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 or 57-bit in the 130 * canonical address checks; exit if it is ever changed. 131 */ 132 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 133 if (best) { 134 int vaddr_bits = (best->eax & 0xff00) >> 8; 135 136 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) 137 return -EINVAL; 138 } 139 140 /* Update physical-address width */ 141 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 142 kvm_mmu_reset_context(vcpu); 143 144 kvm_pmu_refresh(vcpu); 145 return 0; 146 } 147 148 static int is_efer_nx(void) 149 { 150 unsigned long long efer = 0; 151 152 rdmsrl_safe(MSR_EFER, &efer); 153 return efer & EFER_NX; 154 } 155 156 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 157 { 158 int i; 159 struct kvm_cpuid_entry2 *e, *entry; 160 161 entry = NULL; 162 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 163 e = &vcpu->arch.cpuid_entries[i]; 164 if (e->function == 0x80000001) { 165 entry = e; 166 break; 167 } 168 } 169 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 170 entry->edx &= ~F(NX); 171 printk(KERN_INFO "kvm: guest NX capability removed\n"); 172 } 173 } 174 175 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 176 { 177 struct kvm_cpuid_entry2 *best; 178 179 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 180 if (!best || best->eax < 0x80000008) 181 goto not_found; 182 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 183 if (best) 184 return best->eax & 0xff; 185 not_found: 186 return 36; 187 } 188 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 189 190 /* when an old userspace process fills a new kernel module */ 191 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 192 struct kvm_cpuid *cpuid, 193 struct kvm_cpuid_entry __user *entries) 194 { 195 int r, i; 196 struct kvm_cpuid_entry *cpuid_entries = NULL; 197 198 r = -E2BIG; 199 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 200 goto out; 201 r = -ENOMEM; 202 if (cpuid->nent) { 203 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * 204 cpuid->nent); 205 if (!cpuid_entries) 206 goto out; 207 r = -EFAULT; 208 if (copy_from_user(cpuid_entries, entries, 209 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 210 goto out; 211 } 212 for (i = 0; i < cpuid->nent; i++) { 213 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 214 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 215 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 216 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 217 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 218 vcpu->arch.cpuid_entries[i].index = 0; 219 vcpu->arch.cpuid_entries[i].flags = 0; 220 vcpu->arch.cpuid_entries[i].padding[0] = 0; 221 vcpu->arch.cpuid_entries[i].padding[1] = 0; 222 vcpu->arch.cpuid_entries[i].padding[2] = 0; 223 } 224 vcpu->arch.cpuid_nent = cpuid->nent; 225 cpuid_fix_nx_cap(vcpu); 226 kvm_apic_set_version(vcpu); 227 kvm_x86_ops->cpuid_update(vcpu); 228 r = kvm_update_cpuid(vcpu); 229 230 out: 231 vfree(cpuid_entries); 232 return r; 233 } 234 235 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 236 struct kvm_cpuid2 *cpuid, 237 struct kvm_cpuid_entry2 __user *entries) 238 { 239 int r; 240 241 r = -E2BIG; 242 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 243 goto out; 244 r = -EFAULT; 245 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 246 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 247 goto out; 248 vcpu->arch.cpuid_nent = cpuid->nent; 249 kvm_apic_set_version(vcpu); 250 kvm_x86_ops->cpuid_update(vcpu); 251 r = kvm_update_cpuid(vcpu); 252 out: 253 return r; 254 } 255 256 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 257 struct kvm_cpuid2 *cpuid, 258 struct kvm_cpuid_entry2 __user *entries) 259 { 260 int r; 261 262 r = -E2BIG; 263 if (cpuid->nent < vcpu->arch.cpuid_nent) 264 goto out; 265 r = -EFAULT; 266 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 267 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 268 goto out; 269 return 0; 270 271 out: 272 cpuid->nent = vcpu->arch.cpuid_nent; 273 return r; 274 } 275 276 static void cpuid_mask(u32 *word, int wordnum) 277 { 278 *word &= boot_cpu_data.x86_capability[wordnum]; 279 } 280 281 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 282 u32 index) 283 { 284 entry->function = function; 285 entry->index = index; 286 cpuid_count(entry->function, entry->index, 287 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 288 entry->flags = 0; 289 } 290 291 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 292 u32 func, u32 index, int *nent, int maxnent) 293 { 294 switch (func) { 295 case 0: 296 entry->eax = 1; /* only one leaf currently */ 297 ++*nent; 298 break; 299 case 1: 300 entry->ecx = F(MOVBE); 301 ++*nent; 302 break; 303 default: 304 break; 305 } 306 307 entry->function = func; 308 entry->index = index; 309 310 return 0; 311 } 312 313 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 314 u32 index, int *nent, int maxnent) 315 { 316 int r; 317 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 318 #ifdef CONFIG_X86_64 319 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 320 ? F(GBPAGES) : 0; 321 unsigned f_lm = F(LM); 322 #else 323 unsigned f_gbpages = 0; 324 unsigned f_lm = 0; 325 #endif 326 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 327 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 328 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 329 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 330 331 /* cpuid 1.edx */ 332 const u32 kvm_cpuid_1_edx_x86_features = 333 F(FPU) | F(VME) | F(DE) | F(PSE) | 334 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 335 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 336 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 337 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 338 0 /* Reserved, DS, ACPI */ | F(MMX) | 339 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 340 0 /* HTT, TM, Reserved, PBE */; 341 /* cpuid 0x80000001.edx */ 342 const u32 kvm_cpuid_8000_0001_edx_x86_features = 343 F(FPU) | F(VME) | F(DE) | F(PSE) | 344 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 345 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 346 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 347 F(PAT) | F(PSE36) | 0 /* Reserved */ | 348 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 349 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 350 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 351 /* cpuid 1.ecx */ 352 const u32 kvm_cpuid_1_ecx_x86_features = 353 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 354 * but *not* advertised to guests via CPUID ! */ 355 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 356 0 /* DS-CPL, VMX, SMX, EST */ | 357 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 358 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 359 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 360 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 361 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 362 F(F16C) | F(RDRAND); 363 /* cpuid 0x80000001.ecx */ 364 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 365 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 366 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 367 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 368 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM); 369 370 /* cpuid 0xC0000001.edx */ 371 const u32 kvm_cpuid_C000_0001_edx_x86_features = 372 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 373 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 374 F(PMM) | F(PMM_EN); 375 376 /* cpuid 7.0.ebx */ 377 const u32 kvm_cpuid_7_0_ebx_x86_features = 378 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 379 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 380 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 381 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 382 F(SHA_NI) | F(AVX512BW) | F(AVX512VL); 383 384 /* cpuid 0xD.1.eax */ 385 const u32 kvm_cpuid_D_1_eax_x86_features = 386 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 387 388 /* cpuid 7.0.ecx*/ 389 const u32 kvm_cpuid_7_0_ecx_x86_features = 390 F(AVX512VBMI) | F(LA57) | F(PKU) | 391 0 /*OSPKE*/ | F(AVX512_VPOPCNTDQ); 392 393 /* cpuid 7.0.edx*/ 394 const u32 kvm_cpuid_7_0_edx_x86_features = 395 KF(AVX512_4VNNIW) | KF(AVX512_4FMAPS); 396 397 /* all calls to cpuid_count() should be made on the same cpu */ 398 get_cpu(); 399 400 r = -E2BIG; 401 402 if (*nent >= maxnent) 403 goto out; 404 405 do_cpuid_1_ent(entry, function, index); 406 ++*nent; 407 408 switch (function) { 409 case 0: 410 entry->eax = min(entry->eax, (u32)0xd); 411 break; 412 case 1: 413 entry->edx &= kvm_cpuid_1_edx_x86_features; 414 cpuid_mask(&entry->edx, CPUID_1_EDX); 415 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 416 cpuid_mask(&entry->ecx, CPUID_1_ECX); 417 /* we support x2apic emulation even if host does not support 418 * it since we emulate x2apic in software */ 419 entry->ecx |= F(X2APIC); 420 break; 421 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 422 * may return different values. This forces us to get_cpu() before 423 * issuing the first command, and also to emulate this annoying behavior 424 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 425 case 2: { 426 int t, times = entry->eax & 0xff; 427 428 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 429 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 430 for (t = 1; t < times; ++t) { 431 if (*nent >= maxnent) 432 goto out; 433 434 do_cpuid_1_ent(&entry[t], function, 0); 435 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 436 ++*nent; 437 } 438 break; 439 } 440 /* function 4 has additional index. */ 441 case 4: { 442 int i, cache_type; 443 444 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 445 /* read more entries until cache_type is zero */ 446 for (i = 1; ; ++i) { 447 if (*nent >= maxnent) 448 goto out; 449 450 cache_type = entry[i - 1].eax & 0x1f; 451 if (!cache_type) 452 break; 453 do_cpuid_1_ent(&entry[i], function, i); 454 entry[i].flags |= 455 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 456 ++*nent; 457 } 458 break; 459 } 460 case 6: /* Thermal management */ 461 entry->eax = 0x4; /* allow ARAT */ 462 entry->ebx = 0; 463 entry->ecx = 0; 464 entry->edx = 0; 465 break; 466 case 7: { 467 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 468 /* Mask ebx against host capability word 9 */ 469 if (index == 0) { 470 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 471 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 472 // TSC_ADJUST is emulated 473 entry->ebx |= F(TSC_ADJUST); 474 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 475 cpuid_mask(&entry->ecx, CPUID_7_ECX); 476 /* PKU is not yet implemented for shadow paging. */ 477 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 478 entry->ecx &= ~F(PKU); 479 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 480 entry->edx &= get_scattered_cpuid_leaf(7, 0, CPUID_EDX); 481 } else { 482 entry->ebx = 0; 483 entry->ecx = 0; 484 entry->edx = 0; 485 } 486 entry->eax = 0; 487 break; 488 } 489 case 9: 490 break; 491 case 0xa: { /* Architectural Performance Monitoring */ 492 struct x86_pmu_capability cap; 493 union cpuid10_eax eax; 494 union cpuid10_edx edx; 495 496 perf_get_x86_pmu_capability(&cap); 497 498 /* 499 * Only support guest architectural pmu on a host 500 * with architectural pmu. 501 */ 502 if (!cap.version) 503 memset(&cap, 0, sizeof(cap)); 504 505 eax.split.version_id = min(cap.version, 2); 506 eax.split.num_counters = cap.num_counters_gp; 507 eax.split.bit_width = cap.bit_width_gp; 508 eax.split.mask_length = cap.events_mask_len; 509 510 edx.split.num_counters_fixed = cap.num_counters_fixed; 511 edx.split.bit_width_fixed = cap.bit_width_fixed; 512 edx.split.reserved = 0; 513 514 entry->eax = eax.full; 515 entry->ebx = cap.events_mask; 516 entry->ecx = 0; 517 entry->edx = edx.full; 518 break; 519 } 520 /* function 0xb has additional index. */ 521 case 0xb: { 522 int i, level_type; 523 524 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 525 /* read more entries until level_type is zero */ 526 for (i = 1; ; ++i) { 527 if (*nent >= maxnent) 528 goto out; 529 530 level_type = entry[i - 1].ecx & 0xff00; 531 if (!level_type) 532 break; 533 do_cpuid_1_ent(&entry[i], function, i); 534 entry[i].flags |= 535 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 536 ++*nent; 537 } 538 break; 539 } 540 case 0xd: { 541 int idx, i; 542 u64 supported = kvm_supported_xcr0(); 543 544 entry->eax &= supported; 545 entry->ebx = xstate_required_size(supported, false); 546 entry->ecx = entry->ebx; 547 entry->edx &= supported >> 32; 548 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 549 if (!supported) 550 break; 551 552 for (idx = 1, i = 1; idx < 64; ++idx) { 553 u64 mask = ((u64)1 << idx); 554 if (*nent >= maxnent) 555 goto out; 556 557 do_cpuid_1_ent(&entry[i], function, idx); 558 if (idx == 1) { 559 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 560 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 561 entry[i].ebx = 0; 562 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 563 entry[i].ebx = 564 xstate_required_size(supported, 565 true); 566 } else { 567 if (entry[i].eax == 0 || !(supported & mask)) 568 continue; 569 if (WARN_ON_ONCE(entry[i].ecx & 1)) 570 continue; 571 } 572 entry[i].ecx = 0; 573 entry[i].edx = 0; 574 entry[i].flags |= 575 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 576 ++*nent; 577 ++i; 578 } 579 break; 580 } 581 case KVM_CPUID_SIGNATURE: { 582 static const char signature[12] = "KVMKVMKVM\0\0"; 583 const u32 *sigptr = (const u32 *)signature; 584 entry->eax = KVM_CPUID_FEATURES; 585 entry->ebx = sigptr[0]; 586 entry->ecx = sigptr[1]; 587 entry->edx = sigptr[2]; 588 break; 589 } 590 case KVM_CPUID_FEATURES: 591 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 592 (1 << KVM_FEATURE_NOP_IO_DELAY) | 593 (1 << KVM_FEATURE_CLOCKSOURCE2) | 594 (1 << KVM_FEATURE_ASYNC_PF) | 595 (1 << KVM_FEATURE_PV_EOI) | 596 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 597 (1 << KVM_FEATURE_PV_UNHALT); 598 599 if (sched_info_on()) 600 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 601 602 entry->ebx = 0; 603 entry->ecx = 0; 604 entry->edx = 0; 605 break; 606 case 0x80000000: 607 entry->eax = min(entry->eax, 0x8000001a); 608 break; 609 case 0x80000001: 610 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 611 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 612 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 613 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 614 break; 615 case 0x80000007: /* Advanced power management */ 616 /* invariant TSC is CPUID.80000007H:EDX[8] */ 617 entry->edx &= (1 << 8); 618 /* mask against host */ 619 entry->edx &= boot_cpu_data.x86_power; 620 entry->eax = entry->ebx = entry->ecx = 0; 621 break; 622 case 0x80000008: { 623 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 624 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 625 unsigned phys_as = entry->eax & 0xff; 626 627 if (!g_phys_as) 628 g_phys_as = phys_as; 629 entry->eax = g_phys_as | (virt_as << 8); 630 entry->ebx = entry->edx = 0; 631 break; 632 } 633 case 0x80000019: 634 entry->ecx = entry->edx = 0; 635 break; 636 case 0x8000001a: 637 break; 638 case 0x8000001d: 639 break; 640 /*Add support for Centaur's CPUID instruction*/ 641 case 0xC0000000: 642 /*Just support up to 0xC0000004 now*/ 643 entry->eax = min(entry->eax, 0xC0000004); 644 break; 645 case 0xC0000001: 646 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 647 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 648 break; 649 case 3: /* Processor serial number */ 650 case 5: /* MONITOR/MWAIT */ 651 case 0xC0000002: 652 case 0xC0000003: 653 case 0xC0000004: 654 default: 655 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 656 break; 657 } 658 659 kvm_x86_ops->set_supported_cpuid(function, entry); 660 661 r = 0; 662 663 out: 664 put_cpu(); 665 666 return r; 667 } 668 669 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 670 u32 idx, int *nent, int maxnent, unsigned int type) 671 { 672 if (type == KVM_GET_EMULATED_CPUID) 673 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 674 675 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 676 } 677 678 #undef F 679 680 struct kvm_cpuid_param { 681 u32 func; 682 u32 idx; 683 bool has_leaf_count; 684 bool (*qualifier)(const struct kvm_cpuid_param *param); 685 }; 686 687 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 688 { 689 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 690 } 691 692 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 693 __u32 num_entries, unsigned int ioctl_type) 694 { 695 int i; 696 __u32 pad[3]; 697 698 if (ioctl_type != KVM_GET_EMULATED_CPUID) 699 return false; 700 701 /* 702 * We want to make sure that ->padding is being passed clean from 703 * userspace in case we want to use it for something in the future. 704 * 705 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 706 * have to give ourselves satisfied only with the emulated side. /me 707 * sheds a tear. 708 */ 709 for (i = 0; i < num_entries; i++) { 710 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 711 return true; 712 713 if (pad[0] || pad[1] || pad[2]) 714 return true; 715 } 716 return false; 717 } 718 719 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 720 struct kvm_cpuid_entry2 __user *entries, 721 unsigned int type) 722 { 723 struct kvm_cpuid_entry2 *cpuid_entries; 724 int limit, nent = 0, r = -E2BIG, i; 725 u32 func; 726 static const struct kvm_cpuid_param param[] = { 727 { .func = 0, .has_leaf_count = true }, 728 { .func = 0x80000000, .has_leaf_count = true }, 729 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 730 { .func = KVM_CPUID_SIGNATURE }, 731 { .func = KVM_CPUID_FEATURES }, 732 }; 733 734 if (cpuid->nent < 1) 735 goto out; 736 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 737 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 738 739 if (sanity_check_entries(entries, cpuid->nent, type)) 740 return -EINVAL; 741 742 r = -ENOMEM; 743 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 744 if (!cpuid_entries) 745 goto out; 746 747 r = 0; 748 for (i = 0; i < ARRAY_SIZE(param); i++) { 749 const struct kvm_cpuid_param *ent = ¶m[i]; 750 751 if (ent->qualifier && !ent->qualifier(ent)) 752 continue; 753 754 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 755 &nent, cpuid->nent, type); 756 757 if (r) 758 goto out_free; 759 760 if (!ent->has_leaf_count) 761 continue; 762 763 limit = cpuid_entries[nent - 1].eax; 764 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 765 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 766 &nent, cpuid->nent, type); 767 768 if (r) 769 goto out_free; 770 } 771 772 r = -EFAULT; 773 if (copy_to_user(entries, cpuid_entries, 774 nent * sizeof(struct kvm_cpuid_entry2))) 775 goto out_free; 776 cpuid->nent = nent; 777 r = 0; 778 779 out_free: 780 vfree(cpuid_entries); 781 out: 782 return r; 783 } 784 785 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 786 { 787 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 788 struct kvm_cpuid_entry2 *ej; 789 int j = i; 790 int nent = vcpu->arch.cpuid_nent; 791 792 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 793 /* when no next entry is found, the current entry[i] is reselected */ 794 do { 795 j = (j + 1) % nent; 796 ej = &vcpu->arch.cpuid_entries[j]; 797 } while (ej->function != e->function); 798 799 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 800 801 return j; 802 } 803 804 /* find an entry with matching function, matching index (if needed), and that 805 * should be read next (if it's stateful) */ 806 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 807 u32 function, u32 index) 808 { 809 if (e->function != function) 810 return 0; 811 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 812 return 0; 813 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 814 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 815 return 0; 816 return 1; 817 } 818 819 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 820 u32 function, u32 index) 821 { 822 int i; 823 struct kvm_cpuid_entry2 *best = NULL; 824 825 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 826 struct kvm_cpuid_entry2 *e; 827 828 e = &vcpu->arch.cpuid_entries[i]; 829 if (is_matching_cpuid_entry(e, function, index)) { 830 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 831 move_to_next_stateful_cpuid_entry(vcpu, i); 832 best = e; 833 break; 834 } 835 } 836 return best; 837 } 838 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 839 840 /* 841 * If no match is found, check whether we exceed the vCPU's limit 842 * and return the content of the highest valid _standard_ leaf instead. 843 * This is to satisfy the CPUID specification. 844 */ 845 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 846 u32 function, u32 index) 847 { 848 struct kvm_cpuid_entry2 *maxlevel; 849 850 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 851 if (!maxlevel || maxlevel->eax >= function) 852 return NULL; 853 if (function & 0x80000000) { 854 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 855 if (!maxlevel) 856 return NULL; 857 } 858 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 859 } 860 861 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 862 u32 *ecx, u32 *edx, bool check_limit) 863 { 864 u32 function = *eax, index = *ecx; 865 struct kvm_cpuid_entry2 *best; 866 bool entry_found = true; 867 868 best = kvm_find_cpuid_entry(vcpu, function, index); 869 870 if (!best) { 871 entry_found = false; 872 if (!check_limit) 873 goto out; 874 875 best = check_cpuid_limit(vcpu, function, index); 876 } 877 878 out: 879 if (best) { 880 *eax = best->eax; 881 *ebx = best->ebx; 882 *ecx = best->ecx; 883 *edx = best->edx; 884 } else 885 *eax = *ebx = *ecx = *edx = 0; 886 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); 887 return entry_found; 888 } 889 EXPORT_SYMBOL_GPL(kvm_cpuid); 890 891 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 892 { 893 u32 eax, ebx, ecx, edx; 894 895 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 896 return 1; 897 898 eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 899 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 900 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); 901 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 902 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 903 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 904 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 905 return kvm_skip_emulated_instruction(vcpu); 906 } 907 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 908