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 &= 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 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 &= ~(XSTATE_BNDREGS | XSTATE_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); 101 102 /* 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_refresh(vcpu); 115 return 0; 116 } 117 118 static 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 } 125 126 static 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 } 144 145 int 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; 155 not_found: 156 return 36; 157 } 158 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 159 160 /* when an old userspace process fills a new kernel module */ 161 int 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); 196 197 out_free: 198 vfree(cpuid_entries); 199 out: 200 return r; 201 } 202 203 int 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); 220 out: 221 return r; 222 } 223 224 int 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; 238 239 out: 240 cpuid->nent = vcpu->arch.cpuid_nent; 241 return r; 242 } 243 244 static void cpuid_mask(u32 *word, int wordnum) 245 { 246 *word &= boot_cpu_data.x86_capability[wordnum]; 247 } 248 249 static 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 } 258 259 static 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 } 280 281 static 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 6: /* Thermal management */ 419 entry->eax = 0x4; /* allow ARAT */ 420 entry->ebx = 0; 421 entry->ecx = 0; 422 entry->edx = 0; 423 break; 424 case 7: { 425 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 426 /* Mask ebx against host capability word 9 */ 427 if (index == 0) { 428 entry->ebx &= kvm_supported_word9_x86_features; 429 cpuid_mask(&entry->ebx, 9); 430 // TSC_ADJUST is emulated 431 entry->ebx |= F(TSC_ADJUST); 432 } else 433 entry->ebx = 0; 434 entry->eax = 0; 435 entry->ecx = 0; 436 entry->edx = 0; 437 break; 438 } 439 case 9: 440 break; 441 case 0xa: { /* Architectural Performance Monitoring */ 442 struct x86_pmu_capability cap; 443 union cpuid10_eax eax; 444 union cpuid10_edx edx; 445 446 perf_get_x86_pmu_capability(&cap); 447 448 /* 449 * Only support guest architectural pmu on a host 450 * with architectural pmu. 451 */ 452 if (!cap.version) 453 memset(&cap, 0, sizeof(cap)); 454 455 eax.split.version_id = min(cap.version, 2); 456 eax.split.num_counters = cap.num_counters_gp; 457 eax.split.bit_width = cap.bit_width_gp; 458 eax.split.mask_length = cap.events_mask_len; 459 460 edx.split.num_counters_fixed = cap.num_counters_fixed; 461 edx.split.bit_width_fixed = cap.bit_width_fixed; 462 edx.split.reserved = 0; 463 464 entry->eax = eax.full; 465 entry->ebx = cap.events_mask; 466 entry->ecx = 0; 467 entry->edx = edx.full; 468 break; 469 } 470 /* function 0xb has additional index. */ 471 case 0xb: { 472 int i, level_type; 473 474 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 475 /* read more entries until level_type is zero */ 476 for (i = 1; ; ++i) { 477 if (*nent >= maxnent) 478 goto out; 479 480 level_type = entry[i - 1].ecx & 0xff00; 481 if (!level_type) 482 break; 483 do_cpuid_1_ent(&entry[i], function, i); 484 entry[i].flags |= 485 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 486 ++*nent; 487 } 488 break; 489 } 490 case 0xd: { 491 int idx, i; 492 u64 supported = kvm_supported_xcr0(); 493 494 entry->eax &= supported; 495 entry->ebx = xstate_required_size(supported, false); 496 entry->ecx = entry->ebx; 497 entry->edx &= supported >> 32; 498 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 499 if (!supported) 500 break; 501 502 for (idx = 1, i = 1; idx < 64; ++idx) { 503 u64 mask = ((u64)1 << idx); 504 if (*nent >= maxnent) 505 goto out; 506 507 do_cpuid_1_ent(&entry[i], function, idx); 508 if (idx == 1) { 509 entry[i].eax &= kvm_supported_word10_x86_features; 510 entry[i].ebx = 0; 511 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 512 entry[i].ebx = 513 xstate_required_size(supported, 514 true); 515 } else { 516 if (entry[i].eax == 0 || !(supported & mask)) 517 continue; 518 if (WARN_ON_ONCE(entry[i].ecx & 1)) 519 continue; 520 } 521 entry[i].ecx = 0; 522 entry[i].edx = 0; 523 entry[i].flags |= 524 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 525 ++*nent; 526 ++i; 527 } 528 break; 529 } 530 case KVM_CPUID_SIGNATURE: { 531 static const char signature[12] = "KVMKVMKVM\0\0"; 532 const u32 *sigptr = (const u32 *)signature; 533 entry->eax = KVM_CPUID_FEATURES; 534 entry->ebx = sigptr[0]; 535 entry->ecx = sigptr[1]; 536 entry->edx = sigptr[2]; 537 break; 538 } 539 case KVM_CPUID_FEATURES: 540 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 541 (1 << KVM_FEATURE_NOP_IO_DELAY) | 542 (1 << KVM_FEATURE_CLOCKSOURCE2) | 543 (1 << KVM_FEATURE_ASYNC_PF) | 544 (1 << KVM_FEATURE_PV_EOI) | 545 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 546 (1 << KVM_FEATURE_PV_UNHALT); 547 548 if (sched_info_on()) 549 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 550 551 entry->ebx = 0; 552 entry->ecx = 0; 553 entry->edx = 0; 554 break; 555 case 0x80000000: 556 entry->eax = min(entry->eax, 0x8000001a); 557 break; 558 case 0x80000001: 559 entry->edx &= kvm_supported_word1_x86_features; 560 cpuid_mask(&entry->edx, 1); 561 entry->ecx &= kvm_supported_word6_x86_features; 562 cpuid_mask(&entry->ecx, 6); 563 break; 564 case 0x80000007: /* Advanced power management */ 565 /* invariant TSC is CPUID.80000007H:EDX[8] */ 566 entry->edx &= (1 << 8); 567 /* mask against host */ 568 entry->edx &= boot_cpu_data.x86_power; 569 entry->eax = entry->ebx = entry->ecx = 0; 570 break; 571 case 0x80000008: { 572 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 573 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 574 unsigned phys_as = entry->eax & 0xff; 575 576 if (!g_phys_as) 577 g_phys_as = phys_as; 578 entry->eax = g_phys_as | (virt_as << 8); 579 entry->ebx = entry->edx = 0; 580 break; 581 } 582 case 0x80000019: 583 entry->ecx = entry->edx = 0; 584 break; 585 case 0x8000001a: 586 break; 587 case 0x8000001d: 588 break; 589 /*Add support for Centaur's CPUID instruction*/ 590 case 0xC0000000: 591 /*Just support up to 0xC0000004 now*/ 592 entry->eax = min(entry->eax, 0xC0000004); 593 break; 594 case 0xC0000001: 595 entry->edx &= kvm_supported_word5_x86_features; 596 cpuid_mask(&entry->edx, 5); 597 break; 598 case 3: /* Processor serial number */ 599 case 5: /* MONITOR/MWAIT */ 600 case 0xC0000002: 601 case 0xC0000003: 602 case 0xC0000004: 603 default: 604 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 605 break; 606 } 607 608 kvm_x86_ops->set_supported_cpuid(function, entry); 609 610 r = 0; 611 612 out: 613 put_cpu(); 614 615 return r; 616 } 617 618 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 619 u32 idx, int *nent, int maxnent, unsigned int type) 620 { 621 if (type == KVM_GET_EMULATED_CPUID) 622 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 623 624 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 625 } 626 627 #undef F 628 629 struct kvm_cpuid_param { 630 u32 func; 631 u32 idx; 632 bool has_leaf_count; 633 bool (*qualifier)(const struct kvm_cpuid_param *param); 634 }; 635 636 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 637 { 638 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 639 } 640 641 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 642 __u32 num_entries, unsigned int ioctl_type) 643 { 644 int i; 645 __u32 pad[3]; 646 647 if (ioctl_type != KVM_GET_EMULATED_CPUID) 648 return false; 649 650 /* 651 * We want to make sure that ->padding is being passed clean from 652 * userspace in case we want to use it for something in the future. 653 * 654 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 655 * have to give ourselves satisfied only with the emulated side. /me 656 * sheds a tear. 657 */ 658 for (i = 0; i < num_entries; i++) { 659 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 660 return true; 661 662 if (pad[0] || pad[1] || pad[2]) 663 return true; 664 } 665 return false; 666 } 667 668 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 669 struct kvm_cpuid_entry2 __user *entries, 670 unsigned int type) 671 { 672 struct kvm_cpuid_entry2 *cpuid_entries; 673 int limit, nent = 0, r = -E2BIG, i; 674 u32 func; 675 static const struct kvm_cpuid_param param[] = { 676 { .func = 0, .has_leaf_count = true }, 677 { .func = 0x80000000, .has_leaf_count = true }, 678 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 679 { .func = KVM_CPUID_SIGNATURE }, 680 { .func = KVM_CPUID_FEATURES }, 681 }; 682 683 if (cpuid->nent < 1) 684 goto out; 685 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 686 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 687 688 if (sanity_check_entries(entries, cpuid->nent, type)) 689 return -EINVAL; 690 691 r = -ENOMEM; 692 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 693 if (!cpuid_entries) 694 goto out; 695 696 r = 0; 697 for (i = 0; i < ARRAY_SIZE(param); i++) { 698 const struct kvm_cpuid_param *ent = ¶m[i]; 699 700 if (ent->qualifier && !ent->qualifier(ent)) 701 continue; 702 703 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 704 &nent, cpuid->nent, type); 705 706 if (r) 707 goto out_free; 708 709 if (!ent->has_leaf_count) 710 continue; 711 712 limit = cpuid_entries[nent - 1].eax; 713 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 714 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 715 &nent, cpuid->nent, type); 716 717 if (r) 718 goto out_free; 719 } 720 721 r = -EFAULT; 722 if (copy_to_user(entries, cpuid_entries, 723 nent * sizeof(struct kvm_cpuid_entry2))) 724 goto out_free; 725 cpuid->nent = nent; 726 r = 0; 727 728 out_free: 729 vfree(cpuid_entries); 730 out: 731 return r; 732 } 733 734 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 735 { 736 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 737 int j, nent = vcpu->arch.cpuid_nent; 738 739 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 740 /* when no next entry is found, the current entry[i] is reselected */ 741 for (j = i + 1; ; j = (j + 1) % nent) { 742 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 743 if (ej->function == e->function) { 744 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 745 return j; 746 } 747 } 748 return 0; /* silence gcc, even though control never reaches here */ 749 } 750 751 /* find an entry with matching function, matching index (if needed), and that 752 * should be read next (if it's stateful) */ 753 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 754 u32 function, u32 index) 755 { 756 if (e->function != function) 757 return 0; 758 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 759 return 0; 760 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 761 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 762 return 0; 763 return 1; 764 } 765 766 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 767 u32 function, u32 index) 768 { 769 int i; 770 struct kvm_cpuid_entry2 *best = NULL; 771 772 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 773 struct kvm_cpuid_entry2 *e; 774 775 e = &vcpu->arch.cpuid_entries[i]; 776 if (is_matching_cpuid_entry(e, function, index)) { 777 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 778 move_to_next_stateful_cpuid_entry(vcpu, i); 779 best = e; 780 break; 781 } 782 } 783 return best; 784 } 785 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 786 787 /* 788 * If no match is found, check whether we exceed the vCPU's limit 789 * and return the content of the highest valid _standard_ leaf instead. 790 * This is to satisfy the CPUID specification. 791 */ 792 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 793 u32 function, u32 index) 794 { 795 struct kvm_cpuid_entry2 *maxlevel; 796 797 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 798 if (!maxlevel || maxlevel->eax >= function) 799 return NULL; 800 if (function & 0x80000000) { 801 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 802 if (!maxlevel) 803 return NULL; 804 } 805 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 806 } 807 808 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 809 { 810 u32 function = *eax, index = *ecx; 811 struct kvm_cpuid_entry2 *best; 812 813 best = kvm_find_cpuid_entry(vcpu, function, index); 814 815 if (!best) 816 best = check_cpuid_limit(vcpu, function, index); 817 818 /* 819 * Perfmon not yet supported for L2 guest. 820 */ 821 if (is_guest_mode(vcpu) && function == 0xa) 822 best = NULL; 823 824 if (best) { 825 *eax = best->eax; 826 *ebx = best->ebx; 827 *ecx = best->ecx; 828 *edx = best->edx; 829 } else 830 *eax = *ebx = *ecx = *edx = 0; 831 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 832 } 833 EXPORT_SYMBOL_GPL(kvm_cpuid); 834 835 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 836 { 837 u32 function, eax, ebx, ecx, edx; 838 839 function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 840 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 841 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 842 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 843 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 844 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 845 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 846 kvm_x86_ops->skip_emulated_instruction(vcpu); 847 } 848 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 849