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 u64 kvm_supported_xcr0(void) 50 { 51 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 52 53 if (!kvm_x86_ops->mpx_supported()) 54 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); 55 56 return xcr0; 57 } 58 59 #define F(x) bit(X86_FEATURE_##x) 60 61 int 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 = use_eager_fpu() || guest_cpuid_has_mpx(vcpu); 101 if (vcpu->arch.eager_fpu) 102 kvm_x86_ops->fpu_activate(vcpu); 103 104 /* 105 * The existing code assumes virtual address is 48-bit in the canonical 106 * address checks; exit if it is ever changed. 107 */ 108 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 109 if (best && ((best->eax & 0xff00) >> 8) != 48 && 110 ((best->eax & 0xff00) >> 8) != 0) 111 return -EINVAL; 112 113 /* Update physical-address width */ 114 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 115 116 kvm_pmu_refresh(vcpu); 117 return 0; 118 } 119 120 static int is_efer_nx(void) 121 { 122 unsigned long long efer = 0; 123 124 rdmsrl_safe(MSR_EFER, &efer); 125 return efer & EFER_NX; 126 } 127 128 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 129 { 130 int i; 131 struct kvm_cpuid_entry2 *e, *entry; 132 133 entry = NULL; 134 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 135 e = &vcpu->arch.cpuid_entries[i]; 136 if (e->function == 0x80000001) { 137 entry = e; 138 break; 139 } 140 } 141 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 142 entry->edx &= ~F(NX); 143 printk(KERN_INFO "kvm: guest NX capability removed\n"); 144 } 145 } 146 147 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 148 { 149 struct kvm_cpuid_entry2 *best; 150 151 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 152 if (!best || best->eax < 0x80000008) 153 goto not_found; 154 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 155 if (best) 156 return best->eax & 0xff; 157 not_found: 158 return 36; 159 } 160 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 161 162 /* when an old userspace process fills a new kernel module */ 163 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 164 struct kvm_cpuid *cpuid, 165 struct kvm_cpuid_entry __user *entries) 166 { 167 int r, i; 168 struct kvm_cpuid_entry *cpuid_entries; 169 170 r = -E2BIG; 171 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 172 goto out; 173 r = -ENOMEM; 174 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); 175 if (!cpuid_entries) 176 goto out; 177 r = -EFAULT; 178 if (copy_from_user(cpuid_entries, entries, 179 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 180 goto out_free; 181 for (i = 0; i < cpuid->nent; i++) { 182 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 183 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 184 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 185 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 186 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 187 vcpu->arch.cpuid_entries[i].index = 0; 188 vcpu->arch.cpuid_entries[i].flags = 0; 189 vcpu->arch.cpuid_entries[i].padding[0] = 0; 190 vcpu->arch.cpuid_entries[i].padding[1] = 0; 191 vcpu->arch.cpuid_entries[i].padding[2] = 0; 192 } 193 vcpu->arch.cpuid_nent = cpuid->nent; 194 cpuid_fix_nx_cap(vcpu); 195 kvm_apic_set_version(vcpu); 196 kvm_x86_ops->cpuid_update(vcpu); 197 r = kvm_update_cpuid(vcpu); 198 199 out_free: 200 vfree(cpuid_entries); 201 out: 202 return r; 203 } 204 205 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 206 struct kvm_cpuid2 *cpuid, 207 struct kvm_cpuid_entry2 __user *entries) 208 { 209 int r; 210 211 r = -E2BIG; 212 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 213 goto out; 214 r = -EFAULT; 215 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 216 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 217 goto out; 218 vcpu->arch.cpuid_nent = cpuid->nent; 219 kvm_apic_set_version(vcpu); 220 kvm_x86_ops->cpuid_update(vcpu); 221 r = kvm_update_cpuid(vcpu); 222 out: 223 return r; 224 } 225 226 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 227 struct kvm_cpuid2 *cpuid, 228 struct kvm_cpuid_entry2 __user *entries) 229 { 230 int r; 231 232 r = -E2BIG; 233 if (cpuid->nent < vcpu->arch.cpuid_nent) 234 goto out; 235 r = -EFAULT; 236 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 237 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 238 goto out; 239 return 0; 240 241 out: 242 cpuid->nent = vcpu->arch.cpuid_nent; 243 return r; 244 } 245 246 static void cpuid_mask(u32 *word, int wordnum) 247 { 248 *word &= boot_cpu_data.x86_capability[wordnum]; 249 } 250 251 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 252 u32 index) 253 { 254 entry->function = function; 255 entry->index = index; 256 cpuid_count(entry->function, entry->index, 257 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 258 entry->flags = 0; 259 } 260 261 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 262 u32 func, u32 index, int *nent, int maxnent) 263 { 264 switch (func) { 265 case 0: 266 entry->eax = 1; /* only one leaf currently */ 267 ++*nent; 268 break; 269 case 1: 270 entry->ecx = F(MOVBE); 271 ++*nent; 272 break; 273 default: 274 break; 275 } 276 277 entry->function = func; 278 entry->index = index; 279 280 return 0; 281 } 282 283 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 284 u32 index, int *nent, int maxnent) 285 { 286 int r; 287 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 288 #ifdef CONFIG_X86_64 289 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 290 ? F(GBPAGES) : 0; 291 unsigned f_lm = F(LM); 292 #else 293 unsigned f_gbpages = 0; 294 unsigned f_lm = 0; 295 #endif 296 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 297 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 298 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0; 299 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 300 301 /* cpuid 1.edx */ 302 const u32 kvm_supported_word0_x86_features = 303 F(FPU) | F(VME) | F(DE) | F(PSE) | 304 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 305 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 306 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 307 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 308 0 /* Reserved, DS, ACPI */ | F(MMX) | 309 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 310 0 /* HTT, TM, Reserved, PBE */; 311 /* cpuid 0x80000001.edx */ 312 const u32 kvm_supported_word1_x86_features = 313 F(FPU) | F(VME) | F(DE) | F(PSE) | 314 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 315 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 316 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 317 F(PAT) | F(PSE36) | 0 /* Reserved */ | 318 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 319 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 320 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 321 /* cpuid 1.ecx */ 322 const u32 kvm_supported_word4_x86_features = 323 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 324 * but *not* advertised to guests via CPUID ! */ 325 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 326 0 /* DS-CPL, VMX, SMX, EST */ | 327 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 328 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 329 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 330 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 331 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 332 F(F16C) | F(RDRAND); 333 /* cpuid 0x80000001.ecx */ 334 const u32 kvm_supported_word6_x86_features = 335 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 336 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 337 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 338 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 339 340 /* cpuid 0xC0000001.edx */ 341 const u32 kvm_supported_word5_x86_features = 342 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 343 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 344 F(PMM) | F(PMM_EN); 345 346 /* cpuid 7.0.ebx */ 347 const u32 kvm_supported_word9_x86_features = 348 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 349 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 350 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) | 351 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(PCOMMIT); 352 353 /* cpuid 0xD.1.eax */ 354 const u32 kvm_supported_word10_x86_features = 355 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 356 357 /* all calls to cpuid_count() should be made on the same cpu */ 358 get_cpu(); 359 360 r = -E2BIG; 361 362 if (*nent >= maxnent) 363 goto out; 364 365 do_cpuid_1_ent(entry, function, index); 366 ++*nent; 367 368 switch (function) { 369 case 0: 370 entry->eax = min(entry->eax, (u32)0xd); 371 break; 372 case 1: 373 entry->edx &= kvm_supported_word0_x86_features; 374 cpuid_mask(&entry->edx, 0); 375 entry->ecx &= kvm_supported_word4_x86_features; 376 cpuid_mask(&entry->ecx, 4); 377 /* we support x2apic emulation even if host does not support 378 * it since we emulate x2apic in software */ 379 entry->ecx |= F(X2APIC); 380 break; 381 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 382 * may return different values. This forces us to get_cpu() before 383 * issuing the first command, and also to emulate this annoying behavior 384 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 385 case 2: { 386 int t, times = entry->eax & 0xff; 387 388 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 389 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 390 for (t = 1; t < times; ++t) { 391 if (*nent >= maxnent) 392 goto out; 393 394 do_cpuid_1_ent(&entry[t], function, 0); 395 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 396 ++*nent; 397 } 398 break; 399 } 400 /* function 4 has additional index. */ 401 case 4: { 402 int i, cache_type; 403 404 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 405 /* read more entries until cache_type is zero */ 406 for (i = 1; ; ++i) { 407 if (*nent >= maxnent) 408 goto out; 409 410 cache_type = entry[i - 1].eax & 0x1f; 411 if (!cache_type) 412 break; 413 do_cpuid_1_ent(&entry[i], function, i); 414 entry[i].flags |= 415 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 416 ++*nent; 417 } 418 break; 419 } 420 case 6: /* Thermal management */ 421 entry->eax = 0x4; /* allow ARAT */ 422 entry->ebx = 0; 423 entry->ecx = 0; 424 entry->edx = 0; 425 break; 426 case 7: { 427 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 428 /* Mask ebx against host capability word 9 */ 429 if (index == 0) { 430 entry->ebx &= kvm_supported_word9_x86_features; 431 cpuid_mask(&entry->ebx, 9); 432 // TSC_ADJUST is emulated 433 entry->ebx |= F(TSC_ADJUST); 434 } else 435 entry->ebx = 0; 436 entry->eax = 0; 437 entry->ecx = 0; 438 entry->edx = 0; 439 break; 440 } 441 case 9: 442 break; 443 case 0xa: { /* Architectural Performance Monitoring */ 444 struct x86_pmu_capability cap; 445 union cpuid10_eax eax; 446 union cpuid10_edx edx; 447 448 perf_get_x86_pmu_capability(&cap); 449 450 /* 451 * Only support guest architectural pmu on a host 452 * with architectural pmu. 453 */ 454 if (!cap.version) 455 memset(&cap, 0, sizeof(cap)); 456 457 eax.split.version_id = min(cap.version, 2); 458 eax.split.num_counters = cap.num_counters_gp; 459 eax.split.bit_width = cap.bit_width_gp; 460 eax.split.mask_length = cap.events_mask_len; 461 462 edx.split.num_counters_fixed = cap.num_counters_fixed; 463 edx.split.bit_width_fixed = cap.bit_width_fixed; 464 edx.split.reserved = 0; 465 466 entry->eax = eax.full; 467 entry->ebx = cap.events_mask; 468 entry->ecx = 0; 469 entry->edx = edx.full; 470 break; 471 } 472 /* function 0xb has additional index. */ 473 case 0xb: { 474 int i, level_type; 475 476 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 477 /* read more entries until level_type is zero */ 478 for (i = 1; ; ++i) { 479 if (*nent >= maxnent) 480 goto out; 481 482 level_type = entry[i - 1].ecx & 0xff00; 483 if (!level_type) 484 break; 485 do_cpuid_1_ent(&entry[i], function, i); 486 entry[i].flags |= 487 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 488 ++*nent; 489 } 490 break; 491 } 492 case 0xd: { 493 int idx, i; 494 u64 supported = kvm_supported_xcr0(); 495 496 entry->eax &= supported; 497 entry->ebx = xstate_required_size(supported, false); 498 entry->ecx = entry->ebx; 499 entry->edx &= supported >> 32; 500 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 501 if (!supported) 502 break; 503 504 for (idx = 1, i = 1; idx < 64; ++idx) { 505 u64 mask = ((u64)1 << idx); 506 if (*nent >= maxnent) 507 goto out; 508 509 do_cpuid_1_ent(&entry[i], function, idx); 510 if (idx == 1) { 511 entry[i].eax &= kvm_supported_word10_x86_features; 512 entry[i].ebx = 0; 513 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 514 entry[i].ebx = 515 xstate_required_size(supported, 516 true); 517 } else { 518 if (entry[i].eax == 0 || !(supported & mask)) 519 continue; 520 if (WARN_ON_ONCE(entry[i].ecx & 1)) 521 continue; 522 } 523 entry[i].ecx = 0; 524 entry[i].edx = 0; 525 entry[i].flags |= 526 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 527 ++*nent; 528 ++i; 529 } 530 break; 531 } 532 case KVM_CPUID_SIGNATURE: { 533 static const char signature[12] = "KVMKVMKVM\0\0"; 534 const u32 *sigptr = (const u32 *)signature; 535 entry->eax = KVM_CPUID_FEATURES; 536 entry->ebx = sigptr[0]; 537 entry->ecx = sigptr[1]; 538 entry->edx = sigptr[2]; 539 break; 540 } 541 case KVM_CPUID_FEATURES: 542 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 543 (1 << KVM_FEATURE_NOP_IO_DELAY) | 544 (1 << KVM_FEATURE_CLOCKSOURCE2) | 545 (1 << KVM_FEATURE_ASYNC_PF) | 546 (1 << KVM_FEATURE_PV_EOI) | 547 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 548 (1 << KVM_FEATURE_PV_UNHALT); 549 550 if (sched_info_on()) 551 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 552 553 entry->ebx = 0; 554 entry->ecx = 0; 555 entry->edx = 0; 556 break; 557 case 0x80000000: 558 entry->eax = min(entry->eax, 0x8000001a); 559 break; 560 case 0x80000001: 561 entry->edx &= kvm_supported_word1_x86_features; 562 cpuid_mask(&entry->edx, 1); 563 entry->ecx &= kvm_supported_word6_x86_features; 564 cpuid_mask(&entry->ecx, 6); 565 break; 566 case 0x80000007: /* Advanced power management */ 567 /* invariant TSC is CPUID.80000007H:EDX[8] */ 568 entry->edx &= (1 << 8); 569 /* mask against host */ 570 entry->edx &= boot_cpu_data.x86_power; 571 entry->eax = entry->ebx = entry->ecx = 0; 572 break; 573 case 0x80000008: { 574 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 575 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 576 unsigned phys_as = entry->eax & 0xff; 577 578 if (!g_phys_as) 579 g_phys_as = phys_as; 580 entry->eax = g_phys_as | (virt_as << 8); 581 entry->ebx = entry->edx = 0; 582 break; 583 } 584 case 0x80000019: 585 entry->ecx = entry->edx = 0; 586 break; 587 case 0x8000001a: 588 break; 589 case 0x8000001d: 590 break; 591 /*Add support for Centaur's CPUID instruction*/ 592 case 0xC0000000: 593 /*Just support up to 0xC0000004 now*/ 594 entry->eax = min(entry->eax, 0xC0000004); 595 break; 596 case 0xC0000001: 597 entry->edx &= kvm_supported_word5_x86_features; 598 cpuid_mask(&entry->edx, 5); 599 break; 600 case 3: /* Processor serial number */ 601 case 5: /* MONITOR/MWAIT */ 602 case 0xC0000002: 603 case 0xC0000003: 604 case 0xC0000004: 605 default: 606 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 607 break; 608 } 609 610 kvm_x86_ops->set_supported_cpuid(function, entry); 611 612 r = 0; 613 614 out: 615 put_cpu(); 616 617 return r; 618 } 619 620 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 621 u32 idx, int *nent, int maxnent, unsigned int type) 622 { 623 if (type == KVM_GET_EMULATED_CPUID) 624 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 625 626 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 627 } 628 629 #undef F 630 631 struct kvm_cpuid_param { 632 u32 func; 633 u32 idx; 634 bool has_leaf_count; 635 bool (*qualifier)(const struct kvm_cpuid_param *param); 636 }; 637 638 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 639 { 640 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 641 } 642 643 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 644 __u32 num_entries, unsigned int ioctl_type) 645 { 646 int i; 647 __u32 pad[3]; 648 649 if (ioctl_type != KVM_GET_EMULATED_CPUID) 650 return false; 651 652 /* 653 * We want to make sure that ->padding is being passed clean from 654 * userspace in case we want to use it for something in the future. 655 * 656 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 657 * have to give ourselves satisfied only with the emulated side. /me 658 * sheds a tear. 659 */ 660 for (i = 0; i < num_entries; i++) { 661 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 662 return true; 663 664 if (pad[0] || pad[1] || pad[2]) 665 return true; 666 } 667 return false; 668 } 669 670 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 671 struct kvm_cpuid_entry2 __user *entries, 672 unsigned int type) 673 { 674 struct kvm_cpuid_entry2 *cpuid_entries; 675 int limit, nent = 0, r = -E2BIG, i; 676 u32 func; 677 static const struct kvm_cpuid_param param[] = { 678 { .func = 0, .has_leaf_count = true }, 679 { .func = 0x80000000, .has_leaf_count = true }, 680 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 681 { .func = KVM_CPUID_SIGNATURE }, 682 { .func = KVM_CPUID_FEATURES }, 683 }; 684 685 if (cpuid->nent < 1) 686 goto out; 687 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 688 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 689 690 if (sanity_check_entries(entries, cpuid->nent, type)) 691 return -EINVAL; 692 693 r = -ENOMEM; 694 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 695 if (!cpuid_entries) 696 goto out; 697 698 r = 0; 699 for (i = 0; i < ARRAY_SIZE(param); i++) { 700 const struct kvm_cpuid_param *ent = ¶m[i]; 701 702 if (ent->qualifier && !ent->qualifier(ent)) 703 continue; 704 705 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 706 &nent, cpuid->nent, type); 707 708 if (r) 709 goto out_free; 710 711 if (!ent->has_leaf_count) 712 continue; 713 714 limit = cpuid_entries[nent - 1].eax; 715 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 716 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 717 &nent, cpuid->nent, type); 718 719 if (r) 720 goto out_free; 721 } 722 723 r = -EFAULT; 724 if (copy_to_user(entries, cpuid_entries, 725 nent * sizeof(struct kvm_cpuid_entry2))) 726 goto out_free; 727 cpuid->nent = nent; 728 r = 0; 729 730 out_free: 731 vfree(cpuid_entries); 732 out: 733 return r; 734 } 735 736 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 737 { 738 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 739 int j, nent = vcpu->arch.cpuid_nent; 740 741 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 742 /* when no next entry is found, the current entry[i] is reselected */ 743 for (j = i + 1; ; j = (j + 1) % nent) { 744 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 745 if (ej->function == e->function) { 746 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 747 return j; 748 } 749 } 750 return 0; /* silence gcc, even though control never reaches here */ 751 } 752 753 /* find an entry with matching function, matching index (if needed), and that 754 * should be read next (if it's stateful) */ 755 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 756 u32 function, u32 index) 757 { 758 if (e->function != function) 759 return 0; 760 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 761 return 0; 762 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 763 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 764 return 0; 765 return 1; 766 } 767 768 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 769 u32 function, u32 index) 770 { 771 int i; 772 struct kvm_cpuid_entry2 *best = NULL; 773 774 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 775 struct kvm_cpuid_entry2 *e; 776 777 e = &vcpu->arch.cpuid_entries[i]; 778 if (is_matching_cpuid_entry(e, function, index)) { 779 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 780 move_to_next_stateful_cpuid_entry(vcpu, i); 781 best = e; 782 break; 783 } 784 } 785 return best; 786 } 787 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 788 789 /* 790 * If no match is found, check whether we exceed the vCPU's limit 791 * and return the content of the highest valid _standard_ leaf instead. 792 * This is to satisfy the CPUID specification. 793 */ 794 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 795 u32 function, u32 index) 796 { 797 struct kvm_cpuid_entry2 *maxlevel; 798 799 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 800 if (!maxlevel || maxlevel->eax >= function) 801 return NULL; 802 if (function & 0x80000000) { 803 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 804 if (!maxlevel) 805 return NULL; 806 } 807 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 808 } 809 810 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 811 { 812 u32 function = *eax, index = *ecx; 813 struct kvm_cpuid_entry2 *best; 814 815 best = kvm_find_cpuid_entry(vcpu, function, index); 816 817 if (!best) 818 best = check_cpuid_limit(vcpu, function, index); 819 820 /* 821 * Perfmon not yet supported for L2 guest. 822 */ 823 if (is_guest_mode(vcpu) && function == 0xa) 824 best = NULL; 825 826 if (best) { 827 *eax = best->eax; 828 *ebx = best->ebx; 829 *ecx = best->ecx; 830 *edx = best->edx; 831 } else 832 *eax = *ebx = *ecx = *edx = 0; 833 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 834 } 835 EXPORT_SYMBOL_GPL(kvm_cpuid); 836 837 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 838 { 839 u32 function, eax, ebx, ecx, edx; 840 841 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 842 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 843 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 844 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 845 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 846 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 847 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 848 kvm_x86_ops->skip_emulated_instruction(vcpu); 849 } 850 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 851