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/export.h> 17 #include <linux/vmalloc.h> 18 #include <linux/uaccess.h> 19 #include <linux/sched/stat.h> 20 21 #include <asm/processor.h> 22 #include <asm/user.h> 23 #include <asm/fpu/xstate.h> 24 #include "cpuid.h" 25 #include "lapic.h" 26 #include "mmu.h" 27 #include "trace.h" 28 #include "pmu.h" 29 30 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 31 { 32 int feature_bit = 0; 33 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 34 35 xstate_bv &= XFEATURE_MASK_EXTEND; 36 while (xstate_bv) { 37 if (xstate_bv & 0x1) { 38 u32 eax, ebx, ecx, edx, offset; 39 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 40 offset = compacted ? ret : ebx; 41 ret = max(ret, offset + eax); 42 } 43 44 xstate_bv >>= 1; 45 feature_bit++; 46 } 47 48 return ret; 49 } 50 51 bool kvm_mpx_supported(void) 52 { 53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) 54 && kvm_x86_ops->mpx_supported()); 55 } 56 EXPORT_SYMBOL_GPL(kvm_mpx_supported); 57 58 u64 kvm_supported_xcr0(void) 59 { 60 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 61 62 if (!kvm_mpx_supported()) 63 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); 64 65 return xcr0; 66 } 67 68 #define F(x) bit(X86_FEATURE_##x) 69 70 /* These are scattered features in cpufeatures.h. */ 71 #define KVM_CPUID_BIT_AVX512_4VNNIW 2 72 #define KVM_CPUID_BIT_AVX512_4FMAPS 3 73 #define KF(x) bit(KVM_CPUID_BIT_##x) 74 75 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 76 { 77 struct kvm_cpuid_entry2 *best; 78 struct kvm_lapic *apic = vcpu->arch.apic; 79 80 best = kvm_find_cpuid_entry(vcpu, 1, 0); 81 if (!best) 82 return 0; 83 84 /* Update OSXSAVE bit */ 85 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) { 86 best->ecx &= ~F(OSXSAVE); 87 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 88 best->ecx |= F(OSXSAVE); 89 } 90 91 best->edx &= ~F(APIC); 92 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE) 93 best->edx |= F(APIC); 94 95 if (apic) { 96 if (best->ecx & F(TSC_DEADLINE_TIMER)) 97 apic->lapic_timer.timer_mode_mask = 3 << 17; 98 else 99 apic->lapic_timer.timer_mode_mask = 1 << 17; 100 } 101 102 best = kvm_find_cpuid_entry(vcpu, 7, 0); 103 if (best) { 104 /* Update OSPKE bit */ 105 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) { 106 best->ecx &= ~F(OSPKE); 107 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) 108 best->ecx |= F(OSPKE); 109 } 110 } 111 112 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 113 if (!best) { 114 vcpu->arch.guest_supported_xcr0 = 0; 115 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 116 } else { 117 vcpu->arch.guest_supported_xcr0 = 118 (best->eax | ((u64)best->edx << 32)) & 119 kvm_supported_xcr0(); 120 vcpu->arch.guest_xstate_size = best->ebx = 121 xstate_required_size(vcpu->arch.xcr0, false); 122 } 123 124 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 125 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 126 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 127 128 /* 129 * The existing code assumes virtual address is 48-bit in the canonical 130 * address checks; exit if it is ever changed. 131 */ 132 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 133 if (best && ((best->eax & 0xff00) >> 8) != 48 && 134 ((best->eax & 0xff00) >> 8) != 0) 135 return -EINVAL; 136 137 /* Update physical-address width */ 138 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 139 140 kvm_pmu_refresh(vcpu); 141 return 0; 142 } 143 144 static int is_efer_nx(void) 145 { 146 unsigned long long efer = 0; 147 148 rdmsrl_safe(MSR_EFER, &efer); 149 return efer & EFER_NX; 150 } 151 152 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 153 { 154 int i; 155 struct kvm_cpuid_entry2 *e, *entry; 156 157 entry = NULL; 158 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 159 e = &vcpu->arch.cpuid_entries[i]; 160 if (e->function == 0x80000001) { 161 entry = e; 162 break; 163 } 164 } 165 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 166 entry->edx &= ~F(NX); 167 printk(KERN_INFO "kvm: guest NX capability removed\n"); 168 } 169 } 170 171 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 172 { 173 struct kvm_cpuid_entry2 *best; 174 175 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 176 if (!best || best->eax < 0x80000008) 177 goto not_found; 178 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 179 if (best) 180 return best->eax & 0xff; 181 not_found: 182 return 36; 183 } 184 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 185 186 /* when an old userspace process fills a new kernel module */ 187 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 188 struct kvm_cpuid *cpuid, 189 struct kvm_cpuid_entry __user *entries) 190 { 191 int r, i; 192 struct kvm_cpuid_entry *cpuid_entries = NULL; 193 194 r = -E2BIG; 195 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 196 goto out; 197 r = -ENOMEM; 198 if (cpuid->nent) { 199 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * 200 cpuid->nent); 201 if (!cpuid_entries) 202 goto out; 203 r = -EFAULT; 204 if (copy_from_user(cpuid_entries, entries, 205 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 206 goto out; 207 } 208 for (i = 0; i < cpuid->nent; i++) { 209 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 210 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 211 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 212 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 213 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 214 vcpu->arch.cpuid_entries[i].index = 0; 215 vcpu->arch.cpuid_entries[i].flags = 0; 216 vcpu->arch.cpuid_entries[i].padding[0] = 0; 217 vcpu->arch.cpuid_entries[i].padding[1] = 0; 218 vcpu->arch.cpuid_entries[i].padding[2] = 0; 219 } 220 vcpu->arch.cpuid_nent = cpuid->nent; 221 cpuid_fix_nx_cap(vcpu); 222 kvm_apic_set_version(vcpu); 223 kvm_x86_ops->cpuid_update(vcpu); 224 r = kvm_update_cpuid(vcpu); 225 226 out: 227 vfree(cpuid_entries); 228 return r; 229 } 230 231 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 232 struct kvm_cpuid2 *cpuid, 233 struct kvm_cpuid_entry2 __user *entries) 234 { 235 int r; 236 237 r = -E2BIG; 238 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 239 goto out; 240 r = -EFAULT; 241 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 242 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 243 goto out; 244 vcpu->arch.cpuid_nent = cpuid->nent; 245 kvm_apic_set_version(vcpu); 246 kvm_x86_ops->cpuid_update(vcpu); 247 r = kvm_update_cpuid(vcpu); 248 out: 249 return r; 250 } 251 252 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 253 struct kvm_cpuid2 *cpuid, 254 struct kvm_cpuid_entry2 __user *entries) 255 { 256 int r; 257 258 r = -E2BIG; 259 if (cpuid->nent < vcpu->arch.cpuid_nent) 260 goto out; 261 r = -EFAULT; 262 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 263 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 264 goto out; 265 return 0; 266 267 out: 268 cpuid->nent = vcpu->arch.cpuid_nent; 269 return r; 270 } 271 272 static void cpuid_mask(u32 *word, int wordnum) 273 { 274 *word &= boot_cpu_data.x86_capability[wordnum]; 275 } 276 277 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 278 u32 index) 279 { 280 entry->function = function; 281 entry->index = index; 282 cpuid_count(entry->function, entry->index, 283 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 284 entry->flags = 0; 285 } 286 287 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 288 u32 func, u32 index, int *nent, int maxnent) 289 { 290 switch (func) { 291 case 0: 292 entry->eax = 1; /* only one leaf currently */ 293 ++*nent; 294 break; 295 case 1: 296 entry->ecx = F(MOVBE); 297 ++*nent; 298 break; 299 default: 300 break; 301 } 302 303 entry->function = func; 304 entry->index = index; 305 306 return 0; 307 } 308 309 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 310 u32 index, int *nent, int maxnent) 311 { 312 int r; 313 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 314 #ifdef CONFIG_X86_64 315 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 316 ? F(GBPAGES) : 0; 317 unsigned f_lm = F(LM); 318 #else 319 unsigned f_gbpages = 0; 320 unsigned f_lm = 0; 321 #endif 322 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 323 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 324 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 325 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 326 327 /* cpuid 1.edx */ 328 const u32 kvm_cpuid_1_edx_x86_features = 329 F(FPU) | F(VME) | F(DE) | F(PSE) | 330 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 331 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 332 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 333 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 334 0 /* Reserved, DS, ACPI */ | F(MMX) | 335 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 336 0 /* HTT, TM, Reserved, PBE */; 337 /* cpuid 0x80000001.edx */ 338 const u32 kvm_cpuid_8000_0001_edx_x86_features = 339 F(FPU) | F(VME) | F(DE) | F(PSE) | 340 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 341 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 342 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 343 F(PAT) | F(PSE36) | 0 /* Reserved */ | 344 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 345 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 346 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 347 /* cpuid 1.ecx */ 348 const u32 kvm_cpuid_1_ecx_x86_features = 349 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 350 * but *not* advertised to guests via CPUID ! */ 351 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 352 0 /* DS-CPL, VMX, SMX, EST */ | 353 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 354 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 355 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 356 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 357 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 358 F(F16C) | F(RDRAND); 359 /* cpuid 0x80000001.ecx */ 360 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 361 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 362 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 363 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 364 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 365 366 /* cpuid 0xC0000001.edx */ 367 const u32 kvm_cpuid_C000_0001_edx_x86_features = 368 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 369 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 370 F(PMM) | F(PMM_EN); 371 372 /* cpuid 7.0.ebx */ 373 const u32 kvm_cpuid_7_0_ebx_x86_features = 374 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 375 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 376 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 377 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 378 F(SHA_NI) | F(AVX512BW) | F(AVX512VL); 379 380 /* cpuid 0xD.1.eax */ 381 const u32 kvm_cpuid_D_1_eax_x86_features = 382 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 383 384 /* cpuid 7.0.ecx*/ 385 const u32 kvm_cpuid_7_0_ecx_x86_features = 386 F(AVX512VBMI) | F(PKU) | 0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ); 387 388 /* cpuid 7.0.edx*/ 389 const u32 kvm_cpuid_7_0_edx_x86_features = 390 KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS); 391 392 /* all calls to cpuid_count() should be made on the same cpu */ 393 get_cpu(); 394 395 r = -E2BIG; 396 397 if (*nent >= maxnent) 398 goto out; 399 400 do_cpuid_1_ent(entry, function, index); 401 ++*nent; 402 403 switch (function) { 404 case 0: 405 entry->eax = min(entry->eax, (u32)0xd); 406 break; 407 case 1: 408 entry->edx &= kvm_cpuid_1_edx_x86_features; 409 cpuid_mask(&entry->edx, CPUID_1_EDX); 410 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 411 cpuid_mask(&entry->ecx, CPUID_1_ECX); 412 /* we support x2apic emulation even if host does not support 413 * it since we emulate x2apic in software */ 414 entry->ecx |= F(X2APIC); 415 break; 416 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 417 * may return different values. This forces us to get_cpu() before 418 * issuing the first command, and also to emulate this annoying behavior 419 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 420 case 2: { 421 int t, times = entry->eax & 0xff; 422 423 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 424 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 425 for (t = 1; t < times; ++t) { 426 if (*nent >= maxnent) 427 goto out; 428 429 do_cpuid_1_ent(&entry[t], function, 0); 430 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 431 ++*nent; 432 } 433 break; 434 } 435 /* function 4 has additional index. */ 436 case 4: { 437 int i, cache_type; 438 439 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 440 /* read more entries until cache_type is zero */ 441 for (i = 1; ; ++i) { 442 if (*nent >= maxnent) 443 goto out; 444 445 cache_type = entry[i - 1].eax & 0x1f; 446 if (!cache_type) 447 break; 448 do_cpuid_1_ent(&entry[i], function, i); 449 entry[i].flags |= 450 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 451 ++*nent; 452 } 453 break; 454 } 455 case 6: /* Thermal management */ 456 entry->eax = 0x4; /* allow ARAT */ 457 entry->ebx = 0; 458 entry->ecx = 0; 459 entry->edx = 0; 460 break; 461 case 7: { 462 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 463 /* Mask ebx against host capability word 9 */ 464 if (index == 0) { 465 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 466 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 467 // TSC_ADJUST is emulated 468 entry->ebx |= F(TSC_ADJUST); 469 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 470 cpuid_mask(&entry->ecx, CPUID_7_ECX); 471 /* PKU is not yet implemented for shadow paging. */ 472 if (!tdp_enabled) 473 entry->ecx &= ~F(PKU); 474 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 475 entry->edx &= get_scattered_cpuid_leaf(7, 0, CPUID_EDX); 476 } else { 477 entry->ebx = 0; 478 entry->ecx = 0; 479 entry->edx = 0; 480 } 481 entry->eax = 0; 482 break; 483 } 484 case 9: 485 break; 486 case 0xa: { /* Architectural Performance Monitoring */ 487 struct x86_pmu_capability cap; 488 union cpuid10_eax eax; 489 union cpuid10_edx edx; 490 491 perf_get_x86_pmu_capability(&cap); 492 493 /* 494 * Only support guest architectural pmu on a host 495 * with architectural pmu. 496 */ 497 if (!cap.version) 498 memset(&cap, 0, sizeof(cap)); 499 500 eax.split.version_id = min(cap.version, 2); 501 eax.split.num_counters = cap.num_counters_gp; 502 eax.split.bit_width = cap.bit_width_gp; 503 eax.split.mask_length = cap.events_mask_len; 504 505 edx.split.num_counters_fixed = cap.num_counters_fixed; 506 edx.split.bit_width_fixed = cap.bit_width_fixed; 507 edx.split.reserved = 0; 508 509 entry->eax = eax.full; 510 entry->ebx = cap.events_mask; 511 entry->ecx = 0; 512 entry->edx = edx.full; 513 break; 514 } 515 /* function 0xb has additional index. */ 516 case 0xb: { 517 int i, level_type; 518 519 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 520 /* read more entries until level_type is zero */ 521 for (i = 1; ; ++i) { 522 if (*nent >= maxnent) 523 goto out; 524 525 level_type = entry[i - 1].ecx & 0xff00; 526 if (!level_type) 527 break; 528 do_cpuid_1_ent(&entry[i], function, i); 529 entry[i].flags |= 530 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 531 ++*nent; 532 } 533 break; 534 } 535 case 0xd: { 536 int idx, i; 537 u64 supported = kvm_supported_xcr0(); 538 539 entry->eax &= supported; 540 entry->ebx = xstate_required_size(supported, false); 541 entry->ecx = entry->ebx; 542 entry->edx &= supported >> 32; 543 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 544 if (!supported) 545 break; 546 547 for (idx = 1, i = 1; idx < 64; ++idx) { 548 u64 mask = ((u64)1 << idx); 549 if (*nent >= maxnent) 550 goto out; 551 552 do_cpuid_1_ent(&entry[i], function, idx); 553 if (idx == 1) { 554 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 555 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 556 entry[i].ebx = 0; 557 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 558 entry[i].ebx = 559 xstate_required_size(supported, 560 true); 561 } else { 562 if (entry[i].eax == 0 || !(supported & mask)) 563 continue; 564 if (WARN_ON_ONCE(entry[i].ecx & 1)) 565 continue; 566 } 567 entry[i].ecx = 0; 568 entry[i].edx = 0; 569 entry[i].flags |= 570 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 571 ++*nent; 572 ++i; 573 } 574 break; 575 } 576 case KVM_CPUID_SIGNATURE: { 577 static const char signature[12] = "KVMKVMKVM\0\0"; 578 const u32 *sigptr = (const u32 *)signature; 579 entry->eax = KVM_CPUID_FEATURES; 580 entry->ebx = sigptr[0]; 581 entry->ecx = sigptr[1]; 582 entry->edx = sigptr[2]; 583 break; 584 } 585 case KVM_CPUID_FEATURES: 586 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 587 (1 << KVM_FEATURE_NOP_IO_DELAY) | 588 (1 << KVM_FEATURE_CLOCKSOURCE2) | 589 (1 << KVM_FEATURE_ASYNC_PF) | 590 (1 << KVM_FEATURE_PV_EOI) | 591 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 592 (1 << KVM_FEATURE_PV_UNHALT); 593 594 if (sched_info_on()) 595 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 596 597 entry->ebx = 0; 598 entry->ecx = 0; 599 entry->edx = 0; 600 break; 601 case 0x80000000: 602 entry->eax = min(entry->eax, 0x8000001a); 603 break; 604 case 0x80000001: 605 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 606 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 607 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 608 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 609 break; 610 case 0x80000007: /* Advanced power management */ 611 /* invariant TSC is CPUID.80000007H:EDX[8] */ 612 entry->edx &= (1 << 8); 613 /* mask against host */ 614 entry->edx &= boot_cpu_data.x86_power; 615 entry->eax = entry->ebx = entry->ecx = 0; 616 break; 617 case 0x80000008: { 618 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 619 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 620 unsigned phys_as = entry->eax & 0xff; 621 622 if (!g_phys_as) 623 g_phys_as = phys_as; 624 entry->eax = g_phys_as | (virt_as << 8); 625 entry->ebx = entry->edx = 0; 626 break; 627 } 628 case 0x80000019: 629 entry->ecx = entry->edx = 0; 630 break; 631 case 0x8000001a: 632 break; 633 case 0x8000001d: 634 break; 635 /*Add support for Centaur's CPUID instruction*/ 636 case 0xC0000000: 637 /*Just support up to 0xC0000004 now*/ 638 entry->eax = min(entry->eax, 0xC0000004); 639 break; 640 case 0xC0000001: 641 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 642 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 643 break; 644 case 3: /* Processor serial number */ 645 case 5: /* MONITOR/MWAIT */ 646 case 0xC0000002: 647 case 0xC0000003: 648 case 0xC0000004: 649 default: 650 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 651 break; 652 } 653 654 kvm_x86_ops->set_supported_cpuid(function, entry); 655 656 r = 0; 657 658 out: 659 put_cpu(); 660 661 return r; 662 } 663 664 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 665 u32 idx, int *nent, int maxnent, unsigned int type) 666 { 667 if (type == KVM_GET_EMULATED_CPUID) 668 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 669 670 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 671 } 672 673 #undef F 674 675 struct kvm_cpuid_param { 676 u32 func; 677 u32 idx; 678 bool has_leaf_count; 679 bool (*qualifier)(const struct kvm_cpuid_param *param); 680 }; 681 682 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 683 { 684 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 685 } 686 687 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 688 __u32 num_entries, unsigned int ioctl_type) 689 { 690 int i; 691 __u32 pad[3]; 692 693 if (ioctl_type != KVM_GET_EMULATED_CPUID) 694 return false; 695 696 /* 697 * We want to make sure that ->padding is being passed clean from 698 * userspace in case we want to use it for something in the future. 699 * 700 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 701 * have to give ourselves satisfied only with the emulated side. /me 702 * sheds a tear. 703 */ 704 for (i = 0; i < num_entries; i++) { 705 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 706 return true; 707 708 if (pad[0] || pad[1] || pad[2]) 709 return true; 710 } 711 return false; 712 } 713 714 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 715 struct kvm_cpuid_entry2 __user *entries, 716 unsigned int type) 717 { 718 struct kvm_cpuid_entry2 *cpuid_entries; 719 int limit, nent = 0, r = -E2BIG, i; 720 u32 func; 721 static const struct kvm_cpuid_param param[] = { 722 { .func = 0, .has_leaf_count = true }, 723 { .func = 0x80000000, .has_leaf_count = true }, 724 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 725 { .func = KVM_CPUID_SIGNATURE }, 726 { .func = KVM_CPUID_FEATURES }, 727 }; 728 729 if (cpuid->nent < 1) 730 goto out; 731 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 732 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 733 734 if (sanity_check_entries(entries, cpuid->nent, type)) 735 return -EINVAL; 736 737 r = -ENOMEM; 738 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 739 if (!cpuid_entries) 740 goto out; 741 742 r = 0; 743 for (i = 0; i < ARRAY_SIZE(param); i++) { 744 const struct kvm_cpuid_param *ent = ¶m[i]; 745 746 if (ent->qualifier && !ent->qualifier(ent)) 747 continue; 748 749 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 750 &nent, cpuid->nent, type); 751 752 if (r) 753 goto out_free; 754 755 if (!ent->has_leaf_count) 756 continue; 757 758 limit = cpuid_entries[nent - 1].eax; 759 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 760 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 761 &nent, cpuid->nent, type); 762 763 if (r) 764 goto out_free; 765 } 766 767 r = -EFAULT; 768 if (copy_to_user(entries, cpuid_entries, 769 nent * sizeof(struct kvm_cpuid_entry2))) 770 goto out_free; 771 cpuid->nent = nent; 772 r = 0; 773 774 out_free: 775 vfree(cpuid_entries); 776 out: 777 return r; 778 } 779 780 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 781 { 782 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 783 int j, nent = vcpu->arch.cpuid_nent; 784 785 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 786 /* when no next entry is found, the current entry[i] is reselected */ 787 for (j = i + 1; ; j = (j + 1) % nent) { 788 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j]; 789 if (ej->function == e->function) { 790 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 791 return j; 792 } 793 } 794 return 0; /* silence gcc, even though control never reaches here */ 795 } 796 797 /* find an entry with matching function, matching index (if needed), and that 798 * should be read next (if it's stateful) */ 799 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 800 u32 function, u32 index) 801 { 802 if (e->function != function) 803 return 0; 804 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 805 return 0; 806 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 807 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 808 return 0; 809 return 1; 810 } 811 812 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 813 u32 function, u32 index) 814 { 815 int i; 816 struct kvm_cpuid_entry2 *best = NULL; 817 818 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 819 struct kvm_cpuid_entry2 *e; 820 821 e = &vcpu->arch.cpuid_entries[i]; 822 if (is_matching_cpuid_entry(e, function, index)) { 823 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 824 move_to_next_stateful_cpuid_entry(vcpu, i); 825 best = e; 826 break; 827 } 828 } 829 return best; 830 } 831 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 832 833 /* 834 * If no match is found, check whether we exceed the vCPU's limit 835 * and return the content of the highest valid _standard_ leaf instead. 836 * This is to satisfy the CPUID specification. 837 */ 838 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 839 u32 function, u32 index) 840 { 841 struct kvm_cpuid_entry2 *maxlevel; 842 843 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 844 if (!maxlevel || maxlevel->eax >= function) 845 return NULL; 846 if (function & 0x80000000) { 847 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 848 if (!maxlevel) 849 return NULL; 850 } 851 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 852 } 853 854 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx) 855 { 856 u32 function = *eax, index = *ecx; 857 struct kvm_cpuid_entry2 *best; 858 859 best = kvm_find_cpuid_entry(vcpu, function, index); 860 861 if (!best) 862 best = check_cpuid_limit(vcpu, function, index); 863 864 if (best) { 865 *eax = best->eax; 866 *ebx = best->ebx; 867 *ecx = best->ecx; 868 *edx = best->edx; 869 } else 870 *eax = *ebx = *ecx = *edx = 0; 871 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx); 872 } 873 EXPORT_SYMBOL_GPL(kvm_cpuid); 874 875 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 876 { 877 u32 eax, ebx, ecx, edx; 878 879 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 880 return 1; 881 882 eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 883 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 884 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx); 885 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 886 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 887 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 888 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 889 return kvm_skip_emulated_instruction(vcpu); 890 } 891 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 892