86_features; 570 cpuid_mask(&entry->ecx, 6); 571 break; 572 case 0x80000007: /* Advanced power management */ 573 /* invariant TSC is CPUID.80000007H:EDX[8] */ 574 entry->edx &= (1 << 8); 575 /* mask against host */ 576 entry->edx &= boot_cpu_data.x86_power; 577 entry->eax = entry->ebx = entry->ecx = 0; 578 break; 579 case 0x80000008: { 580 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 581 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 582 unsigned phys_as = entry->eax & 0xff; 583 584 if (!g_phys_as) 585 g_phys_as = phys_as; 586 entry->eax = g_phys_as | (virt_as << 8); 587 entry->ebx = entry->edx = 0; 588 break; 589 } 590 case 0x80000019: 591 entry->ecx = entry->edx = 0; 592 break; 593 case 0x8000001a: 594 break; 595 case 0x8000001d: 596 break; 597 /*Add support for Centaur's CPUID instruction*/ 598 case 0xC0000000: 599 /*Just support up to 0xC0000004 now*/ 600 entry->eax = min(entry->eax, 0xC0000004); 601 break; 602 case 0xC0000001: 603 entry->edx &= kvm_supported_word5_x86_features; 604 cpuid_mask(&entry->edx, 5); 605 break; 606 case 3: /* Processor serial number */ 607 case 5: /* MONITOR/MWAIT */ 608 case 0xC0000002: 609 case 0xC0000003: 610 case 0xC0000004: 611 default: 612 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 613 break; 614 } 615 616 kvm_x86_ops->set_supported_cpuid(function, entry); 617 618 r = 0; 619 620 out: 621 put_cpu(); 622 623 return r; 624 } 625 626 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 627 u32 idx, int *nent, int maxnent, unsigned int type) 628 { 629 if (type == KVM_GET_EMULATED_CPUID) 630 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 631 632 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 633 } 634 635 #undef F 636 637 struct kvm_cpuid_param { 638 u32 func; 639 u32 idx; 640 bool has_leaf_count; 641 bool (*qualifier)(const struct kvm_cpuid_param *param); 642 }; 643 644 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 645 { 646 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 647 } 648 649 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 650 __u32 num_entries, unsigned int ioctl_type) 651 { 652 int i; 653 __u32 pad[3]; 654 655 if (ioctl_type != KVM_GET_EMULATED_CPUID) 656 return false; 657 658 /* 659 * We want to make sure that ->padding is being passed clean from 660 * userspace in case we want to use it for something in the future. 661 * 662 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 663 * have to give ourselves satisfied only with the emulated side. /me 664 * sheds a tear. 665 */ 666 for (i = 0; i < num_entries; i++) { 667 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 668 return true; 669 670 if (pad[0] || pad[1] || pad[2]) 671 return true; 672 } 673 return false; 674 } 675 676 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 677 struct kvm_cpuid_entry2 __user *entries, 678 unsigned int type) 679 { 680 struct kvm_cpuid_entry2 *cpuid_entries; 681 int limit, nent = 0, r = -E2BIG, i; 682 u32 func; 683 static const struct kvm_cpuid_param param[] = { 684 { .func = 0, .has_leaf_count = true }, 685 { .func = 0x80000000, .has_leaf_count = true }, 686 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 687 { .func = KVM_CPUID_SIGNATURE }, 688 { .func = KVM_CPUID_FEATURES }, 689 }; 690 691 if (cpuid->nent < 1) 692 goto out; 693 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 694 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 695 696 if (sanity_check_entries(entries, cpuid->nent, type)) 697 return -EINVAL; 698 699 r = -ENOMEM; 700 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 701 if (!cpuid_entries) 702 goto out; 703 704 r = 0; 705 for (i = 0; i < ARRAY_SIZE(param); i++) { 706 const struct kvm_cpuid_param *ent = ¶m[i]; 707 708 if (ent->qualifier && !ent->qualifier(ent)) 709 continue; 710 711 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 712 &nent, cpuid->nent, type); 713 714 if (r) 715 goto out_free; 716 717 if (!ent->has_leaf_count) 718 continue; 719 720 limit = cpuid_entries[nent - 1].eax; 721 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 722 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 723 &nent, cpuid->nent, type); 724 725 if (r) 726 goto out_free; 727 } 728 729 r = -EFAULT; 730 if (copy_to_user(entries, cpuid_entries, 731 nent * sizeof(struct kvm_cpuid_entry2))) 732 goto out_free; 733 cpuid->nent = nent; 734 r = 0; 735 736 out_free: 737 vfree(cpuid_entries); 738 out: 739 return r; 740 } 741 742 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 743 { 744 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 745 int j, nent = vcpu->arch.cpuid_nent; 746 747 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 748 /* when no next entry is found, the current entry[i] is reselected */ 749 for (j = i + 1; ; j = (j + 1) % nent) { 750 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 751 if (ej->function == e->function) { 752 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 753 return j; 754 } 755 } 756 return 0; /* silence gcc, even though control never reaches here */ 757 } 758 759 /* find an entry with matching function, matching index (if needed), and that 760 * should be read next (if it's stateful) */ 761 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 762 u32 function, u32 index) 763 { 764 if (e->function != function) 765 return 0; 766 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 767 return 0; 768 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 769 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 770 return 0; 771 return 1; 772 } 773 774 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 775 u32 function, u32 index) 776 { 777 int i; 778 struct kvm_cpuid_entry2 *best = NULL; 779 780 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 781 struct kvm_cpuid_entry2 *e; 782 783 e = &vcpu->arch.cpuid_entries[i]; 784 if (is_matching_cpuid_entry(e, function, index)) { 785 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 786 move_to_next_stateful_cpuid_entry(vcpu, i); 787 best = e; 788 break; 789 } 790 } 791 return best; 792 } 793 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 794 795 /* 796 * If no match is found, check whether we exceed the vCPU's limit 797 * and return the content of the highest valid _standard_ leaf instead. 798 * This is to satisfy the CPUID specification. 799 */ 800 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 801 u32 function, u32 index) 802 { 803 struct kvm_cpuid_entry2 *maxlevel; 804 805 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 806 if (!maxlevel || maxlevel->eax >= function) 807 return NULL; 808 if (function & 0x80000000) { 809 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 810 if (!maxlevel) 811 return NULL; 812 } 813 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 814 } 815 816 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 817 { 818 u32 function = *eax, index = *ecx; 819 struct kvm_cpuid_entry2 *best; 820 821 best = kvm_find_cpuid_entry(vcpu, function, index); 822 823 if (!best) 824 best = check_cpuid_limit(vcpu, function, index); 825 826 /* 827 * Perfmon not yet supported for L2 guest. 828 */ 829 if (is_guest_mode(vcpu) && function == 0xa) 830 best = NULL; 831 832 if (best) { 833 *eax = best->eax; 834 *ebx = best->ebx; 835 *ecx = best->ecx; 836 *edx = best->edx; 837 } else 838 *eax = *ebx = *ecx = *edx = 0; 839 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 840 } 841 EXPORT_SYMBOL_GPL(kvm_cpuid); 842 843 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 844 { 845 u32 function, eax, ebx, ecx, edx; 846 847 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 848 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 849 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 850 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 851 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 852 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 853 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 854 kvm_x86_ops->skip_emulated_instruction(vcpu); 855 } 856 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 857