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 "cpuid.h" 22 #include "lapic.h" 23 #include "mmu.h" 24 #include "trace.h" 25 #include "pmu.h" 26 27 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 28 { 29 int feature_bit = 0; 30 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 31 32 xstate_bv &= XFEATURE_MASK_EXTEND; 33 while (xstate_bv) { 34 if (xstate_bv & 0x1) { 35 u32 eax, ebx, ecx, edx, offset; 36 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 37 offset = compacted ? ret : ebx; 38 ret = max(ret, offset + eax); 39 } 40 41 xstate_bv >>= 1; 42 feature_bit++; 43 } 44 45 return ret; 46 } 47 48 bool kvm_mpx_supported(void) 49 { 50 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) 51 && kvm_x86_ops->mpx_supported()); 52 } 53 EXPORT_SYMBOL_GPL(kvm_mpx_supported); 54 55 u64 kvm_supported_xcr0(void) 56 { 57 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 58 59 if (!kvm_mpx_supported()) 60 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); 61 62 return xcr0; 63 } 64 65 #define F(x) bit(X86_FEATURE_##x) 66 67 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 68 { 69 struct kvm_cpuid_entry2 *best; 70 struct kvm_lapic *apic = vcpu->arch.apic; 71 72 best = kvm_find_cpuid_entry(vcpu, 1, 0); 73 if (!best) 74 return 0; 75 76 /* Update OSXSAVE bit */ 77 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) { 78 best->ecx &= ~F(OSXSAVE); 79 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 80 best->ecx |= F(OSXSAVE); 81 } 82 83 best->edx &= ~F(APIC); 84 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE) 85 best->edx |= F(APIC); 86 87 if (apic) { 88 if (best->ecx & F(TSC_DEADLINE_TIMER)) 89 apic->lapic_timer.timer_mode_mask = 3 << 17; 90 else 91 apic->lapic_timer.timer_mode_mask = 1 << 17; 92 } 93 94 best = kvm_find_cpuid_entry(vcpu, 7, 0); 95 if (best) { 96 /* Update OSPKE bit */ 97 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) { 98 best->ecx &= ~F(OSPKE); 99 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) 100 best->ecx |= F(OSPKE); 101 } 102 } 103 104 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 105 if (!best) { 106 vcpu->arch.guest_supported_xcr0 = 0; 107 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 108 } else { 109 vcpu->arch.guest_supported_xcr0 = 110 (best->eax | ((u64)best->edx << 32)) & 111 kvm_supported_xcr0(); 112 vcpu->arch.guest_xstate_size = best->ebx = 113 xstate_required_size(vcpu->arch.xcr0, false); 114 } 115 116 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 117 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 118 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 119 120 /* 121 * The existing code assumes virtual address is 48-bit or 57-bit in the 122 * canonical address checks; exit if it is ever changed. 123 */ 124 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 125 if (best) { 126 int vaddr_bits = (best->eax & 0xff00) >> 8; 127 128 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) 129 return -EINVAL; 130 } 131 132 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0); 133 if (kvm_hlt_in_guest(vcpu->kvm) && best && 134 (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) 135 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); 136 137 if (!kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_MISC_ENABLE_NO_MWAIT)) { 138 best = kvm_find_cpuid_entry(vcpu, 0x1, 0); 139 if (best) { 140 if (vcpu->arch.ia32_misc_enable_msr & MSR_IA32_MISC_ENABLE_MWAIT) 141 best->ecx |= F(MWAIT); 142 else 143 best->ecx &= ~F(MWAIT); 144 } 145 } 146 147 /* Update physical-address width */ 148 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 149 kvm_mmu_reset_context(vcpu); 150 151 kvm_pmu_refresh(vcpu); 152 return 0; 153 } 154 155 static int is_efer_nx(void) 156 { 157 unsigned long long efer = 0; 158 159 rdmsrl_safe(MSR_EFER, &efer); 160 return efer & EFER_NX; 161 } 162 163 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 164 { 165 int i; 166 struct kvm_cpuid_entry2 *e, *entry; 167 168 entry = NULL; 169 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 170 e = &vcpu->arch.cpuid_entries[i]; 171 if (e->function == 0x80000001) { 172 entry = e; 173 break; 174 } 175 } 176 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 177 entry->edx &= ~F(NX); 178 printk(KERN_INFO "kvm: guest NX capability removed\n"); 179 } 180 } 181 182 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 183 { 184 struct kvm_cpuid_entry2 *best; 185 186 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 187 if (!best || best->eax < 0x80000008) 188 goto not_found; 189 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 190 if (best) 191 return best->eax & 0xff; 192 not_found: 193 return 36; 194 } 195 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 196 197 /* when an old userspace process fills a new kernel module */ 198 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 199 struct kvm_cpuid *cpuid, 200 struct kvm_cpuid_entry __user *entries) 201 { 202 int r, i; 203 struct kvm_cpuid_entry *cpuid_entries = NULL; 204 205 r = -E2BIG; 206 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 207 goto out; 208 r = -ENOMEM; 209 if (cpuid->nent) { 210 cpuid_entries = 211 vmalloc(array_size(sizeof(struct kvm_cpuid_entry), 212 cpuid->nent)); 213 if (!cpuid_entries) 214 goto out; 215 r = -EFAULT; 216 if (copy_from_user(cpuid_entries, entries, 217 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 218 goto out; 219 } 220 for (i = 0; i < cpuid->nent; i++) { 221 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 222 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 223 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 224 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 225 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 226 vcpu->arch.cpuid_entries[i].index = 0; 227 vcpu->arch.cpuid_entries[i].flags = 0; 228 vcpu->arch.cpuid_entries[i].padding[0] = 0; 229 vcpu->arch.cpuid_entries[i].padding[1] = 0; 230 vcpu->arch.cpuid_entries[i].padding[2] = 0; 231 } 232 vcpu->arch.cpuid_nent = cpuid->nent; 233 cpuid_fix_nx_cap(vcpu); 234 kvm_apic_set_version(vcpu); 235 kvm_x86_ops->cpuid_update(vcpu); 236 r = kvm_update_cpuid(vcpu); 237 238 out: 239 vfree(cpuid_entries); 240 return r; 241 } 242 243 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 244 struct kvm_cpuid2 *cpuid, 245 struct kvm_cpuid_entry2 __user *entries) 246 { 247 int r; 248 249 r = -E2BIG; 250 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 251 goto out; 252 r = -EFAULT; 253 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 254 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 255 goto out; 256 vcpu->arch.cpuid_nent = cpuid->nent; 257 kvm_apic_set_version(vcpu); 258 kvm_x86_ops->cpuid_update(vcpu); 259 r = kvm_update_cpuid(vcpu); 260 out: 261 return r; 262 } 263 264 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 265 struct kvm_cpuid2 *cpuid, 266 struct kvm_cpuid_entry2 __user *entries) 267 { 268 int r; 269 270 r = -E2BIG; 271 if (cpuid->nent < vcpu->arch.cpuid_nent) 272 goto out; 273 r = -EFAULT; 274 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 275 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 276 goto out; 277 return 0; 278 279 out: 280 cpuid->nent = vcpu->arch.cpuid_nent; 281 return r; 282 } 283 284 static void cpuid_mask(u32 *word, int wordnum) 285 { 286 *word &= boot_cpu_data.x86_capability[wordnum]; 287 } 288 289 static void do_host_cpuid(struct kvm_cpuid_entry2 *entry, u32 function, 290 u32 index) 291 { 292 entry->function = function; 293 entry->index = index; 294 entry->flags = 0; 295 296 cpuid_count(entry->function, entry->index, 297 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 298 299 switch (function) { 300 case 2: 301 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 302 break; 303 case 4: 304 case 7: 305 case 0xb: 306 case 0xd: 307 case 0xf: 308 case 0x10: 309 case 0x12: 310 case 0x14: 311 case 0x17: 312 case 0x18: 313 case 0x1f: 314 case 0x8000001d: 315 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 316 break; 317 } 318 } 319 320 static int __do_cpuid_func_emulated(struct kvm_cpuid_entry2 *entry, 321 u32 func, int *nent, int maxnent) 322 { 323 entry->function = func; 324 entry->index = 0; 325 entry->flags = 0; 326 327 switch (func) { 328 case 0: 329 entry->eax = 7; 330 ++*nent; 331 break; 332 case 1: 333 entry->ecx = F(MOVBE); 334 ++*nent; 335 break; 336 case 7: 337 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 338 entry->eax = 0; 339 entry->ecx = F(RDPID); 340 ++*nent; 341 default: 342 break; 343 } 344 345 return 0; 346 } 347 348 static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index) 349 { 350 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 351 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 352 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0; 353 unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0; 354 unsigned f_la57; 355 356 /* cpuid 7.0.ebx */ 357 const u32 kvm_cpuid_7_0_ebx_x86_features = 358 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 359 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 360 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 361 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 362 F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt; 363 364 /* cpuid 7.0.ecx*/ 365 const u32 kvm_cpuid_7_0_ecx_x86_features = 366 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | 367 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 368 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | 369 F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B) | 0 /*WAITPKG*/; 370 371 /* cpuid 7.0.edx*/ 372 const u32 kvm_cpuid_7_0_edx_x86_features = 373 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 374 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) | 375 F(MD_CLEAR); 376 377 /* cpuid 7.1.eax */ 378 const u32 kvm_cpuid_7_1_eax_x86_features = 379 F(AVX512_BF16); 380 381 switch (index) { 382 case 0: 383 entry->eax = min(entry->eax, 1u); 384 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 385 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 386 /* TSC_ADJUST is emulated */ 387 entry->ebx |= F(TSC_ADJUST); 388 389 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 390 f_la57 = entry->ecx & F(LA57); 391 cpuid_mask(&entry->ecx, CPUID_7_ECX); 392 /* Set LA57 based on hardware capability. */ 393 entry->ecx |= f_la57; 394 entry->ecx |= f_umip; 395 /* PKU is not yet implemented for shadow paging. */ 396 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 397 entry->ecx &= ~F(PKU); 398 399 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 400 cpuid_mask(&entry->edx, CPUID_7_EDX); 401 if (boot_cpu_has(X86_FEATURE_IBPB) && boot_cpu_has(X86_FEATURE_IBRS)) 402 entry->edx |= F(SPEC_CTRL); 403 if (boot_cpu_has(X86_FEATURE_STIBP)) 404 entry->edx |= F(INTEL_STIBP); 405 if (boot_cpu_has(X86_FEATURE_SSBD)) 406 entry->edx |= F(SPEC_CTRL_SSBD); 407 /* 408 * We emulate ARCH_CAPABILITIES in software even 409 * if the host doesn't support it. 410 */ 411 entry->edx |= F(ARCH_CAPABILITIES); 412 break; 413 case 1: 414 entry->eax &= kvm_cpuid_7_1_eax_x86_features; 415 entry->ebx = 0; 416 entry->ecx = 0; 417 entry->edx = 0; 418 break; 419 default: 420 WARN_ON_ONCE(1); 421 entry->eax = 0; 422 entry->ebx = 0; 423 entry->ecx = 0; 424 entry->edx = 0; 425 break; 426 } 427 } 428 429 static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function, 430 int *nent, int maxnent) 431 { 432 int r; 433 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 434 #ifdef CONFIG_X86_64 435 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 436 ? F(GBPAGES) : 0; 437 unsigned f_lm = F(LM); 438 #else 439 unsigned f_gbpages = 0; 440 unsigned f_lm = 0; 441 #endif 442 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 443 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 444 unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0; 445 446 /* cpuid 1.edx */ 447 const u32 kvm_cpuid_1_edx_x86_features = 448 F(FPU) | F(VME) | F(DE) | F(PSE) | 449 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 450 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 451 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 452 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 453 0 /* Reserved, DS, ACPI */ | F(MMX) | 454 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 455 0 /* HTT, TM, Reserved, PBE */; 456 /* cpuid 0x80000001.edx */ 457 const u32 kvm_cpuid_8000_0001_edx_x86_features = 458 F(FPU) | F(VME) | F(DE) | F(PSE) | 459 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 460 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 461 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 462 F(PAT) | F(PSE36) | 0 /* Reserved */ | 463 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 464 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 465 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 466 /* cpuid 1.ecx */ 467 const u32 kvm_cpuid_1_ecx_x86_features = 468 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 469 * but *not* advertised to guests via CPUID ! */ 470 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 471 0 /* DS-CPL, VMX, SMX, EST */ | 472 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 473 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 474 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 475 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 476 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 477 F(F16C) | F(RDRAND); 478 /* cpuid 0x80000001.ecx */ 479 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 480 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 481 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 482 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 483 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 484 F(TOPOEXT) | F(PERFCTR_CORE); 485 486 /* cpuid 0x80000008.ebx */ 487 const u32 kvm_cpuid_8000_0008_ebx_x86_features = 488 F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | 489 F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON); 490 491 /* cpuid 0xC0000001.edx */ 492 const u32 kvm_cpuid_C000_0001_edx_x86_features = 493 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 494 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 495 F(PMM) | F(PMM_EN); 496 497 /* cpuid 0xD.1.eax */ 498 const u32 kvm_cpuid_D_1_eax_x86_features = 499 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 500 501 /* all calls to cpuid_count() should be made on the same cpu */ 502 get_cpu(); 503 504 r = -E2BIG; 505 506 if (*nent >= maxnent) 507 goto out; 508 509 do_host_cpuid(entry, function, 0); 510 ++*nent; 511 512 switch (function) { 513 case 0: 514 /* Limited to the highest leaf implemented in KVM. */ 515 entry->eax = min(entry->eax, 0x1fU); 516 break; 517 case 1: 518 entry->edx &= kvm_cpuid_1_edx_x86_features; 519 cpuid_mask(&entry->edx, CPUID_1_EDX); 520 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 521 cpuid_mask(&entry->ecx, CPUID_1_ECX); 522 /* we support x2apic emulation even if host does not support 523 * it since we emulate x2apic in software */ 524 entry->ecx |= F(X2APIC); 525 break; 526 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 527 * may return different values. This forces us to get_cpu() before 528 * issuing the first command, and also to emulate this annoying behavior 529 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 530 case 2: { 531 int t, times = entry->eax & 0xff; 532 533 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 534 for (t = 1; t < times; ++t) { 535 if (*nent >= maxnent) 536 goto out; 537 538 do_host_cpuid(&entry[t], function, 0); 539 ++*nent; 540 } 541 break; 542 } 543 /* functions 4 and 0x8000001d have additional index. */ 544 case 4: 545 case 0x8000001d: { 546 int i, cache_type; 547 548 /* read more entries until cache_type is zero */ 549 for (i = 1; ; ++i) { 550 if (*nent >= maxnent) 551 goto out; 552 553 cache_type = entry[i - 1].eax & 0x1f; 554 if (!cache_type) 555 break; 556 do_host_cpuid(&entry[i], function, i); 557 ++*nent; 558 } 559 break; 560 } 561 case 6: /* Thermal management */ 562 entry->eax = 0x4; /* allow ARAT */ 563 entry->ebx = 0; 564 entry->ecx = 0; 565 entry->edx = 0; 566 break; 567 /* function 7 has additional index. */ 568 case 7: { 569 int i; 570 571 for (i = 0; ; ) { 572 do_cpuid_7_mask(&entry[i], i); 573 if (i == entry->eax) 574 break; 575 if (*nent >= maxnent) 576 goto out; 577 578 ++i; 579 do_host_cpuid(&entry[i], function, i); 580 ++*nent; 581 } 582 break; 583 } 584 case 9: 585 break; 586 case 0xa: { /* Architectural Performance Monitoring */ 587 struct x86_pmu_capability cap; 588 union cpuid10_eax eax; 589 union cpuid10_edx edx; 590 591 perf_get_x86_pmu_capability(&cap); 592 593 /* 594 * Only support guest architectural pmu on a host 595 * with architectural pmu. 596 */ 597 if (!cap.version) 598 memset(&cap, 0, sizeof(cap)); 599 600 eax.split.version_id = min(cap.version, 2); 601 eax.split.num_counters = cap.num_counters_gp; 602 eax.split.bit_width = cap.bit_width_gp; 603 eax.split.mask_length = cap.events_mask_len; 604 605 edx.split.num_counters_fixed = cap.num_counters_fixed; 606 edx.split.bit_width_fixed = cap.bit_width_fixed; 607 edx.split.reserved = 0; 608 609 entry->eax = eax.full; 610 entry->ebx = cap.events_mask; 611 entry->ecx = 0; 612 entry->edx = edx.full; 613 break; 614 } 615 /* 616 * Per Intel's SDM, the 0x1f is a superset of 0xb, 617 * thus they can be handled by common code. 618 */ 619 case 0x1f: 620 case 0xb: { 621 int i, level_type; 622 623 /* read more entries until level_type is zero */ 624 for (i = 1; ; ++i) { 625 if (*nent >= maxnent) 626 goto out; 627 628 level_type = entry[i - 1].ecx & 0xff00; 629 if (!level_type) 630 break; 631 do_host_cpuid(&entry[i], function, i); 632 ++*nent; 633 } 634 break; 635 } 636 case 0xd: { 637 int idx, i; 638 u64 supported = kvm_supported_xcr0(); 639 640 entry->eax &= supported; 641 entry->ebx = xstate_required_size(supported, false); 642 entry->ecx = entry->ebx; 643 entry->edx &= supported >> 32; 644 if (!supported) 645 break; 646 647 for (idx = 1, i = 1; idx < 64; ++idx) { 648 u64 mask = ((u64)1 << idx); 649 if (*nent >= maxnent) 650 goto out; 651 652 do_host_cpuid(&entry[i], function, idx); 653 if (idx == 1) { 654 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 655 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 656 entry[i].ebx = 0; 657 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 658 entry[i].ebx = 659 xstate_required_size(supported, 660 true); 661 } else { 662 if (entry[i].eax == 0 || !(supported & mask)) 663 continue; 664 if (WARN_ON_ONCE(entry[i].ecx & 1)) 665 continue; 666 } 667 entry[i].ecx = 0; 668 entry[i].edx = 0; 669 ++*nent; 670 ++i; 671 } 672 break; 673 } 674 /* Intel PT */ 675 case 0x14: { 676 int t, times = entry->eax; 677 678 if (!f_intel_pt) 679 break; 680 681 for (t = 1; t <= times; ++t) { 682 if (*nent >= maxnent) 683 goto out; 684 do_host_cpuid(&entry[t], function, t); 685 ++*nent; 686 } 687 break; 688 } 689 case KVM_CPUID_SIGNATURE: { 690 static const char signature[12] = "KVMKVMKVM\0\0"; 691 const u32 *sigptr = (const u32 *)signature; 692 entry->eax = KVM_CPUID_FEATURES; 693 entry->ebx = sigptr[0]; 694 entry->ecx = sigptr[1]; 695 entry->edx = sigptr[2]; 696 break; 697 } 698 case KVM_CPUID_FEATURES: 699 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 700 (1 << KVM_FEATURE_NOP_IO_DELAY) | 701 (1 << KVM_FEATURE_CLOCKSOURCE2) | 702 (1 << KVM_FEATURE_ASYNC_PF) | 703 (1 << KVM_FEATURE_PV_EOI) | 704 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 705 (1 << KVM_FEATURE_PV_UNHALT) | 706 (1 << KVM_FEATURE_PV_TLB_FLUSH) | 707 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | 708 (1 << KVM_FEATURE_PV_SEND_IPI) | 709 (1 << KVM_FEATURE_POLL_CONTROL) | 710 (1 << KVM_FEATURE_PV_SCHED_YIELD); 711 712 if (sched_info_on()) 713 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 714 715 entry->ebx = 0; 716 entry->ecx = 0; 717 entry->edx = 0; 718 break; 719 case 0x80000000: 720 entry->eax = min(entry->eax, 0x8000001f); 721 break; 722 case 0x80000001: 723 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 724 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 725 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 726 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 727 break; 728 case 0x80000007: /* Advanced power management */ 729 /* invariant TSC is CPUID.80000007H:EDX[8] */ 730 entry->edx &= (1 << 8); 731 /* mask against host */ 732 entry->edx &= boot_cpu_data.x86_power; 733 entry->eax = entry->ebx = entry->ecx = 0; 734 break; 735 case 0x80000008: { 736 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 737 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 738 unsigned phys_as = entry->eax & 0xff; 739 740 if (!g_phys_as) 741 g_phys_as = phys_as; 742 entry->eax = g_phys_as | (virt_as << 8); 743 entry->edx = 0; 744 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; 745 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); 746 /* 747 * AMD has separate bits for each SPEC_CTRL bit. 748 * arch/x86/kernel/cpu/bugs.c is kind enough to 749 * record that in cpufeatures so use them. 750 */ 751 if (boot_cpu_has(X86_FEATURE_IBPB)) 752 entry->ebx |= F(AMD_IBPB); 753 if (boot_cpu_has(X86_FEATURE_IBRS)) 754 entry->ebx |= F(AMD_IBRS); 755 if (boot_cpu_has(X86_FEATURE_STIBP)) 756 entry->ebx |= F(AMD_STIBP); 757 if (boot_cpu_has(X86_FEATURE_SSBD)) 758 entry->ebx |= F(AMD_SSBD); 759 if (!boot_cpu_has_bug(X86_BUG_SPEC_STORE_BYPASS)) 760 entry->ebx |= F(AMD_SSB_NO); 761 /* 762 * The preference is to use SPEC CTRL MSR instead of the 763 * VIRT_SPEC MSR. 764 */ 765 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && 766 !boot_cpu_has(X86_FEATURE_AMD_SSBD)) 767 entry->ebx |= F(VIRT_SSBD); 768 break; 769 } 770 case 0x80000019: 771 entry->ecx = entry->edx = 0; 772 break; 773 case 0x8000001a: 774 case 0x8000001e: 775 break; 776 /*Add support for Centaur's CPUID instruction*/ 777 case 0xC0000000: 778 /*Just support up to 0xC0000004 now*/ 779 entry->eax = min(entry->eax, 0xC0000004); 780 break; 781 case 0xC0000001: 782 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 783 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 784 break; 785 case 3: /* Processor serial number */ 786 case 5: /* MONITOR/MWAIT */ 787 case 0xC0000002: 788 case 0xC0000003: 789 case 0xC0000004: 790 default: 791 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 792 break; 793 } 794 795 kvm_x86_ops->set_supported_cpuid(function, entry); 796 797 r = 0; 798 799 out: 800 put_cpu(); 801 802 return r; 803 } 804 805 static int do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 func, 806 int *nent, int maxnent, unsigned int type) 807 { 808 if (type == KVM_GET_EMULATED_CPUID) 809 return __do_cpuid_func_emulated(entry, func, nent, maxnent); 810 811 return __do_cpuid_func(entry, func, nent, maxnent); 812 } 813 814 #undef F 815 816 struct kvm_cpuid_param { 817 u32 func; 818 bool (*qualifier)(const struct kvm_cpuid_param *param); 819 }; 820 821 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 822 { 823 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 824 } 825 826 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 827 __u32 num_entries, unsigned int ioctl_type) 828 { 829 int i; 830 __u32 pad[3]; 831 832 if (ioctl_type != KVM_GET_EMULATED_CPUID) 833 return false; 834 835 /* 836 * We want to make sure that ->padding is being passed clean from 837 * userspace in case we want to use it for something in the future. 838 * 839 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 840 * have to give ourselves satisfied only with the emulated side. /me 841 * sheds a tear. 842 */ 843 for (i = 0; i < num_entries; i++) { 844 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 845 return true; 846 847 if (pad[0] || pad[1] || pad[2]) 848 return true; 849 } 850 return false; 851 } 852 853 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 854 struct kvm_cpuid_entry2 __user *entries, 855 unsigned int type) 856 { 857 struct kvm_cpuid_entry2 *cpuid_entries; 858 int limit, nent = 0, r = -E2BIG, i; 859 u32 func; 860 static const struct kvm_cpuid_param param[] = { 861 { .func = 0 }, 862 { .func = 0x80000000 }, 863 { .func = 0xC0000000, .qualifier = is_centaur_cpu }, 864 { .func = KVM_CPUID_SIGNATURE }, 865 }; 866 867 if (cpuid->nent < 1) 868 goto out; 869 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 870 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 871 872 if (sanity_check_entries(entries, cpuid->nent, type)) 873 return -EINVAL; 874 875 r = -ENOMEM; 876 cpuid_entries = vzalloc(array_size(sizeof(struct kvm_cpuid_entry2), 877 cpuid->nent)); 878 if (!cpuid_entries) 879 goto out; 880 881 r = 0; 882 for (i = 0; i < ARRAY_SIZE(param); i++) { 883 const struct kvm_cpuid_param *ent = ¶m[i]; 884 885 if (ent->qualifier && !ent->qualifier(ent)) 886 continue; 887 888 r = do_cpuid_func(&cpuid_entries[nent], ent->func, 889 &nent, cpuid->nent, type); 890 891 if (r) 892 goto out_free; 893 894 limit = cpuid_entries[nent - 1].eax; 895 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 896 r = do_cpuid_func(&cpuid_entries[nent], func, 897 &nent, cpuid->nent, type); 898 899 if (r) 900 goto out_free; 901 } 902 903 r = -EFAULT; 904 if (copy_to_user(entries, cpuid_entries, 905 nent * sizeof(struct kvm_cpuid_entry2))) 906 goto out_free; 907 cpuid->nent = nent; 908 r = 0; 909 910 out_free: 911 vfree(cpuid_entries); 912 out: 913 return r; 914 } 915 916 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 917 { 918 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 919 struct kvm_cpuid_entry2 *ej; 920 int j = i; 921 int nent = vcpu->arch.cpuid_nent; 922 923 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 924 /* when no next entry is found, the current entry[i] is reselected */ 925 do { 926 j = (j + 1) % nent; 927 ej = &vcpu->arch.cpuid_entries[j]; 928 } while (ej->function != e->function); 929 930 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 931 932 return j; 933 } 934 935 /* find an entry with matching function, matching index (if needed), and that 936 * should be read next (if it's stateful) */ 937 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 938 u32 function, u32 index) 939 { 940 if (e->function != function) 941 return 0; 942 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 943 return 0; 944 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 945 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 946 return 0; 947 return 1; 948 } 949 950 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 951 u32 function, u32 index) 952 { 953 int i; 954 struct kvm_cpuid_entry2 *best = NULL; 955 956 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 957 struct kvm_cpuid_entry2 *e; 958 959 e = &vcpu->arch.cpuid_entries[i]; 960 if (is_matching_cpuid_entry(e, function, index)) { 961 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 962 move_to_next_stateful_cpuid_entry(vcpu, i); 963 best = e; 964 break; 965 } 966 } 967 return best; 968 } 969 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 970 971 /* 972 * If no match is found, check whether we exceed the vCPU's limit 973 * and return the content of the highest valid _standard_ leaf instead. 974 * This is to satisfy the CPUID specification. 975 */ 976 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 977 u32 function, u32 index) 978 { 979 struct kvm_cpuid_entry2 *maxlevel; 980 981 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 982 if (!maxlevel || maxlevel->eax >= function) 983 return NULL; 984 if (function & 0x80000000) { 985 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 986 if (!maxlevel) 987 return NULL; 988 } 989 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 990 } 991 992 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 993 u32 *ecx, u32 *edx, bool check_limit) 994 { 995 u32 function = *eax, index = *ecx; 996 struct kvm_cpuid_entry2 *best; 997 bool entry_found = true; 998 999 best = kvm_find_cpuid_entry(vcpu, function, index); 1000 1001 if (!best) { 1002 entry_found = false; 1003 if (!check_limit) 1004 goto out; 1005 1006 best = check_cpuid_limit(vcpu, function, index); 1007 } 1008 1009 out: 1010 if (best) { 1011 *eax = best->eax; 1012 *ebx = best->ebx; 1013 *ecx = best->ecx; 1014 *edx = best->edx; 1015 } else 1016 *eax = *ebx = *ecx = *edx = 0; 1017 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); 1018 return entry_found; 1019 } 1020 EXPORT_SYMBOL_GPL(kvm_cpuid); 1021 1022 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 1023 { 1024 u32 eax, ebx, ecx, edx; 1025 1026 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 1027 return 1; 1028 1029 eax = kvm_rax_read(vcpu); 1030 ecx = kvm_rcx_read(vcpu); 1031 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); 1032 kvm_rax_write(vcpu, eax); 1033 kvm_rbx_write(vcpu, ebx); 1034 kvm_rcx_write(vcpu, ecx); 1035 kvm_rdx_write(vcpu, edx); 1036 return kvm_skip_emulated_instruction(vcpu); 1037 } 1038 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 1039