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 int 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 0; 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 /* 92 * The existing code assumes virtual address is 48-bit in the canonical 93 * address checks; exit if it is ever changed. 94 */ 95 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 96 if (best && ((best->eax & 0xff00) >> 8) != 48 && 97 ((best->eax & 0xff00) >> 8) != 0) 98 return -EINVAL; 99 100 kvm_pmu_cpuid_update(vcpu); 101 return 0; 102 } 103 104 static int is_efer_nx(void) 105 { 106 unsigned long long efer = 0; 107 108 rdmsrl_safe(MSR_EFER, &efer); 109 return efer & EFER_NX; 110 } 111 112 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 113 { 114 int i; 115 struct kvm_cpuid_entry2 *e, *entry; 116 117 entry = NULL; 118 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 119 e = &vcpu->arch.cpuid_entries[i]; 120 if (e->function == 0x80000001) { 121 entry = e; 122 break; 123 } 124 } 125 if (entry && (entry->edx & bit(X86_FEATURE_NX)) && !is_efer_nx()) { 126 entry->edx &= ~bit(X86_FEATURE_NX); 127 printk(KERN_INFO "kvm: guest NX capability removed\n"); 128 } 129 } 130 131 /* when an old userspace process fills a new kernel module */ 132 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 133 struct kvm_cpuid *cpuid, 134 struct kvm_cpuid_entry __user *entries) 135 { 136 int r, i; 137 struct kvm_cpuid_entry *cpuid_entries; 138 139 r = -E2BIG; 140 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 141 goto out; 142 r = -ENOMEM; 143 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent); 144 if (!cpuid_entries) 145 goto out; 146 r = -EFAULT; 147 if (copy_from_user(cpuid_entries, entries, 148 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 149 goto out_free; 150 for (i = 0; i < cpuid->nent; i++) { 151 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 152 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 153 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 154 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 155 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 156 vcpu->arch.cpuid_entries[i].index = 0; 157 vcpu->arch.cpuid_entries[i].flags = 0; 158 vcpu->arch.cpuid_entries[i].padding[0] = 0; 159 vcpu->arch.cpuid_entries[i].padding[1] = 0; 160 vcpu->arch.cpuid_entries[i].padding[2] = 0; 161 } 162 vcpu->arch.cpuid_nent = cpuid->nent; 163 cpuid_fix_nx_cap(vcpu); 164 kvm_apic_set_version(vcpu); 165 kvm_x86_ops->cpuid_update(vcpu); 166 r = kvm_update_cpuid(vcpu); 167 168 out_free: 169 vfree(cpuid_entries); 170 out: 171 return r; 172 } 173 174 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 175 struct kvm_cpuid2 *cpuid, 176 struct kvm_cpuid_entry2 __user *entries) 177 { 178 int r; 179 180 r = -E2BIG; 181 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 182 goto out; 183 r = -EFAULT; 184 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 185 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 186 goto out; 187 vcpu->arch.cpuid_nent = cpuid->nent; 188 kvm_apic_set_version(vcpu); 189 kvm_x86_ops->cpuid_update(vcpu); 190 r = kvm_update_cpuid(vcpu); 191 out: 192 return r; 193 } 194 195 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 196 struct kvm_cpuid2 *cpuid, 197 struct kvm_cpuid_entry2 __user *entries) 198 { 199 int r; 200 201 r = -E2BIG; 202 if (cpuid->nent < vcpu->arch.cpuid_nent) 203 goto out; 204 r = -EFAULT; 205 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 206 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 207 goto out; 208 return 0; 209 210 out: 211 cpuid->nent = vcpu->arch.cpuid_nent; 212 return r; 213 } 214 215 static void cpuid_mask(u32 *word, int wordnum) 216 { 217 *word &= boot_cpu_data.x86_capability[wordnum]; 218 } 219 220 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 221 u32 index) 222 { 223 entry->function = function; 224 entry->index = index; 225 cpuid_count(entry->function, entry->index, 226 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 227 entry->flags = 0; 228 } 229 230 #define F(x) bit(X86_FEATURE_##x) 231 232 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 233 u32 func, u32 index, int *nent, int maxnent) 234 { 235 switch (func) { 236 case 0: 237 entry->eax = 1; /* only one leaf currently */ 238 ++*nent; 239 break; 240 case 1: 241 entry->ecx = F(MOVBE); 242 ++*nent; 243 break; 244 default: 245 break; 246 } 247 248 entry->function = func; 249 entry->index = index; 250 251 return 0; 252 } 253 254 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 255 u32 index, int *nent, int maxnent) 256 { 257 int r; 258 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 259 #ifdef CONFIG_X86_64 260 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 261 ? F(GBPAGES) : 0; 262 unsigned f_lm = F(LM); 263 #else 264 unsigned f_gbpages = 0; 265 unsigned f_lm = 0; 266 #endif 267 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 268 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 269 unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0; 270 271 /* cpuid 1.edx */ 272 const u32 kvm_supported_word0_x86_features = 273 F(FPU) | F(VME) | F(DE) | F(PSE) | 274 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 275 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 276 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 277 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 278 0 /* Reserved, DS, ACPI */ | F(MMX) | 279 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 280 0 /* HTT, TM, Reserved, PBE */; 281 /* cpuid 0x80000001.edx */ 282 const u32 kvm_supported_word1_x86_features = 283 F(FPU) | F(VME) | F(DE) | F(PSE) | 284 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 285 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 286 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 287 F(PAT) | F(PSE36) | 0 /* Reserved */ | 288 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 289 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 290 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 291 /* cpuid 1.ecx */ 292 const u32 kvm_supported_word4_x86_features = 293 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 294 * but *not* advertised to guests via CPUID ! */ 295 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 296 0 /* DS-CPL, VMX, SMX, EST */ | 297 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 298 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 299 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 300 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 301 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 302 F(F16C) | F(RDRAND); 303 /* cpuid 0x80000001.ecx */ 304 const u32 kvm_supported_word6_x86_features = 305 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 306 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 307 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 308 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 309 310 /* cpuid 0xC0000001.edx */ 311 const u32 kvm_supported_word5_x86_features = 312 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 313 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 314 F(PMM) | F(PMM_EN); 315 316 /* cpuid 7.0.ebx */ 317 const u32 kvm_supported_word9_x86_features = 318 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 319 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 320 F(ADX) | F(SMAP); 321 322 /* all calls to cpuid_count() should be made on the same cpu */ 323 get_cpu(); 324 325 r = -E2BIG; 326 327 if (*nent >= maxnent) 328 goto out; 329 330 do_cpuid_1_ent(entry, function, index); 331 ++*nent; 332 333 switch (function) { 334 case 0: 335 entry->eax = min(entry->eax, (u32)0xd); 336 break; 337 case 1: 338 entry->edx &= kvm_supported_word0_x86_features; 339 cpuid_mask(&entry->edx, 0); 340 entry->ecx &= kvm_supported_word4_x86_features; 341 cpuid_mask(&entry->ecx, 4); 342 /* we support x2apic emulation even if host does not support 343 * it since we emulate x2apic in software */ 344 entry->ecx |= F(X2APIC); 345 break; 346 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 347 * may return different values. This forces us to get_cpu() before 348 * issuing the first command, and also to emulate this annoying behavior 349 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 350 case 2: { 351 int t, times = entry->eax & 0xff; 352 353 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 354 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 355 for (t = 1; t < times; ++t) { 356 if (*nent >= maxnent) 357 goto out; 358 359 do_cpuid_1_ent(&entry[t], function, 0); 360 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 361 ++*nent; 362 } 363 break; 364 } 365 /* function 4 has additional index. */ 366 case 4: { 367 int i, cache_type; 368 369 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 370 /* read more entries until cache_type is zero */ 371 for (i = 1; ; ++i) { 372 if (*nent >= maxnent) 373 goto out; 374 375 cache_type = entry[i - 1].eax & 0x1f; 376 if (!cache_type) 377 break; 378 do_cpuid_1_ent(&entry[i], function, i); 379 entry[i].flags |= 380 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 381 ++*nent; 382 } 383 break; 384 } 385 case 7: { 386 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 387 /* Mask ebx against host capability word 9 */ 388 if (index == 0) { 389 entry->ebx &= kvm_supported_word9_x86_features; 390 cpuid_mask(&entry->ebx, 9); 391 // TSC_ADJUST is emulated 392 entry->ebx |= F(TSC_ADJUST); 393 } else 394 entry->ebx = 0; 395 entry->eax = 0; 396 entry->ecx = 0; 397 entry->edx = 0; 398 break; 399 } 400 case 9: 401 break; 402 case 0xa: { /* Architectural Performance Monitoring */ 403 struct x86_pmu_capability cap; 404 union cpuid10_eax eax; 405 union cpuid10_edx edx; 406 407 perf_get_x86_pmu_capability(&cap); 408 409 /* 410 * Only support guest architectural pmu on a host 411 * with architectural pmu. 412 */ 413 if (!cap.version) 414 memset(&cap, 0, sizeof(cap)); 415 416 eax.split.version_id = min(cap.version, 2); 417 eax.split.num_counters = cap.num_counters_gp; 418 eax.split.bit_width = cap.bit_width_gp; 419 eax.split.mask_length = cap.events_mask_len; 420 421 edx.split.num_counters_fixed = cap.num_counters_fixed; 422 edx.split.bit_width_fixed = cap.bit_width_fixed; 423 edx.split.reserved = 0; 424 425 entry->eax = eax.full; 426 entry->ebx = cap.events_mask; 427 entry->ecx = 0; 428 entry->edx = edx.full; 429 break; 430 } 431 /* function 0xb has additional index. */ 432 case 0xb: { 433 int i, level_type; 434 435 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 436 /* read more entries until level_type is zero */ 437 for (i = 1; ; ++i) { 438 if (*nent >= maxnent) 439 goto out; 440 441 level_type = entry[i - 1].ecx & 0xff00; 442 if (!level_type) 443 break; 444 do_cpuid_1_ent(&entry[i], function, i); 445 entry[i].flags |= 446 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 447 ++*nent; 448 } 449 break; 450 } 451 case 0xd: { 452 int idx, i; 453 u64 supported = kvm_supported_xcr0(); 454 455 entry->eax &= supported; 456 entry->edx &= supported >> 32; 457 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 458 for (idx = 1, i = 1; idx < 64; ++idx) { 459 u64 mask = ((u64)1 << idx); 460 if (*nent >= maxnent) 461 goto out; 462 463 do_cpuid_1_ent(&entry[i], function, idx); 464 if (entry[i].eax == 0 || !(supported & mask)) 465 continue; 466 entry[i].flags |= 467 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 468 ++*nent; 469 ++i; 470 } 471 break; 472 } 473 case KVM_CPUID_SIGNATURE: { 474 static const char signature[12] = "KVMKVMKVM\0\0"; 475 const u32 *sigptr = (const u32 *)signature; 476 entry->eax = KVM_CPUID_FEATURES; 477 entry->ebx = sigptr[0]; 478 entry->ecx = sigptr[1]; 479 entry->edx = sigptr[2]; 480 break; 481 } 482 case KVM_CPUID_FEATURES: 483 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 484 (1 << KVM_FEATURE_NOP_IO_DELAY) | 485 (1 << KVM_FEATURE_CLOCKSOURCE2) | 486 (1 << KVM_FEATURE_ASYNC_PF) | 487 (1 << KVM_FEATURE_PV_EOI) | 488 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 489 (1 << KVM_FEATURE_PV_UNHALT); 490 491 if (sched_info_on()) 492 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 493 494 entry->ebx = 0; 495 entry->ecx = 0; 496 entry->edx = 0; 497 break; 498 case 0x80000000: 499 entry->eax = min(entry->eax, 0x8000001a); 500 break; 501 case 0x80000001: 502 entry->edx &= kvm_supported_word1_x86_features; 503 cpuid_mask(&entry->edx, 1); 504 entry->ecx &= kvm_supported_word6_x86_features; 505 cpuid_mask(&entry->ecx, 6); 506 break; 507 case 0x80000007: /* Advanced power management */ 508 /* invariant TSC is CPUID.80000007H:EDX[8] */ 509 entry->edx &= (1 << 8); 510 /* mask against host */ 511 entry->edx &= boot_cpu_data.x86_power; 512 entry->eax = entry->ebx = entry->ecx = 0; 513 break; 514 case 0x80000008: { 515 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 516 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 517 unsigned phys_as = entry->eax & 0xff; 518 519 if (!g_phys_as) 520 g_phys_as = phys_as; 521 entry->eax = g_phys_as | (virt_as << 8); 522 entry->ebx = entry->edx = 0; 523 break; 524 } 525 case 0x80000019: 526 entry->ecx = entry->edx = 0; 527 break; 528 case 0x8000001a: 529 break; 530 case 0x8000001d: 531 break; 532 /*Add support for Centaur's CPUID instruction*/ 533 case 0xC0000000: 534 /*Just support up to 0xC0000004 now*/ 535 entry->eax = min(entry->eax, 0xC0000004); 536 break; 537 case 0xC0000001: 538 entry->edx &= kvm_supported_word5_x86_features; 539 cpuid_mask(&entry->edx, 5); 540 break; 541 case 3: /* Processor serial number */ 542 case 5: /* MONITOR/MWAIT */ 543 case 6: /* Thermal management */ 544 case 0xC0000002: 545 case 0xC0000003: 546 case 0xC0000004: 547 default: 548 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 549 break; 550 } 551 552 kvm_x86_ops->set_supported_cpuid(function, entry); 553 554 r = 0; 555 556 out: 557 put_cpu(); 558 559 return r; 560 } 561 562 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 563 u32 idx, int *nent, int maxnent, unsigned int type) 564 { 565 if (type == KVM_GET_EMULATED_CPUID) 566 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 567 568 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 569 } 570 571 #undef F 572 573 struct kvm_cpuid_param { 574 u32 func; 575 u32 idx; 576 bool has_leaf_count; 577 bool (*qualifier)(const struct kvm_cpuid_param *param); 578 }; 579 580 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 581 { 582 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 583 } 584 585 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 586 __u32 num_entries, unsigned int ioctl_type) 587 { 588 int i; 589 __u32 pad[3]; 590 591 if (ioctl_type != KVM_GET_EMULATED_CPUID) 592 return false; 593 594 /* 595 * We want to make sure that ->padding is being passed clean from 596 * userspace in case we want to use it for something in the future. 597 * 598 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 599 * have to give ourselves satisfied only with the emulated side. /me 600 * sheds a tear. 601 */ 602 for (i = 0; i < num_entries; i++) { 603 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 604 return true; 605 606 if (pad[0] || pad[1] || pad[2]) 607 return true; 608 } 609 return false; 610 } 611 612 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 613 struct kvm_cpuid_entry2 __user *entries, 614 unsigned int type) 615 { 616 struct kvm_cpuid_entry2 *cpuid_entries; 617 int limit, nent = 0, r = -E2BIG, i; 618 u32 func; 619 static const struct kvm_cpuid_param param[] = { 620 { .func = 0, .has_leaf_count = true }, 621 { .func = 0x80000000, .has_leaf_count = true }, 622 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 623 { .func = KVM_CPUID_SIGNATURE }, 624 { .func = KVM_CPUID_FEATURES }, 625 }; 626 627 if (cpuid->nent < 1) 628 goto out; 629 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 630 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 631 632 if (sanity_check_entries(entries, cpuid->nent, type)) 633 return -EINVAL; 634 635 r = -ENOMEM; 636 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 637 if (!cpuid_entries) 638 goto out; 639 640 r = 0; 641 for (i = 0; i < ARRAY_SIZE(param); i++) { 642 const struct kvm_cpuid_param *ent = ¶m[i]; 643 644 if (ent->qualifier && !ent->qualifier(ent)) 645 continue; 646 647 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 648 &nent, cpuid->nent, type); 649 650 if (r) 651 goto out_free; 652 653 if (!ent->has_leaf_count) 654 continue; 655 656 limit = cpuid_entries[nent - 1].eax; 657 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 658 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 659 &nent, cpuid->nent, type); 660 661 if (r) 662 goto out_free; 663 } 664 665 r = -EFAULT; 666 if (copy_to_user(entries, cpuid_entries, 667 nent * sizeof(struct kvm_cpuid_entry2))) 668 goto out_free; 669 cpuid->nent = nent; 670 r = 0; 671 672 out_free: 673 vfree(cpuid_entries); 674 out: 675 return r; 676 } 677 678 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 679 { 680 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 681 int j, nent = vcpu->arch.cpuid_nent; 682 683 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 684 /* when no next entry is found, the current entry[i] is reselected */ 685 for (j = i + 1; ; j = (j + 1) % nent) { 686 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 687 if (ej->function == e->function) { 688 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 689 return j; 690 } 691 } 692 return 0; /* silence gcc, even though control never reaches here */ 693 } 694 695 /* find an entry with matching function, matching index (if needed), and that 696 * should be read next (if it's stateful) */ 697 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 698 u32 function, u32 index) 699 { 700 if (e->function != function) 701 return 0; 702 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 703 return 0; 704 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 705 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 706 return 0; 707 return 1; 708 } 709 710 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 711 u32 function, u32 index) 712 { 713 int i; 714 struct kvm_cpuid_entry2 *best = NULL; 715 716 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 717 struct kvm_cpuid_entry2 *e; 718 719 e = &vcpu->arch.cpuid_entries[i]; 720 if (is_matching_cpuid_entry(e, function, index)) { 721 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 722 move_to_next_stateful_cpuid_entry(vcpu, i); 723 best = e; 724 break; 725 } 726 } 727 return best; 728 } 729 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 730 731 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu) 732 { 733 struct kvm_cpuid_entry2 *best; 734 735 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 736 if (!best || best->eax < 0x80000008) 737 goto not_found; 738 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 739 if (best) 740 return best->eax & 0xff; 741 not_found: 742 return 36; 743 } 744 EXPORT_SYMBOL_GPL(cpuid_maxphyaddr); 745 746 /* 747 * If no match is found, check whether we exceed the vCPU's limit 748 * and return the content of the highest valid _standard_ leaf instead. 749 * This is to satisfy the CPUID specification. 750 */ 751 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 752 u32 function, u32 index) 753 { 754 struct kvm_cpuid_entry2 *maxlevel; 755 756 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 757 if (!maxlevel || maxlevel->eax >= function) 758 return NULL; 759 if (function & 0x80000000) { 760 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 761 if (!maxlevel) 762 return NULL; 763 } 764 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 765 } 766 767 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 768 { 769 u32 function = *eax, index = *ecx; 770 struct kvm_cpuid_entry2 *best; 771 772 best = kvm_find_cpuid_entry(vcpu, function, index); 773 774 if (!best) 775 best = check_cpuid_limit(vcpu, function, index); 776 777 /* 778 * Perfmon not yet supported for L2 guest. 779 */ 780 if (is_guest_mode(vcpu) && function == 0xa) 781 best = NULL; 782 783 if (best) { 784 *eax = best->eax; 785 *ebx = best->ebx; 786 *ecx = best->ecx; 787 *edx = best->edx; 788 } else 789 *eax = *ebx = *ecx = *edx = 0; 790 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 791 } 792 EXPORT_SYMBOL_GPL(kvm_cpuid); 793 794 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 795 { 796 u32 function, eax, ebx, ecx, edx; 797 798 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 799 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 800 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 801 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 802 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 803 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 804 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 805 kvm_x86_ops->skip_emulated_instruction(vcpu); 806 } 807 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 808