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 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0); 139 if (kvm_hlt_in_guest(vcpu->kvm) && best && 140 (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) 141 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); 142 143 /* Update physical-address width */ 144 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 145 kvm_mmu_reset_context(vcpu); 146 147 kvm_pmu_refresh(vcpu); 148 return 0; 149 } 150 151 static int is_efer_nx(void) 152 { 153 unsigned long long efer = 0; 154 155 rdmsrl_safe(MSR_EFER, &efer); 156 return efer & EFER_NX; 157 } 158 159 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 160 { 161 int i; 162 struct kvm_cpuid_entry2 *e, *entry; 163 164 entry = NULL; 165 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 166 e = &vcpu->arch.cpuid_entries[i]; 167 if (e->function == 0x80000001) { 168 entry = e; 169 break; 170 } 171 } 172 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 173 entry->edx &= ~F(NX); 174 printk(KERN_INFO "kvm: guest NX capability removed\n"); 175 } 176 } 177 178 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 179 { 180 struct kvm_cpuid_entry2 *best; 181 182 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 183 if (!best || best->eax < 0x80000008) 184 goto not_found; 185 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 186 if (best) 187 return best->eax & 0xff; 188 not_found: 189 return 36; 190 } 191 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 192 193 /* when an old userspace process fills a new kernel module */ 194 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 195 struct kvm_cpuid *cpuid, 196 struct kvm_cpuid_entry __user *entries) 197 { 198 int r, i; 199 struct kvm_cpuid_entry *cpuid_entries = NULL; 200 201 r = -E2BIG; 202 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 203 goto out; 204 r = -ENOMEM; 205 if (cpuid->nent) { 206 cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * 207 cpuid->nent); 208 if (!cpuid_entries) 209 goto out; 210 r = -EFAULT; 211 if (copy_from_user(cpuid_entries, entries, 212 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 213 goto out; 214 } 215 for (i = 0; i < cpuid->nent; i++) { 216 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 217 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 218 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 219 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 220 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 221 vcpu->arch.cpuid_entries[i].index = 0; 222 vcpu->arch.cpuid_entries[i].flags = 0; 223 vcpu->arch.cpuid_entries[i].padding[0] = 0; 224 vcpu->arch.cpuid_entries[i].padding[1] = 0; 225 vcpu->arch.cpuid_entries[i].padding[2] = 0; 226 } 227 vcpu->arch.cpuid_nent = cpuid->nent; 228 cpuid_fix_nx_cap(vcpu); 229 kvm_apic_set_version(vcpu); 230 kvm_x86_ops->cpuid_update(vcpu); 231 r = kvm_update_cpuid(vcpu); 232 233 out: 234 vfree(cpuid_entries); 235 return r; 236 } 237 238 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 239 struct kvm_cpuid2 *cpuid, 240 struct kvm_cpuid_entry2 __user *entries) 241 { 242 int r; 243 244 r = -E2BIG; 245 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 246 goto out; 247 r = -EFAULT; 248 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 249 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 250 goto out; 251 vcpu->arch.cpuid_nent = cpuid->nent; 252 kvm_apic_set_version(vcpu); 253 kvm_x86_ops->cpuid_update(vcpu); 254 r = kvm_update_cpuid(vcpu); 255 out: 256 return r; 257 } 258 259 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 260 struct kvm_cpuid2 *cpuid, 261 struct kvm_cpuid_entry2 __user *entries) 262 { 263 int r; 264 265 r = -E2BIG; 266 if (cpuid->nent < vcpu->arch.cpuid_nent) 267 goto out; 268 r = -EFAULT; 269 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 270 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 271 goto out; 272 return 0; 273 274 out: 275 cpuid->nent = vcpu->arch.cpuid_nent; 276 return r; 277 } 278 279 static void cpuid_mask(u32 *word, int wordnum) 280 { 281 *word &= boot_cpu_data.x86_capability[wordnum]; 282 } 283 284 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 285 u32 index) 286 { 287 entry->function = function; 288 entry->index = index; 289 cpuid_count(entry->function, entry->index, 290 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 291 entry->flags = 0; 292 } 293 294 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 295 u32 func, u32 index, int *nent, int maxnent) 296 { 297 switch (func) { 298 case 0: 299 entry->eax = 7; 300 ++*nent; 301 break; 302 case 1: 303 entry->ecx = F(MOVBE); 304 ++*nent; 305 break; 306 case 7: 307 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 308 if (index == 0) 309 entry->ecx = F(RDPID); 310 ++*nent; 311 default: 312 break; 313 } 314 315 entry->function = func; 316 entry->index = index; 317 318 return 0; 319 } 320 321 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 322 u32 index, int *nent, int maxnent) 323 { 324 int r; 325 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 326 #ifdef CONFIG_X86_64 327 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 328 ? F(GBPAGES) : 0; 329 unsigned f_lm = F(LM); 330 #else 331 unsigned f_gbpages = 0; 332 unsigned f_lm = 0; 333 #endif 334 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 335 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 336 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 337 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 338 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0; 339 340 /* cpuid 1.edx */ 341 const u32 kvm_cpuid_1_edx_x86_features = 342 F(FPU) | F(VME) | F(DE) | F(PSE) | 343 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 344 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 345 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 346 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 347 0 /* Reserved, DS, ACPI */ | F(MMX) | 348 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 349 0 /* HTT, TM, Reserved, PBE */; 350 /* cpuid 0x80000001.edx */ 351 const u32 kvm_cpuid_8000_0001_edx_x86_features = 352 F(FPU) | F(VME) | F(DE) | F(PSE) | 353 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 354 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 355 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 356 F(PAT) | F(PSE36) | 0 /* Reserved */ | 357 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 358 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 359 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 360 /* cpuid 1.ecx */ 361 const u32 kvm_cpuid_1_ecx_x86_features = 362 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 363 * but *not* advertised to guests via CPUID ! */ 364 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 365 0 /* DS-CPL, VMX, SMX, EST */ | 366 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 367 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 368 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 369 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 370 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 371 F(F16C) | F(RDRAND); 372 /* cpuid 0x80000001.ecx */ 373 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 374 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 375 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 376 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 377 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 378 F(TOPOEXT) | F(PERFCTR_CORE); 379 380 /* cpuid 0x80000008.ebx */ 381 const u32 kvm_cpuid_8000_0008_ebx_x86_features = 382 F(AMD_IBPB) | F(AMD_IBRS) | F(VIRT_SSBD); 383 384 /* cpuid 0xC0000001.edx */ 385 const u32 kvm_cpuid_C000_0001_edx_x86_features = 386 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 387 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 388 F(PMM) | F(PMM_EN); 389 390 /* cpuid 7.0.ebx */ 391 const u32 kvm_cpuid_7_0_ebx_x86_features = 392 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 393 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 394 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 395 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 396 F(SHA_NI) | F(AVX512BW) | F(AVX512VL); 397 398 /* cpuid 0xD.1.eax */ 399 const u32 kvm_cpuid_D_1_eax_x86_features = 400 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 401 402 /* cpuid 7.0.ecx*/ 403 const u32 kvm_cpuid_7_0_ecx_x86_features = 404 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | 405 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 406 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG); 407 408 /* cpuid 7.0.edx*/ 409 const u32 kvm_cpuid_7_0_edx_x86_features = 410 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 411 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES); 412 413 /* all calls to cpuid_count() should be made on the same cpu */ 414 get_cpu(); 415 416 r = -E2BIG; 417 418 if (*nent >= maxnent) 419 goto out; 420 421 do_cpuid_1_ent(entry, function, index); 422 ++*nent; 423 424 switch (function) { 425 case 0: 426 entry->eax = min(entry->eax, (u32)0xd); 427 break; 428 case 1: 429 entry->edx &= kvm_cpuid_1_edx_x86_features; 430 cpuid_mask(&entry->edx, CPUID_1_EDX); 431 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 432 cpuid_mask(&entry->ecx, CPUID_1_ECX); 433 /* we support x2apic emulation even if host does not support 434 * it since we emulate x2apic in software */ 435 entry->ecx |= F(X2APIC); 436 break; 437 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 438 * may return different values. This forces us to get_cpu() before 439 * issuing the first command, and also to emulate this annoying behavior 440 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 441 case 2: { 442 int t, times = entry->eax & 0xff; 443 444 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 445 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 446 for (t = 1; t < times; ++t) { 447 if (*nent >= maxnent) 448 goto out; 449 450 do_cpuid_1_ent(&entry[t], function, 0); 451 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 452 ++*nent; 453 } 454 break; 455 } 456 /* function 4 has additional index. */ 457 case 4: { 458 int i, cache_type; 459 460 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 461 /* read more entries until cache_type is zero */ 462 for (i = 1; ; ++i) { 463 if (*nent >= maxnent) 464 goto out; 465 466 cache_type = entry[i - 1].eax & 0x1f; 467 if (!cache_type) 468 break; 469 do_cpuid_1_ent(&entry[i], function, i); 470 entry[i].flags |= 471 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 472 ++*nent; 473 } 474 break; 475 } 476 case 6: /* Thermal management */ 477 entry->eax = 0x4; /* allow ARAT */ 478 entry->ebx = 0; 479 entry->ecx = 0; 480 entry->edx = 0; 481 break; 482 case 7: { 483 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 484 /* Mask ebx against host capability word 9 */ 485 if (index == 0) { 486 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 487 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 488 // TSC_ADJUST is emulated 489 entry->ebx |= F(TSC_ADJUST); 490 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 491 cpuid_mask(&entry->ecx, CPUID_7_ECX); 492 entry->ecx |= f_umip; 493 /* PKU is not yet implemented for shadow paging. */ 494 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 495 entry->ecx &= ~F(PKU); 496 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 497 cpuid_mask(&entry->edx, CPUID_7_EDX); 498 /* 499 * We emulate ARCH_CAPABILITIES in software even 500 * if the host doesn't support it. 501 */ 502 entry->edx |= F(ARCH_CAPABILITIES); 503 } else { 504 entry->ebx = 0; 505 entry->ecx = 0; 506 entry->edx = 0; 507 } 508 entry->eax = 0; 509 break; 510 } 511 case 9: 512 break; 513 case 0xa: { /* Architectural Performance Monitoring */ 514 struct x86_pmu_capability cap; 515 union cpuid10_eax eax; 516 union cpuid10_edx edx; 517 518 perf_get_x86_pmu_capability(&cap); 519 520 /* 521 * Only support guest architectural pmu on a host 522 * with architectural pmu. 523 */ 524 if (!cap.version) 525 memset(&cap, 0, sizeof(cap)); 526 527 eax.split.version_id = min(cap.version, 2); 528 eax.split.num_counters = cap.num_counters_gp; 529 eax.split.bit_width = cap.bit_width_gp; 530 eax.split.mask_length = cap.events_mask_len; 531 532 edx.split.num_counters_fixed = cap.num_counters_fixed; 533 edx.split.bit_width_fixed = cap.bit_width_fixed; 534 edx.split.reserved = 0; 535 536 entry->eax = eax.full; 537 entry->ebx = cap.events_mask; 538 entry->ecx = 0; 539 entry->edx = edx.full; 540 break; 541 } 542 /* function 0xb has additional index. */ 543 case 0xb: { 544 int i, level_type; 545 546 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 547 /* read more entries until level_type is zero */ 548 for (i = 1; ; ++i) { 549 if (*nent >= maxnent) 550 goto out; 551 552 level_type = entry[i - 1].ecx & 0xff00; 553 if (!level_type) 554 break; 555 do_cpuid_1_ent(&entry[i], function, i); 556 entry[i].flags |= 557 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 558 ++*nent; 559 } 560 break; 561 } 562 case 0xd: { 563 int idx, i; 564 u64 supported = kvm_supported_xcr0(); 565 566 entry->eax &= supported; 567 entry->ebx = xstate_required_size(supported, false); 568 entry->ecx = entry->ebx; 569 entry->edx &= supported >> 32; 570 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 571 if (!supported) 572 break; 573 574 for (idx = 1, i = 1; idx < 64; ++idx) { 575 u64 mask = ((u64)1 << idx); 576 if (*nent >= maxnent) 577 goto out; 578 579 do_cpuid_1_ent(&entry[i], function, idx); 580 if (idx == 1) { 581 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 582 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 583 entry[i].ebx = 0; 584 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 585 entry[i].ebx = 586 xstate_required_size(supported, 587 true); 588 } else { 589 if (entry[i].eax == 0 || !(supported & mask)) 590 continue; 591 if (WARN_ON_ONCE(entry[i].ecx & 1)) 592 continue; 593 } 594 entry[i].ecx = 0; 595 entry[i].edx = 0; 596 entry[i].flags |= 597 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 598 ++*nent; 599 ++i; 600 } 601 break; 602 } 603 case KVM_CPUID_SIGNATURE: { 604 static const char signature[12] = "KVMKVMKVM\0\0"; 605 const u32 *sigptr = (const u32 *)signature; 606 entry->eax = KVM_CPUID_FEATURES; 607 entry->ebx = sigptr[0]; 608 entry->ecx = sigptr[1]; 609 entry->edx = sigptr[2]; 610 break; 611 } 612 case KVM_CPUID_FEATURES: 613 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 614 (1 << KVM_FEATURE_NOP_IO_DELAY) | 615 (1 << KVM_FEATURE_CLOCKSOURCE2) | 616 (1 << KVM_FEATURE_ASYNC_PF) | 617 (1 << KVM_FEATURE_PV_EOI) | 618 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 619 (1 << KVM_FEATURE_PV_UNHALT) | 620 (1 << KVM_FEATURE_PV_TLB_FLUSH) | 621 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT); 622 623 if (sched_info_on()) 624 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 625 626 entry->ebx = 0; 627 entry->ecx = 0; 628 entry->edx = 0; 629 break; 630 case 0x80000000: 631 entry->eax = min(entry->eax, 0x8000001f); 632 break; 633 case 0x80000001: 634 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 635 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 636 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 637 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 638 break; 639 case 0x80000007: /* Advanced power management */ 640 /* invariant TSC is CPUID.80000007H:EDX[8] */ 641 entry->edx &= (1 << 8); 642 /* mask against host */ 643 entry->edx &= boot_cpu_data.x86_power; 644 entry->eax = entry->ebx = entry->ecx = 0; 645 break; 646 case 0x80000008: { 647 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 648 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 649 unsigned phys_as = entry->eax & 0xff; 650 651 if (!g_phys_as) 652 g_phys_as = phys_as; 653 entry->eax = g_phys_as | (virt_as << 8); 654 entry->edx = 0; 655 /* 656 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in 657 * hardware cpuid 658 */ 659 if (boot_cpu_has(X86_FEATURE_AMD_IBPB)) 660 entry->ebx |= F(AMD_IBPB); 661 if (boot_cpu_has(X86_FEATURE_AMD_IBRS)) 662 entry->ebx |= F(AMD_IBRS); 663 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD)) 664 entry->ebx |= F(VIRT_SSBD); 665 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; 666 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); 667 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD)) 668 entry->ebx |= F(VIRT_SSBD); 669 break; 670 } 671 case 0x80000019: 672 entry->ecx = entry->edx = 0; 673 break; 674 case 0x8000001a: 675 break; 676 case 0x8000001d: 677 break; 678 /*Add support for Centaur's CPUID instruction*/ 679 case 0xC0000000: 680 /*Just support up to 0xC0000004 now*/ 681 entry->eax = min(entry->eax, 0xC0000004); 682 break; 683 case 0xC0000001: 684 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 685 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 686 break; 687 case 3: /* Processor serial number */ 688 case 5: /* MONITOR/MWAIT */ 689 case 0xC0000002: 690 case 0xC0000003: 691 case 0xC0000004: 692 default: 693 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 694 break; 695 } 696 697 kvm_x86_ops->set_supported_cpuid(function, entry); 698 699 r = 0; 700 701 out: 702 put_cpu(); 703 704 return r; 705 } 706 707 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 708 u32 idx, int *nent, int maxnent, unsigned int type) 709 { 710 if (type == KVM_GET_EMULATED_CPUID) 711 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 712 713 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 714 } 715 716 #undef F 717 718 struct kvm_cpuid_param { 719 u32 func; 720 u32 idx; 721 bool has_leaf_count; 722 bool (*qualifier)(const struct kvm_cpuid_param *param); 723 }; 724 725 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 726 { 727 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 728 } 729 730 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 731 __u32 num_entries, unsigned int ioctl_type) 732 { 733 int i; 734 __u32 pad[3]; 735 736 if (ioctl_type != KVM_GET_EMULATED_CPUID) 737 return false; 738 739 /* 740 * We want to make sure that ->padding is being passed clean from 741 * userspace in case we want to use it for something in the future. 742 * 743 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 744 * have to give ourselves satisfied only with the emulated side. /me 745 * sheds a tear. 746 */ 747 for (i = 0; i < num_entries; i++) { 748 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 749 return true; 750 751 if (pad[0] || pad[1] || pad[2]) 752 return true; 753 } 754 return false; 755 } 756 757 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 758 struct kvm_cpuid_entry2 __user *entries, 759 unsigned int type) 760 { 761 struct kvm_cpuid_entry2 *cpuid_entries; 762 int limit, nent = 0, r = -E2BIG, i; 763 u32 func; 764 static const struct kvm_cpuid_param param[] = { 765 { .func = 0, .has_leaf_count = true }, 766 { .func = 0x80000000, .has_leaf_count = true }, 767 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 768 { .func = KVM_CPUID_SIGNATURE }, 769 { .func = KVM_CPUID_FEATURES }, 770 }; 771 772 if (cpuid->nent < 1) 773 goto out; 774 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 775 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 776 777 if (sanity_check_entries(entries, cpuid->nent, type)) 778 return -EINVAL; 779 780 r = -ENOMEM; 781 cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent); 782 if (!cpuid_entries) 783 goto out; 784 785 r = 0; 786 for (i = 0; i < ARRAY_SIZE(param); i++) { 787 const struct kvm_cpuid_param *ent = ¶m[i]; 788 789 if (ent->qualifier && !ent->qualifier(ent)) 790 continue; 791 792 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 793 &nent, cpuid->nent, type); 794 795 if (r) 796 goto out_free; 797 798 if (!ent->has_leaf_count) 799 continue; 800 801 limit = cpuid_entries[nent - 1].eax; 802 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 803 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 804 &nent, cpuid->nent, type); 805 806 if (r) 807 goto out_free; 808 } 809 810 r = -EFAULT; 811 if (copy_to_user(entries, cpuid_entries, 812 nent * sizeof(struct kvm_cpuid_entry2))) 813 goto out_free; 814 cpuid->nent = nent; 815 r = 0; 816 817 out_free: 818 vfree(cpuid_entries); 819 out: 820 return r; 821 } 822 823 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 824 { 825 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 826 struct kvm_cpuid_entry2 *ej; 827 int j = i; 828 int nent = vcpu->arch.cpuid_nent; 829 830 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 831 /* when no next entry is found, the current entry[i] is reselected */ 832 do { 833 j = (j + 1) % nent; 834 ej = &vcpu->arch.cpuid_entries[j]; 835 } while (ej->function != e->function); 836 837 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 838 839 return j; 840 } 841 842 /* find an entry with matching function, matching index (if needed), and that 843 * should be read next (if it's stateful) */ 844 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 845 u32 function, u32 index) 846 { 847 if (e->function != function) 848 return 0; 849 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 850 return 0; 851 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 852 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 853 return 0; 854 return 1; 855 } 856 857 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 858 u32 function, u32 index) 859 { 860 int i; 861 struct kvm_cpuid_entry2 *best = NULL; 862 863 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 864 struct kvm_cpuid_entry2 *e; 865 866 e = &vcpu->arch.cpuid_entries[i]; 867 if (is_matching_cpuid_entry(e, function, index)) { 868 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 869 move_to_next_stateful_cpuid_entry(vcpu, i); 870 best = e; 871 break; 872 } 873 } 874 return best; 875 } 876 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 877 878 /* 879 * If no match is found, check whether we exceed the vCPU's limit 880 * and return the content of the highest valid _standard_ leaf instead. 881 * This is to satisfy the CPUID specification. 882 */ 883 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 884 u32 function, u32 index) 885 { 886 struct kvm_cpuid_entry2 *maxlevel; 887 888 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 889 if (!maxlevel || maxlevel->eax >= function) 890 return NULL; 891 if (function & 0x80000000) { 892 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 893 if (!maxlevel) 894 return NULL; 895 } 896 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 897 } 898 899 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 900 u32 *ecx, u32 *edx, bool check_limit) 901 { 902 u32 function = *eax, index = *ecx; 903 struct kvm_cpuid_entry2 *best; 904 bool entry_found = true; 905 906 best = kvm_find_cpuid_entry(vcpu, function, index); 907 908 if (!best) { 909 entry_found = false; 910 if (!check_limit) 911 goto out; 912 913 best = check_cpuid_limit(vcpu, function, index); 914 } 915 916 out: 917 if (best) { 918 *eax = best->eax; 919 *ebx = best->ebx; 920 *ecx = best->ecx; 921 *edx = best->edx; 922 } else 923 *eax = *ebx = *ecx = *edx = 0; 924 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); 925 return entry_found; 926 } 927 EXPORT_SYMBOL_GPL(kvm_cpuid); 928 929 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 930 { 931 u32 eax, ebx, ecx, edx; 932 933 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 934 return 1; 935 936 eax = kvm_register_read(vcpu, VCPU_REGS_RAX); 937 ecx = kvm_register_read(vcpu, VCPU_REGS_RCX); 938 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); 939 kvm_register_write(vcpu, VCPU_REGS_RAX, eax); 940 kvm_register_write(vcpu, VCPU_REGS_RBX, ebx); 941 kvm_register_write(vcpu, VCPU_REGS_RCX, ecx); 942 kvm_register_write(vcpu, VCPU_REGS_RDX, edx); 943 return kvm_skip_emulated_instruction(vcpu); 944 } 945 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 946