1 /* 2 * Kernel-based Virtual Machine driver for Linux 3 * cpuid support routines 4 * 5 * derived from arch/x86/kvm/x86.c 6 * 7 * Copyright 2011 Red Hat, Inc. and/or its affiliates. 8 * Copyright IBM Corporation, 2008 9 * 10 * This work is licensed under the terms of the GNU GPL, version 2. See 11 * the COPYING file in the top-level directory. 12 * 13 */ 14 15 #include <linux/kvm_host.h> 16 #include <linux/export.h> 17 #include <linux/vmalloc.h> 18 #include <linux/uaccess.h> 19 #include <linux/sched/stat.h> 20 21 #include <asm/processor.h> 22 #include <asm/user.h> 23 #include <asm/fpu/xstate.h> 24 #include "cpuid.h" 25 #include "lapic.h" 26 #include "mmu.h" 27 #include "trace.h" 28 #include "pmu.h" 29 30 static u32 xstate_required_size(u64 xstate_bv, bool compacted) 31 { 32 int feature_bit = 0; 33 u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 34 35 xstate_bv &= XFEATURE_MASK_EXTEND; 36 while (xstate_bv) { 37 if (xstate_bv & 0x1) { 38 u32 eax, ebx, ecx, edx, offset; 39 cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx); 40 offset = compacted ? ret : ebx; 41 ret = max(ret, offset + eax); 42 } 43 44 xstate_bv >>= 1; 45 feature_bit++; 46 } 47 48 return ret; 49 } 50 51 bool kvm_mpx_supported(void) 52 { 53 return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR)) 54 && kvm_x86_ops->mpx_supported()); 55 } 56 EXPORT_SYMBOL_GPL(kvm_mpx_supported); 57 58 u64 kvm_supported_xcr0(void) 59 { 60 u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0; 61 62 if (!kvm_mpx_supported()) 63 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR); 64 65 return xcr0; 66 } 67 68 #define F(x) bit(X86_FEATURE_##x) 69 70 int kvm_update_cpuid(struct kvm_vcpu *vcpu) 71 { 72 struct kvm_cpuid_entry2 *best; 73 struct kvm_lapic *apic = vcpu->arch.apic; 74 75 best = kvm_find_cpuid_entry(vcpu, 1, 0); 76 if (!best) 77 return 0; 78 79 /* Update OSXSAVE bit */ 80 if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) { 81 best->ecx &= ~F(OSXSAVE); 82 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE)) 83 best->ecx |= F(OSXSAVE); 84 } 85 86 best->edx &= ~F(APIC); 87 if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE) 88 best->edx |= F(APIC); 89 90 if (apic) { 91 if (best->ecx & F(TSC_DEADLINE_TIMER)) 92 apic->lapic_timer.timer_mode_mask = 3 << 17; 93 else 94 apic->lapic_timer.timer_mode_mask = 1 << 17; 95 } 96 97 best = kvm_find_cpuid_entry(vcpu, 7, 0); 98 if (best) { 99 /* Update OSPKE bit */ 100 if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) { 101 best->ecx &= ~F(OSPKE); 102 if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE)) 103 best->ecx |= F(OSPKE); 104 } 105 } 106 107 best = kvm_find_cpuid_entry(vcpu, 0xD, 0); 108 if (!best) { 109 vcpu->arch.guest_supported_xcr0 = 0; 110 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET; 111 } else { 112 vcpu->arch.guest_supported_xcr0 = 113 (best->eax | ((u64)best->edx << 32)) & 114 kvm_supported_xcr0(); 115 vcpu->arch.guest_xstate_size = best->ebx = 116 xstate_required_size(vcpu->arch.xcr0, false); 117 } 118 119 best = kvm_find_cpuid_entry(vcpu, 0xD, 1); 120 if (best && (best->eax & (F(XSAVES) | F(XSAVEC)))) 121 best->ebx = xstate_required_size(vcpu->arch.xcr0, true); 122 123 /* 124 * The existing code assumes virtual address is 48-bit or 57-bit in the 125 * canonical address checks; exit if it is ever changed. 126 */ 127 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 128 if (best) { 129 int vaddr_bits = (best->eax & 0xff00) >> 8; 130 131 if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0) 132 return -EINVAL; 133 } 134 135 best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0); 136 if (kvm_hlt_in_guest(vcpu->kvm) && best && 137 (best->eax & (1 << KVM_FEATURE_PV_UNHALT))) 138 best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT); 139 140 /* Update physical-address width */ 141 vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu); 142 kvm_mmu_reset_context(vcpu); 143 144 kvm_pmu_refresh(vcpu); 145 return 0; 146 } 147 148 static int is_efer_nx(void) 149 { 150 unsigned long long efer = 0; 151 152 rdmsrl_safe(MSR_EFER, &efer); 153 return efer & EFER_NX; 154 } 155 156 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu) 157 { 158 int i; 159 struct kvm_cpuid_entry2 *e, *entry; 160 161 entry = NULL; 162 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 163 e = &vcpu->arch.cpuid_entries[i]; 164 if (e->function == 0x80000001) { 165 entry = e; 166 break; 167 } 168 } 169 if (entry && (entry->edx & F(NX)) && !is_efer_nx()) { 170 entry->edx &= ~F(NX); 171 printk(KERN_INFO "kvm: guest NX capability removed\n"); 172 } 173 } 174 175 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu) 176 { 177 struct kvm_cpuid_entry2 *best; 178 179 best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0); 180 if (!best || best->eax < 0x80000008) 181 goto not_found; 182 best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0); 183 if (best) 184 return best->eax & 0xff; 185 not_found: 186 return 36; 187 } 188 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr); 189 190 /* when an old userspace process fills a new kernel module */ 191 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 192 struct kvm_cpuid *cpuid, 193 struct kvm_cpuid_entry __user *entries) 194 { 195 int r, i; 196 struct kvm_cpuid_entry *cpuid_entries = NULL; 197 198 r = -E2BIG; 199 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 200 goto out; 201 r = -ENOMEM; 202 if (cpuid->nent) { 203 cpuid_entries = 204 vmalloc(array_size(sizeof(struct kvm_cpuid_entry), 205 cpuid->nent)); 206 if (!cpuid_entries) 207 goto out; 208 r = -EFAULT; 209 if (copy_from_user(cpuid_entries, entries, 210 cpuid->nent * sizeof(struct kvm_cpuid_entry))) 211 goto out; 212 } 213 for (i = 0; i < cpuid->nent; i++) { 214 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function; 215 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax; 216 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx; 217 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx; 218 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx; 219 vcpu->arch.cpuid_entries[i].index = 0; 220 vcpu->arch.cpuid_entries[i].flags = 0; 221 vcpu->arch.cpuid_entries[i].padding[0] = 0; 222 vcpu->arch.cpuid_entries[i].padding[1] = 0; 223 vcpu->arch.cpuid_entries[i].padding[2] = 0; 224 } 225 vcpu->arch.cpuid_nent = cpuid->nent; 226 cpuid_fix_nx_cap(vcpu); 227 kvm_apic_set_version(vcpu); 228 kvm_x86_ops->cpuid_update(vcpu); 229 r = kvm_update_cpuid(vcpu); 230 231 out: 232 vfree(cpuid_entries); 233 return r; 234 } 235 236 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 237 struct kvm_cpuid2 *cpuid, 238 struct kvm_cpuid_entry2 __user *entries) 239 { 240 int r; 241 242 r = -E2BIG; 243 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 244 goto out; 245 r = -EFAULT; 246 if (copy_from_user(&vcpu->arch.cpuid_entries, entries, 247 cpuid->nent * sizeof(struct kvm_cpuid_entry2))) 248 goto out; 249 vcpu->arch.cpuid_nent = cpuid->nent; 250 kvm_apic_set_version(vcpu); 251 kvm_x86_ops->cpuid_update(vcpu); 252 r = kvm_update_cpuid(vcpu); 253 out: 254 return r; 255 } 256 257 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 258 struct kvm_cpuid2 *cpuid, 259 struct kvm_cpuid_entry2 __user *entries) 260 { 261 int r; 262 263 r = -E2BIG; 264 if (cpuid->nent < vcpu->arch.cpuid_nent) 265 goto out; 266 r = -EFAULT; 267 if (copy_to_user(entries, &vcpu->arch.cpuid_entries, 268 vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2))) 269 goto out; 270 return 0; 271 272 out: 273 cpuid->nent = vcpu->arch.cpuid_nent; 274 return r; 275 } 276 277 static void cpuid_mask(u32 *word, int wordnum) 278 { 279 *word &= boot_cpu_data.x86_capability[wordnum]; 280 } 281 282 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function, 283 u32 index) 284 { 285 entry->function = function; 286 entry->index = index; 287 cpuid_count(entry->function, entry->index, 288 &entry->eax, &entry->ebx, &entry->ecx, &entry->edx); 289 entry->flags = 0; 290 } 291 292 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry, 293 u32 func, u32 index, int *nent, int maxnent) 294 { 295 switch (func) { 296 case 0: 297 entry->eax = 7; 298 ++*nent; 299 break; 300 case 1: 301 entry->ecx = F(MOVBE); 302 ++*nent; 303 break; 304 case 7: 305 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 306 if (index == 0) 307 entry->ecx = F(RDPID); 308 ++*nent; 309 default: 310 break; 311 } 312 313 entry->function = func; 314 entry->index = index; 315 316 return 0; 317 } 318 319 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, 320 u32 index, int *nent, int maxnent) 321 { 322 int r; 323 unsigned f_nx = is_efer_nx() ? F(NX) : 0; 324 #ifdef CONFIG_X86_64 325 unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL) 326 ? F(GBPAGES) : 0; 327 unsigned f_lm = F(LM); 328 #else 329 unsigned f_gbpages = 0; 330 unsigned f_lm = 0; 331 #endif 332 unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0; 333 unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0; 334 unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0; 335 unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0; 336 unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0; 337 unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0; 338 unsigned f_la57 = 0; 339 340 /* cpuid 1.edx */ 341 const u32 kvm_cpuid_1_edx_x86_features = 342 F(FPU) | F(VME) | F(DE) | F(PSE) | 343 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 344 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) | 345 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 346 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) | 347 0 /* Reserved, DS, ACPI */ | F(MMX) | 348 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) | 349 0 /* HTT, TM, Reserved, PBE */; 350 /* cpuid 0x80000001.edx */ 351 const u32 kvm_cpuid_8000_0001_edx_x86_features = 352 F(FPU) | F(VME) | F(DE) | F(PSE) | 353 F(TSC) | F(MSR) | F(PAE) | F(MCE) | 354 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) | 355 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) | 356 F(PAT) | F(PSE36) | 0 /* Reserved */ | 357 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) | 358 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp | 359 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW); 360 /* cpuid 1.ecx */ 361 const u32 kvm_cpuid_1_ecx_x86_features = 362 /* NOTE: MONITOR (and MWAIT) are emulated as NOP, 363 * but *not* advertised to guests via CPUID ! */ 364 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ | 365 0 /* DS-CPL, VMX, SMX, EST */ | 366 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ | 367 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ | 368 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) | 369 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) | 370 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) | 371 F(F16C) | F(RDRAND); 372 /* cpuid 0x80000001.ecx */ 373 const u32 kvm_cpuid_8000_0001_ecx_x86_features = 374 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ | 375 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) | 376 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) | 377 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) | 378 F(TOPOEXT) | F(PERFCTR_CORE); 379 380 /* cpuid 0x80000008.ebx */ 381 const u32 kvm_cpuid_8000_0008_ebx_x86_features = 382 F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) | 383 F(AMD_SSB_NO) | F(AMD_STIBP); 384 385 /* cpuid 0xC0000001.edx */ 386 const u32 kvm_cpuid_C000_0001_edx_x86_features = 387 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) | 388 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) | 389 F(PMM) | F(PMM_EN); 390 391 /* cpuid 7.0.ebx */ 392 const u32 kvm_cpuid_7_0_ebx_x86_features = 393 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) | 394 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) | 395 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) | 396 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) | 397 F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt; 398 399 /* cpuid 0xD.1.eax */ 400 const u32 kvm_cpuid_D_1_eax_x86_features = 401 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves; 402 403 /* cpuid 7.0.ecx*/ 404 const u32 kvm_cpuid_7_0_ecx_x86_features = 405 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ | 406 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) | 407 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) | 408 F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B); 409 410 /* cpuid 7.0.edx*/ 411 const u32 kvm_cpuid_7_0_edx_x86_features = 412 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) | 413 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) | 414 F(MD_CLEAR); 415 416 /* all calls to cpuid_count() should be made on the same cpu */ 417 get_cpu(); 418 419 r = -E2BIG; 420 421 if (*nent >= maxnent) 422 goto out; 423 424 do_cpuid_1_ent(entry, function, index); 425 ++*nent; 426 427 switch (function) { 428 case 0: 429 entry->eax = min(entry->eax, (u32)(f_intel_pt ? 0x14 : 0xd)); 430 break; 431 case 1: 432 entry->edx &= kvm_cpuid_1_edx_x86_features; 433 cpuid_mask(&entry->edx, CPUID_1_EDX); 434 entry->ecx &= kvm_cpuid_1_ecx_x86_features; 435 cpuid_mask(&entry->ecx, CPUID_1_ECX); 436 /* we support x2apic emulation even if host does not support 437 * it since we emulate x2apic in software */ 438 entry->ecx |= F(X2APIC); 439 break; 440 /* function 2 entries are STATEFUL. That is, repeated cpuid commands 441 * may return different values. This forces us to get_cpu() before 442 * issuing the first command, and also to emulate this annoying behavior 443 * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */ 444 case 2: { 445 int t, times = entry->eax & 0xff; 446 447 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 448 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 449 for (t = 1; t < times; ++t) { 450 if (*nent >= maxnent) 451 goto out; 452 453 do_cpuid_1_ent(&entry[t], function, 0); 454 entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC; 455 ++*nent; 456 } 457 break; 458 } 459 /* function 4 has additional index. */ 460 case 4: { 461 int i, cache_type; 462 463 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 464 /* read more entries until cache_type is zero */ 465 for (i = 1; ; ++i) { 466 if (*nent >= maxnent) 467 goto out; 468 469 cache_type = entry[i - 1].eax & 0x1f; 470 if (!cache_type) 471 break; 472 do_cpuid_1_ent(&entry[i], function, i); 473 entry[i].flags |= 474 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 475 ++*nent; 476 } 477 break; 478 } 479 case 6: /* Thermal management */ 480 entry->eax = 0x4; /* allow ARAT */ 481 entry->ebx = 0; 482 entry->ecx = 0; 483 entry->edx = 0; 484 break; 485 case 7: { 486 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 487 /* Mask ebx against host capability word 9 */ 488 if (index == 0) { 489 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features; 490 cpuid_mask(&entry->ebx, CPUID_7_0_EBX); 491 // TSC_ADJUST is emulated 492 entry->ebx |= F(TSC_ADJUST); 493 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features; 494 f_la57 = entry->ecx & F(LA57); 495 cpuid_mask(&entry->ecx, CPUID_7_ECX); 496 /* Set LA57 based on hardware capability. */ 497 entry->ecx |= f_la57; 498 entry->ecx |= f_umip; 499 /* PKU is not yet implemented for shadow paging. */ 500 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE)) 501 entry->ecx &= ~F(PKU); 502 entry->edx &= kvm_cpuid_7_0_edx_x86_features; 503 cpuid_mask(&entry->edx, CPUID_7_EDX); 504 /* 505 * We emulate ARCH_CAPABILITIES in software even 506 * if the host doesn't support it. 507 */ 508 entry->edx |= F(ARCH_CAPABILITIES); 509 } else { 510 entry->ebx = 0; 511 entry->ecx = 0; 512 entry->edx = 0; 513 } 514 entry->eax = 0; 515 break; 516 } 517 case 9: 518 break; 519 case 0xa: { /* Architectural Performance Monitoring */ 520 struct x86_pmu_capability cap; 521 union cpuid10_eax eax; 522 union cpuid10_edx edx; 523 524 perf_get_x86_pmu_capability(&cap); 525 526 /* 527 * Only support guest architectural pmu on a host 528 * with architectural pmu. 529 */ 530 if (!cap.version) 531 memset(&cap, 0, sizeof(cap)); 532 533 eax.split.version_id = min(cap.version, 2); 534 eax.split.num_counters = cap.num_counters_gp; 535 eax.split.bit_width = cap.bit_width_gp; 536 eax.split.mask_length = cap.events_mask_len; 537 538 edx.split.num_counters_fixed = cap.num_counters_fixed; 539 edx.split.bit_width_fixed = cap.bit_width_fixed; 540 edx.split.reserved = 0; 541 542 entry->eax = eax.full; 543 entry->ebx = cap.events_mask; 544 entry->ecx = 0; 545 entry->edx = edx.full; 546 break; 547 } 548 /* function 0xb has additional index. */ 549 case 0xb: { 550 int i, level_type; 551 552 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 553 /* read more entries until level_type is zero */ 554 for (i = 1; ; ++i) { 555 if (*nent >= maxnent) 556 goto out; 557 558 level_type = entry[i - 1].ecx & 0xff00; 559 if (!level_type) 560 break; 561 do_cpuid_1_ent(&entry[i], function, i); 562 entry[i].flags |= 563 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 564 ++*nent; 565 } 566 break; 567 } 568 case 0xd: { 569 int idx, i; 570 u64 supported = kvm_supported_xcr0(); 571 572 entry->eax &= supported; 573 entry->ebx = xstate_required_size(supported, false); 574 entry->ecx = entry->ebx; 575 entry->edx &= supported >> 32; 576 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 577 if (!supported) 578 break; 579 580 for (idx = 1, i = 1; idx < 64; ++idx) { 581 u64 mask = ((u64)1 << idx); 582 if (*nent >= maxnent) 583 goto out; 584 585 do_cpuid_1_ent(&entry[i], function, idx); 586 if (idx == 1) { 587 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features; 588 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX); 589 entry[i].ebx = 0; 590 if (entry[i].eax & (F(XSAVES)|F(XSAVEC))) 591 entry[i].ebx = 592 xstate_required_size(supported, 593 true); 594 } else { 595 if (entry[i].eax == 0 || !(supported & mask)) 596 continue; 597 if (WARN_ON_ONCE(entry[i].ecx & 1)) 598 continue; 599 } 600 entry[i].ecx = 0; 601 entry[i].edx = 0; 602 entry[i].flags |= 603 KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 604 ++*nent; 605 ++i; 606 } 607 break; 608 } 609 /* Intel PT */ 610 case 0x14: { 611 int t, times = entry->eax; 612 613 if (!f_intel_pt) 614 break; 615 616 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 617 for (t = 1; t <= times; ++t) { 618 if (*nent >= maxnent) 619 goto out; 620 do_cpuid_1_ent(&entry[t], function, t); 621 entry[t].flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX; 622 ++*nent; 623 } 624 break; 625 } 626 case KVM_CPUID_SIGNATURE: { 627 static const char signature[12] = "KVMKVMKVM\0\0"; 628 const u32 *sigptr = (const u32 *)signature; 629 entry->eax = KVM_CPUID_FEATURES; 630 entry->ebx = sigptr[0]; 631 entry->ecx = sigptr[1]; 632 entry->edx = sigptr[2]; 633 break; 634 } 635 case KVM_CPUID_FEATURES: 636 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | 637 (1 << KVM_FEATURE_NOP_IO_DELAY) | 638 (1 << KVM_FEATURE_CLOCKSOURCE2) | 639 (1 << KVM_FEATURE_ASYNC_PF) | 640 (1 << KVM_FEATURE_PV_EOI) | 641 (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) | 642 (1 << KVM_FEATURE_PV_UNHALT) | 643 (1 << KVM_FEATURE_PV_TLB_FLUSH) | 644 (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) | 645 (1 << KVM_FEATURE_PV_SEND_IPI); 646 647 if (sched_info_on()) 648 entry->eax |= (1 << KVM_FEATURE_STEAL_TIME); 649 650 entry->ebx = 0; 651 entry->ecx = 0; 652 entry->edx = 0; 653 break; 654 case 0x80000000: 655 entry->eax = min(entry->eax, 0x8000001f); 656 break; 657 case 0x80000001: 658 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features; 659 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX); 660 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features; 661 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX); 662 break; 663 case 0x80000007: /* Advanced power management */ 664 /* invariant TSC is CPUID.80000007H:EDX[8] */ 665 entry->edx &= (1 << 8); 666 /* mask against host */ 667 entry->edx &= boot_cpu_data.x86_power; 668 entry->eax = entry->ebx = entry->ecx = 0; 669 break; 670 case 0x80000008: { 671 unsigned g_phys_as = (entry->eax >> 16) & 0xff; 672 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U); 673 unsigned phys_as = entry->eax & 0xff; 674 675 if (!g_phys_as) 676 g_phys_as = phys_as; 677 entry->eax = g_phys_as | (virt_as << 8); 678 entry->edx = 0; 679 /* 680 * IBRS, IBPB and VIRT_SSBD aren't necessarily present in 681 * hardware cpuid 682 */ 683 if (boot_cpu_has(X86_FEATURE_AMD_IBPB)) 684 entry->ebx |= F(AMD_IBPB); 685 if (boot_cpu_has(X86_FEATURE_AMD_IBRS)) 686 entry->ebx |= F(AMD_IBRS); 687 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD)) 688 entry->ebx |= F(VIRT_SSBD); 689 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features; 690 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX); 691 /* 692 * The preference is to use SPEC CTRL MSR instead of the 693 * VIRT_SPEC MSR. 694 */ 695 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) && 696 !boot_cpu_has(X86_FEATURE_AMD_SSBD)) 697 entry->ebx |= F(VIRT_SSBD); 698 break; 699 } 700 case 0x80000019: 701 entry->ecx = entry->edx = 0; 702 break; 703 case 0x8000001a: 704 break; 705 case 0x8000001d: 706 break; 707 /*Add support for Centaur's CPUID instruction*/ 708 case 0xC0000000: 709 /*Just support up to 0xC0000004 now*/ 710 entry->eax = min(entry->eax, 0xC0000004); 711 break; 712 case 0xC0000001: 713 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features; 714 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX); 715 break; 716 case 3: /* Processor serial number */ 717 case 5: /* MONITOR/MWAIT */ 718 case 0xC0000002: 719 case 0xC0000003: 720 case 0xC0000004: 721 default: 722 entry->eax = entry->ebx = entry->ecx = entry->edx = 0; 723 break; 724 } 725 726 kvm_x86_ops->set_supported_cpuid(function, entry); 727 728 r = 0; 729 730 out: 731 put_cpu(); 732 733 return r; 734 } 735 736 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func, 737 u32 idx, int *nent, int maxnent, unsigned int type) 738 { 739 if (type == KVM_GET_EMULATED_CPUID) 740 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent); 741 742 return __do_cpuid_ent(entry, func, idx, nent, maxnent); 743 } 744 745 #undef F 746 747 struct kvm_cpuid_param { 748 u32 func; 749 u32 idx; 750 bool has_leaf_count; 751 bool (*qualifier)(const struct kvm_cpuid_param *param); 752 }; 753 754 static bool is_centaur_cpu(const struct kvm_cpuid_param *param) 755 { 756 return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR; 757 } 758 759 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries, 760 __u32 num_entries, unsigned int ioctl_type) 761 { 762 int i; 763 __u32 pad[3]; 764 765 if (ioctl_type != KVM_GET_EMULATED_CPUID) 766 return false; 767 768 /* 769 * We want to make sure that ->padding is being passed clean from 770 * userspace in case we want to use it for something in the future. 771 * 772 * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we 773 * have to give ourselves satisfied only with the emulated side. /me 774 * sheds a tear. 775 */ 776 for (i = 0; i < num_entries; i++) { 777 if (copy_from_user(pad, entries[i].padding, sizeof(pad))) 778 return true; 779 780 if (pad[0] || pad[1] || pad[2]) 781 return true; 782 } 783 return false; 784 } 785 786 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 787 struct kvm_cpuid_entry2 __user *entries, 788 unsigned int type) 789 { 790 struct kvm_cpuid_entry2 *cpuid_entries; 791 int limit, nent = 0, r = -E2BIG, i; 792 u32 func; 793 static const struct kvm_cpuid_param param[] = { 794 { .func = 0, .has_leaf_count = true }, 795 { .func = 0x80000000, .has_leaf_count = true }, 796 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true }, 797 { .func = KVM_CPUID_SIGNATURE }, 798 { .func = KVM_CPUID_FEATURES }, 799 }; 800 801 if (cpuid->nent < 1) 802 goto out; 803 if (cpuid->nent > KVM_MAX_CPUID_ENTRIES) 804 cpuid->nent = KVM_MAX_CPUID_ENTRIES; 805 806 if (sanity_check_entries(entries, cpuid->nent, type)) 807 return -EINVAL; 808 809 r = -ENOMEM; 810 cpuid_entries = vzalloc(array_size(sizeof(struct kvm_cpuid_entry2), 811 cpuid->nent)); 812 if (!cpuid_entries) 813 goto out; 814 815 r = 0; 816 for (i = 0; i < ARRAY_SIZE(param); i++) { 817 const struct kvm_cpuid_param *ent = ¶m[i]; 818 819 if (ent->qualifier && !ent->qualifier(ent)) 820 continue; 821 822 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx, 823 &nent, cpuid->nent, type); 824 825 if (r) 826 goto out_free; 827 828 if (!ent->has_leaf_count) 829 continue; 830 831 limit = cpuid_entries[nent - 1].eax; 832 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func) 833 r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx, 834 &nent, cpuid->nent, type); 835 836 if (r) 837 goto out_free; 838 } 839 840 r = -EFAULT; 841 if (copy_to_user(entries, cpuid_entries, 842 nent * sizeof(struct kvm_cpuid_entry2))) 843 goto out_free; 844 cpuid->nent = nent; 845 r = 0; 846 847 out_free: 848 vfree(cpuid_entries); 849 out: 850 return r; 851 } 852 853 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i) 854 { 855 struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i]; 856 struct kvm_cpuid_entry2 *ej; 857 int j = i; 858 int nent = vcpu->arch.cpuid_nent; 859 860 e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT; 861 /* when no next entry is found, the current entry[i] is reselected */ 862 do { 863 j = (j + 1) % nent; 864 ej = &vcpu->arch.cpuid_entries[j]; 865 } while (ej->function != e->function); 866 867 ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT; 868 869 return j; 870 } 871 872 /* find an entry with matching function, matching index (if needed), and that 873 * should be read next (if it's stateful) */ 874 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e, 875 u32 function, u32 index) 876 { 877 if (e->function != function) 878 return 0; 879 if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index) 880 return 0; 881 if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) && 882 !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT)) 883 return 0; 884 return 1; 885 } 886 887 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 888 u32 function, u32 index) 889 { 890 int i; 891 struct kvm_cpuid_entry2 *best = NULL; 892 893 for (i = 0; i < vcpu->arch.cpuid_nent; ++i) { 894 struct kvm_cpuid_entry2 *e; 895 896 e = &vcpu->arch.cpuid_entries[i]; 897 if (is_matching_cpuid_entry(e, function, index)) { 898 if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) 899 move_to_next_stateful_cpuid_entry(vcpu, i); 900 best = e; 901 break; 902 } 903 } 904 return best; 905 } 906 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry); 907 908 /* 909 * If no match is found, check whether we exceed the vCPU's limit 910 * and return the content of the highest valid _standard_ leaf instead. 911 * This is to satisfy the CPUID specification. 912 */ 913 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu, 914 u32 function, u32 index) 915 { 916 struct kvm_cpuid_entry2 *maxlevel; 917 918 maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0); 919 if (!maxlevel || maxlevel->eax >= function) 920 return NULL; 921 if (function & 0x80000000) { 922 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0); 923 if (!maxlevel) 924 return NULL; 925 } 926 return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index); 927 } 928 929 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 930 u32 *ecx, u32 *edx, bool check_limit) 931 { 932 u32 function = *eax, index = *ecx; 933 struct kvm_cpuid_entry2 *best; 934 bool entry_found = true; 935 936 best = kvm_find_cpuid_entry(vcpu, function, index); 937 938 if (!best) { 939 entry_found = false; 940 if (!check_limit) 941 goto out; 942 943 best = check_cpuid_limit(vcpu, function, index); 944 } 945 946 out: 947 if (best) { 948 *eax = best->eax; 949 *ebx = best->ebx; 950 *ecx = best->ecx; 951 *edx = best->edx; 952 } else 953 *eax = *ebx = *ecx = *edx = 0; 954 trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found); 955 return entry_found; 956 } 957 EXPORT_SYMBOL_GPL(kvm_cpuid); 958 959 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu) 960 { 961 u32 eax, ebx, ecx, edx; 962 963 if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0)) 964 return 1; 965 966 eax = kvm_rax_read(vcpu); 967 ecx = kvm_rcx_read(vcpu); 968 kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true); 969 kvm_rax_write(vcpu, eax); 970 kvm_rbx_write(vcpu, ebx); 971 kvm_rcx_write(vcpu, ecx); 972 kvm_rdx_write(vcpu, edx); 973 return kvm_skip_emulated_instruction(vcpu); 974 } 975 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid); 976