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) 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; 35 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 36 ret = max(ret, eax + ebx); 37 } 38 39 xstate_bv >>= 1; 40 feature_bit++; 41 } 42 43 return ret; 44 } 45 46 u64 kvm_supported_xcr0(void) 47 { 48 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 49 50 if (!kvm_x86_ops->mpx_supported()) 51 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR); 52 53 return xcr0; 54 } 55 56 void kvm_update_cpuid(struct kvm_vcpu *vcpu) 57 { 58 struct kvm_cpuid_entry2 *best; 59 struct kvm_lapic *apic = vcpu->arch.apic; 60 61 best = kvm_find_cpuid_entry(vcpu, 1, 0); 62 if (!best) 63 return; 64 65 /* Update OSXSAVE bit */ 66 if (cpu_has_xsave && best->function == 0x1) { 67 best->ecx &= ~(bit(X86_FEATURE_OSXSAVE)); 68 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 69 best->ecx |= bit(X86_FEATURE_OSXSAVE); 70 } 71 72 if (apic) { 73 if (best->ecx & bit(X86_FEATURE_TSC_DEADLINE_TIMER)) 74 apic->lapic_timer.timer_mode_mask = 3 << 17; 75 else 76 apic->lapic_timer.timer_mode_mask = 1 << 17; 77 } 78 79 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 80 if (!best) { 81 vcpu->arch.guest_supported_xcr0 = 0; 82 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 83 } else { 84 vcpu->arch.guest_supported_xcr0 = 85 (best->eax | ((u64)best->edx << 32)) & 86 kvm_supported_xcr0(); 87 vcpu->arch.guest_xstate_size = best->ebx = 88 xstate_required_size(vcpu->arch.xcr0); 89 } 90 91 kvm_pmu_cpuid_update(vcpu); 92 } 93 94 static int is_efer_nx(void) 95 { 96 unsigned long long efer = 0; 97 98 rdmsrl_safe(MSR_EFER, &efer); 99 return efer & EFER_NX; 100 } 101 102 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 103 { 104 int i; 105 struct kvm_cpuid_entry2 *e, *entry; 106 107 entry = NULL; 108 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 109 e = &vcpu->arch.cpuid_entries[i]; 110 if (e->function == 0x80000001) { 111 entry = e; 112 break; 113 } 114 } 115 if (entry && (entry->edx & (1 << 20)) && !is_efer_nx()) { 116 entry->edx &= ~(1 << 20); 117 printk(KERN_INFO "kvm: guest NX capability removed\n"); 118 } 119 } 120 121 /* when an old userspace process fills a new kernel module */ 122 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 123 struct kvm_cpuid *cpuid, 124 struct kvm_cpuid_entry __user *entries) 125 { 126 int r, i; 127 struct kvm_cpuid_entry *cpuid_entries; 128 129 r = -E2BIG; 130 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 131 goto out; 132 r = -ENOMEM; 133 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); 134 if (!cpuid_entries) 135 goto out; 136 r = -EFAULT; 137 if (copy_from_user(cpuid_entries, entries, 138 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 139 goto out_free; 140 for (i = 0; i < cpuid->nent; i++) { 141 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 142 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 143 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 144 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 145 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 146 vcpu->arch.cpuid_entries[i].index = 0; 147 vcpu->arch.cpuid_entries[i].flags = 0; 148 vcpu->arch.cpuid_entries[i].padding[0] = 0; 149 vcpu->arch.cpuid_entries[i].padding[1] = 0; 150 vcpu->arch.cpuid_entries[i].padding[2] = 0; 151 } 152 vcpu->arch.cpuid_nent = cpuid->nent; 153 cpuid_fix_nx_cap(vcpu); 154 r = 0; 155 kvm_apic_set_version(vcpu); 156 kvm_x86_ops->cpuid_update(vcpu); 157 kvm_update_cpuid(vcpu); 158 159 out_free: 160 vfree(cpuid_entries); 161 out: 162 return r; 163 } 164 165 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 166 struct kvm_cpuid2 *cpuid, 167 struct kvm_cpuid_entry2 __user *entries) 168 { 169 int r; 170 171 r = -E2BIG; 172 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 173 goto out; 174 r = -EFAULT; 175 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 176 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 177 goto out; 178 vcpu->arch.cpuid_nent = cpuid->nent; 179 kvm_apic_set_version(vcpu); 180 kvm_x86_ops->cpuid_update(vcpu); 181 kvm_update_cpuid(vcpu); 182 return 0; 183 184 out: 185 return r; 186 } 187 188 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 189 struct kvm_cpuid2 *cpuid, 190 struct kvm_cpuid_entry2 __user *entries) 191 { 192 int r; 193 194 r = -E2BIG; 195 if (cpuid->nent < vcpu->arch.cpuid_nent) 196 goto out; 197 r = -EFAULT; 198 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 199 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 200 goto out; 201 return 0; 202 203 out: 204 cpuid->nent = vcpu->arch.cpuid_nent; 205 return r; 206 } 207 208 static void cpuid_mask(u32 *word, int wordnum) 209 { 210 *word &= boot_cpu_data.x86_capability[wordnum]; 211 } 212 213 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 214 u32 index) 215 { 216 entry->function = function; 217 entry->index = index; 218 cpuid_count(entry->function, entry->index, 219 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 220 entry->flags = 0; 221 } 222 223 #define F(x) bit(X86_FEATURE_##x) 224 225 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 226 u32 func, u32 index, int *nent, int maxnent) 227 { 228 switch (func) { 229 case 0: 230 entry->eax = 1; /* only one leaf currently */ 231 ++*nent; 232 break; 233 case 1: 234 entry->ecx = F(MOVBE); 235 ++*nent; 236 break; 237 default: 238 break; 239 } 240 241 entry->function = func; 242 entry->index = index; 243 244 return 0; 245 } 246 247 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 248 u32 index, int *nent, int maxnent) 249 { 250 int r; 251 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 252 #ifdef CONFIG_X86_64 253 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 254 ? F(GBPAGES) : 0; 255 unsigned f_lm = F(LM); 256 #else 257 unsigned f_gbpages = 0; 258 unsigned f_lm = 0; 259 #endif 260 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 261 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 262 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0; 263 264 /* cpuid 1.edx */ 265 const u32 kvm_supported_word0_x86_features = 266 F(FPU) | F(VME) | F(DE) | F(PSE) | 267 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 268 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 269 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 270 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 271 0 /* Reserved, DS, ACPI */ | F(MMX) | 272 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 273 0 /* HTT, TM, Reserved, PBE */; 274 /* cpuid 0x80000001.edx */ 275 const u32 kvm_supported_word1_x86_features = 276 F(FPU) | F(VME) | F(DE) | F(PSE) | 277 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 278 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 279 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 280 F(PAT) | F(PSE36) | 0 /* Reserved */ | 281 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 282 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 283 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 284 /* cpuid 1.ecx */ 285 const u32 kvm_supported_word4_x86_features = 286 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 287 0 /* DS-CPL, VMX, SMX, EST */ | 288 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 289 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 290 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 291 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 292 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 293 F(F16C) | F(RDRAND); 294 /* cpuid 0x80000001.ecx */ 295 const u32 kvm_supported_word6_x86_features = 296 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 297 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 298 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 299 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 300 301 /* cpuid 0xC0000001.edx */ 302 const u32 kvm_supported_word5_x86_features = 303 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 304 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 305 F(PMM) | F(PMM_EN); 306 307 /* cpuid 7.0.ebx */ 308 const u32 kvm_supported_word9_x86_features = 309 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 310 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 311 F(ADX); 312 313 /* all calls to cpuid_count() should be made on the same cpu */ 314 get_cpu(); 315 316 r = -E2BIG; 317 318 if (*nent >= maxnent) 319 goto out; 320 321 do_cpuid_1_ent(entry, function, index); 322 ++*nent; 323 324 switch (function) { 325 case 0: 326 entry->eax = min(entry->eax, (u32)0xd); 327 break; 328 case 1: 329 entry->edx &= kvm_supported_word0_x86_features; 330 cpuid_mask(&entry->edx, 0); 331 entry->ecx &= kvm_supported_word4_x86_features; 332 cpuid_mask(&entry->ecx, 4); 333 /* we support x2apic emulation even if host does not support 334 * it since we emulate x2apic in software */ 335 entry->ecx |= F(X2APIC); 336 break; 337 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 338 * may return different values. This forces us to get_cpu() before 339 * issuing the first command, and also to emulate this annoying behavior 340 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 341 case 2: { 342 int t, times = entry->eax & 0xff; 343 344 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 345 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 346 for (t = 1; t < times; ++t) { 347 if (*nent >= maxnent) 348 goto out; 349 350 do_cpuid_1_ent(&entry[t], function, 0); 351 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 352 ++*nent; 353 } 354 break; 355 } 356 /* function 4 has additional index. */ 357 case 4: { 358 int i, cache_type; 359 360 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 361 /* read more entries until cache_type is zero */ 362 for (i = 1; ; ++i) { 363 if (*nent >= maxnent) 364 goto out; 365 366 cache_type = entry[i - 1].eax & 0x1f; 367 if (!cache_type) 368 break; 369 do_cpuid_1_ent(&entry[i], function, i); 370 entry[i].flags |= 371 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 372 ++*nent; 373 } 374 break; 375 } 376 case 7: { 377 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 378 /* Mask ebx against host capability word 9 */ 379 if (index == 0) { 380 entry->ebx &= kvm_supported_word9_x86_features; 381 cpuid_mask(&entry->ebx, 9); 382 // TSC_ADJUST is emulated 383 entry->ebx |= F(TSC_ADJUST); 384 } else 385 entry->ebx = 0; 386 entry->eax = 0; 387 entry->ecx = 0; 388 entry->edx = 0; 389 break; 390 } 391 case 9: 392 break; 393 case 0xa: { /* Architectural Performance Monitoring */ 394 struct x86_pmu_capability cap; 395 union cpuid10_eax eax; 396 union cpuid10_edx edx; 397 398 perf_get_x86_pmu_capability(&cap); 399 400 /* 401 * Only support guest architectural pmu on a host 402 * with architectural pmu. 403 */ 404 if (!cap.version) 405 memset(&cap, 0, sizeof(cap)); 406 407 eax.split.version_id = min(cap.version, 2); 408 eax.split.num_counters = cap.num_counters_gp; 409 eax.split.bit_width = cap.bit_width_gp; 410 eax.split.mask_length = cap.events_mask_len; 411 412 edx.split.num_counters_fixed = cap.num_counters_fixed; 413 edx.split.bit_width_fixed = cap.bit_width_fixed; 414 edx.split.reserved = 0; 415 416 entry->eax = eax.full; 417 entry->ebx = cap.events_mask; 418 entry->ecx = 0; 419 entry->edx = edx.full; 420 break; 421 } 422 /* function 0xb has additional index. */ 423 case 0xb: { 424 int i, level_type; 425 426 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 427 /* read more entries until level_type is zero */ 428 for (i = 1; ; ++i) { 429 if (*nent >= maxnent) 430 goto out; 431 432 level_type = entry[i - 1].ecx & 0xff00; 433 if (!level_type) 434 break; 435 do_cpuid_1_ent(&entry[i], function, i); 436 entry[i].flags |= 437 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 438 ++*nent; 439 } 440 break; 441 } 442 case 0xd: { 443 int idx, i; 444 u64 supported = kvm_supported_xcr0(); 445 446 entry->eax &= supported; 447 entry->edx &= supported >> 32; 448 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 449 for (idx = 1, i = 1; idx < 64; ++idx) { 450 u64 mask = ((u64)1 << idx); 451 if (*nent >= maxnent) 452 goto out; 453 454 do_cpuid_1_ent(&entry[i], function, idx); 455 if (entry[i].eax == 0 || !(supported & mask)) 456 continue; 457 entry[i].flags |= 458 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 459 ++*nent; 460 ++i; 461 } 462 break; 463 } 464 case KVM_CPUID_SIGNATURE: { 465 static const char signature[12] = "KVMKVMKVM\0\0"; 466 const u32 *sigptr = (const u32 *)signature; 467 entry->eax = KVM_CPUID_FEATURES; 468 entry->ebx = sigptr[0]; 469 entry->ecx = sigptr[1]; 470 entry->edx = sigptr[2]; 471 break; 472 } 473 case KVM_CPUID_FEATURES: 474 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 475 (1 << KVM_FEATURE_NOP_IO_DELAY) | 476 (1 << KVM_FEATURE_CLOCKSOURCE2) | 477 (1 << KVM_FEATURE_ASYNC_PF) | 478 (1 << KVM_FEATURE_PV_EOI) | 479 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 480 (1 << KVM_FEATURE_PV_UNHALT); 481 482 if (sched_info_on()) 483 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 484 485 entry->ebx = 0; 486 entry->ecx = 0; 487 entry->edx = 0; 488 break; 489 case 0x80000000: 490 entry->eax = min(entry->eax, 0x8000001a); 491 break; 492 case 0x80000001: 493 entry->edx &= kvm_supported_word1_x86_features; 494 cpuid_mask(&entry->edx, 1); 495 entry->ecx &= kvm_supported_word6_x86_features; 496 cpuid_mask(&entry->ecx, 6); 497 break; 498 case 0x80000008: { 499 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 500 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 501 unsigned phys_as = entry->eax & 0xff; 502 503 if (!g_phys_as) 504 g_phys_as = phys_as; 505 entry->eax = g_phys_as | (virt_as << 8); 506 entry->ebx = entry->edx = 0; 507 break; 508 } 509 case 0x80000019: 510 entry->ecx = entry->edx = 0; 511 break; 512 case 0x8000001a: 513 break; 514 case 0x8000001d: 515 break; 516 /*Add support for Centaur's CPUID instruction*/ 517 case 0xC0000000: 518 /*Just support up to 0xC0000004 now*/ 519 entry->eax = min(entry->eax, 0xC0000004); 520 break; 521 case 0xC0000001: 522 entry->edx &= kvm_supported_word5_x86_features; 523 cpuid_mask(&entry->edx, 5); 524 break; 525 case 3: /* Processor serial number */ 526 case 5: /* MONITOR/MWAIT */ 527 case 6: /* Thermal management */ 528 case 0x80000007: /* Advanced power management */ 529 case 0xC0000002: 530 case 0xC0000003: 531 case 0xC0000004: 532 default: 533 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 534 break; 535 } 536 537 kvm_x86_ops->set_supported_cpuid(function, entry); 538 539 r = 0; 540 541 out: 542 put_cpu(); 543 544 return r; 545 } 546 547 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 548 u32 idx, int *nent, int maxnent, unsigned int type) 549 { 550 if (type == KVM_GET_EMULATED_CPUID) 551 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 552 553 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 554 } 555 556 #undef F 557 558 struct kvm_cpuid_param { 559 u32 func; 560 u32 idx; 561 bool has_leaf_count; 562 bool (*qualifier)(const struct kvm_cpuid_param *param); 563 }; 564 565 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 566 { 567 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 568 } 569 570 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 571 __u32 num_entries, unsigned int ioctl_type) 572 { 573 int i; 574 __u32 pad[3]; 575 576 if (ioctl_type != KVM_GET_EMULATED_CPUID) 577 return false; 578 579 /* 580 * We want to make sure that ->padding is being passed clean from 581 * userspace in case we want to use it for something in the future. 582 * 583 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 584 * have to give ourselves satisfied only with the emulated side. /me 585 * sheds a tear. 586 */ 587 for (i = 0; i < num_entries; i++) { 588 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 589 return true; 590 591 if (pad[0] || pad[1] || pad[2]) 592 return true; 593 } 594 return false; 595 } 596 597 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 598 struct kvm_cpuid_entry2 __user *entries, 599 unsigned int type) 600 { 601 struct kvm_cpuid_entry2 *cpuid_entries; 602 int limit, nent = 0, r = -E2BIG, i; 603 u32 func; 604 static const struct kvm_cpuid_param param[] = { 605 { .func = 0, .has_leaf_count = true }, 606 { .func = 0x80000000, .has_leaf_count = true }, 607 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 608 { .func = KVM_CPUID_SIGNATURE }, 609 { .func = KVM_CPUID_FEATURES }, 610 }; 611 612 if (cpuid->nent < 1) 613 goto out; 614 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 615 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 616 617 if (sanity_check_entries(entries, cpuid->nent, type)) 618 return -EINVAL; 619 620 r = -ENOMEM; 621 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 622 if (!cpuid_entries) 623 goto out; 624 625 r = 0; 626 for (i = 0; i < ARRAY_SIZE(param); i++) { 627 const struct kvm_cpuid_param *ent = ¶m[i]; 628 629 if (ent->qualifier && !ent->qualifier(ent)) 630 continue; 631 632 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 633 &nent, cpuid->nent, type); 634 635 if (r) 636 goto out_free; 637 638 if (!ent->has_leaf_count) 639 continue; 640 641 limit = cpuid_entries[nent - 1].eax; 642 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 643 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 644 &nent, cpuid->nent, type); 645 646 if (r) 647 goto out_free; 648 } 649 650 r = -EFAULT; 651 if (copy_to_user(entries, cpuid_entries, 652 nent * sizeof(struct kvm_cpuid_entry2))) 653 goto out_free; 654 cpuid->nent = nent; 655 r = 0; 656 657 out_free: 658 vfree(cpuid_entries); 659 out: 660 return r; 661 } 662 663 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 664 { 665 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 666 int j, nent = vcpu->arch.cpuid_nent; 667 668 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 669 /* when no next entry is found, the current entry[i] is reselected */ 670 for (j = i + 1; ; j = (j + 1) % nent) { 671 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 672 if (ej->function == e->function) { 673 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 674 return j; 675 } 676 } 677 return 0; /* silence gcc, even though control never reaches here */ 678 } 679 680 /* find an entry with matching function, matching index (if needed), and that 681 * should be read next (if it's stateful) */ 682 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 683 u32 function, u32 index) 684 { 685 if (e->function != function) 686 return 0; 687 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 688 return 0; 689 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 690 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 691 return 0; 692 return 1; 693 } 694 695 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 696 u32 function, u32 index) 697 { 698 int i; 699 struct kvm_cpuid_entry2 *best = NULL; 700 701 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 702 struct kvm_cpuid_entry2 *e; 703 704 e = &vcpu->arch.cpuid_entries[i]; 705 if (is_matching_cpuid_entry(e, function, index)) { 706 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 707 move_to_next_stateful_cpuid_entry(vcpu, i); 708 best = e; 709 break; 710 } 711 } 712 return best; 713 } 714 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 715 716 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu) 717 { 718 struct kvm_cpuid_entry2 *best; 719 720 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 721 if (!best || best->eax < 0x80000008) 722 goto not_found; 723 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 724 if (best) 725 return best->eax & 0xff; 726 not_found: 727 return 36; 728 } 729 730 /* 731 * If no match is found, check whether we exceed the vCPU's limit 732 * and return the content of the highest valid _standard_ leaf instead. 733 * This is to satisfy the CPUID specification. 734 */ 735 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 736 u32 function, u32 index) 737 { 738 struct kvm_cpuid_entry2 *maxlevel; 739 740 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 741 if (!maxlevel || maxlevel->eax >= function) 742 return NULL; 743 if (function & 0x80000000) { 744 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 745 if (!maxlevel) 746 return NULL; 747 } 748 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 749 } 750 751 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 752 { 753 u32 function = *eax, index = *ecx; 754 struct kvm_cpuid_entry2 *best; 755 756 best = kvm_find_cpuid_entry(vcpu, function, index); 757 758 if (!best) 759 best = check_cpuid_limit(vcpu, function, index); 760 761 if (best) { 762 *eax = best->eax; 763 *ebx = best->ebx; 764 *ecx = best->ecx; 765 *edx = best->edx; 766 } else 767 *eax = *ebx = *ecx = *edx = 0; 768 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 769 } 770 EXPORT_SYMBOL_GPL(kvm_cpuid); 771 772 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 773 { 774 u32 function, eax, ebx, ecx, edx; 775 776 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 777 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 778 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 779 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 780 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 781 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 782 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 783 kvm_x86_ops->skip_emulated_instruction(vcpu); 784 } 785 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 786