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 "cpuid.h" 23 #include "lapic.h" 24 #include "mmu.h" 25 #include "trace.h" 26 #include "pmu.h" 27 28 /* 29 * Unlike "struct cpuinfo_x86.x86_capability", kvm_cpu_caps doesn't need to be 30 * aligned to sizeof(unsigned long) because it's not accessed via bitops. 31 */ 32 u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly; 33 EXPORT_SYMBOL_GPL(kvm_cpu_caps); 34 35 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 36 { 37 int feature_bit = 0; 38 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 39 40 xstate_bv &= XFEATURE_MASK_EXTEND; 41 while (xstate_bv) { 42 if (xstate_bv & 0x1) { 43 u32 eax, ebx, ecx, edx, offset; 44 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 45 offset = compacted ? ret : ebx; 46 ret = max(ret, offset + eax); 47 } 48 49 xstate_bv >>= 1; 50 feature_bit++; 51 } 52 53 return ret; 54 } 55 56 #define F feature_bit 57 #define SF(name) (boot_cpu_has(X86_FEATURE_##name) ? F(name) : 0) 58 59 static inline struct kvm_cpuid_entry2 *cpuid_entry2_find( 60 struct kvm_cpuid_entry2 *entries, int nent, u32 function, u32 index) 61 { 62 struct kvm_cpuid_entry2 *e; 63 int i; 64 65 for (i = 0; i < nent; i++) { 66 e = &entries[i]; 67 68 if (e->function == function && (e->index == index || 69 !(e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX))) 70 return e; 71 } 72 73 return NULL; 74 } 75 76 static int kvm_check_cpuid(struct kvm_cpuid_entry2 *entries, int nent) 77 { 78 struct kvm_cpuid_entry2 *best; 79 80 /* 81 * The existing code assumes virtual address is 48-bit or 57-bit in the 82 * canonical address checks; exit if it is ever changed. 83 */ 84 best = cpuid_entry2_find(entries, nent, 0x80000008, 0); 85 if (best) { 86 int vaddr_bits = (best->eax & 0xff00) >> 8; 87 88 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) 89 return -EINVAL; 90 } 91 92 return 0; 93 } 94 95 void kvm_update_pv_runtime(struct kvm_vcpu *vcpu) 96 { 97 struct kvm_cpuid_entry2 *best; 98 99 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0); 100 101 /* 102 * save the feature bitmap to avoid cpuid lookup for every PV 103 * operation 104 */ 105 if (best) 106 vcpu->arch.pv_cpuid.features = best->eax; 107 } 108 109 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu) 110 { 111 struct kvm_cpuid_entry2 *best; 112 113 best = kvm_find_cpuid_entry(vcpu, 1, 0); 114 if (best) { 115 /* Update OSXSAVE bit */ 116 if (boot_cpu_has(X86_FEATURE_XSAVE)) 117 cpuid_entry_change(best, X86_FEATURE_OSXSAVE, 118 kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)); 119 120 cpuid_entry_change(best, X86_FEATURE_APIC, 121 vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE); 122 } 123 124 best = kvm_find_cpuid_entry(vcpu, 7, 0); 125 if (best && boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) 126 cpuid_entry_change(best, X86_FEATURE_OSPKE, 127 kvm_read_cr4_bits(vcpu, X86_CR4_PKE)); 128 129 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 130 if (best) 131 best->ebx = xstate_required_size(vcpu->arch.xcr0, false); 132 133 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 134 if (best && (cpuid_entry_has(best, X86_FEATURE_XSAVES) || 135 cpuid_entry_has(best, X86_FEATURE_XSAVEC))) 136 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 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 if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) { 144 best = kvm_find_cpuid_entry(vcpu, 0x1, 0); 145 if (best) 146 cpuid_entry_change(best, X86_FEATURE_MWAIT, 147 vcpu->arch.ia32_misc_enable_msr & 148 MSR_IA32_MISC_ENABLE_MWAIT); 149 } 150 } 151 EXPORT_SYMBOL_GPL(kvm_update_cpuid_runtime); 152 153 static void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) 154 { 155 struct kvm_lapic *apic = vcpu->arch.apic; 156 struct kvm_cpuid_entry2 *best; 157 158 best = kvm_find_cpuid_entry(vcpu, 1, 0); 159 if (best && apic) { 160 if (cpuid_entry_has(best, X86_FEATURE_TSC_DEADLINE_TIMER)) 161 apic->lapic_timer.timer_mode_mask = 3 << 17; 162 else 163 apic->lapic_timer.timer_mode_mask = 1 << 17; 164 165 kvm_apic_set_version(vcpu); 166 } 167 168 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 169 if (!best) 170 vcpu->arch.guest_supported_xcr0 = 0; 171 else 172 vcpu->arch.guest_supported_xcr0 = 173 (best->eax | ((u64)best->edx << 32)) & supported_xcr0; 174 175 /* 176 * Bits 127:0 of the allowed SECS.ATTRIBUTES (CPUID.0x12.0x1) enumerate 177 * the supported XSAVE Feature Request Mask (XFRM), i.e. the enclave's 178 * requested XCR0 value. The enclave's XFRM must be a subset of XCRO 179 * at the time of EENTER, thus adjust the allowed XFRM by the guest's 180 * supported XCR0. Similar to XCR0 handling, FP and SSE are forced to 181 * '1' even on CPUs that don't support XSAVE. 182 */ 183 best = kvm_find_cpuid_entry(vcpu, 0x12, 0x1); 184 if (best) { 185 best->ecx &= vcpu->arch.guest_supported_xcr0 & 0xffffffff; 186 best->edx &= vcpu->arch.guest_supported_xcr0 >> 32; 187 best->ecx |= XFEATURE_MASK_FPSSE; 188 } 189 190 kvm_update_pv_runtime(vcpu); 191 192 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 193 vcpu->arch.reserved_gpa_bits = kvm_vcpu_reserved_gpa_bits_raw(vcpu); 194 195 kvm_pmu_refresh(vcpu); 196 vcpu->arch.cr4_guest_rsvd_bits = 197 __cr4_reserved_bits(guest_cpuid_has, vcpu); 198 199 kvm_hv_set_cpuid(vcpu); 200 201 /* Invoke the vendor callback only after the above state is updated. */ 202 static_call(kvm_x86_vcpu_after_set_cpuid)(vcpu); 203 204 /* 205 * Except for the MMU, which needs to be reset after any vendor 206 * specific adjustments to the reserved GPA bits. 207 */ 208 kvm_mmu_reset_context(vcpu); 209 } 210 211 static int is_efer_nx(void) 212 { 213 return host_efer & EFER_NX; 214 } 215 216 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 217 { 218 int i; 219 struct kvm_cpuid_entry2 *e, *entry; 220 221 entry = NULL; 222 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 223 e = &vcpu->arch.cpuid_entries[i]; 224 if (e->function == 0x80000001) { 225 entry = e; 226 break; 227 } 228 } 229 if (entry && cpuid_entry_has(entry, X86_FEATURE_NX) && !is_efer_nx()) { 230 cpuid_entry_clear(entry, X86_FEATURE_NX); 231 printk(KERN_INFO "kvm: guest NX capability removed\n"); 232 } 233 } 234 235 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 236 { 237 struct kvm_cpuid_entry2 *best; 238 239 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 240 if (!best || best->eax < 0x80000008) 241 goto not_found; 242 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 243 if (best) 244 return best->eax & 0xff; 245 not_found: 246 return 36; 247 } 248 249 /* 250 * This "raw" version returns the reserved GPA bits without any adjustments for 251 * encryption technologies that usurp bits. The raw mask should be used if and 252 * only if hardware does _not_ strip the usurped bits, e.g. in virtual MTRRs. 253 */ 254 u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu) 255 { 256 return rsvd_bits(cpuid_maxphyaddr(vcpu), 63); 257 } 258 259 /* when an old userspace process fills a new kernel module */ 260 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 261 struct kvm_cpuid *cpuid, 262 struct kvm_cpuid_entry __user *entries) 263 { 264 int r, i; 265 struct kvm_cpuid_entry *e = NULL; 266 struct kvm_cpuid_entry2 *e2 = NULL; 267 268 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 269 return -E2BIG; 270 271 if (cpuid->nent) { 272 e = vmemdup_user(entries, array_size(sizeof(*e), cpuid->nent)); 273 if (IS_ERR(e)) 274 return PTR_ERR(e); 275 276 e2 = kvmalloc_array(cpuid->nent, sizeof(*e2), GFP_KERNEL_ACCOUNT); 277 if (!e2) { 278 r = -ENOMEM; 279 goto out_free_cpuid; 280 } 281 } 282 for (i = 0; i < cpuid->nent; i++) { 283 e2[i].function = e[i].function; 284 e2[i].eax = e[i].eax; 285 e2[i].ebx = e[i].ebx; 286 e2[i].ecx = e[i].ecx; 287 e2[i].edx = e[i].edx; 288 e2[i].index = 0; 289 e2[i].flags = 0; 290 e2[i].padding[0] = 0; 291 e2[i].padding[1] = 0; 292 e2[i].padding[2] = 0; 293 } 294 295 r = kvm_check_cpuid(e2, cpuid->nent); 296 if (r) { 297 kvfree(e2); 298 goto out_free_cpuid; 299 } 300 301 kvfree(vcpu->arch.cpuid_entries); 302 vcpu->arch.cpuid_entries = e2; 303 vcpu->arch.cpuid_nent = cpuid->nent; 304 305 cpuid_fix_nx_cap(vcpu); 306 kvm_update_cpuid_runtime(vcpu); 307 kvm_vcpu_after_set_cpuid(vcpu); 308 309 out_free_cpuid: 310 kvfree(e); 311 312 return r; 313 } 314 315 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 316 struct kvm_cpuid2 *cpuid, 317 struct kvm_cpuid_entry2 __user *entries) 318 { 319 struct kvm_cpuid_entry2 *e2 = NULL; 320 int r; 321 322 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 323 return -E2BIG; 324 325 if (cpuid->nent) { 326 e2 = vmemdup_user(entries, array_size(sizeof(*e2), cpuid->nent)); 327 if (IS_ERR(e2)) 328 return PTR_ERR(e2); 329 } 330 331 r = kvm_check_cpuid(e2, cpuid->nent); 332 if (r) { 333 kvfree(e2); 334 return r; 335 } 336 337 kvfree(vcpu->arch.cpuid_entries); 338 vcpu->arch.cpuid_entries = e2; 339 vcpu->arch.cpuid_nent = cpuid->nent; 340 341 kvm_update_cpuid_runtime(vcpu); 342 kvm_vcpu_after_set_cpuid(vcpu); 343 344 return 0; 345 } 346 347 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 348 struct kvm_cpuid2 *cpuid, 349 struct kvm_cpuid_entry2 __user *entries) 350 { 351 int r; 352 353 r = -E2BIG; 354 if (cpuid->nent < vcpu->arch.cpuid_nent) 355 goto out; 356 r = -EFAULT; 357 if (copy_to_user(entries, vcpu->arch.cpuid_entries, 358 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 359 goto out; 360 return 0; 361 362 out: 363 cpuid->nent = vcpu->arch.cpuid_nent; 364 return r; 365 } 366 367 /* Mask kvm_cpu_caps for @leaf with the raw CPUID capabilities of this CPU. */ 368 static __always_inline void __kvm_cpu_cap_mask(unsigned int leaf) 369 { 370 const struct cpuid_reg cpuid = x86_feature_cpuid(leaf * 32); 371 struct kvm_cpuid_entry2 entry; 372 373 reverse_cpuid_check(leaf); 374 375 cpuid_count(cpuid.function, cpuid.index, 376 &entry.eax, &entry.ebx, &entry.ecx, &entry.edx); 377 378 kvm_cpu_caps[leaf] &= *__cpuid_entry_get_reg(&entry, cpuid.reg); 379 } 380 381 static __always_inline 382 void kvm_cpu_cap_init_scattered(enum kvm_only_cpuid_leafs leaf, u32 mask) 383 { 384 /* Use kvm_cpu_cap_mask for non-scattered leafs. */ 385 BUILD_BUG_ON(leaf < NCAPINTS); 386 387 kvm_cpu_caps[leaf] = mask; 388 389 __kvm_cpu_cap_mask(leaf); 390 } 391 392 static __always_inline void kvm_cpu_cap_mask(enum cpuid_leafs leaf, u32 mask) 393 { 394 /* Use kvm_cpu_cap_init_scattered for scattered leafs. */ 395 BUILD_BUG_ON(leaf >= NCAPINTS); 396 397 kvm_cpu_caps[leaf] &= mask; 398 399 __kvm_cpu_cap_mask(leaf); 400 } 401 402 void kvm_set_cpu_caps(void) 403 { 404 unsigned int f_nx = is_efer_nx() ? F(NX) : 0; 405 #ifdef CONFIG_X86_64 406 unsigned int f_gbpages = F(GBPAGES); 407 unsigned int f_lm = F(LM); 408 #else 409 unsigned int f_gbpages = 0; 410 unsigned int f_lm = 0; 411 #endif 412 memset(kvm_cpu_caps, 0, sizeof(kvm_cpu_caps)); 413 414 BUILD_BUG_ON(sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps)) > 415 sizeof(boot_cpu_data.x86_capability)); 416 417 memcpy(&kvm_cpu_caps, &boot_cpu_data.x86_capability, 418 sizeof(kvm_cpu_caps) - (NKVMCAPINTS * sizeof(*kvm_cpu_caps))); 419 420 kvm_cpu_cap_mask(CPUID_1_ECX, 421 /* 422 * NOTE: MONITOR (and MWAIT) are emulated as NOP, but *not* 423 * advertised to guests via CPUID! 424 */ 425 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 426 0 /* DS-CPL, VMX, SMX, EST */ | 427 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 428 F(FMA) | F(CX16) | 0 /* xTPR Update */ | F(PDCM) | 429 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 430 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 431 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 432 F(F16C) | F(RDRAND) 433 ); 434 /* KVM emulates x2apic in software irrespective of host support. */ 435 kvm_cpu_cap_set(X86_FEATURE_X2APIC); 436 437 kvm_cpu_cap_mask(CPUID_1_EDX, 438 F(FPU) | F(VME) | F(DE) | F(PSE) | 439 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 440 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 441 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 442 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 443 0 /* Reserved, DS, ACPI */ | F(MMX) | 444 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 445 0 /* HTT, TM, Reserved, PBE */ 446 ); 447 448 kvm_cpu_cap_mask(CPUID_7_0_EBX, 449 F(FSGSBASE) | F(SGX) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 450 F(BMI2) | F(ERMS) | F(INVPCID) | F(RTM) | 0 /*MPX*/ | F(RDSEED) | 451 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 452 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 453 F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | 0 /*INTEL_PT*/ 454 ); 455 456 kvm_cpu_cap_mask(CPUID_7_ECX, 457 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | F(RDPID) | 458 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 459 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | 460 F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/ | 461 F(SGX_LC) 462 ); 463 /* Set LA57 based on hardware capability. */ 464 if (cpuid_ecx(7) & F(LA57)) 465 kvm_cpu_cap_set(X86_FEATURE_LA57); 466 467 /* 468 * PKU not yet implemented for shadow paging and requires OSPKE 469 * to be set on the host. Clear it if that is not the case 470 */ 471 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 472 kvm_cpu_cap_clear(X86_FEATURE_PKU); 473 474 kvm_cpu_cap_mask(CPUID_7_EDX, 475 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 476 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) | 477 F(MD_CLEAR) | F(AVX512_VP2INTERSECT) | F(FSRM) | 478 F(SERIALIZE) | F(TSXLDTRK) | F(AVX512_FP16) 479 ); 480 481 /* TSC_ADJUST and ARCH_CAPABILITIES are emulated in software. */ 482 kvm_cpu_cap_set(X86_FEATURE_TSC_ADJUST); 483 kvm_cpu_cap_set(X86_FEATURE_ARCH_CAPABILITIES); 484 485 if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS)) 486 kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL); 487 if (boot_cpu_has(X86_FEATURE_STIBP)) 488 kvm_cpu_cap_set(X86_FEATURE_INTEL_STIBP); 489 if (boot_cpu_has(X86_FEATURE_AMD_SSBD)) 490 kvm_cpu_cap_set(X86_FEATURE_SPEC_CTRL_SSBD); 491 492 kvm_cpu_cap_mask(CPUID_7_1_EAX, 493 F(AVX_VNNI) | F(AVX512_BF16) 494 ); 495 496 kvm_cpu_cap_mask(CPUID_D_1_EAX, 497 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | F(XSAVES) 498 ); 499 500 kvm_cpu_cap_init_scattered(CPUID_12_EAX, 501 SF(SGX1) | SF(SGX2) 502 ); 503 504 kvm_cpu_cap_mask(CPUID_8000_0001_ECX, 505 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 506 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 507 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 508 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 509 F(TOPOEXT) | F(PERFCTR_CORE) 510 ); 511 512 kvm_cpu_cap_mask(CPUID_8000_0001_EDX, 513 F(FPU) | F(VME) | F(DE) | F(PSE) | 514 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 515 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 516 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 517 F(PAT) | F(PSE36) | 0 /* Reserved */ | 518 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 519 F(FXSR) | F(FXSR_OPT) | f_gbpages | F(RDTSCP) | 520 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW) 521 ); 522 523 if (!tdp_enabled && IS_ENABLED(CONFIG_X86_64)) 524 kvm_cpu_cap_set(X86_FEATURE_GBPAGES); 525 526 kvm_cpu_cap_mask(CPUID_8000_0008_EBX, 527 F(CLZERO) | F(XSAVEERPTR) | 528 F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | 529 F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON) 530 ); 531 532 /* 533 * AMD has separate bits for each SPEC_CTRL bit. 534 * arch/x86/kernel/cpu/bugs.c is kind enough to 535 * record that in cpufeatures so use them. 536 */ 537 if (boot_cpu_has(X86_FEATURE_IBPB)) 538 kvm_cpu_cap_set(X86_FEATURE_AMD_IBPB); 539 if (boot_cpu_has(X86_FEATURE_IBRS)) 540 kvm_cpu_cap_set(X86_FEATURE_AMD_IBRS); 541 if (boot_cpu_has(X86_FEATURE_STIBP)) 542 kvm_cpu_cap_set(X86_FEATURE_AMD_STIBP); 543 if (boot_cpu_has(X86_FEATURE_SPEC_CTRL_SSBD)) 544 kvm_cpu_cap_set(X86_FEATURE_AMD_SSBD); 545 if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS)) 546 kvm_cpu_cap_set(X86_FEATURE_AMD_SSB_NO); 547 /* 548 * The preference is to use SPEC CTRL MSR instead of the 549 * VIRT_SPEC MSR. 550 */ 551 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && 552 !boot_cpu_has(X86_FEATURE_AMD_SSBD)) 553 kvm_cpu_cap_set(X86_FEATURE_VIRT_SSBD); 554 555 /* 556 * Hide all SVM features by default, SVM will set the cap bits for 557 * features it emulates and/or exposes for L1. 558 */ 559 kvm_cpu_cap_mask(CPUID_8000_000A_EDX, 0); 560 561 kvm_cpu_cap_mask(CPUID_8000_001F_EAX, 562 0 /* SME */ | F(SEV) | 0 /* VM_PAGE_FLUSH */ | F(SEV_ES) | 563 F(SME_COHERENT)); 564 565 kvm_cpu_cap_mask(CPUID_C000_0001_EDX, 566 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 567 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 568 F(PMM) | F(PMM_EN) 569 ); 570 } 571 EXPORT_SYMBOL_GPL(kvm_set_cpu_caps); 572 573 struct kvm_cpuid_array { 574 struct kvm_cpuid_entry2 *entries; 575 int maxnent; 576 int nent; 577 }; 578 579 static struct kvm_cpuid_entry2 *do_host_cpuid(struct kvm_cpuid_array *array, 580 u32 function, u32 index) 581 { 582 struct kvm_cpuid_entry2 *entry; 583 584 if (array->nent >= array->maxnent) 585 return NULL; 586 587 entry = &array->entries[array->nent++]; 588 589 entry->function = function; 590 entry->index = index; 591 entry->flags = 0; 592 593 cpuid_count(entry->function, entry->index, 594 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 595 596 switch (function) { 597 case 4: 598 case 7: 599 case 0xb: 600 case 0xd: 601 case 0xf: 602 case 0x10: 603 case 0x12: 604 case 0x14: 605 case 0x17: 606 case 0x18: 607 case 0x1f: 608 case 0x8000001d: 609 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 610 break; 611 } 612 613 return entry; 614 } 615 616 static int __do_cpuid_func_emulated(struct kvm_cpuid_array *array, u32 func) 617 { 618 struct kvm_cpuid_entry2 *entry; 619 620 if (array->nent >= array->maxnent) 621 return -E2BIG; 622 623 entry = &array->entries[array->nent]; 624 entry->function = func; 625 entry->index = 0; 626 entry->flags = 0; 627 628 switch (func) { 629 case 0: 630 entry->eax = 7; 631 ++array->nent; 632 break; 633 case 1: 634 entry->ecx = F(MOVBE); 635 ++array->nent; 636 break; 637 case 7: 638 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 639 entry->eax = 0; 640 entry->ecx = F(RDPID); 641 ++array->nent; 642 default: 643 break; 644 } 645 646 return 0; 647 } 648 649 static inline int __do_cpuid_func(struct kvm_cpuid_array *array, u32 function) 650 { 651 struct kvm_cpuid_entry2 *entry; 652 int r, i, max_idx; 653 654 /* all calls to cpuid_count() should be made on the same cpu */ 655 get_cpu(); 656 657 r = -E2BIG; 658 659 entry = do_host_cpuid(array, function, 0); 660 if (!entry) 661 goto out; 662 663 switch (function) { 664 case 0: 665 /* Limited to the highest leaf implemented in KVM. */ 666 entry->eax = min(entry->eax, 0x1fU); 667 break; 668 case 1: 669 cpuid_entry_override(entry, CPUID_1_EDX); 670 cpuid_entry_override(entry, CPUID_1_ECX); 671 break; 672 case 2: 673 /* 674 * On ancient CPUs, function 2 entries are STATEFUL. That is, 675 * CPUID(function=2, index=0) may return different results each 676 * time, with the least-significant byte in EAX enumerating the 677 * number of times software should do CPUID(2, 0). 678 * 679 * Modern CPUs, i.e. every CPU KVM has *ever* run on are less 680 * idiotic. Intel's SDM states that EAX & 0xff "will always 681 * return 01H. Software should ignore this value and not 682 * interpret it as an informational descriptor", while AMD's 683 * APM states that CPUID(2) is reserved. 684 * 685 * WARN if a frankenstein CPU that supports virtualization and 686 * a stateful CPUID.0x2 is encountered. 687 */ 688 WARN_ON_ONCE((entry->eax & 0xff) > 1); 689 break; 690 /* functions 4 and 0x8000001d have additional index. */ 691 case 4: 692 case 0x8000001d: 693 /* 694 * Read entries until the cache type in the previous entry is 695 * zero, i.e. indicates an invalid entry. 696 */ 697 for (i = 1; entry->eax & 0x1f; ++i) { 698 entry = do_host_cpuid(array, function, i); 699 if (!entry) 700 goto out; 701 } 702 break; 703 case 6: /* Thermal management */ 704 entry->eax = 0x4; /* allow ARAT */ 705 entry->ebx = 0; 706 entry->ecx = 0; 707 entry->edx = 0; 708 break; 709 /* function 7 has additional index. */ 710 case 7: 711 entry->eax = min(entry->eax, 1u); 712 cpuid_entry_override(entry, CPUID_7_0_EBX); 713 cpuid_entry_override(entry, CPUID_7_ECX); 714 cpuid_entry_override(entry, CPUID_7_EDX); 715 716 /* KVM only supports 0x7.0 and 0x7.1, capped above via min(). */ 717 if (entry->eax == 1) { 718 entry = do_host_cpuid(array, function, 1); 719 if (!entry) 720 goto out; 721 722 cpuid_entry_override(entry, CPUID_7_1_EAX); 723 entry->ebx = 0; 724 entry->ecx = 0; 725 entry->edx = 0; 726 } 727 break; 728 case 9: 729 break; 730 case 0xa: { /* Architectural Performance Monitoring */ 731 struct x86_pmu_capability cap; 732 union cpuid10_eax eax; 733 union cpuid10_edx edx; 734 735 perf_get_x86_pmu_capability(&cap); 736 737 /* 738 * Only support guest architectural pmu on a host 739 * with architectural pmu. 740 */ 741 if (!cap.version) 742 memset(&cap, 0, sizeof(cap)); 743 744 eax.split.version_id = min(cap.version, 2); 745 eax.split.num_counters = cap.num_counters_gp; 746 eax.split.bit_width = cap.bit_width_gp; 747 eax.split.mask_length = cap.events_mask_len; 748 749 edx.split.num_counters_fixed = min(cap.num_counters_fixed, MAX_FIXED_COUNTERS); 750 edx.split.bit_width_fixed = cap.bit_width_fixed; 751 edx.split.anythread_deprecated = 1; 752 edx.split.reserved1 = 0; 753 edx.split.reserved2 = 0; 754 755 entry->eax = eax.full; 756 entry->ebx = cap.events_mask; 757 entry->ecx = 0; 758 entry->edx = edx.full; 759 break; 760 } 761 /* 762 * Per Intel's SDM, the 0x1f is a superset of 0xb, 763 * thus they can be handled by common code. 764 */ 765 case 0x1f: 766 case 0xb: 767 /* 768 * Populate entries until the level type (ECX[15:8]) of the 769 * previous entry is zero. Note, CPUID EAX.{0x1f,0xb}.0 is 770 * the starting entry, filled by the primary do_host_cpuid(). 771 */ 772 for (i = 1; entry->ecx & 0xff00; ++i) { 773 entry = do_host_cpuid(array, function, i); 774 if (!entry) 775 goto out; 776 } 777 break; 778 case 0xd: 779 entry->eax &= supported_xcr0; 780 entry->ebx = xstate_required_size(supported_xcr0, false); 781 entry->ecx = entry->ebx; 782 entry->edx &= supported_xcr0 >> 32; 783 if (!supported_xcr0) 784 break; 785 786 entry = do_host_cpuid(array, function, 1); 787 if (!entry) 788 goto out; 789 790 cpuid_entry_override(entry, CPUID_D_1_EAX); 791 if (entry->eax & (F(XSAVES)|F(XSAVEC))) 792 entry->ebx = xstate_required_size(supported_xcr0 | supported_xss, 793 true); 794 else { 795 WARN_ON_ONCE(supported_xss != 0); 796 entry->ebx = 0; 797 } 798 entry->ecx &= supported_xss; 799 entry->edx &= supported_xss >> 32; 800 801 for (i = 2; i < 64; ++i) { 802 bool s_state; 803 if (supported_xcr0 & BIT_ULL(i)) 804 s_state = false; 805 else if (supported_xss & BIT_ULL(i)) 806 s_state = true; 807 else 808 continue; 809 810 entry = do_host_cpuid(array, function, i); 811 if (!entry) 812 goto out; 813 814 /* 815 * The supported check above should have filtered out 816 * invalid sub-leafs. Only valid sub-leafs should 817 * reach this point, and they should have a non-zero 818 * save state size. Furthermore, check whether the 819 * processor agrees with supported_xcr0/supported_xss 820 * on whether this is an XCR0- or IA32_XSS-managed area. 821 */ 822 if (WARN_ON_ONCE(!entry->eax || (entry->ecx & 0x1) != s_state)) { 823 --array->nent; 824 continue; 825 } 826 entry->edx = 0; 827 } 828 break; 829 case 0x12: 830 /* Intel SGX */ 831 if (!kvm_cpu_cap_has(X86_FEATURE_SGX)) { 832 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 833 break; 834 } 835 836 /* 837 * Index 0: Sub-features, MISCSELECT (a.k.a extended features) 838 * and max enclave sizes. The SGX sub-features and MISCSELECT 839 * are restricted by kernel and KVM capabilities (like most 840 * feature flags), while enclave size is unrestricted. 841 */ 842 cpuid_entry_override(entry, CPUID_12_EAX); 843 entry->ebx &= SGX_MISC_EXINFO; 844 845 entry = do_host_cpuid(array, function, 1); 846 if (!entry) 847 goto out; 848 849 /* 850 * Index 1: SECS.ATTRIBUTES. ATTRIBUTES are restricted a la 851 * feature flags. Advertise all supported flags, including 852 * privileged attributes that require explicit opt-in from 853 * userspace. ATTRIBUTES.XFRM is not adjusted as userspace is 854 * expected to derive it from supported XCR0. 855 */ 856 entry->eax &= SGX_ATTR_DEBUG | SGX_ATTR_MODE64BIT | 857 SGX_ATTR_PROVISIONKEY | SGX_ATTR_EINITTOKENKEY | 858 SGX_ATTR_KSS; 859 entry->ebx &= 0; 860 break; 861 /* Intel PT */ 862 case 0x14: 863 if (!kvm_cpu_cap_has(X86_FEATURE_INTEL_PT)) { 864 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 865 break; 866 } 867 868 for (i = 1, max_idx = entry->eax; i <= max_idx; ++i) { 869 if (!do_host_cpuid(array, function, i)) 870 goto out; 871 } 872 break; 873 case KVM_CPUID_SIGNATURE: { 874 static const char signature[12] = "KVMKVMKVM\0\0"; 875 const u32 *sigptr = (const u32 *)signature; 876 entry->eax = KVM_CPUID_FEATURES; 877 entry->ebx = sigptr[0]; 878 entry->ecx = sigptr[1]; 879 entry->edx = sigptr[2]; 880 break; 881 } 882 case KVM_CPUID_FEATURES: 883 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 884 (1 << KVM_FEATURE_NOP_IO_DELAY) | 885 (1 << KVM_FEATURE_CLOCKSOURCE2) | 886 (1 << KVM_FEATURE_ASYNC_PF) | 887 (1 << KVM_FEATURE_PV_EOI) | 888 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 889 (1 << KVM_FEATURE_PV_UNHALT) | 890 (1 << KVM_FEATURE_PV_TLB_FLUSH) | 891 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | 892 (1 << KVM_FEATURE_PV_SEND_IPI) | 893 (1 << KVM_FEATURE_POLL_CONTROL) | 894 (1 << KVM_FEATURE_PV_SCHED_YIELD) | 895 (1 << KVM_FEATURE_ASYNC_PF_INT); 896 897 if (sched_info_on()) 898 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 899 900 entry->ebx = 0; 901 entry->ecx = 0; 902 entry->edx = 0; 903 break; 904 case 0x80000000: 905 entry->eax = min(entry->eax, 0x8000001f); 906 break; 907 case 0x80000001: 908 cpuid_entry_override(entry, CPUID_8000_0001_EDX); 909 cpuid_entry_override(entry, CPUID_8000_0001_ECX); 910 break; 911 case 0x80000006: 912 /* L2 cache and TLB: pass through host info. */ 913 break; 914 case 0x80000007: /* Advanced power management */ 915 /* invariant TSC is CPUID.80000007H:EDX[8] */ 916 entry->edx &= (1 << 8); 917 /* mask against host */ 918 entry->edx &= boot_cpu_data.x86_power; 919 entry->eax = entry->ebx = entry->ecx = 0; 920 break; 921 case 0x80000008: { 922 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 923 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 924 unsigned phys_as = entry->eax & 0xff; 925 926 if (!g_phys_as) 927 g_phys_as = phys_as; 928 entry->eax = g_phys_as | (virt_as << 8); 929 entry->edx = 0; 930 cpuid_entry_override(entry, CPUID_8000_0008_EBX); 931 break; 932 } 933 case 0x8000000A: 934 if (!kvm_cpu_cap_has(X86_FEATURE_SVM)) { 935 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 936 break; 937 } 938 entry->eax = 1; /* SVM revision 1 */ 939 entry->ebx = 8; /* Lets support 8 ASIDs in case we add proper 940 ASID emulation to nested SVM */ 941 entry->ecx = 0; /* Reserved */ 942 cpuid_entry_override(entry, CPUID_8000_000A_EDX); 943 break; 944 case 0x80000019: 945 entry->ecx = entry->edx = 0; 946 break; 947 case 0x8000001a: 948 case 0x8000001e: 949 break; 950 /* Support memory encryption cpuid if host supports it */ 951 case 0x8000001F: 952 if (!kvm_cpu_cap_has(X86_FEATURE_SEV)) 953 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 954 else 955 cpuid_entry_override(entry, CPUID_8000_001F_EAX); 956 break; 957 /*Add support for Centaur's CPUID instruction*/ 958 case 0xC0000000: 959 /*Just support up to 0xC0000004 now*/ 960 entry->eax = min(entry->eax, 0xC0000004); 961 break; 962 case 0xC0000001: 963 cpuid_entry_override(entry, CPUID_C000_0001_EDX); 964 break; 965 case 3: /* Processor serial number */ 966 case 5: /* MONITOR/MWAIT */ 967 case 0xC0000002: 968 case 0xC0000003: 969 case 0xC0000004: 970 default: 971 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 972 break; 973 } 974 975 r = 0; 976 977 out: 978 put_cpu(); 979 980 return r; 981 } 982 983 static int do_cpuid_func(struct kvm_cpuid_array *array, u32 func, 984 unsigned int type) 985 { 986 if (type == KVM_GET_EMULATED_CPUID) 987 return __do_cpuid_func_emulated(array, func); 988 989 return __do_cpuid_func(array, func); 990 } 991 992 #define CENTAUR_CPUID_SIGNATURE 0xC0000000 993 994 static int get_cpuid_func(struct kvm_cpuid_array *array, u32 func, 995 unsigned int type) 996 { 997 u32 limit; 998 int r; 999 1000 if (func == CENTAUR_CPUID_SIGNATURE && 1001 boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR) 1002 return 0; 1003 1004 r = do_cpuid_func(array, func, type); 1005 if (r) 1006 return r; 1007 1008 limit = array->entries[array->nent - 1].eax; 1009 for (func = func + 1; func <= limit; ++func) { 1010 r = do_cpuid_func(array, func, type); 1011 if (r) 1012 break; 1013 } 1014 1015 return r; 1016 } 1017 1018 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 1019 __u32 num_entries, unsigned int ioctl_type) 1020 { 1021 int i; 1022 __u32 pad[3]; 1023 1024 if (ioctl_type != KVM_GET_EMULATED_CPUID) 1025 return false; 1026 1027 /* 1028 * We want to make sure that ->padding is being passed clean from 1029 * userspace in case we want to use it for something in the future. 1030 * 1031 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 1032 * have to give ourselves satisfied only with the emulated side. /me 1033 * sheds a tear. 1034 */ 1035 for (i = 0; i < num_entries; i++) { 1036 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 1037 return true; 1038 1039 if (pad[0] || pad[1] || pad[2]) 1040 return true; 1041 } 1042 return false; 1043 } 1044 1045 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 1046 struct kvm_cpuid_entry2 __user *entries, 1047 unsigned int type) 1048 { 1049 static const u32 funcs[] = { 1050 0, 0x80000000, CENTAUR_CPUID_SIGNATURE, KVM_CPUID_SIGNATURE, 1051 }; 1052 1053 struct kvm_cpuid_array array = { 1054 .nent = 0, 1055 }; 1056 int r, i; 1057 1058 if (cpuid->nent < 1) 1059 return -E2BIG; 1060 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 1061 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 1062 1063 if (sanity_check_entries(entries, cpuid->nent, type)) 1064 return -EINVAL; 1065 1066 array.entries = vzalloc(array_size(sizeof(struct kvm_cpuid_entry2), 1067 cpuid->nent)); 1068 if (!array.entries) 1069 return -ENOMEM; 1070 1071 array.maxnent = cpuid->nent; 1072 1073 for (i = 0; i < ARRAY_SIZE(funcs); i++) { 1074 r = get_cpuid_func(&array, funcs[i], type); 1075 if (r) 1076 goto out_free; 1077 } 1078 cpuid->nent = array.nent; 1079 1080 if (copy_to_user(entries, array.entries, 1081 array.nent * sizeof(struct kvm_cpuid_entry2))) 1082 r = -EFAULT; 1083 1084 out_free: 1085 vfree(array.entries); 1086 return r; 1087 } 1088 1089 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 1090 u32 function, u32 index) 1091 { 1092 return cpuid_entry2_find(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, 1093 function, index); 1094 } 1095 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 1096 1097 /* 1098 * Intel CPUID semantics treats any query for an out-of-range leaf as if the 1099 * highest basic leaf (i.e. CPUID.0H:EAX) were requested. AMD CPUID semantics 1100 * returns all zeroes for any undefined leaf, whether or not the leaf is in 1101 * range. Centaur/VIA follows Intel semantics. 1102 * 1103 * A leaf is considered out-of-range if its function is higher than the maximum 1104 * supported leaf of its associated class or if its associated class does not 1105 * exist. 1106 * 1107 * There are three primary classes to be considered, with their respective 1108 * ranges described as "<base> - <top>[,<base2> - <top2>] inclusive. A primary 1109 * class exists if a guest CPUID entry for its <base> leaf exists. For a given 1110 * class, CPUID.<base>.EAX contains the max supported leaf for the class. 1111 * 1112 * - Basic: 0x00000000 - 0x3fffffff, 0x50000000 - 0x7fffffff 1113 * - Hypervisor: 0x40000000 - 0x4fffffff 1114 * - Extended: 0x80000000 - 0xbfffffff 1115 * - Centaur: 0xc0000000 - 0xcfffffff 1116 * 1117 * The Hypervisor class is further subdivided into sub-classes that each act as 1118 * their own independent class associated with a 0x100 byte range. E.g. if Qemu 1119 * is advertising support for both HyperV and KVM, the resulting Hypervisor 1120 * CPUID sub-classes are: 1121 * 1122 * - HyperV: 0x40000000 - 0x400000ff 1123 * - KVM: 0x40000100 - 0x400001ff 1124 */ 1125 static struct kvm_cpuid_entry2 * 1126 get_out_of_range_cpuid_entry(struct kvm_vcpu *vcpu, u32 *fn_ptr, u32 index) 1127 { 1128 struct kvm_cpuid_entry2 *basic, *class; 1129 u32 function = *fn_ptr; 1130 1131 basic = kvm_find_cpuid_entry(vcpu, 0, 0); 1132 if (!basic) 1133 return NULL; 1134 1135 if (is_guest_vendor_amd(basic->ebx, basic->ecx, basic->edx) || 1136 is_guest_vendor_hygon(basic->ebx, basic->ecx, basic->edx)) 1137 return NULL; 1138 1139 if (function >= 0x40000000 && function <= 0x4fffffff) 1140 class = kvm_find_cpuid_entry(vcpu, function & 0xffffff00, 0); 1141 else if (function >= 0xc0000000) 1142 class = kvm_find_cpuid_entry(vcpu, 0xc0000000, 0); 1143 else 1144 class = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 1145 1146 if (class && function <= class->eax) 1147 return NULL; 1148 1149 /* 1150 * Leaf specific adjustments are also applied when redirecting to the 1151 * max basic entry, e.g. if the max basic leaf is 0xb but there is no 1152 * entry for CPUID.0xb.index (see below), then the output value for EDX 1153 * needs to be pulled from CPUID.0xb.1. 1154 */ 1155 *fn_ptr = basic->eax; 1156 1157 /* 1158 * The class does not exist or the requested function is out of range; 1159 * the effective CPUID entry is the max basic leaf. Note, the index of 1160 * the original requested leaf is observed! 1161 */ 1162 return kvm_find_cpuid_entry(vcpu, basic->eax, index); 1163 } 1164 1165 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 1166 u32 *ecx, u32 *edx, bool exact_only) 1167 { 1168 u32 orig_function = *eax, function = *eax, index = *ecx; 1169 struct kvm_cpuid_entry2 *entry; 1170 bool exact, used_max_basic = false; 1171 1172 entry = kvm_find_cpuid_entry(vcpu, function, index); 1173 exact = !!entry; 1174 1175 if (!entry && !exact_only) { 1176 entry = get_out_of_range_cpuid_entry(vcpu, &function, index); 1177 used_max_basic = !!entry; 1178 } 1179 1180 if (entry) { 1181 *eax = entry->eax; 1182 *ebx = entry->ebx; 1183 *ecx = entry->ecx; 1184 *edx = entry->edx; 1185 if (function == 7 && index == 0) { 1186 u64 data; 1187 if (!__kvm_get_msr(vcpu, MSR_IA32_TSX_CTRL, &data, true) && 1188 (data & TSX_CTRL_CPUID_CLEAR)) 1189 *ebx &= ~(F(RTM) | F(HLE)); 1190 } 1191 } else { 1192 *eax = *ebx = *ecx = *edx = 0; 1193 /* 1194 * When leaf 0BH or 1FH is defined, CL is pass-through 1195 * and EDX is always the x2APIC ID, even for undefined 1196 * subleaves. Index 1 will exist iff the leaf is 1197 * implemented, so we pass through CL iff leaf 1 1198 * exists. EDX can be copied from any existing index. 1199 */ 1200 if (function == 0xb || function == 0x1f) { 1201 entry = kvm_find_cpuid_entry(vcpu, function, 1); 1202 if (entry) { 1203 *ecx = index & 0xff; 1204 *edx = entry->edx; 1205 } 1206 } 1207 } 1208 trace_kvm_cpuid(orig_function, index, *eax, *ebx, *ecx, *edx, exact, 1209 used_max_basic); 1210 return exact; 1211 } 1212 EXPORT_SYMBOL_GPL(kvm_cpuid); 1213 1214 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 1215 { 1216 u32 eax, ebx, ecx, edx; 1217 1218 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 1219 return 1; 1220 1221 eax = kvm_rax_read(vcpu); 1222 ecx = kvm_rcx_read(vcpu); 1223 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, false); 1224 kvm_rax_write(vcpu, eax); 1225 kvm_rbx_write(vcpu, ebx); 1226 kvm_rcx_write(vcpu, ecx); 1227 kvm_rdx_write(vcpu, edx); 1228 return kvm_skip_emulated_instruction(vcpu); 1229 } 1230 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 1231