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 /* For scattered features from cpufeatures.h; we currently expose none */ 71 #define KF(x) bit(KVM_CPUID_BIT_##x) 72 73 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 74 { 75 struct kvm_cpuid_entry2 *best; 76 struct kvm_lapic *apic = vcpu->arch.apic; 77 78 best = kvm_find_cpuid_entry(vcpu, 1, 0); 79 if (!best) 80 return 0; 81 82 /* Update OSXSAVE bit */ 83 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) { 84 best->ecx &= ~F(OSXSAVE); 85 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 86 best->ecx |= F(OSXSAVE); 87 } 88 89 best->edx &= ~F(APIC); 90 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE) 91 best->edx |= F(APIC); 92 93 if (apic) { 94 if (best->ecx & F(TSC_DEADLINE_TIMER)) 95 apic->lapic_timer.timer_mode_mask = 3 << 17; 96 else 97 apic->lapic_timer.timer_mode_mask = 1 << 17; 98 } 99 100 best = kvm_find_cpuid_entry(vcpu, 7, 0); 101 if (best) { 102 /* Update OSPKE bit */ 103 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) { 104 best->ecx &= ~F(OSPKE); 105 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) 106 best->ecx |= F(OSPKE); 107 } 108 } 109 110 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 111 if (!best) { 112 vcpu->arch.guest_supported_xcr0 = 0; 113 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 114 } else { 115 vcpu->arch.guest_supported_xcr0 = 116 (best->eax | ((u64)best->edx << 32)) & 117 kvm_supported_xcr0(); 118 vcpu->arch.guest_xstate_size = best->ebx = 119 xstate_required_size(vcpu->arch.xcr0, false); 120 } 121 122 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 123 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 124 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 125 126 /* 127 * The existing code assumes virtual address is 48-bit or 57-bit in the 128 * canonical address checks; exit if it is ever changed. 129 */ 130 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 131 if (best) { 132 int vaddr_bits = (best->eax & 0xff00) >> 8; 133 134 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) 135 return -EINVAL; 136 } 137 138 /* Update physical-address width */ 139 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 140 kvm_mmu_reset_context(vcpu); 141 142 kvm_pmu_refresh(vcpu); 143 return 0; 144 } 145 146 static int is_efer_nx(void) 147 { 148 unsigned long long efer = 0; 149 150 rdmsrl_safe(MSR_EFER, &efer); 151 return efer & EFER_NX; 152 } 153 154 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 155 { 156 int i; 157 struct kvm_cpuid_entry2 *e, *entry; 158 159 entry = NULL; 160 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 161 e = &vcpu->arch.cpuid_entries[i]; 162 if (e->function == 0x80000001) { 163 entry = e; 164 break; 165 } 166 } 167 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 168 entry->edx &= ~F(NX); 169 printk(KERN_INFO "kvm: guest NX capability removed\n"); 170 } 171 } 172 173 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 174 { 175 struct kvm_cpuid_entry2 *best; 176 177 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 178 if (!best || best->eax < 0x80000008) 179 goto not_found; 180 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 181 if (best) 182 return best->eax & 0xff; 183 not_found: 184 return 36; 185 } 186 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 187 188 /* when an old userspace process fills a new kernel module */ 189 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 190 struct kvm_cpuid *cpuid, 191 struct kvm_cpuid_entry __user *entries) 192 { 193 int r, i; 194 struct kvm_cpuid_entry *cpuid_entries = NULL; 195 196 r = -E2BIG; 197 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 198 goto out; 199 r = -ENOMEM; 200 if (cpuid->nent) { 201 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * 202 cpuid->nent); 203 if (!cpuid_entries) 204 goto out; 205 r = -EFAULT; 206 if (copy_from_user(cpuid_entries, entries, 207 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 208 goto out; 209 } 210 for (i = 0; i < cpuid->nent; i++) { 211 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 212 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 213 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 214 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 215 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 216 vcpu->arch.cpuid_entries[i].index = 0; 217 vcpu->arch.cpuid_entries[i].flags = 0; 218 vcpu->arch.cpuid_entries[i].padding[0] = 0; 219 vcpu->arch.cpuid_entries[i].padding[1] = 0; 220 vcpu->arch.cpuid_entries[i].padding[2] = 0; 221 } 222 vcpu->arch.cpuid_nent = cpuid->nent; 223 cpuid_fix_nx_cap(vcpu); 224 kvm_apic_set_version(vcpu); 225 kvm_x86_ops->cpuid_update(vcpu); 226 r = kvm_update_cpuid(vcpu); 227 228 out: 229 vfree(cpuid_entries); 230 return r; 231 } 232 233 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 234 struct kvm_cpuid2 *cpuid, 235 struct kvm_cpuid_entry2 __user *entries) 236 { 237 int r; 238 239 r = -E2BIG; 240 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 241 goto out; 242 r = -EFAULT; 243 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 244 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 245 goto out; 246 vcpu->arch.cpuid_nent = cpuid->nent; 247 kvm_apic_set_version(vcpu); 248 kvm_x86_ops->cpuid_update(vcpu); 249 r = kvm_update_cpuid(vcpu); 250 out: 251 return r; 252 } 253 254 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 255 struct kvm_cpuid2 *cpuid, 256 struct kvm_cpuid_entry2 __user *entries) 257 { 258 int r; 259 260 r = -E2BIG; 261 if (cpuid->nent < vcpu->arch.cpuid_nent) 262 goto out; 263 r = -EFAULT; 264 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 265 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 266 goto out; 267 return 0; 268 269 out: 270 cpuid->nent = vcpu->arch.cpuid_nent; 271 return r; 272 } 273 274 static void cpuid_mask(u32 *word, int wordnum) 275 { 276 *word &= boot_cpu_data.x86_capability[wordnum]; 277 } 278 279 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 280 u32 index) 281 { 282 entry->function = function; 283 entry->index = index; 284 cpuid_count(entry->function, entry->index, 285 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 286 entry->flags = 0; 287 } 288 289 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 290 u32 func, u32 index, int *nent, int maxnent) 291 { 292 switch (func) { 293 case 0: 294 entry->eax = 7; 295 ++*nent; 296 break; 297 case 1: 298 entry->ecx = F(MOVBE); 299 ++*nent; 300 break; 301 case 7: 302 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 303 if (index == 0) 304 entry->ecx = F(RDPID); 305 ++*nent; 306 default: 307 break; 308 } 309 310 entry->function = func; 311 entry->index = index; 312 313 return 0; 314 } 315 316 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 317 u32 index, int *nent, int maxnent) 318 { 319 int r; 320 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 321 #ifdef CONFIG_X86_64 322 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 323 ? F(GBPAGES) : 0; 324 unsigned f_lm = F(LM); 325 #else 326 unsigned f_gbpages = 0; 327 unsigned f_lm = 0; 328 #endif 329 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 330 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 331 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 332 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 333 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0; 334 335 /* cpuid 1.edx */ 336 const u32 kvm_cpuid_1_edx_x86_features = 337 F(FPU) | F(VME) | F(DE) | F(PSE) | 338 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 339 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 340 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 341 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 342 0 /* Reserved, DS, ACPI */ | F(MMX) | 343 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 344 0 /* HTT, TM, Reserved, PBE */; 345 /* cpuid 0x80000001.edx */ 346 const u32 kvm_cpuid_8000_0001_edx_x86_features = 347 F(FPU) | F(VME) | F(DE) | F(PSE) | 348 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 349 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 350 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 351 F(PAT) | F(PSE36) | 0 /* Reserved */ | 352 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 353 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 354 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 355 /* cpuid 1.ecx */ 356 const u32 kvm_cpuid_1_ecx_x86_features = 357 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 358 * but *not* advertised to guests via CPUID ! */ 359 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 360 0 /* DS-CPL, VMX, SMX, EST */ | 361 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 362 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 363 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 364 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 365 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 366 F(F16C) | F(RDRAND); 367 /* cpuid 0x80000001.ecx */ 368 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 369 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 370 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 371 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 372 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 373 F(TOPOEXT); 374 375 /* cpuid 0x80000008.ebx */ 376 const u32 kvm_cpuid_8000_0008_ebx_x86_features = 377 F(IBPB) | F(IBRS); 378 379 /* cpuid 0xC0000001.edx */ 380 const u32 kvm_cpuid_C000_0001_edx_x86_features = 381 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 382 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 383 F(PMM) | F(PMM_EN); 384 385 /* cpuid 7.0.ebx */ 386 const u32 kvm_cpuid_7_0_ebx_x86_features = 387 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 388 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 389 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 390 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 391 F(SHA_NI) | F(AVX512BW) | F(AVX512VL); 392 393 /* cpuid 0xD.1.eax */ 394 const u32 kvm_cpuid_D_1_eax_x86_features = 395 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 396 397 /* cpuid 7.0.ecx*/ 398 const u32 kvm_cpuid_7_0_ecx_x86_features = 399 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | 400 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 401 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG); 402 403 /* cpuid 7.0.edx*/ 404 const u32 kvm_cpuid_7_0_edx_x86_features = 405 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 406 F(ARCH_CAPABILITIES); 407 408 /* all calls to cpuid_count() should be made on the same cpu */ 409 get_cpu(); 410 411 r = -E2BIG; 412 413 if (*nent >= maxnent) 414 goto out; 415 416 do_cpuid_1_ent(entry, function, index); 417 ++*nent; 418 419 switch (function) { 420 case 0: 421 entry->eax = min(entry->eax, (u32)0xd); 422 break; 423 case 1: 424 entry->edx &= kvm_cpuid_1_edx_x86_features; 425 cpuid_mask(&entry->edx, CPUID_1_EDX); 426 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 427 cpuid_mask(&entry->ecx, CPUID_1_ECX); 428 /* we support x2apic emulation even if host does not support 429 * it since we emulate x2apic in software */ 430 entry->ecx |= F(X2APIC); 431 break; 432 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 433 * may return different values. This forces us to get_cpu() before 434 * issuing the first command, and also to emulate this annoying behavior 435 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 436 case 2: { 437 int t, times = entry->eax & 0xff; 438 439 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 440 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 441 for (t = 1; t < times; ++t) { 442 if (*nent >= maxnent) 443 goto out; 444 445 do_cpuid_1_ent(&entry[t], function, 0); 446 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 447 ++*nent; 448 } 449 break; 450 } 451 /* function 4 has additional index. */ 452 case 4: { 453 int i, cache_type; 454 455 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 456 /* read more entries until cache_type is zero */ 457 for (i = 1; ; ++i) { 458 if (*nent >= maxnent) 459 goto out; 460 461 cache_type = entry[i - 1].eax & 0x1f; 462 if (!cache_type) 463 break; 464 do_cpuid_1_ent(&entry[i], function, i); 465 entry[i].flags |= 466 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 467 ++*nent; 468 } 469 break; 470 } 471 case 6: /* Thermal management */ 472 entry->eax = 0x4; /* allow ARAT */ 473 entry->ebx = 0; 474 entry->ecx = 0; 475 entry->edx = 0; 476 break; 477 case 7: { 478 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 479 /* Mask ebx against host capability word 9 */ 480 if (index == 0) { 481 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 482 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 483 // TSC_ADJUST is emulated 484 entry->ebx |= F(TSC_ADJUST); 485 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 486 cpuid_mask(&entry->ecx, CPUID_7_ECX); 487 entry->ecx |= f_umip; 488 /* PKU is not yet implemented for shadow paging. */ 489 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 490 entry->ecx &= ~F(PKU); 491 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 492 cpuid_mask(&entry->edx, CPUID_7_EDX); 493 } else { 494 entry->ebx = 0; 495 entry->ecx = 0; 496 entry->edx = 0; 497 } 498 entry->eax = 0; 499 break; 500 } 501 case 9: 502 break; 503 case 0xa: { /* Architectural Performance Monitoring */ 504 struct x86_pmu_capability cap; 505 union cpuid10_eax eax; 506 union cpuid10_edx edx; 507 508 perf_get_x86_pmu_capability(&cap); 509 510 /* 511 * Only support guest architectural pmu on a host 512 * with architectural pmu. 513 */ 514 if (!cap.version) 515 memset(&cap, 0, sizeof(cap)); 516 517 eax.split.version_id = min(cap.version, 2); 518 eax.split.num_counters = cap.num_counters_gp; 519 eax.split.bit_width = cap.bit_width_gp; 520 eax.split.mask_length = cap.events_mask_len; 521 522 edx.split.num_counters_fixed = cap.num_counters_fixed; 523 edx.split.bit_width_fixed = cap.bit_width_fixed; 524 edx.split.reserved = 0; 525 526 entry->eax = eax.full; 527 entry->ebx = cap.events_mask; 528 entry->ecx = 0; 529 entry->edx = edx.full; 530 break; 531 } 532 /* function 0xb has additional index. */ 533 case 0xb: { 534 int i, level_type; 535 536 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 537 /* read more entries until level_type is zero */ 538 for (i = 1; ; ++i) { 539 if (*nent >= maxnent) 540 goto out; 541 542 level_type = entry[i - 1].ecx & 0xff00; 543 if (!level_type) 544 break; 545 do_cpuid_1_ent(&entry[i], function, i); 546 entry[i].flags |= 547 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 548 ++*nent; 549 } 550 break; 551 } 552 case 0xd: { 553 int idx, i; 554 u64 supported = kvm_supported_xcr0(); 555 556 entry->eax &= supported; 557 entry->ebx = xstate_required_size(supported, false); 558 entry->ecx = entry->ebx; 559 entry->edx &= supported >> 32; 560 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 561 if (!supported) 562 break; 563 564 for (idx = 1, i = 1; idx < 64; ++idx) { 565 u64 mask = ((u64)1 << idx); 566 if (*nent >= maxnent) 567 goto out; 568 569 do_cpuid_1_ent(&entry[i], function, idx); 570 if (idx == 1) { 571 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 572 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 573 entry[i].ebx = 0; 574 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 575 entry[i].ebx = 576 xstate_required_size(supported, 577 true); 578 } else { 579 if (entry[i].eax == 0 || !(supported & mask)) 580 continue; 581 if (WARN_ON_ONCE(entry[i].ecx & 1)) 582 continue; 583 } 584 entry[i].ecx = 0; 585 entry[i].edx = 0; 586 entry[i].flags |= 587 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 588 ++*nent; 589 ++i; 590 } 591 break; 592 } 593 case KVM_CPUID_SIGNATURE: { 594 static const char signature[12] = "KVMKVMKVM\0\0"; 595 const u32 *sigptr = (const u32 *)signature; 596 entry->eax = KVM_CPUID_FEATURES; 597 entry->ebx = sigptr[0]; 598 entry->ecx = sigptr[1]; 599 entry->edx = sigptr[2]; 600 break; 601 } 602 case KVM_CPUID_FEATURES: 603 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 604 (1 << KVM_FEATURE_NOP_IO_DELAY) | 605 (1 << KVM_FEATURE_CLOCKSOURCE2) | 606 (1 << KVM_FEATURE_ASYNC_PF) | 607 (1 << KVM_FEATURE_PV_EOI) | 608 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 609 (1 << KVM_FEATURE_PV_UNHALT) | 610 (1 << KVM_FEATURE_PV_TLB_FLUSH); 611 612 if (sched_info_on()) 613 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 614 615 entry->ebx = 0; 616 entry->ecx = 0; 617 entry->edx = 0; 618 break; 619 case 0x80000000: 620 entry->eax = min(entry->eax, 0x8000001f); 621 break; 622 case 0x80000001: 623 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 624 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 625 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 626 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 627 break; 628 case 0x80000007: /* Advanced power management */ 629 /* invariant TSC is CPUID.80000007H:EDX[8] */ 630 entry->edx &= (1 << 8); 631 /* mask against host */ 632 entry->edx &= boot_cpu_data.x86_power; 633 entry->eax = entry->ebx = entry->ecx = 0; 634 break; 635 case 0x80000008: { 636 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 637 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 638 unsigned phys_as = entry->eax & 0xff; 639 640 if (!g_phys_as) 641 g_phys_as = phys_as; 642 entry->eax = g_phys_as | (virt_as << 8); 643 entry->edx = 0; 644 /* IBRS and IBPB aren't necessarily present in hardware cpuid */ 645 if (boot_cpu_has(X86_FEATURE_IBPB)) 646 entry->ebx |= F(IBPB); 647 if (boot_cpu_has(X86_FEATURE_IBRS)) 648 entry->ebx |= F(IBRS); 649 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; 650 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); 651 break; 652 } 653 case 0x80000019: 654 entry->ecx = entry->edx = 0; 655 break; 656 case 0x8000001a: 657 break; 658 case 0x8000001d: 659 break; 660 /*Add support for Centaur's CPUID instruction*/ 661 case 0xC0000000: 662 /*Just support up to 0xC0000004 now*/ 663 entry->eax = min(entry->eax, 0xC0000004); 664 break; 665 case 0xC0000001: 666 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 667 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 668 break; 669 case 3: /* Processor serial number */ 670 case 5: /* MONITOR/MWAIT */ 671 case 0xC0000002: 672 case 0xC0000003: 673 case 0xC0000004: 674 default: 675 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 676 break; 677 } 678 679 kvm_x86_ops->set_supported_cpuid(function, entry); 680 681 r = 0; 682 683 out: 684 put_cpu(); 685 686 return r; 687 } 688 689 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 690 u32 idx, int *nent, int maxnent, unsigned int type) 691 { 692 if (type == KVM_GET_EMULATED_CPUID) 693 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 694 695 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 696 } 697 698 #undef F 699 700 struct kvm_cpuid_param { 701 u32 func; 702 u32 idx; 703 bool has_leaf_count; 704 bool (*qualifier)(const struct kvm_cpuid_param *param); 705 }; 706 707 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 708 { 709 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 710 } 711 712 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 713 __u32 num_entries, unsigned int ioctl_type) 714 { 715 int i; 716 __u32 pad[3]; 717 718 if (ioctl_type != KVM_GET_EMULATED_CPUID) 719 return false; 720 721 /* 722 * We want to make sure that ->padding is being passed clean from 723 * userspace in case we want to use it for something in the future. 724 * 725 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 726 * have to give ourselves satisfied only with the emulated side. /me 727 * sheds a tear. 728 */ 729 for (i = 0; i < num_entries; i++) { 730 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 731 return true; 732 733 if (pad[0] || pad[1] || pad[2]) 734 return true; 735 } 736 return false; 737 } 738 739 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 740 struct kvm_cpuid_entry2 __user *entries, 741 unsigned int type) 742 { 743 struct kvm_cpuid_entry2 *cpuid_entries; 744 int limit, nent = 0, r = -E2BIG, i; 745 u32 func; 746 static const struct kvm_cpuid_param param[] = { 747 { .func = 0, .has_leaf_count = true }, 748 { .func = 0x80000000, .has_leaf_count = true }, 749 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 750 { .func = KVM_CPUID_SIGNATURE }, 751 { .func = KVM_CPUID_FEATURES }, 752 }; 753 754 if (cpuid->nent < 1) 755 goto out; 756 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 757 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 758 759 if (sanity_check_entries(entries, cpuid->nent, type)) 760 return -EINVAL; 761 762 r = -ENOMEM; 763 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 764 if (!cpuid_entries) 765 goto out; 766 767 r = 0; 768 for (i = 0; i < ARRAY_SIZE(param); i++) { 769 const struct kvm_cpuid_param *ent = ¶m[i]; 770 771 if (ent->qualifier && !ent->qualifier(ent)) 772 continue; 773 774 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 775 &nent, cpuid->nent, type); 776 777 if (r) 778 goto out_free; 779 780 if (!ent->has_leaf_count) 781 continue; 782 783 limit = cpuid_entries[nent - 1].eax; 784 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 785 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 786 &nent, cpuid->nent, type); 787 788 if (r) 789 goto out_free; 790 } 791 792 r = -EFAULT; 793 if (copy_to_user(entries, cpuid_entries, 794 nent * sizeof(struct kvm_cpuid_entry2))) 795 goto out_free; 796 cpuid->nent = nent; 797 r = 0; 798 799 out_free: 800 vfree(cpuid_entries); 801 out: 802 return r; 803 } 804 805 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 806 { 807 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 808 struct kvm_cpuid_entry2 *ej; 809 int j = i; 810 int nent = vcpu->arch.cpuid_nent; 811 812 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 813 /* when no next entry is found, the current entry[i] is reselected */ 814 do { 815 j = (j + 1) % nent; 816 ej = &vcpu->arch.cpuid_entries[j]; 817 } while (ej->function != e->function); 818 819 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 820 821 return j; 822 } 823 824 /* find an entry with matching function, matching index (if needed), and that 825 * should be read next (if it's stateful) */ 826 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 827 u32 function, u32 index) 828 { 829 if (e->function != function) 830 return 0; 831 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 832 return 0; 833 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 834 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 835 return 0; 836 return 1; 837 } 838 839 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 840 u32 function, u32 index) 841 { 842 int i; 843 struct kvm_cpuid_entry2 *best = NULL; 844 845 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 846 struct kvm_cpuid_entry2 *e; 847 848 e = &vcpu->arch.cpuid_entries[i]; 849 if (is_matching_cpuid_entry(e, function, index)) { 850 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 851 move_to_next_stateful_cpuid_entry(vcpu, i); 852 best = e; 853 break; 854 } 855 } 856 return best; 857 } 858 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 859 860 /* 861 * If no match is found, check whether we exceed the vCPU's limit 862 * and return the content of the highest valid _standard_ leaf instead. 863 * This is to satisfy the CPUID specification. 864 */ 865 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 866 u32 function, u32 index) 867 { 868 struct kvm_cpuid_entry2 *maxlevel; 869 870 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 871 if (!maxlevel || maxlevel->eax >= function) 872 return NULL; 873 if (function & 0x80000000) { 874 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 875 if (!maxlevel) 876 return NULL; 877 } 878 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 879 } 880 881 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 882 u32 *ecx, u32 *edx, bool check_limit) 883 { 884 u32 function = *eax, index = *ecx; 885 struct kvm_cpuid_entry2 *best; 886 bool entry_found = true; 887 888 best = kvm_find_cpuid_entry(vcpu, function, index); 889 890 if (!best) { 891 entry_found = false; 892 if (!check_limit) 893 goto out; 894 895 best = check_cpuid_limit(vcpu, function, index); 896 } 897 898 out: 899 if (best) { 900 *eax = best->eax; 901 *ebx = best->ebx; 902 *ecx = best->ecx; 903 *edx = best->edx; 904 } else 905 *eax = *ebx = *ecx = *edx = 0; 906 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); 907 return entry_found; 908 } 909 EXPORT_SYMBOL_GPL(kvm_cpuid); 910 911 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 912 { 913 u32 eax, ebx, ecx, edx; 914 915 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 916 return 1; 917 918 eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 919 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 920 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); 921 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 922 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 923 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 924 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 925 return kvm_skip_emulated_instruction(vcpu); 926 } 927 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 928