1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Kernel-based Virtual Machine driver for Linux 4 * cpuid support routines 5 * 6 * derived from arch/x86/kvm/x86.c 7 * 8 * Copyright 2011 Red Hat, Inc. and/or its affiliates. 9 * Copyright IBM Corporation, 2008 10 */ 11 12 #include <linux/kvm_host.h> 13 #include <linux/export.h> 14 #include <linux/vmalloc.h> 15 #include <linux/uaccess.h> 16 #include <linux/sched/stat.h> 17 18 #include <asm/processor.h> 19 #include <asm/user.h> 20 #include <asm/fpu/xstate.h> 21 #include <asm/sgx.h> 22 #include <asm/cpuid.h> 23 #include "cpuid.h" 24 #include "lapic.h" 25 #include "mmu.h" 26 #include "trace.h" 27 #include "pmu.h" 28 29 /* 30 * Unlike "struct cpuinfo_x86.x86_capability", kvm_cpu_caps doesn't need to be 31 * aligned to sizeof(unsigned long) because it's not accessed via bitops. 32 */ 33 u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly; 34 EXPORT_SYMBOL_GPL(kvm_cpu_caps); 35 36 u32 xstate_required_size(u64 xstate_bv, bool compacted) 37 { 38 int feature_bit = 0; 39 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 40 41 xstate_bv &= XFEATURE_MASK_EXTEND; 42 while (xstate_bv) { 43 if (xstate_bv & 0x1) { 44 u32 eax, ebx, ecx, edx, offset; 45 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 46 /* ECX[1]: 64B alignment in compacted form */ 47 if (compacted) 48 offset = (ecx & 0x2) ? ALIGN(ret, 64) : ret; 49 else 50 offset = ebx; 51 ret = max(ret, offset + eax); 52 } 53 54 xstate_bv >>= 1; 55 feature_bit++; 56 } 57 58 return ret; 59 } 60 61 /* 62 * This one is tied to SSB in the user API, and not 63 * visible in /proc/cpuinfo. 64 */ 65 #define KVM_X86_FEATURE_PSFD (13*32+28) /* Predictive Store Forwarding Disable */ 66 67 #define F feature_bit 68 #define SF(name) (boot_cpu_has(X86_FEATURE_##name) ? F(name) : 0) 69 70 /* 71 * Magic value used by KVM when querying userspace-provided CPUID entries and 72 * doesn't care about the CPIUD index because the index of the function in 73 * question is not significant. Note, this magic value must have at least one 74 * bit set in bits[63:32] and must be consumed as a u64 by cpuid_entry2_find() 75 * to avoid false positives when processing guest CPUID input. 76 */ 77 #define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull 78 79 static inline struct kvm_cpuid_entry2 *cpuid_entry2_find( 80 struct kvm_cpuid_entry2 *entries, int nent, u32 function, u64 index) 81 { 82 struct kvm_cpuid_entry2 *e; 83 int i; 84 85 for (i = 0; i < nent; i++) { 86 e = &entries[i]; 87 88 if (e->function != function) 89 continue; 90 91 /* 92 * If the index isn't significant, use the first entry with a 93 * matching function. It's userspace's responsibilty to not 94 * provide "duplicate" entries in all cases. 95 */ 96 if (!(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) || e->index == index) 97 return e; 98 99 100 /* 101 * Similarly, use the first matching entry if KVM is doing a 102 * lookup (as opposed to emulating CPUID) for a function that's 103 * architecturally defined as not having a significant index. 104 */ 105 if (index == KVM_CPUID_INDEX_NOT_SIGNIFICANT) { 106 /* 107 * Direct lookups from KVM should not diverge from what 108 * KVM defines internally (the architectural behavior). 109 */ 110 WARN_ON_ONCE(cpuid_function_is_indexed(function)); 111 return e; 112 } 113 } 114 115 return NULL; 116 } 117 118 static int kvm_check_cpuid(struct kvm_vcpu *vcpu, 119 struct kvm_cpuid_entry2 *entries, 120 int nent) 121 { 122 struct kvm_cpuid_entry2 *best; 123 u64 xfeatures; 124 125 /* 126 * The existing code assumes virtual address is 48-bit or 57-bit in the 127 * canonical address checks; exit if it is ever changed. 128 */ 129 best = cpuid_entry2_find(entries, nent, 0x80000008, 130 KVM_CPUID_INDEX_NOT_SIGNIFICANT); 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 /* 139 * Exposing dynamic xfeatures to the guest requires additional 140 * enabling in the FPU, e.g. to expand the guest XSAVE state size. 141 */ 142 best = cpuid_entry2_find(entries, nent, 0xd, 0); 143 if (!best) 144 return 0; 145 146 xfeatures = best->eax | ((u64)best->edx << 32); 147 xfeatures &= XFEATURE_MASK_USER_DYNAMIC; 148 if (!xfeatures) 149 return 0; 150 151 return fpu_enable_guest_xfd_features(&vcpu->arch.guest_fpu, xfeatures); 152 } 153 154 /* Check whether the supplied CPUID data is equal to what is already set for the vCPU. */ 155 static int kvm_cpuid_check_equal(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, 156 int nent) 157 { 158 struct kvm_cpuid_entry2 *orig; 159 int i; 160 161 if (nent != vcpu->arch.cpuid_nent) 162 return -EINVAL; 163 164 for (i = 0; i < nent; i++) { 165 orig = &vcpu->arch.cpuid_entries[i]; 166 if (e2[i].function != orig->function || 167 e2[i].index != orig->index || 168 e2[i].flags != orig->flags || 169 e2[i].eax != orig->eax || e2[i].ebx != orig->ebx || 170 e2[i].ecx != orig->ecx || e2[i].edx != orig->edx) 171 return -EINVAL; 172 } 173 174 return 0; 175 } 176 177 static void kvm_update_kvm_cpuid_base(struct kvm_vcpu *vcpu) 178 { 179 u32 function; 180 struct kvm_cpuid_entry2 *entry; 181 182 vcpu->arch.kvm_cpuid_base = 0; 183 184 for_each_possible_hypervisor_cpuid_base(function) { 185 entry = kvm_find_cpuid_entry(vcpu, function); 186 187 if (entry) { 188 u32 signature[3]; 189 190 signature[0] = entry->ebx; 191 signature[1] = entry->ecx; 192 signature[2] = entry->edx; 193 194 BUILD_BUG_ON(sizeof(signature) > sizeof(KVM_SIGNATURE)); 195 if (!memcmp(signature, KVM_SIGNATURE, sizeof(signature))) { 196 vcpu->arch.kvm_cpuid_base = function; 197 break; 198 } 199 } 200 } 201 } 202 203 static struct kvm_cpuid_entry2 *__kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu, 204 struct kvm_cpuid_entry2 *entries, int nent) 205 { 206 u32 base = vcpu->arch.kvm_cpuid_base; 207 208 if (!base) 209 return NULL; 210 211 return cpuid_entry2_find(entries, nent, base | KVM_CPUID_FEATURES, 212 KVM_CPUID_INDEX_NOT_SIGNIFICANT); 213 } 214 215 static struct kvm_cpuid_entry2 *kvm_find_kvm_cpuid_features(struct kvm_vcpu *vcpu) 216 { 217 return __kvm_find_kvm_cpuid_features(vcpu, vcpu->arch.cpuid_entries, 218 vcpu->arch.cpuid_nent); 219 } 220 221 void kvm_update_pv_runtime(struct kvm_vcpu *vcpu) 222 { 223 struct kvm_cpuid_entry2 *best = kvm_find_kvm_cpuid_features(vcpu); 224 225 /* 226 * save the feature bitmap to avoid cpuid lookup for every PV 227 * operation 228 */ 229 if (best) 230 vcpu->arch.pv_cpuid.features = best->eax; 231 } 232 233 /* 234 * Calculate guest's supported XCR0 taking into account guest CPUID data and 235 * KVM's supported XCR0 (comprised of host's XCR0 and KVM_SUPPORTED_XCR0). 236 */ 237 static u64 cpuid_get_supported_xcr0(struct kvm_cpuid_entry2 *entries, int nent) 238 { 239 struct kvm_cpuid_entry2 *best; 240 241 best = cpuid_entry2_find(entries, nent, 0xd, 0); 242 if (!best) 243 return 0; 244 245 return (best->eax | ((u64)best->edx << 32)) & kvm_caps.supported_xcr0; 246 } 247 248 static void __kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *entries, 249 int nent) 250 { 251 struct kvm_cpuid_entry2 *best; 252 u64 guest_supported_xcr0 = cpuid_get_supported_xcr0(entries, nent); 253 254 best = cpuid_entry2_find(entries, nent, 1, KVM_CPUID_INDEX_NOT_SIGNIFICANT); 255 if (best) { 256 /* Update OSXSAVE bit */ 257 if (boot_cpu_has(X86_FEATURE_XSAVE)) 258 cpuid_entry_change(best, X86_FEATURE_OSXSAVE, 259 kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)); 260 261 cpuid_entry_change(best, X86_FEATURE_APIC, 262 vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE); 263 } 264 265 best = cpuid_entry2_find(entries, nent, 7, 0); 266 if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) 267 cpuid_entry_change(best, X86_FEATURE_OSPKE, 268 kvm_read_cr4_bits(vcpu, X86_CR4_PKE)); 269 270 best = cpuid_entry2_find(entries, nent, 0xD, 0); 271 if (best) 272 best->ebx = xstate_required_size(vcpu->arch.xcr0, false); 273 274 best = cpuid_entry2_find(entries, nent, 0xD, 1); 275 if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || 276 cpuid_entry_has(best, X86_FEATURE_XSAVEC))) 277 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 278 279 best = __kvm_find_kvm_cpuid_features(vcpu, entries, nent); 280 if (kvm_hlt_in_guest(vcpu->kvm) && best && 281 (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) 282 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); 283 284 if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) { 285 best = cpuid_entry2_find(entries, nent, 0x1, KVM_CPUID_INDEX_NOT_SIGNIFICANT); 286 if (best) 287 cpuid_entry_change(best, X86_FEATURE_MWAIT, 288 vcpu->arch.ia32_misc_enable_msr & 289 MSR_IA32_MISC_ENABLE_MWAIT); 290 } 291 292 /* 293 * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate 294 * the supported XSAVE Feature Request Mask (XFRM), i.e. the enclave's 295 * requested XCR0 value. The enclave's XFRM must be a subset of XCRO 296 * at the time of EENTER, thus adjust the allowed XFRM by the guest's 297 * supported XCR0. Similar to XCR0 handling, FP and SSE are forced to 298 * '1' even on CPUs that don't support XSAVE. 299 */ 300 best = cpuid_entry2_find(entries, nent, 0x12, 0x1); 301 if (best) { 302 best->ecx &= guest_supported_xcr0 & 0xffffffff; 303 best->edx &= guest_supported_xcr0 >> 32; 304 best->ecx |= XFEATURE_MASK_FPSSE; 305 } 306 } 307 308 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) 309 { 310 __kvm_update_cpuid_runtime(vcpu, vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); 311 } 312 EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime); 313 314 static bool kvm_cpuid_has_hyperv(struct kvm_cpuid_entry2 *entries, int nent) 315 { 316 struct kvm_cpuid_entry2 *entry; 317 318 entry = cpuid_entry2_find(entries, nent, HYPERV_CPUID_INTERFACE, 319 KVM_CPUID_INDEX_NOT_SIGNIFICANT); 320 return entry && entry->eax == HYPERV_CPUID_SIGNATURE_EAX; 321 } 322 323 static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) 324 { 325 struct kvm_lapic *apic = vcpu->arch.apic; 326 struct kvm_cpuid_entry2 *best; 327 328 best = kvm_find_cpuid_entry(vcpu, 1); 329 if (best && apic) { 330 if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER)) 331 apic->lapic_timer.timer_mode_mask = 3 << 17; 332 else 333 apic->lapic_timer.timer_mode_mask = 1 << 17; 334 335 kvm_apic_set_version(vcpu); 336 } 337 338 vcpu->arch.guest_supported_xcr0 = 339 cpuid_get_supported_xcr0(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent); 340 341 /* 342 * FP+SSE can always be saved/restored via KVM_{G,S}ET_XSAVE, even if 343 * XSAVE/XCRO are not exposed to the guest, and even if XSAVE isn't 344 * supported by the host. 345 */ 346 vcpu->arch.guest_fpu.fpstate->user_xfeatures = vcpu->arch.guest_supported_xcr0 | 347 XFEATURE_MASK_FPSSE; 348 349 kvm_update_pv_runtime(vcpu); 350 351 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 352 vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu); 353 354 kvm_pmu_refresh(vcpu); 355 vcpu->arch.cr4_guest_rsvd_bits = 356 __cr4_reserved_bits(guest_cpuid_has, vcpu); 357 358 kvm_hv_set_cpuid(vcpu, kvm_cpuid_has_hyperv(vcpu->arch.cpuid_entries, 359 vcpu->arch.cpuid_nent)); 360 361 /* Invoke the vendor callback only after the above state is updated. */ 362 static_call(kvm_x86_vcpu_after_set_cpuid)(vcpu); 363 364 /* 365 * Except for the MMU, which needs to do its thing any vendor specific 366 * adjustments to the reserved GPA bits. 367 */ 368 kvm_mmu_after_set_cpuid(vcpu); 369 } 370 371 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 372 { 373 struct kvm_cpuid_entry2 *best; 374 375 best = kvm_find_cpuid_entry(vcpu, 0x80000000); 376 if (!best || best->eax < 0x80000008) 377 goto not_found; 378 best = kvm_find_cpuid_entry(vcpu, 0x80000008); 379 if (best) 380 return best->eax & 0xff; 381 not_found: 382 return 36; 383 } 384 385 /* 386 * This "raw" version returns the reserved GPA bits without any adjustments for 387 * encryption technologies that usurp bits. The raw mask should be used if and 388 * only if hardware does _not_ strip the usurped bits, e.g. in virtual MTRRs. 389 */ 390 u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu) 391 { 392 return rsvd_bits(cpuid_maxphyaddr(vcpu), 63); 393 } 394 395 static int kvm_set_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid_entry2 *e2, 396 int nent) 397 { 398 int r; 399 400 __kvm_update_cpuid_runtime(vcpu, e2, nent); 401 402 /* 403 * KVM does not correctly handle changing guest CPUID after KVM_RUN, as 404 * MAXPHYADDR, GBPAGES support, AMD reserved bit behavior, etc.. aren't 405 * tracked in kvm_mmu_page_role. As a result, KVM may miss guest page 406 * faults due to reusing SPs/SPTEs. In practice no sane VMM mucks with 407 * the core vCPU model on the fly. It would've been better to forbid any 408 * KVM_SET_CPUID{,2} calls after KVM_RUN altogether but unfortunately 409 * some VMMs (e.g. QEMU) reuse vCPU fds for CPU hotplug/unplug and do 410 * KVM_SET_CPUID{,2} again. To support this legacy behavior, check 411 * whether the supplied CPUID data is equal to what's already set. 412 */ 413 if (vcpu->arch.last_vmentry_cpu != -1) { 414 r = kvm_cpuid_check_equal(vcpu, e2, nent); 415 if (r) 416 return r; 417 418 kvfree(e2); 419 return 0; 420 } 421 422 if (kvm_cpuid_has_hyperv(e2, nent)) { 423 r = kvm_hv_vcpu_init(vcpu); 424 if (r) 425 return r; 426 } 427 428 r = kvm_check_cpuid(vcpu, e2, nent); 429 if (r) 430 return r; 431 432 kvfree(vcpu->arch.cpuid_entries); 433 vcpu->arch.cpuid_entries = e2; 434 vcpu->arch.cpuid_nent = nent; 435 436 kvm_update_kvm_cpuid_base(vcpu); 437 kvm_vcpu_after_set_cpuid(vcpu); 438 439 return 0; 440 } 441 442 /* when an old userspace process fills a new kernel module */ 443 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 444 struct kvm_cpuid *cpuid, 445 struct kvm_cpuid_entry __user *entries) 446 { 447 int r, i; 448 struct kvm_cpuid_entry *e = NULL; 449 struct kvm_cpuid_entry2 *e2 = NULL; 450 451 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 452 return -E2BIG; 453 454 if (cpuid->nent) { 455 e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent)); 456 if (IS_ERR(e)) 457 return PTR_ERR(e); 458 459 e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT); 460 if (!e2) { 461 r = -ENOMEM; 462 goto out_free_cpuid; 463 } 464 } 465 for (i = 0; i < cpuid->nent; i++) { 466 e2[i].function = e[i].function; 467 e2[i].eax = e[i].eax; 468 e2[i].ebx = e[i].ebx; 469 e2[i].ecx = e[i].ecx; 470 e2[i].edx = e[i].edx; 471 e2[i].index = 0; 472 e2[i].flags = 0; 473 e2[i].padding[0] = 0; 474 e2[i].padding[1] = 0; 475 e2[i].padding[2] = 0; 476 } 477 478 r = kvm_set_cpuid(vcpu, e2, cpuid->nent); 479 if (r) 480 kvfree(e2); 481 482 out_free_cpuid: 483 kvfree(e); 484 485 return r; 486 } 487 488 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 489 struct kvm_cpuid2 *cpuid, 490 struct kvm_cpuid_entry2 __user *entries) 491 { 492 struct kvm_cpuid_entry2 *e2 = NULL; 493 int r; 494 495 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 496 return -E2BIG; 497 498 if (cpuid->nent) { 499 e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent)); 500 if (IS_ERR(e2)) 501 return PTR_ERR(e2); 502 } 503 504 r = kvm_set_cpuid(vcpu, e2, cpuid->nent); 505 if (r) 506 kvfree(e2); 507 508 return r; 509 } 510 511 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 512 struct kvm_cpuid2 *cpuid, 513 struct kvm_cpuid_entry2 __user *entries) 514 { 515 int r; 516 517 r = -E2BIG; 518 if (cpuid->nent < vcpu->arch.cpuid_nent) 519 goto out; 520 r = -EFAULT; 521 if (copy_to_user(entries, vcpu->arch.cpuid_entries, 522 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 523 goto out; 524 return 0; 525 526 out: 527 cpuid->nent = vcpu->arch.cpuid_nent; 528 return r; 529 } 530 531 /* Mask kvm_cpu_caps for @leaf with the raw CPUID capabilities of this CPU. */ 532 static __always_inline void __kvm_cpu_cap_mask(unsigned int leaf) 533 { 534 const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32); 535 struct kvm_cpuid_entry2 entry; 536 537 reverse_cpuid_check(leaf); 538 539 cpuid_count(cpuid.function, cpuid.index, 540 &entry.eax, &entry.ebx, &entry.ecx, &entry.edx); 541 542 kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, cpuid.reg); 543 } 544 545 static __always_inline 546 void kvm_cpu_cap_init_scattered(enum kvm_only_cpuid_leafs leaf, u32 mask) 547 { 548 /* Use kvm_cpu_cap_mask for non-scattered leafs. */ 549 BUILD_BUG_ON(leaf < NCAPINTS); 550 551 kvm_cpu_caps[leaf] = mask; 552 553 __kvm_cpu_cap_mask(leaf); 554 } 555 556 static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) 557 { 558 /* Use kvm_cpu_cap_init_scattered for scattered leafs. */ 559 BUILD_BUG_ON(leaf >= NCAPINTS); 560 561 kvm_cpu_caps[leaf] &= mask; 562 563 __kvm_cpu_cap_mask(leaf); 564 } 565 566 void kvm_set_cpu_caps(void) 567 { 568 #ifdef CONFIG_X86_64 569 unsigned int f_gbpages = F(GBPAGES); 570 unsigned int f_lm = F(LM); 571 unsigned int f_xfd = F(XFD); 572 #else 573 unsigned int f_gbpages = 0; 574 unsigned int f_lm = 0; 575 unsigned int f_xfd = 0; 576 #endif 577 memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps)); 578 579 BUILD_BUG_ON(sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps)) > 580 sizeof(boot_cpu_data.x86_capability)); 581 582 memcpy(&kvm_cpu_caps, &boot_cpu_data.x86_capability, 583 sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps))); 584 585 kvm_cpu_cap_mask(CPUID_1_ECX, 586 /* 587 * NOTE: MONITOR (and MWAIT) are emulated as NOP, but *not* 588 * advertised to guests via CPUID! 589 */ 590 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 591 0 /* DS-CPL, VMX, SMX, EST */ | 592 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 593 F(FMA) | F(CX16) | 0 /* xTPR Update */ | F(PDCM) | 594 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 595 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 596 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 597 F(F16C) | F(RDRAND) 598 ); 599 /* KVM emulates x2apic in software irrespective of host support. */ 600 kvm_cpu_cap_set(X86_FEATURE_X2APIC); 601 602 kvm_cpu_cap_mask(CPUID_1_EDX, 603 F(FPU) | F(VME) | F(DE) | F(PSE) | 604 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 605 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 606 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 607 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 608 0 /* Reserved, DS, ACPI */ | F(MMX) | 609 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 610 0 /* HTT, TM, Reserved, PBE */ 611 ); 612 613 kvm_cpu_cap_mask(CPUID_7_0_EBX, 614 F(FSGSBASE) | F(SGX) | F(BMI1) | F(HLE) | F(AVX2) | 615 F(FDP_EXCPTN_ONLY) | F(SMEP) | F(BMI2) | F(ERMS) | F(INVPCID) | 616 F(RTM) | F(ZERO_FCS_FDS) | 0 /*MPX*/ | F(AVX512F) | 617 F(AVX512DQ) | F(RDSEED) | F(ADX) | F(SMAP) | F(AVX512IFMA) | 618 F(CLFLUSHOPT) | F(CLWB) | 0 /*INTEL_PT*/ | F(AVX512PF) | 619 F(AVX512ER) | F(AVX512CD) | F(SHA_NI) | F(AVX512BW) | 620 F(AVX512VL)); 621 622 kvm_cpu_cap_mask(CPUID_7_ECX, 623 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(RDPID) | 624 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 625 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | 626 F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/ | 627 F(SGX_LC) | F(BUS_LOCK_DETECT) 628 ); 629 /* Set LA57 based on hardware capability. */ 630 if (cpuid_ecx(7) & F(LA57)) 631 kvm_cpu_cap_set(X86_FEATURE_LA57); 632 633 /* 634 * PKU not yet implemented for shadow paging and requires OSPKE 635 * to be set on the host. Clear it if that is not the case 636 */ 637 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 638 kvm_cpu_cap_clear(X86_FEATURE_PKU); 639 640 kvm_cpu_cap_mask(CPUID_7_EDX, 641 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 642 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) | 643 F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) | 644 F(SERIALIZE) | F(TSXLDTRK) | F(AVX512_FP16) | 645 F(AMX_TILE) | F(AMX_INT8) | F(AMX_BF16) 646 ); 647 648 /* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */ 649 kvm_cpu_cap_set(X86_FEATURE_TSC_ADJUST); 650 kvm_cpu_cap_set(X86_FEATURE_ARCH_CAPABILITIES); 651 652 if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS)) 653 kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL); 654 if (boot_cpu_has(X86_FEATURE_STIBP)) 655 kvm_cpu_cap_set(X86_FEATURE_INTEL_STIBP); 656 if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) 657 kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD); 658 659 kvm_cpu_cap_mask(CPUID_7_1_EAX, 660 F(AVX_VNNI) | F(AVX512_BF16) 661 ); 662 663 kvm_cpu_cap_mask(CPUID_D_1_EAX, 664 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) | f_xfd 665 ); 666 667 kvm_cpu_cap_init_scattered(CPUID_12_EAX, 668 SF(SGX1) | SF(SGX2) | SF(SGX_EDECCSSA) 669 ); 670 671 kvm_cpu_cap_mask(CPUID_8000_0001_ECX, 672 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 673 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 674 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 675 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 676 F(TOPOEXT) | 0 /* PERFCTR_CORE */ 677 ); 678 679 kvm_cpu_cap_mask(CPUID_8000_0001_EDX, 680 F(FPU) | F(VME) | F(DE) | F(PSE) | 681 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 682 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 683 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 684 F(PAT) | F(PSE36) | 0 /* Reserved */ | 685 F(NX) | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 686 F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) | 687 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW) 688 ); 689 690 if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64)) 691 kvm_cpu_cap_set(X86_FEATURE_GBPAGES); 692 693 kvm_cpu_cap_mask(CPUID_8000_0008_EBX, 694 F(CLZERO) | F(XSAVEERPTR) | 695 F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | 696 F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON) | 697 __feature_bit(KVM_X86_FEATURE_PSFD) 698 ); 699 700 /* 701 * AMD has separate bits for each SPEC_CTRL bit. 702 * arch/x86/kernel/cpu/bugs.c is kind enough to 703 * record that in cpufeatures so use them. 704 */ 705 if (boot_cpu_has(X86_FEATURE_IBPB)) 706 kvm_cpu_cap_set(X86_FEATURE_AMD_IBPB); 707 if (boot_cpu_has(X86_FEATURE_IBRS)) 708 kvm_cpu_cap_set(X86_FEATURE_AMD_IBRS); 709 if (boot_cpu_has(X86_FEATURE_STIBP)) 710 kvm_cpu_cap_set(X86_FEATURE_AMD_STIBP); 711 if (boot_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD)) 712 kvm_cpu_cap_set(X86_FEATURE_AMD_SSBD); 713 if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS)) 714 kvm_cpu_cap_set(X86_FEATURE_AMD_SSB_NO); 715 /* 716 * The preference is to use SPEC CTRL MSR instead of the 717 * VIRT_SPEC MSR. 718 */ 719 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && 720 !boot_cpu_has(X86_FEATURE_AMD_SSBD)) 721 kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD); 722 723 /* 724 * Hide all SVM features by default, SVM will set the cap bits for 725 * features it emulates and/or exposes for L1. 726 */ 727 kvm_cpu_cap_mask(CPUID_8000_000A_EDX, 0); 728 729 kvm_cpu_cap_mask(CPUID_8000_001F_EAX, 730 0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) | 731 F(SME_COHERENT)); 732 733 kvm_cpu_cap_mask(CPUID_C000_0001_EDX, 734 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 735 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 736 F(PMM) | F(PMM_EN) 737 ); 738 739 /* 740 * Hide RDTSCP and RDPID if either feature is reported as supported but 741 * probing MSR_TSC_AUX failed. This is purely a sanity check and 742 * should never happen, but the guest will likely crash if RDTSCP or 743 * RDPID is misreported, and KVM has botched MSR_TSC_AUX emulation in 744 * the past. For example, the sanity check may fire if this instance of 745 * KVM is running as L1 on top of an older, broken KVM. 746 */ 747 if (WARN_ON((kvm_cpu_cap_has(X86_FEATURE_RDTSCP) || 748 kvm_cpu_cap_has(X86_FEATURE_RDPID)) && 749 !kvm_is_supported_user_return_msr(MSR_TSC_AUX))) { 750 kvm_cpu_cap_clear(X86_FEATURE_RDTSCP); 751 kvm_cpu_cap_clear(X86_FEATURE_RDPID); 752 } 753 } 754 EXPORT_SYMBOL_GPL(kvm_set_cpu_caps); 755 756 struct kvm_cpuid_array { 757 struct kvm_cpuid_entry2 *entries; 758 int maxnent; 759 int nent; 760 }; 761 762 static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array, 763 u32 function, u32 index) 764 { 765 struct kvm_cpuid_entry2 *entry; 766 767 if (array->nent >= array->maxnent) 768 return NULL; 769 770 entry = &array->entries[array->nent++]; 771 772 memset(entry, 0, sizeof(*entry)); 773 entry->function = function; 774 entry->index = index; 775 switch (function & 0xC0000000) { 776 case 0x40000000: 777 /* Hypervisor leaves are always synthesized by __do_cpuid_func. */ 778 return entry; 779 780 case 0x80000000: 781 /* 782 * 0x80000021 is sometimes synthesized by __do_cpuid_func, which 783 * would result in out-of-bounds calls to do_host_cpuid. 784 */ 785 { 786 static int max_cpuid_80000000; 787 if (!READ_ONCE(max_cpuid_80000000)) 788 WRITE_ONCE(max_cpuid_80000000, cpuid_eax(0x80000000)); 789 if (function > READ_ONCE(max_cpuid_80000000)) 790 return entry; 791 } 792 break; 793 794 default: 795 break; 796 } 797 798 cpuid_count(entry->function, entry->index, 799 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 800 801 if (cpuid_function_is_indexed(function)) 802 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 803 804 return entry; 805 } 806 807 static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) 808 { 809 struct kvm_cpuid_entry2 *entry; 810 811 if (array->nent >= array->maxnent) 812 return -E2BIG; 813 814 entry = &array->entries[array->nent]; 815 entry->function = func; 816 entry->index = 0; 817 entry->flags = 0; 818 819 switch (func) { 820 case 0: 821 entry->eax = 7; 822 ++array->nent; 823 break; 824 case 1: 825 entry->ecx = F(MOVBE); 826 ++array->nent; 827 break; 828 case 7: 829 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 830 entry->eax = 0; 831 if (kvm_cpu_cap_has(X86_FEATURE_RDTSCP)) 832 entry->ecx = F(RDPID); 833 ++array->nent; 834 break; 835 default: 836 break; 837 } 838 839 return 0; 840 } 841 842 static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) 843 { 844 struct kvm_cpuid_entry2 *entry; 845 int r, i, max_idx; 846 847 /* all calls to cpuid_count() should be made on the same cpu */ 848 get_cpu(); 849 850 r = -E2BIG; 851 852 entry = do_host_cpuid(array, function, 0); 853 if (!entry) 854 goto out; 855 856 switch (function) { 857 case 0: 858 /* Limited to the highest leaf implemented in KVM. */ 859 entry->eax = min(entry->eax, 0x1fU); 860 break; 861 case 1: 862 cpuid_entry_override(entry, CPUID_1_EDX); 863 cpuid_entry_override(entry, CPUID_1_ECX); 864 break; 865 case 2: 866 /* 867 * On ancient CPUs, function 2 entries are STATEFUL. That is, 868 * CPUID(function=2, index=0) may return different results each 869 * time, with the least-significant byte in EAX enumerating the 870 * number of times software should do CPUID(2, 0). 871 * 872 * Modern CPUs, i.e. every CPU KVM has *ever* run on are less 873 * idiotic. Intel's SDM states that EAX & 0xff "will always 874 * return 01H. Software should ignore this value and not 875 * interpret it as an informational descriptor", while AMD's 876 * APM states that CPUID(2) is reserved. 877 * 878 * WARN if a frankenstein CPU that supports virtualization and 879 * a stateful CPUID.0x2 is encountered. 880 */ 881 WARN_ON_ONCE((entry->eax & 0xff) > 1); 882 break; 883 /* functions 4 and 0x8000001d have additional index. */ 884 case 4: 885 case 0x8000001d: 886 /* 887 * Read entries until the cache type in the previous entry is 888 * zero, i.e. indicates an invalid entry. 889 */ 890 for (i = 1; entry->eax & 0x1f; ++i) { 891 entry = do_host_cpuid(array, function, i); 892 if (!entry) 893 goto out; 894 } 895 break; 896 case 6: /* Thermal management */ 897 entry->eax = 0x4; /* allow ARAT */ 898 entry->ebx = 0; 899 entry->ecx = 0; 900 entry->edx = 0; 901 break; 902 /* function 7 has additional index. */ 903 case 7: 904 entry->eax = min(entry->eax, 1u); 905 cpuid_entry_override(entry, CPUID_7_0_EBX); 906 cpuid_entry_override(entry, CPUID_7_ECX); 907 cpuid_entry_override(entry, CPUID_7_EDX); 908 909 /* KVM only supports 0x7.0 and 0x7.1, capped above via min(). */ 910 if (entry->eax == 1) { 911 entry = do_host_cpuid(array, function, 1); 912 if (!entry) 913 goto out; 914 915 cpuid_entry_override(entry, CPUID_7_1_EAX); 916 entry->ebx = 0; 917 entry->ecx = 0; 918 entry->edx = 0; 919 } 920 break; 921 case 0xa: { /* Architectural Performance Monitoring */ 922 union cpuid10_eax eax; 923 union cpuid10_edx edx; 924 925 if (!static_cpu_has(X86_FEATURE_ARCH_PERFMON)) { 926 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 927 break; 928 } 929 930 eax.split.version_id = kvm_pmu_cap.version; 931 eax.split.num_counters = kvm_pmu_cap.num_counters_gp; 932 eax.split.bit_width = kvm_pmu_cap.bit_width_gp; 933 eax.split.mask_length = kvm_pmu_cap.events_mask_len; 934 edx.split.num_counters_fixed = kvm_pmu_cap.num_counters_fixed; 935 edx.split.bit_width_fixed = kvm_pmu_cap.bit_width_fixed; 936 937 if (kvm_pmu_cap.version) 938 edx.split.anythread_deprecated = 1; 939 edx.split.reserved1 = 0; 940 edx.split.reserved2 = 0; 941 942 entry->eax = eax.full; 943 entry->ebx = kvm_pmu_cap.events_mask; 944 entry->ecx = 0; 945 entry->edx = edx.full; 946 break; 947 } 948 /* 949 * Per Intel's SDM, the 0x1f is a superset of 0xb, 950 * thus they can be handled by common code. 951 */ 952 case 0x1f: 953 case 0xb: 954 /* 955 * Populate entries until the level type (ECX[15:8]) of the 956 * previous entry is zero. Note, CPUID EAX.{0x1f,0xb}.0 is 957 * the starting entry, filled by the primary do_host_cpuid(). 958 */ 959 for (i = 1; entry->ecx & 0xff00; ++i) { 960 entry = do_host_cpuid(array, function, i); 961 if (!entry) 962 goto out; 963 } 964 break; 965 case 0xd: { 966 u64 permitted_xcr0 = kvm_caps.supported_xcr0 & xstate_get_guest_group_perm(); 967 u64 permitted_xss = kvm_caps.supported_xss; 968 969 entry->eax &= permitted_xcr0; 970 entry->ebx = xstate_required_size(permitted_xcr0, false); 971 entry->ecx = entry->ebx; 972 entry->edx &= permitted_xcr0 >> 32; 973 if (!permitted_xcr0) 974 break; 975 976 entry = do_host_cpuid(array, function, 1); 977 if (!entry) 978 goto out; 979 980 cpuid_entry_override(entry, CPUID_D_1_EAX); 981 if (entry->eax & (F(XSAVES)|F(XSAVEC))) 982 entry->ebx = xstate_required_size(permitted_xcr0 | permitted_xss, 983 true); 984 else { 985 WARN_ON_ONCE(permitted_xss != 0); 986 entry->ebx = 0; 987 } 988 entry->ecx &= permitted_xss; 989 entry->edx &= permitted_xss >> 32; 990 991 for (i = 2; i < 64; ++i) { 992 bool s_state; 993 if (permitted_xcr0 & BIT_ULL(i)) 994 s_state = false; 995 else if (permitted_xss & BIT_ULL(i)) 996 s_state = true; 997 else 998 continue; 999 1000 entry = do_host_cpuid(array, function, i); 1001 if (!entry) 1002 goto out; 1003 1004 /* 1005 * The supported check above should have filtered out 1006 * invalid sub-leafs. Only valid sub-leafs should 1007 * reach this point, and they should have a non-zero 1008 * save state size. Furthermore, check whether the 1009 * processor agrees with permitted_xcr0/permitted_xss 1010 * on whether this is an XCR0- or IA32_XSS-managed area. 1011 */ 1012 if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) { 1013 --array->nent; 1014 continue; 1015 } 1016 1017 if (!kvm_cpu_cap_has(X86_FEATURE_XFD)) 1018 entry->ecx &= ~BIT_ULL(2); 1019 entry->edx = 0; 1020 } 1021 break; 1022 } 1023 case 0x12: 1024 /* Intel SGX */ 1025 if (!kvm_cpu_cap_has(X86_FEATURE_SGX)) { 1026 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1027 break; 1028 } 1029 1030 /* 1031 * Index 0: Sub-features, MISCSELECT (a.k.a extended features) 1032 * and max enclave sizes. The SGX sub-features and MISCSELECT 1033 * are restricted by kernel and KVM capabilities (like most 1034 * feature flags), while enclave size is unrestricted. 1035 */ 1036 cpuid_entry_override(entry, CPUID_12_EAX); 1037 entry->ebx &= SGX_MISC_EXINFO; 1038 1039 entry = do_host_cpuid(array, function, 1); 1040 if (!entry) 1041 goto out; 1042 1043 /* 1044 * Index 1: SECS.ATTRIBUTES. ATTRIBUTES are restricted a la 1045 * feature flags. Advertise all supported flags, including 1046 * privileged attributes that require explicit opt-in from 1047 * userspace. ATTRIBUTES.XFRM is not adjusted as userspace is 1048 * expected to derive it from supported XCR0. 1049 */ 1050 entry->eax &= SGX_ATTR_PRIV_MASK | SGX_ATTR_UNPRIV_MASK; 1051 entry->ebx &= 0; 1052 break; 1053 /* Intel PT */ 1054 case 0x14: 1055 if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT)) { 1056 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1057 break; 1058 } 1059 1060 for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) { 1061 if (!do_host_cpuid(array, function, i)) 1062 goto out; 1063 } 1064 break; 1065 /* Intel AMX TILE */ 1066 case 0x1d: 1067 if (!kvm_cpu_cap_has(X86_FEATURE_AMX_TILE)) { 1068 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1069 break; 1070 } 1071 1072 for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) { 1073 if (!do_host_cpuid(array, function, i)) 1074 goto out; 1075 } 1076 break; 1077 case 0x1e: /* TMUL information */ 1078 if (!kvm_cpu_cap_has(X86_FEATURE_AMX_TILE)) { 1079 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1080 break; 1081 } 1082 break; 1083 case KVM_CPUID_SIGNATURE: { 1084 const u32 *sigptr = (const u32 *)KVM_SIGNATURE; 1085 entry->eax = KVM_CPUID_FEATURES; 1086 entry->ebx = sigptr[0]; 1087 entry->ecx = sigptr[1]; 1088 entry->edx = sigptr[2]; 1089 break; 1090 } 1091 case KVM_CPUID_FEATURES: 1092 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 1093 (1 << KVM_FEATURE_NOP_IO_DELAY) | 1094 (1 << KVM_FEATURE_CLOCKSOURCE2) | 1095 (1 << KVM_FEATURE_ASYNC_PF) | 1096 (1 << KVM_FEATURE_PV_EOI) | 1097 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 1098 (1 << KVM_FEATURE_PV_UNHALT) | 1099 (1 << KVM_FEATURE_PV_TLB_FLUSH) | 1100 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | 1101 (1 << KVM_FEATURE_PV_SEND_IPI) | 1102 (1 << KVM_FEATURE_POLL_CONTROL) | 1103 (1 << KVM_FEATURE_PV_SCHED_YIELD) | 1104 (1 << KVM_FEATURE_ASYNC_PF_INT); 1105 1106 if (sched_info_on()) 1107 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 1108 1109 entry->ebx = 0; 1110 entry->ecx = 0; 1111 entry->edx = 0; 1112 break; 1113 case 0x80000000: 1114 entry->eax = min(entry->eax, 0x80000021); 1115 /* 1116 * Serializing LFENCE is reported in a multitude of ways, and 1117 * NullSegClearsBase is not reported in CPUID on Zen2; help 1118 * userspace by providing the CPUID leaf ourselves. 1119 * 1120 * However, only do it if the host has CPUID leaf 0x8000001d. 1121 * QEMU thinks that it can query the host blindly for that 1122 * CPUID leaf if KVM reports that it supports 0x8000001d or 1123 * above. The processor merrily returns values from the 1124 * highest Intel leaf which QEMU tries to use as the guest's 1125 * 0x8000001d. Even worse, this can result in an infinite 1126 * loop if said highest leaf has no subleaves indexed by ECX. 1127 */ 1128 if (entry->eax >= 0x8000001d && 1129 (static_cpu_has(X86_FEATURE_LFENCE_RDTSC) 1130 || !static_cpu_has_bug(X86_BUG_NULL_SEG))) 1131 entry->eax = max(entry->eax, 0x80000021); 1132 break; 1133 case 0x80000001: 1134 entry->ebx &= ~GENMASK(27, 16); 1135 cpuid_entry_override(entry, CPUID_8000_0001_EDX); 1136 cpuid_entry_override(entry, CPUID_8000_0001_ECX); 1137 break; 1138 case 0x80000006: 1139 /* Drop reserved bits, pass host L2 cache and TLB info. */ 1140 entry->edx &= ~GENMASK(17, 16); 1141 break; 1142 case 0x80000007: /* Advanced power management */ 1143 /* invariant TSC is CPUID.80000007H:EDX[8] */ 1144 entry->edx &= (1 << 8); 1145 /* mask against host */ 1146 entry->edx &= boot_cpu_data.x86_power; 1147 entry->eax = entry->ebx = entry->ecx = 0; 1148 break; 1149 case 0x80000008: { 1150 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 1151 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 1152 unsigned phys_as = entry->eax & 0xff; 1153 1154 /* 1155 * If TDP (NPT) is disabled use the adjusted host MAXPHYADDR as 1156 * the guest operates in the same PA space as the host, i.e. 1157 * reductions in MAXPHYADDR for memory encryption affect shadow 1158 * paging, too. 1159 * 1160 * If TDP is enabled but an explicit guest MAXPHYADDR is not 1161 * provided, use the raw bare metal MAXPHYADDR as reductions to 1162 * the HPAs do not affect GPAs. 1163 */ 1164 if (!tdp_enabled) 1165 g_phys_as = boot_cpu_data.x86_phys_bits; 1166 else if (!g_phys_as) 1167 g_phys_as = phys_as; 1168 1169 entry->eax = g_phys_as | (virt_as << 8); 1170 entry->ecx &= ~(GENMASK(31, 16) | GENMASK(11, 8)); 1171 entry->edx = 0; 1172 cpuid_entry_override(entry, CPUID_8000_0008_EBX); 1173 break; 1174 } 1175 case 0x8000000A: 1176 if (!kvm_cpu_cap_has(X86_FEATURE_SVM)) { 1177 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1178 break; 1179 } 1180 entry->eax = 1; /* SVM revision 1 */ 1181 entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper 1182 ASID emulation to nested SVM */ 1183 entry->ecx = 0; /* Reserved */ 1184 cpuid_entry_override(entry, CPUID_8000_000A_EDX); 1185 break; 1186 case 0x80000019: 1187 entry->ecx = entry->edx = 0; 1188 break; 1189 case 0x8000001a: 1190 entry->eax &= GENMASK(2, 0); 1191 entry->ebx = entry->ecx = entry->edx = 0; 1192 break; 1193 case 0x8000001e: 1194 break; 1195 case 0x8000001F: 1196 if (!kvm_cpu_cap_has(X86_FEATURE_SEV)) { 1197 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1198 } else { 1199 cpuid_entry_override(entry, CPUID_8000_001F_EAX); 1200 /* Clear NumVMPL since KVM does not support VMPL. */ 1201 entry->ebx &= ~GENMASK(31, 12); 1202 /* 1203 * Enumerate '0' for "PA bits reduction", the adjusted 1204 * MAXPHYADDR is enumerated directly (see 0x80000008). 1205 */ 1206 entry->ebx &= ~GENMASK(11, 6); 1207 } 1208 break; 1209 case 0x80000020: 1210 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1211 break; 1212 case 0x80000021: 1213 entry->ebx = entry->ecx = entry->edx = 0; 1214 /* 1215 * Pass down these bits: 1216 * EAX 0 NNDBP, Processor ignores nested data breakpoints 1217 * EAX 2 LAS, LFENCE always serializing 1218 * EAX 6 NSCB, Null selector clear base 1219 * 1220 * Other defined bits are for MSRs that KVM does not expose: 1221 * EAX 3 SPCL, SMM page configuration lock 1222 * EAX 13 PCMSR, Prefetch control MSR 1223 */ 1224 entry->eax &= BIT(0) | BIT(2) | BIT(6); 1225 if (static_cpu_has(X86_FEATURE_LFENCE_RDTSC)) 1226 entry->eax |= BIT(2); 1227 if (!static_cpu_has_bug(X86_BUG_NULL_SEG)) 1228 entry->eax |= BIT(6); 1229 break; 1230 /*Add support for Centaur's CPUID instruction*/ 1231 case 0xC0000000: 1232 /*Just support up to 0xC0000004 now*/ 1233 entry->eax = min(entry->eax, 0xC0000004); 1234 break; 1235 case 0xC0000001: 1236 cpuid_entry_override(entry, CPUID_C000_0001_EDX); 1237 break; 1238 case 3: /* Processor serial number */ 1239 case 5: /* MONITOR/MWAIT */ 1240 case 0xC0000002: 1241 case 0xC0000003: 1242 case 0xC0000004: 1243 default: 1244 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 1245 break; 1246 } 1247 1248 r = 0; 1249 1250 out: 1251 put_cpu(); 1252 1253 return r; 1254 } 1255 1256 static int do_cpuid_func(struct kvm_cpuid_array *array, u32 func, 1257 unsigned int type) 1258 { 1259 if (type == KVM_GET_EMULATED_CPUID) 1260 return __do_cpuid_func_emulated(array, func); 1261 1262 return __do_cpuid_func(array, func); 1263 } 1264 1265 #define CENTAUR_CPUID_SIGNATURE 0xC0000000 1266 1267 static int get_cpuid_func(struct kvm_cpuid_array *array, u32 func, 1268 unsigned int type) 1269 { 1270 u32 limit; 1271 int r; 1272 1273 if (func == CENTAUR_CPUID_SIGNATURE && 1274 boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR) 1275 return 0; 1276 1277 r = do_cpuid_func(array, func, type); 1278 if (r) 1279 return r; 1280 1281 limit = array->entries[array->nent - 1].eax; 1282 for (func = func + 1; func <= limit; ++func) { 1283 r = do_cpuid_func(array, func, type); 1284 if (r) 1285 break; 1286 } 1287 1288 return r; 1289 } 1290 1291 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 1292 __u32 num_entries, unsigned int ioctl_type) 1293 { 1294 int i; 1295 __u32 pad[3]; 1296 1297 if (ioctl_type != KVM_GET_EMULATED_CPUID) 1298 return false; 1299 1300 /* 1301 * We want to make sure that ->padding is being passed clean from 1302 * userspace in case we want to use it for something in the future. 1303 * 1304 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 1305 * have to give ourselves satisfied only with the emulated side. /me 1306 * sheds a tear. 1307 */ 1308 for (i = 0; i < num_entries; i++) { 1309 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 1310 return true; 1311 1312 if (pad[0] || pad[1] || pad[2]) 1313 return true; 1314 } 1315 return false; 1316 } 1317 1318 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 1319 struct kvm_cpuid_entry2 __user *entries, 1320 unsigned int type) 1321 { 1322 static const u32 funcs[] = { 1323 0, 0x80000000, CENTAUR_CPUID_SIGNATURE, KVM_CPUID_SIGNATURE, 1324 }; 1325 1326 struct kvm_cpuid_array array = { 1327 .nent = 0, 1328 }; 1329 int r, i; 1330 1331 if (cpuid->nent < 1) 1332 return -E2BIG; 1333 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 1334 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 1335 1336 if (sanity_check_entries(entries, cpuid->nent, type)) 1337 return -EINVAL; 1338 1339 array.entries = kvcalloc(cpuid->nent, sizeof(struct kvm_cpuid_entry2), GFP_KERNEL); 1340 if (!array.entries) 1341 return -ENOMEM; 1342 1343 array.maxnent = cpuid->nent; 1344 1345 for (i = 0; i < ARRAY_SIZE(funcs); i++) { 1346 r = get_cpuid_func(&array, funcs[i], type); 1347 if (r) 1348 goto out_free; 1349 } 1350 cpuid->nent = array.nent; 1351 1352 if (copy_to_user(entries, array.entries, 1353 array.nent * sizeof(struct kvm_cpuid_entry2))) 1354 r = -EFAULT; 1355 1356 out_free: 1357 kvfree(array.entries); 1358 return r; 1359 } 1360 1361 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu, 1362 u32 function, u32 index) 1363 { 1364 return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, 1365 function, index); 1366 } 1367 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry_index); 1368 1369 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 1370 u32 function) 1371 { 1372 return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, 1373 function, KVM_CPUID_INDEX_NOT_SIGNIFICANT); 1374 } 1375 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 1376 1377 /* 1378 * Intel CPUID semantics treats any query for an out-of-range leaf as if the 1379 * highest basic leaf (i.e. CPUID.0H:EAX) were requested. AMD CPUID semantics 1380 * returns all zeroes for any undefined leaf, whether or not the leaf is in 1381 * range. Centaur/VIA follows Intel semantics. 1382 * 1383 * A leaf is considered out-of-range if its function is higher than the maximum 1384 * supported leaf of its associated class or if its associated class does not 1385 * exist. 1386 * 1387 * There are three primary classes to be considered, with their respective 1388 * ranges described as "<base> - <top>[,<base2> - <top2>] inclusive. A primary 1389 * class exists if a guest CPUID entry for its <base> leaf exists. For a given 1390 * class, CPUID.<base>.EAX contains the max supported leaf for the class. 1391 * 1392 * - Basic: 0x00000000 - 0x3fffffff, 0x50000000 - 0x7fffffff 1393 * - Hypervisor: 0x40000000 - 0x4fffffff 1394 * - Extended: 0x80000000 - 0xbfffffff 1395 * - Centaur: 0xc0000000 - 0xcfffffff 1396 * 1397 * The Hypervisor class is further subdivided into sub-classes that each act as 1398 * their own independent class associated with a 0x100 byte range. E.g. if Qemu 1399 * is advertising support for both HyperV and KVM, the resulting Hypervisor 1400 * CPUID sub-classes are: 1401 * 1402 * - HyperV: 0x40000000 - 0x400000ff 1403 * - KVM: 0x40000100 - 0x400001ff 1404 */ 1405 static struct kvm_cpuid_entry2 * 1406 get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index) 1407 { 1408 struct kvm_cpuid_entry2 *basic, *class; 1409 u32 function = *fn_ptr; 1410 1411 basic = kvm_find_cpuid_entry(vcpu, 0); 1412 if (!basic) 1413 return NULL; 1414 1415 if (is_guest_vendor_amd(basic->ebx, basic->ecx, basic->edx) || 1416 is_guest_vendor_hygon(basic->ebx, basic->ecx, basic->edx)) 1417 return NULL; 1418 1419 if (function >= 0x40000000 && function <= 0x4fffffff) 1420 class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00); 1421 else if (function >= 0xc0000000) 1422 class = kvm_find_cpuid_entry(vcpu, 0xc0000000); 1423 else 1424 class = kvm_find_cpuid_entry(vcpu, function & 0x80000000); 1425 1426 if (class && function <= class->eax) 1427 return NULL; 1428 1429 /* 1430 * Leaf specific adjustments are also applied when redirecting to the 1431 * max basic entry, e.g. if the max basic leaf is 0xb but there is no 1432 * entry for CPUID.0xb.index (see below), then the output value for EDX 1433 * needs to be pulled from CPUID.0xb.1. 1434 */ 1435 *fn_ptr = basic->eax; 1436 1437 /* 1438 * The class does not exist or the requested function is out of range; 1439 * the effective CPUID entry is the max basic leaf. Note, the index of 1440 * the original requested leaf is observed! 1441 */ 1442 return kvm_find_cpuid_entry_index(vcpu, basic->eax, index); 1443 } 1444 1445 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 1446 u32 *ecx, u32 *edx, bool exact_only) 1447 { 1448 u32 orig_function = *eax, function = *eax, index = *ecx; 1449 struct kvm_cpuid_entry2 *entry; 1450 bool exact, used_max_basic = false; 1451 1452 entry = kvm_find_cpuid_entry_index(vcpu, function, index); 1453 exact = !!entry; 1454 1455 if (!entry && !exact_only) { 1456 entry = get_out_of_range_cpuid_entry(vcpu, &function, index); 1457 used_max_basic = !!entry; 1458 } 1459 1460 if (entry) { 1461 *eax = entry->eax; 1462 *ebx = entry->ebx; 1463 *ecx = entry->ecx; 1464 *edx = entry->edx; 1465 if (function == 7 && index == 0) { 1466 u64 data; 1467 if (!__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) && 1468 (data & TSX_CTRL_CPUID_CLEAR)) 1469 *ebx &= ~(F(RTM) | F(HLE)); 1470 } 1471 } else { 1472 *eax = *ebx = *ecx = *edx = 0; 1473 /* 1474 * When leaf 0BH or 1FH is defined, CL is pass-through 1475 * and EDX is always the x2APIC ID, even for undefined 1476 * subleaves. Index 1 will exist iff the leaf is 1477 * implemented, so we pass through CL iff leaf 1 1478 * exists. EDX can be copied from any existing index. 1479 */ 1480 if (function == 0xb || function == 0x1f) { 1481 entry = kvm_find_cpuid_entry_index(vcpu, function, 1); 1482 if (entry) { 1483 *ecx = index & 0xff; 1484 *edx = entry->edx; 1485 } 1486 } 1487 } 1488 trace_kvm_cpuid(orig_function, index, *eax, *ebx, *ecx, *edx, exact, 1489 used_max_basic); 1490 return exact; 1491 } 1492 EXPORT_SYMBOL_GPL(kvm_cpuid); 1493 1494 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 1495 { 1496 u32 eax, ebx, ecx, edx; 1497 1498 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 1499 return 1; 1500 1501 eax = kvm_rax_read(vcpu); 1502 ecx = kvm_rcx_read(vcpu); 1503 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, false); 1504 kvm_rax_write(vcpu, eax); 1505 kvm_rbx_write(vcpu, ebx); 1506 kvm_rcx_write(vcpu, ecx); 1507 kvm_rdx_write(vcpu, edx); 1508 return kvm_skip_emulated_instruction(vcpu); 1509 } 1510 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 1511