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/i387.h> /* For use_eager_fpu. Ugh! */ 20#include <asm/fpu-internal.h> /* For use_eager_fpu. Ugh! */ 21#include <asm/user.h> 22#include <asm/xsave.h> 23#include "cpuid.h" 24#include "lapic.h" 25#include "mmu.h" 26#include "trace.h" 27 28static 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 &= XSTATE_EXTEND_MASK; 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 49u64 kvm_supported_xcr0(void) 50{ 51 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 52 53 if (!kvm_x86_ops->mpx_supported()) 54 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR); 55 56 return xcr0; 57} 58 59#define F(x) bit(X86_FEATURE_##x) 60 61int kvm_update_cpuid(struct kvm_vcpu *vcpu) 62{ 63 struct kvm_cpuid_entry2 *best; 64 struct kvm_lapic *apic = vcpu->arch.apic; 65 66 best = kvm_find_cpuid_entry(vcpu, 1, 0); 67 if (!best) 68 return 0; 69 70 /* Update OSXSAVE bit */ 71 if (cpu_has_xsave && best->function == 0x1) { 72 best->ecx &= ~F(OSXSAVE); 73 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 74 best->ecx |= F(OSXSAVE); 75 } 76 77 if (apic) { 78 if (best->ecx & F(TSC_DEADLINE_TIMER)) 79 apic->lapic_timer.timer_mode_mask = 3 << 17; 80 else 81 apic->lapic_timer.timer_mode_mask = 1 << 17; 82 } 83 84 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 85 if (!best) { 86 vcpu->arch.guest_supported_xcr0 = 0; 87 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 88 } else { 89 vcpu->arch.guest_supported_xcr0 = 90 (best->eax | ((u64)best->edx << 32)) & 91 kvm_supported_xcr0(); 92 vcpu->arch.guest_xstate_size = best->ebx = 93 xstate_required_size(vcpu->arch.xcr0, false); 94 } 95 96 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 97 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 98 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 99 100 vcpu->arch.eager_fpu = guest_cpuid_has_mpx(vcpu); 101 102 /* 103 * The existing code assumes virtual address is 48-bit in the canonical 104 * address checks; exit if it is ever changed. 105 */ 106 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 107 if (best && ((best->eax & 0xff00) >> 8) != 48 && 108 ((best->eax & 0xff00) >> 8) != 0) 109 return -EINVAL; 110 111 /* Update physical-address width */ 112 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 113 114 kvm_pmu_cpuid_update(vcpu); 115 return 0; 116} 117 118static int is_efer_nx(void) 119{ 120 unsigned long long efer = 0; 121 122 rdmsrl_safe(MSR_EFER, &efer); 123 return efer & EFER_NX; 124} 125 126static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 127{ 128 int i; 129 struct kvm_cpuid_entry2 *e, *entry; 130 131 entry = NULL; 132 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 133 e = &vcpu->arch.cpuid_entries[i]; 134 if (e->function == 0x80000001) { 135 entry = e; 136 break; 137 } 138 } 139 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 140 entry->edx &= ~F(NX); 141 printk(KERN_INFO "kvm: guest NX capability removed\n"); 142 } 143} 144 145int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 146{ 147 struct kvm_cpuid_entry2 *best; 148 149 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 150 if (!best || best->eax < 0x80000008) 151 goto not_found; 152 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 153 if (best) 154 return best->eax & 0xff; 155not_found: 156 return 36; 157} 158EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 159 160/* when an old userspace process fills a new kernel module */ 161int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 162 struct kvm_cpuid *cpuid, 163 struct kvm_cpuid_entry __user *entries) 164{ 165 int r, i; 166 struct kvm_cpuid_entry *cpuid_entries; 167 168 r = -E2BIG; 169 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 170 goto out; 171 r = -ENOMEM; 172 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); 173 if (!cpuid_entries) 174 goto out; 175 r = -EFAULT; 176 if (copy_from_user(cpuid_entries, entries, 177 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 178 goto out_free; 179 for (i = 0; i < cpuid->nent; i++) { 180 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 181 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 182 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 183 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 184 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 185 vcpu->arch.cpuid_entries[i].index = 0; 186 vcpu->arch.cpuid_entries[i].flags = 0; 187 vcpu->arch.cpuid_entries[i].padding[0] = 0; 188 vcpu->arch.cpuid_entries[i].padding[1] = 0; 189 vcpu->arch.cpuid_entries[i].padding[2] = 0; 190 } 191 vcpu->arch.cpuid_nent = cpuid->nent; 192 cpuid_fix_nx_cap(vcpu); 193 kvm_apic_set_version(vcpu); 194 kvm_x86_ops->cpuid_update(vcpu); 195 r = kvm_update_cpuid(vcpu); 196 197out_free: 198 vfree(cpuid_entries); 199out: 200 return r; 201} 202 203int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 204 struct kvm_cpuid2 *cpuid, 205 struct kvm_cpuid_entry2 __user *entries) 206{ 207 int r; 208 209 r = -E2BIG; 210 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 211 goto out; 212 r = -EFAULT; 213 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 214 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 215 goto out; 216 vcpu->arch.cpuid_nent = cpuid->nent; 217 kvm_apic_set_version(vcpu); 218 kvm_x86_ops->cpuid_update(vcpu); 219 r = kvm_update_cpuid(vcpu); 220out: 221 return r; 222} 223 224int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 225 struct kvm_cpuid2 *cpuid, 226 struct kvm_cpuid_entry2 __user *entries) 227{ 228 int r; 229 230 r = -E2BIG; 231 if (cpuid->nent < vcpu->arch.cpuid_nent) 232 goto out; 233 r = -EFAULT; 234 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 235 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 236 goto out; 237 return 0; 238 239out: 240 cpuid->nent = vcpu->arch.cpuid_nent; 241 return r; 242} 243 244static void cpuid_mask(u32 *word, int wordnum) 245{ 246 *word &= boot_cpu_data.x86_capability[wordnum]; 247} 248 249static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 250 u32 index) 251{ 252 entry->function = function; 253 entry->index = index; 254 cpuid_count(entry->function, entry->index, 255 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 256 entry->flags = 0; 257} 258 259static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 260 u32 func, u32 index, int *nent, int maxnent) 261{ 262 switch (func) { 263 case 0: 264 entry->eax = 1; /* only one leaf currently */ 265 ++*nent; 266 break; 267 case 1: 268 entry->ecx = F(MOVBE); 269 ++*nent; 270 break; 271 default: 272 break; 273 } 274 275 entry->function = func; 276 entry->index = index; 277 278 return 0; 279} 280 281static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 282 u32 index, int *nent, int maxnent) 283{ 284 int r; 285 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 286#ifdef CONFIG_X86_64 287 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 288 ? F(GBPAGES) : 0; 289 unsigned f_lm = F(LM); 290#else 291 unsigned f_gbpages = 0; 292 unsigned f_lm = 0; 293#endif 294 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 295 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 296 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0; 297 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 298 299 /* cpuid 1.edx */ 300 const u32 kvm_supported_word0_x86_features = 301 F(FPU) | F(VME) | F(DE) | F(PSE) | 302 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 303 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 304 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 305 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 306 0 /* Reserved, DS, ACPI */ | F(MMX) | 307 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 308 0 /* HTT, TM, Reserved, PBE */; 309 /* cpuid 0x80000001.edx */ 310 const u32 kvm_supported_word1_x86_features = 311 F(FPU) | F(VME) | F(DE) | F(PSE) | 312 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 313 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 314 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 315 F(PAT) | F(PSE36) | 0 /* Reserved */ | 316 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 317 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 318 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 319 /* cpuid 1.ecx */ 320 const u32 kvm_supported_word4_x86_features = 321 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 322 * but *not* advertised to guests via CPUID ! */ 323 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 324 0 /* DS-CPL, VMX, SMX, EST */ | 325 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 326 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 327 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 328 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 329 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 330 F(F16C) | F(RDRAND); 331 /* cpuid 0x80000001.ecx */ 332 const u32 kvm_supported_word6_x86_features = 333 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 334 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 335 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 336 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 337 338 /* cpuid 0xC0000001.edx */ 339 const u32 kvm_supported_word5_x86_features = 340 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 341 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 342 F(PMM) | F(PMM_EN); 343 344 /* cpuid 7.0.ebx */ 345 const u32 kvm_supported_word9_x86_features = 346 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 347 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 348 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) | 349 F(AVX512CD); 350 351 /* cpuid 0xD.1.eax */ 352 const u32 kvm_supported_word10_x86_features = 353 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 354 355 /* all calls to cpuid_count() should be made on the same cpu */ 356 get_cpu(); 357 358 r = -E2BIG; 359 360 if (*nent >= maxnent) 361 goto out; 362 363 do_cpuid_1_ent(entry, function, index); 364 ++*nent; 365 366 switch (function) { 367 case 0: 368 entry->eax = min(entry->eax, (u32)0xd); 369 break; 370 case 1: 371 entry->edx &= kvm_supported_word0_x86_features; 372 cpuid_mask(&entry->edx, 0); 373 entry->ecx &= kvm_supported_word4_x86_features; 374 cpuid_mask(&entry->ecx, 4); 375 /* we support x2apic emulation even if host does not support 376 * it since we emulate x2apic in software */ 377 entry->ecx |= F(X2APIC); 378 break; 379 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 380 * may return different values. This forces us to get_cpu() before 381 * issuing the first command, and also to emulate this annoying behavior 382 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 383 case 2: { 384 int t, times = entry->eax & 0xff; 385 386 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 387 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 388 for (t = 1; t < times; ++t) { 389 if (*nent >= maxnent) 390 goto out; 391 392 do_cpuid_1_ent(&entry[t], function, 0); 393 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 394 ++*nent; 395 } 396 break; 397 } 398 /* function 4 has additional index. */ 399 case 4: { 400 int i, cache_type; 401 402 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 403 /* read more entries until cache_type is zero */ 404 for (i = 1; ; ++i) { 405 if (*nent >= maxnent) 406 goto out; 407 408 cache_type = entry[i - 1].eax & 0x1f; 409 if (!cache_type) 410 break; 411 do_cpuid_1_ent(&entry[i], function, i); 412 entry[i].flags |= 413 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 414 ++*nent; 415 } 416 break; 417 } 418 case 7: { 419 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 420 /* Mask ebx against host capability word 9 */ 421 if (index == 0) { 422 entry->ebx &= kvm_supported_word9_x86_features; 423 cpuid_mask(&entry->ebx, 9); 424 // TSC_ADJUST is emulated 425 entry->ebx |= F(TSC_ADJUST); 426 } else 427 entry->ebx = 0; 428 entry->eax = 0; 429 entry->ecx = 0; 430 entry->edx = 0; 431 break; 432 } 433 case 9: 434 break; 435 case 0xa: { /* Architectural Performance Monitoring */ 436 struct x86_pmu_capability cap; 437 union cpuid10_eax eax; 438 union cpuid10_edx edx; 439 440 perf_get_x86_pmu_capability(&cap); 441 442 /* 443 * Only support guest architectural pmu on a host 444 * with architectural pmu. 445 */ 446 if (!cap.version) 447 memset(&cap, 0, sizeof(cap)); 448 449 eax.split.version_id = min(cap.version, 2); 450 eax.split.num_counters = cap.num_counters_gp; 451 eax.split.bit_width = cap.bit_width_gp; 452 eax.split.mask_length = cap.events_mask_len; 453 454 edx.split.num_counters_fixed = cap.num_counters_fixed; 455 edx.split.bit_width_fixed = cap.bit_width_fixed; 456 edx.split.reserved = 0; 457 458 entry->eax = eax.full; 459 entry->ebx = cap.events_mask; 460 entry->ecx = 0; 461 entry->edx = edx.full; 462 break; 463 } 464 /* function 0xb has additional index. */ 465 case 0xb: { 466 int i, level_type; 467 468 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 469 /* read more entries until level_type is zero */ 470 for (i = 1; ; ++i) { 471 if (*nent >= maxnent) 472 goto out; 473 474 level_type = entry[i - 1].ecx & 0xff00; 475 if (!level_type) 476 break; 477 do_cpuid_1_ent(&entry[i], function, i); 478 entry[i].flags |= 479 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 480 ++*nent; 481 } 482 break; 483 } 484 case 0xd: { 485 int idx, i; 486 u64 supported = kvm_supported_xcr0(); 487 488 entry->eax &= supported; 489 entry->ebx = xstate_required_size(supported, false); 490 entry->ecx = entry->ebx; 491 entry->edx &= supported >> 32; 492 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 493 if (!supported) 494 break; 495 496 for (idx = 1, i = 1; idx < 64; ++idx) { 497 u64 mask = ((u64)1 << idx); 498 if (*nent >= maxnent) 499 goto out; 500 501 do_cpuid_1_ent(&entry[i], function, idx); 502 if (idx == 1) { 503 entry[i].eax &= kvm_supported_word10_x86_features; 504 entry[i].ebx = 0; 505 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 506 entry[i].ebx = 507 xstate_required_size(supported, 508 true); 509 } else { 510 if (entry[i].eax == 0 || !(supported & mask)) 511 continue; 512 if (WARN_ON_ONCE(entry[i].ecx & 1)) 513 continue; 514 } 515 entry[i].ecx = 0; 516 entry[i].edx = 0; 517 entry[i].flags |= 518 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 519 ++*nent; 520 ++i; 521 } 522 break; 523 } 524 case KVM_CPUID_SIGNATURE: { 525 static const char signature[12] = "KVMKVMKVM\0\0"; 526 const u32 *sigptr = (const u32 *)signature; 527 entry->eax = KVM_CPUID_FEATURES; 528 entry->ebx = sigptr[0]; 529 entry->ecx = sigptr[1]; 530 entry->edx = sigptr[2]; 531 break; 532 } 533 case KVM_CPUID_FEATURES: 534 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 535 (1 << KVM_FEATURE_NOP_IO_DELAY) | 536 (1 << KVM_FEATURE_CLOCKSOURCE2) | 537 (1 << KVM_FEATURE_ASYNC_PF) | 538 (1 << KVM_FEATURE_PV_EOI) | 539 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 540 (1 << KVM_FEATURE_PV_UNHALT); 541 542 if (sched_info_on()) 543 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 544 545 entry->ebx = 0; 546 entry->ecx = 0; 547 entry->edx = 0; 548 break; 549 case 0x80000000: 550 entry->eax = min(entry->eax, 0x8000001a); 551 break; 552 case 0x80000001: 553 entry->edx &= kvm_supported_word1_x86_features; 554 cpuid_mask(&entry->edx, 1); 555 entry->ecx &= kvm_supported_word6_x86_features; 556 cpuid_mask(&entry->ecx, 6); 557 break; 558 case 0x80000007: /* Advanced power management */ 559 /* invariant TSC is CPUID.80000007H:EDX[8] */ 560 entry->edx &= (1 << 8); 561 /* mask against host */ 562 entry->edx &= boot_cpu_data.x86_power; 563 entry->eax = entry->ebx = entry->ecx = 0; 564 break; 565 case 0x80000008: { 566 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 567 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 568 unsigned phys_as = entry->eax & 0xff; 569 570 if (!g_phys_as) 571 g_phys_as = phys_as; 572 entry->eax = g_phys_as | (virt_as << 8); 573 entry->ebx = entry->edx = 0; 574 break; 575 } 576 case 0x80000019: 577 entry->ecx = entry->edx = 0; 578 break; 579 case 0x8000001a: 580 break; 581 case 0x8000001d: 582 break; 583 /*Add support for Centaur's CPUID instruction*/ 584 case 0xC0000000: 585 /*Just support up to 0xC0000004 now*/ 586 entry->eax = min(entry->eax, 0xC0000004); 587 break; 588 case 0xC0000001: 589 entry->edx &= kvm_supported_word5_x86_features; 590 cpuid_mask(&entry->edx, 5); 591 break; 592 case 3: /* Processor serial number */ 593 case 5: /* MONITOR/MWAIT */ 594 case 6: /* Thermal management */ 595 case 0xC0000002: 596 case 0xC0000003: 597 case 0xC0000004: 598 default: 599 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 600 break; 601 } 602 603 kvm_x86_ops->set_supported_cpuid(function, entry); 604 605 r = 0; 606 607out: 608 put_cpu(); 609 610 return r; 611} 612 613static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 614 u32 idx, int *nent, int maxnent, unsigned int type) 615{ 616 if (type == KVM_GET_EMULATED_CPUID) 617 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 618 619 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 620} 621 622#undef F 623 624struct kvm_cpuid_param { 625 u32 func; 626 u32 idx; 627 bool has_leaf_count; 628 bool (*qualifier)(const struct kvm_cpuid_param *param); 629}; 630 631static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 632{ 633 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 634} 635 636static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 637 __u32 num_entries, unsigned int ioctl_type) 638{ 639 int i; 640 __u32 pad[3]; 641 642 if (ioctl_type != KVM_GET_EMULATED_CPUID) 643 return false; 644 645 /* 646 * We want to make sure that ->padding is being passed clean from 647 * userspace in case we want to use it for something in the future. 648 * 649 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 650 * have to give ourselves satisfied only with the emulated side. /me 651 * sheds a tear. 652 */ 653 for (i = 0; i < num_entries; i++) { 654 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 655 return true; 656 657 if (pad[0] || pad[1] || pad[2]) 658 return true; 659 } 660 return false; 661} 662 663int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 664 struct kvm_cpuid_entry2 __user *entries, 665 unsigned int type) 666{ 667 struct kvm_cpuid_entry2 *cpuid_entries; 668 int limit, nent = 0, r = -E2BIG, i; 669 u32 func; 670 static const struct kvm_cpuid_param param[] = { 671 { .func = 0, .has_leaf_count = true }, 672 { .func = 0x80000000, .has_leaf_count = true }, 673 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 674 { .func = KVM_CPUID_SIGNATURE }, 675 { .func = KVM_CPUID_FEATURES }, 676 }; 677 678 if (cpuid->nent < 1) 679 goto out; 680 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 681 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 682 683 if (sanity_check_entries(entries, cpuid->nent, type)) 684 return -EINVAL; 685 686 r = -ENOMEM; 687 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 688 if (!cpuid_entries) 689 goto out; 690 691 r = 0; 692 for (i = 0; i < ARRAY_SIZE(param); i++) { 693 const struct kvm_cpuid_param *ent = ¶m[i]; 694 695 if (ent->qualifier && !ent->qualifier(ent)) 696 continue; 697 698 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 699 &nent, cpuid->nent, type); 700 701 if (r) 702 goto out_free; 703 704 if (!ent->has_leaf_count) 705 continue; 706 707 limit = cpuid_entries[nent - 1].eax; 708 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 709 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 710 &nent, cpuid->nent, type); 711 712 if (r) 713 goto out_free; 714 } 715 716 r = -EFAULT; 717 if (copy_to_user(entries, cpuid_entries, 718 nent * sizeof(struct kvm_cpuid_entry2))) 719 goto out_free; 720 cpuid->nent = nent; 721 r = 0; 722 723out_free: 724 vfree(cpuid_entries); 725out: 726 return r; 727} 728 729static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 730{ 731 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 732 int j, nent = vcpu->arch.cpuid_nent; 733 734 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 735 /* when no next entry is found, the current entry[i] is reselected */ 736 for (j = i + 1; ; j = (j + 1) % nent) { 737 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 738 if (ej->function == e->function) { 739 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 740 return j; 741 } 742 } 743 return 0; /* silence gcc, even though control never reaches here */ 744} 745 746/* find an entry with matching function, matching index (if needed), and that 747 * should be read next (if it's stateful) */ 748static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 749 u32 function, u32 index) 750{ 751 if (e->function != function) 752 return 0; 753 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 754 return 0; 755 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 756 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 757 return 0; 758 return 1; 759} 760 761struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 762 u32 function, u32 index) 763{ 764 int i; 765 struct kvm_cpuid_entry2 *best = NULL; 766 767 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 768 struct kvm_cpuid_entry2 *e; 769 770 e = &vcpu->arch.cpuid_entries[i]; 771 if (is_matching_cpuid_entry(e, function, index)) { 772 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 773 move_to_next_stateful_cpuid_entry(vcpu, i); 774 best = e; 775 break; 776 } 777 } 778 return best; 779} 780EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 781 782/* 783 * If no match is found, check whether we exceed the vCPU's limit 784 * and return the content of the highest valid _standard_ leaf instead. 785 * This is to satisfy the CPUID specification. 786 */ 787static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 788 u32 function, u32 index) 789{ 790 struct kvm_cpuid_entry2 *maxlevel; 791 792 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 793 if (!maxlevel || maxlevel->eax >= function) 794 return NULL; 795 if (function & 0x80000000) { 796 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 797 if (!maxlevel) 798 return NULL; 799 } 800 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 801} 802 803void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 804{ 805 u32 function = *eax, index = *ecx; 806 struct kvm_cpuid_entry2 *best; 807 808 best = kvm_find_cpuid_entry(vcpu, function, index); 809 810 if (!best) 811 best = check_cpuid_limit(vcpu, function, index); 812 813 /* 814 * Perfmon not yet supported for L2 guest. 815 */ 816 if (is_guest_mode(vcpu) && function == 0xa) 817 best = NULL; 818 819 if (best) { 820 *eax = best->eax; 821 *ebx = best->ebx; 822 *ecx = best->ecx; 823 *edx = best->edx; 824 } else 825 *eax = *ebx = *ecx = *edx = 0; 826 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 827} 828EXPORT_SYMBOL_GPL(kvm_cpuid); 829 830void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 831{ 832 u32 function, eax, ebx, ecx, edx; 833 834 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 835 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 836 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 837 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 838 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 839 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 840 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 841 kvm_x86_ops->skip_emulated_instruction(vcpu); 842} 843EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 844