arch/x86/kvm/cpuid.c

   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 0x14:
 308         case 0x8000001d:
 309                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 310                 break;
 311         }
 312 }
 313
 314 static int __do_cpuid_func_emulated(struct kvm_cpuid_entry2 *entry,
 315                                     u32 func, int *nent, int maxnent)
 316 {
 317         entry->function = func;
 318         entry->index = 0;
 319         entry->flags = 0;
 320
 321         switch (func) {
 322         case 0:
 323                 entry->eax = 7;
 324                 ++*nent;
 325                 break;
 326         case 1:
 327                 entry->ecx = F(MOVBE);
 328                 ++*nent;
 329                 break;
 330         case 7:
 331                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 332                 entry->eax = 0;
 333                 entry->ecx = F(RDPID);
 334                 ++*nent;
 335         default:
 336                 break;
 337         }
 338
 339         return 0;
 340 }
 341
 342 static inline void do_cpuid_7_mask(struct kvm_cpuid_entry2 *entry, int index)
 343 {
 344         unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
 345         unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
 346         unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
 347         unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;
 348         unsigned f_la57;
 349
 350         /* cpuid 7.0.ebx */
 351         const u32 kvm_cpuid_7_0_ebx_x86_features =
 352                 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
 353                 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
 354                 F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
 355                 F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
 356                 F(SHA_NI) | F(AVX512BW) | F(AVX512VL) | f_intel_pt;
 357
 358         /* cpuid 7.0.ecx*/
 359         const u32 kvm_cpuid_7_0_ecx_x86_features =
 360                 F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
 361                 F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
 362                 F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG) |
 363                 F(CLDEMOTE) | F(MOVDIRI) | F(MOVDIR64B);
 364
 365         /* cpuid 7.0.edx*/
 366         const u32 kvm_cpuid_7_0_edx_x86_features =
 367                 F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
 368                 F(SPEC_CTRL_SSBD) | F(ARCH_CAPABILITIES) | F(INTEL_STIBP) |
 369                 F(MD_CLEAR);
 370
 371         switch (index) {
 372         case 0:
 373                 entry->eax = 0;
 374                 entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
 375                 cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
 376                 /* TSC_ADJUST is emulated */
 377                 entry->ebx |= F(TSC_ADJUST);
 378
 379                 entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
 380                 f_la57 = entry->ecx & F(LA57);
 381                 cpuid_mask(&entry->ecx, CPUID_7_ECX);
 382                 /* Set LA57 based on hardware capability. */
 383                 entry->ecx |= f_la57;
 384                 entry->ecx |= f_umip;
 385                 /* PKU is not yet implemented for shadow paging. */
 386                 if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
 387                         entry->ecx &= ~F(PKU);
 388
 389                 entry->edx &= kvm_cpuid_7_0_edx_x86_features;
 390                 cpuid_mask(&entry->edx, CPUID_7_EDX);
 391                 /*
 392                  * We emulate ARCH_CAPABILITIES in software even
 393                  * if the host doesn't support it.
 394                  */
 395                 entry->edx |= F(ARCH_CAPABILITIES);
 396                 break;
 397         default:
 398                 WARN_ON_ONCE(1);
 399                 entry->eax = 0;
 400                 entry->ebx = 0;
 401                 entry->ecx = 0;
 402                 entry->edx = 0;
 403                 break;
 404         }
 405 }
 406
 407 static inline int __do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 function,
 408                                   int *nent, int maxnent)
 409 {
 410         int r;
 411         unsigned f_nx = is_efer_nx() ? F(NX) : 0;
 412 #ifdef CONFIG_X86_64
 413         unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
 414                                 ? F(GBPAGES) : 0;
 415         unsigned f_lm = F(LM);
 416 #else
 417         unsigned f_gbpages = 0;
 418         unsigned f_lm = 0;
 419 #endif
 420         unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
 421         unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
 422         unsigned f_intel_pt = kvm_x86_ops->pt_supported() ? F(INTEL_PT) : 0;
 423
 424         /* cpuid 1.edx */
 425         const u32 kvm_cpuid_1_edx_x86_features =
 426                 F(FPU) | F(VME) | F(DE) | F(PSE) |
 427                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
 428                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
 429                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 430                 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
 431                 0 /* Reserved, DS, ACPI */ | F(MMX) |
 432                 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
 433                 0 /* HTT, TM, Reserved, PBE */;
 434         /* cpuid 0x80000001.edx */
 435         const u32 kvm_cpuid_8000_0001_edx_x86_features =
 436                 F(FPU) | F(VME) | F(DE) | F(PSE) |
 437                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
 438                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
 439                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 440                 F(PAT) | F(PSE36) | 0 /* Reserved */ |
 441                 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
 442                 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
 443                 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
 444         /* cpuid 1.ecx */
 445         const u32 kvm_cpuid_1_ecx_x86_features =
 446                 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
 447                  * but *not* advertised to guests via CPUID ! */
 448                 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
 449                 0 /* DS-CPL, VMX, SMX, EST */ |
 450                 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
 451                 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
 452                 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
 453                 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
 454                 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
 455                 F(F16C) | F(RDRAND);
 456         /* cpuid 0x80000001.ecx */
 457         const u32 kvm_cpuid_8000_0001_ecx_x86_features =
 458                 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
 459                 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
 460                 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
 461                 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
 462                 F(TOPOEXT) | F(PERFCTR_CORE);
 463
 464         /* cpuid 0x80000008.ebx */
 465         const u32 kvm_cpuid_8000_0008_ebx_x86_features =
 466                 F(WBNOINVD) | F(AMD_IBPB) | F(AMD_IBRS) | F(AMD_SSBD) | F(VIRT_SSBD) |
 467                 F(AMD_SSB_NO) | F(AMD_STIBP) | F(AMD_STIBP_ALWAYS_ON);
 468
 469         /* cpuid 0xC0000001.edx */
 470         const u32 kvm_cpuid_C000_0001_edx_x86_features =
 471                 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
 472                 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
 473                 F(PMM) | F(PMM_EN);
 474
 475         /* cpuid 0xD.1.eax */
 476         const u32 kvm_cpuid_D_1_eax_x86_features =
 477                 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
 478
 479         /* all calls to cpuid_count() should be made on the same cpu */
 480         get_cpu();
 481
 482         r = -E2BIG;
 483
 484         if (*nent >= maxnent)
 485                 goto out;
 486
 487         do_host_cpuid(entry, function, 0);
 488         ++*nent;
 489
 490         switch (function) {
 491         case 0:
 492                 /* Limited to the highest leaf implemented in KVM. */
 493                 entry->eax = min(entry->eax, 0x1fU);
 494                 break;
 495         case 1:
 496                 entry->edx &= kvm_cpuid_1_edx_x86_features;
 497                 cpuid_mask(&entry->edx, CPUID_1_EDX);
 498                 entry->ecx &= kvm_cpuid_1_ecx_x86_features;
 499                 cpuid_mask(&entry->ecx, CPUID_1_ECX);
 500                 /* we support x2apic emulation even if host does not support
 501                  * it since we emulate x2apic in software */
 502                 entry->ecx |= F(X2APIC);
 503                 break;
 504         /* function 2 entries are STATEFUL. That is, repeated cpuid commands
 505          * may return different values. This forces us to get_cpu() before
 506          * issuing the first command, and also to emulate this annoying behavior
 507          * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
 508         case 2: {
 509                 int t, times = entry->eax & 0xff;
 510
 511                 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
 512                 for (t = 1; t < times; ++t) {
 513                         if (*nent >= maxnent)
 514                                 goto out;
 515
 516                         do_host_cpuid(&entry[t], function, 0);
 517                         ++*nent;
 518                 }
 519                 break;
 520         }
 521         /* functions 4 and 0x8000001d have additional index. */
 522         case 4:
 523         case 0x8000001d: {
 524                 int i, cache_type;
 525
 526                 /* read more entries until cache_type is zero */
 527                 for (i = 1; ; ++i) {
 528                         if (*nent >= maxnent)
 529                                 goto out;
 530
 531                         cache_type = entry[i - 1].eax & 0x1f;
 532                         if (!cache_type)
 533                                 break;
 534                         do_host_cpuid(&entry[i], function, i);
 535                         ++*nent;
 536                 }
 537                 break;
 538         }
 539         case 6: /* Thermal management */
 540                 entry->eax = 0x4; /* allow ARAT */
 541                 entry->ebx = 0;
 542                 entry->ecx = 0;
 543                 entry->edx = 0;
 544                 break;
 545         /* function 7 has additional index. */
 546         case 7: {
 547                 int i;
 548
 549                 for (i = 0; ; ) {
 550                         do_cpuid_7_mask(&entry[i], i);
 551                         if (i == entry->eax)
 552                                 break;
 553                         if (*nent >= maxnent)
 554                                 goto out;
 555
 556                         ++i;
 557                         do_host_cpuid(&entry[i], function, i);
 558                         ++*nent;
 559                 }
 560                 break;
 561         }
 562         case 9:
 563                 break;
 564         case 0xa: { /* Architectural Performance Monitoring */
 565                 struct x86_pmu_capability cap;
 566                 union cpuid10_eax eax;
 567                 union cpuid10_edx edx;
 568
 569                 perf_get_x86_pmu_capability(&cap);
 570
 571                 /*
 572                  * Only support guest architectural pmu on a host
 573                  * with architectural pmu.
 574                  */
 575                 if (!cap.version)
 576                         memset(&cap, 0, sizeof(cap));
 577
 578                 eax.split.version_id = min(cap.version, 2);
 579                 eax.split.num_counters = cap.num_counters_gp;
 580                 eax.split.bit_width = cap.bit_width_gp;
 581                 eax.split.mask_length = cap.events_mask_len;
 582
 583                 edx.split.num_counters_fixed = cap.num_counters_fixed;
 584                 edx.split.bit_width_fixed = cap.bit_width_fixed;
 585                 edx.split.reserved = 0;
 586
 587                 entry->eax = eax.full;
 588                 entry->ebx = cap.events_mask;
 589                 entry->ecx = 0;
 590                 entry->edx = edx.full;
 591                 break;
 592         }
 593         /*
 594          * Per Intel's SDM, the 0x1f is a superset of 0xb,
 595          * thus they can be handled by common code.
 596          */
 597         case 0x1f:
 598         case 0xb: {
 599                 int i, level_type;
 600
 601                 /* read more entries until level_type is zero */
 602                 for (i = 1; ; ++i) {
 603                         if (*nent >= maxnent)
 604                                 goto out;
 605
 606                         level_type = entry[i - 1].ecx & 0xff00;
 607                         if (!level_type)
 608                                 break;
 609                         do_host_cpuid(&entry[i], function, i);
 610                         ++*nent;
 611                 }
 612                 break;
 613         }
 614         case 0xd: {
 615                 int idx, i;
 616                 u64 supported = kvm_supported_xcr0();
 617
 618                 entry->eax &= supported;
 619                 entry->ebx = xstate_required_size(supported, false);
 620                 entry->ecx = entry->ebx;
 621                 entry->edx &= supported >> 32;
 622                 if (!supported)
 623                         break;
 624
 625                 for (idx = 1, i = 1; idx < 64; ++idx) {
 626                         u64 mask = ((u64)1 << idx);
 627                         if (*nent >= maxnent)
 628                                 goto out;
 629
 630                         do_host_cpuid(&entry[i], function, idx);
 631                         if (idx == 1) {
 632                                 entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
 633                                 cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
 634                                 entry[i].ebx = 0;
 635                                 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
 636                                         entry[i].ebx =
 637                                                 xstate_required_size(supported,
 638                                                                      true);
 639                         } else {
 640                                 if (entry[i].eax == 0 || !(supported & mask))
 641                                         continue;
 642                                 if (WARN_ON_ONCE(entry[i].ecx & 1))
 643                                         continue;
 644                         }
 645                         entry[i].ecx = 0;
 646                         entry[i].edx = 0;
 647                         ++*nent;
 648                         ++i;
 649                 }
 650                 break;
 651         }
 652         /* Intel PT */
 653         case 0x14: {
 654                 int t, times = entry->eax;
 655
 656                 if (!f_intel_pt)
 657                         break;
 658
 659                 for (t = 1; t <= times; ++t) {
 660                         if (*nent >= maxnent)
 661                                 goto out;
 662                         do_host_cpuid(&entry[t], function, t);
 663                         ++*nent;
 664                 }
 665                 break;
 666         }
 667         case KVM_CPUID_SIGNATURE: {
 668                 static const char signature[12] = "KVMKVMKVM\0\0";
 669                 const u32 *sigptr = (const u32 *)signature;
 670                 entry->eax = KVM_CPUID_FEATURES;
 671                 entry->ebx = sigptr[0];
 672                 entry->ecx = sigptr[1];
 673                 entry->edx = sigptr[2];
 674                 break;
 675         }
 676         case KVM_CPUID_FEATURES:
 677                 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
 678                              (1 << KVM_FEATURE_NOP_IO_DELAY) |
 679                              (1 << KVM_FEATURE_CLOCKSOURCE2) |
 680                              (1 << KVM_FEATURE_ASYNC_PF) |
 681                              (1 << KVM_FEATURE_PV_EOI) |
 682                              (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
 683                              (1 << KVM_FEATURE_PV_UNHALT) |
 684                              (1 << KVM_FEATURE_PV_TLB_FLUSH) |
 685                              (1 << KVM_FEATURE_ASYNC_PF_VMEXIT) |
 686                              (1 << KVM_FEATURE_PV_SEND_IPI) |
 687                              (1 << KVM_FEATURE_POLL_CONTROL) |
 688                              (1 << KVM_FEATURE_PV_SCHED_YIELD);
 689
 690                 if (sched_info_on())
 691                         entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
 692
 693                 entry->ebx = 0;
 694                 entry->ecx = 0;
 695                 entry->edx = 0;
 696                 break;
 697         case 0x80000000:
 698                 entry->eax = min(entry->eax, 0x8000001f);
 699                 break;
 700         case 0x80000001:
 701                 entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
 702                 cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
 703                 entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
 704                 cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
 705                 break;
 706         case 0x80000007: /* Advanced power management */
 707                 /* invariant TSC is CPUID.80000007H:EDX[8] */
 708                 entry->edx &= (1 << 8);
 709                 /* mask against host */
 710                 entry->edx &= boot_cpu_data.x86_power;
 711                 entry->eax = entry->ebx = entry->ecx = 0;
 712                 break;
 713         case 0x80000008: {
 714                 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
 715                 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
 716                 unsigned phys_as = entry->eax & 0xff;
 717
 718                 if (!g_phys_as)
 719                         g_phys_as = phys_as;
 720                 entry->eax = g_phys_as | (virt_as << 8);
 721                 entry->edx = 0;
 722                 /*
 723                  * IBRS, IBPB and VIRT_SSBD aren't necessarily present in
 724                  * hardware cpuid
 725                  */
 726                 if (boot_cpu_has(X86_FEATURE_AMD_IBPB))
 727                         entry->ebx |= F(AMD_IBPB);
 728                 if (boot_cpu_has(X86_FEATURE_AMD_IBRS))
 729                         entry->ebx |= F(AMD_IBRS);
 730                 if (boot_cpu_has(X86_FEATURE_VIRT_SSBD))
 731                         entry->ebx |= F(VIRT_SSBD);
 732                 entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
 733                 cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
 734                 /*
 735                  * The preference is to use SPEC CTRL MSR instead of the
 736                  * VIRT_SPEC MSR.
 737                  */
 738                 if (boot_cpu_has(X86_FEATURE_LS_CFG_SSBD) &&
 739                     !boot_cpu_has(X86_FEATURE_AMD_SSBD))
 740                         entry->ebx |= F(VIRT_SSBD);
 741                 break;
 742         }
 743         case 0x80000019:
 744                 entry->ecx = entry->edx = 0;
 745                 break;
 746         case 0x8000001a:
 747         case 0x8000001e:
 748                 break;
 749         /*Add support for Centaur's CPUID instruction*/
 750         case 0xC0000000:
 751                 /*Just support up to 0xC0000004 now*/
 752                 entry->eax = min(entry->eax, 0xC0000004);
 753                 break;
 754         case 0xC0000001:
 755                 entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
 756                 cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
 757                 break;
 758         case 3: /* Processor serial number */
 759         case 5: /* MONITOR/MWAIT */
 760         case 0xC0000002:
 761         case 0xC0000003:
 762         case 0xC0000004:
 763         default:
 764                 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
 765                 break;
 766         }
 767
 768         kvm_x86_ops->set_supported_cpuid(function, entry);
 769
 770         r = 0;
 771
 772 out:
 773         put_cpu();
 774
 775         return r;
 776 }
 777
 778 static int do_cpuid_func(struct kvm_cpuid_entry2 *entry, u32 func,
 779                          int *nent, int maxnent, unsigned int type)
 780 {
 781         if (type == KVM_GET_EMULATED_CPUID)
 782                 return __do_cpuid_func_emulated(entry, func, nent, maxnent);
 783
 784         return __do_cpuid_func(entry, func, nent, maxnent);
 785 }
 786
 787 #undef F
 788
 789 struct kvm_cpuid_param {
 790         u32 func;
 791         bool (*qualifier)(const struct kvm_cpuid_param *param);
 792 };
 793
 794 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
 795 {
 796         return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
 797 }
 798
 799 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
 800                                  __u32 num_entries, unsigned int ioctl_type)
 801 {
 802         int i;
 803         __u32 pad[3];
 804
 805         if (ioctl_type != KVM_GET_EMULATED_CPUID)
 806                 return false;
 807
 808         /*
 809          * We want to make sure that ->padding is being passed clean from
 810          * userspace in case we want to use it for something in the future.
 811          *
 812          * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
 813          * have to give ourselves satisfied only with the emulated side. /me
 814          * sheds a tear.
 815          */
 816         for (i = 0; i < num_entries; i++) {
 817                 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
 818                         return true;
 819
 820                 if (pad[0] || pad[1] || pad[2])
 821                         return true;
 822         }
 823         return false;
 824 }
 825
 826 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
 827                             struct kvm_cpuid_entry2 __user *entries,
 828                             unsigned int type)
 829 {
 830         struct kvm_cpuid_entry2 *cpuid_entries;
 831         int limit, nent = 0, r = -E2BIG, i;
 832         u32 func;
 833         static const struct kvm_cpuid_param param[] = {
 834                 { .func = 0 },
 835                 { .func = 0x80000000 },
 836                 { .func = 0xC0000000, .qualifier = is_centaur_cpu },
 837                 { .func = KVM_CPUID_SIGNATURE },
 838         };
 839
 840         if (cpuid->nent < 1)
 841                 goto out;
 842         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 843                 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
 844
 845         if (sanity_check_entries(entries, cpuid->nent, type))
 846                 return -EINVAL;
 847
 848         r = -ENOMEM;
 849         cpuid_entries = vzalloc(array_size(sizeof(struct kvm_cpuid_entry2),
 850                                            cpuid->nent));
 851         if (!cpuid_entries)
 852                 goto out;
 853
 854         r = 0;
 855         for (i = 0; i < ARRAY_SIZE(param); i++) {
 856                 const struct kvm_cpuid_param *ent = &param[i];
 857
 858                 if (ent->qualifier && !ent->qualifier(ent))
 859                         continue;
 860
 861                 r = do_cpuid_func(&cpuid_entries[nent], ent->func,
 862                                   &nent, cpuid->nent, type);
 863
 864                 if (r)
 865                         goto out_free;
 866
 867                 limit = cpuid_entries[nent - 1].eax;
 868                 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
 869                         r = do_cpuid_func(&cpuid_entries[nent], func,
 870                                           &nent, cpuid->nent, type);
 871
 872                 if (r)
 873                         goto out_free;
 874         }
 875
 876         r = -EFAULT;
 877         if (copy_to_user(entries, cpuid_entries,
 878                          nent * sizeof(struct kvm_cpuid_entry2)))
 879                 goto out_free;
 880         cpuid->nent = nent;
 881         r = 0;
 882
 883 out_free:
 884         vfree(cpuid_entries);
 885 out:
 886         return r;
 887 }
 888
 889 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
 890 {
 891         struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
 892         struct kvm_cpuid_entry2 *ej;
 893         int j = i;
 894         int nent = vcpu->arch.cpuid_nent;
 895
 896         e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
 897         /* when no next entry is found, the current entry[i] is reselected */
 898         do {
 899                 j = (j + 1) % nent;
 900                 ej = &vcpu->arch.cpuid_entries[j];
 901         } while (ej->function != e->function);
 902
 903         ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
 904
 905         return j;
 906 }
 907
 908 /* find an entry with matching function, matching index (if needed), and that
 909  * should be read next (if it's stateful) */
 910 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
 911         u32 function, u32 index)
 912 {
 913         if (e->function != function)
 914                 return 0;
 915         if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
 916                 return 0;
 917         if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
 918             !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
 919                 return 0;
 920         return 1;
 921 }
 922
 923 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
 924                                               u32 function, u32 index)
 925 {
 926         int i;
 927         struct kvm_cpuid_entry2 *best = NULL;
 928
 929         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
 930                 struct kvm_cpuid_entry2 *e;
 931
 932                 e = &vcpu->arch.cpuid_entries[i];
 933                 if (is_matching_cpuid_entry(e, function, index)) {
 934                         if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
 935                                 move_to_next_stateful_cpuid_entry(vcpu, i);
 936                         best = e;
 937                         break;
 938                 }
 939         }
 940         return best;
 941 }
 942 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
 943
 944 /*
 945  * If no match is found, check whether we exceed the vCPU's limit
 946  * and return the content of the highest valid _standard_ leaf instead.
 947  * This is to satisfy the CPUID specification.
 948  */
 949 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
 950                                                   u32 function, u32 index)
 951 {
 952         struct kvm_cpuid_entry2 *maxlevel;
 953
 954         maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
 955         if (!maxlevel || maxlevel->eax >= function)
 956                 return NULL;
 957         if (function & 0x80000000) {
 958                 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
 959                 if (!maxlevel)
 960                         return NULL;
 961         }
 962         return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
 963 }
 964
 965 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
 966                u32 *ecx, u32 *edx, bool check_limit)
 967 {
 968         u32 function = *eax, index = *ecx;
 969         struct kvm_cpuid_entry2 *best;
 970         bool entry_found = true;
 971
 972         best = kvm_find_cpuid_entry(vcpu, function, index);
 973
 974         if (!best) {
 975                 entry_found = false;
 976                 if (!check_limit)
 977                         goto out;
 978
 979                 best = check_cpuid_limit(vcpu, function, index);
 980         }
 981
 982 out:
 983         if (best) {
 984                 *eax = best->eax;
 985                 *ebx = best->ebx;
 986                 *ecx = best->ecx;
 987                 *edx = best->edx;
 988         } else
 989                 *eax = *ebx = *ecx = *edx = 0;
 990         trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
 991         return entry_found;
 992 }
 993 EXPORT_SYMBOL_GPL(kvm_cpuid);
 994
 995 int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
 996 {
 997         u32 eax, ebx, ecx, edx;
 998
 999         if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
1000                 return 1;
1001
1002         eax = kvm_rax_read(vcpu);
1003         ecx = kvm_rcx_read(vcpu);
1004         kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
1005         kvm_rax_write(vcpu, eax);
1006         kvm_rbx_write(vcpu, ebx);
1007         kvm_rcx_write(vcpu, ecx);
1008         kvm_rdx_write(vcpu, edx);
1009         return kvm_skip_emulated_instruction(vcpu);
1010 }
1011 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);