arch/x86/kvm/cpuid.c

   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/module.h>
  17 #include <linux/vmalloc.h>
  18 #include <linux/uaccess.h>
  19 #include <asm/user.h>
  20 #include <asm/xsave.h>
  21 #include "cpuid.h"
  22 #include "lapic.h"
  23 #include "mmu.h"
  24 #include "trace.h"
  25
  26 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
  27 {
  28         int feature_bit = 0;
  29         u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
  30
  31         xstate_bv &= XSTATE_EXTEND_MASK;
  32         while (xstate_bv) {
  33                 if (xstate_bv & 0x1) {
  34                         u32 eax, ebx, ecx, edx, offset;
  35                         cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
  36                         offset = compacted ? ret : ebx;
  37                         ret = max(ret, offset + eax);
  38                 }
  39
  40                 xstate_bv >>= 1;
  41                 feature_bit++;
  42         }
  43
  44         return ret;
  45 }
  46
  47 u64 kvm_supported_xcr0(void)
  48 {
  49         u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
  50
  51         if (!kvm_x86_ops->mpx_supported())
  52                 xcr0 &= ~(XSTATE_BNDREGS | XSTATE_BNDCSR);
  53
  54         return xcr0;
  55 }
  56
  57 #define F(x) bit(X86_FEATURE_##x)
  58
  59 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
  60 {
  61         struct kvm_cpuid_entry2 *best;
  62         struct kvm_lapic *apic = vcpu->arch.apic;
  63
  64         best = kvm_find_cpuid_entry(vcpu, 1, 0);
  65         if (!best)
  66                 return 0;
  67
  68         /* Update OSXSAVE bit */
  69         if (cpu_has_xsave && best->function == 0x1) {
  70                 best->ecx &= ~F(OSXSAVE);
  71                 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
  72                         best->ecx |= F(OSXSAVE);
  73         }
  74
  75         if (apic) {
  76                 if (best->ecx & F(TSC_DEADLINE_TIMER))
  77                         apic->lapic_timer.timer_mode_mask = 3 << 17;
  78                 else
  79                         apic->lapic_timer.timer_mode_mask = 1 << 17;
  80         }
  81
  82         best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
  83         if (!best) {
  84                 vcpu->arch.guest_supported_xcr0 = 0;
  85                 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
  86         } else {
  87                 vcpu->arch.guest_supported_xcr0 =
  88                         (best->eax | ((u64)best->edx << 32)) &
  89                         kvm_supported_xcr0();
  90                 vcpu->arch.guest_xstate_size = best->ebx =
  91                         xstate_required_size(vcpu->arch.xcr0, false);
  92         }
  93
  94         best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
  95         if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
  96                 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
  97
  98         /*
  99          * The existing code assumes virtual address is 48-bit in the canonical
 100          * address checks; exit if it is ever changed.
 101          */
 102         best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
 103         if (best && ((best->eax & 0xff00) >> 8) != 48 &&
 104                 ((best->eax & 0xff00) >> 8) != 0)
 105                 return -EINVAL;
 106
 107         kvm_pmu_cpuid_update(vcpu);
 108         return 0;
 109 }
 110
 111 static int is_efer_nx(void)
 112 {
 113         unsigned long long efer = 0;
 114
 115         rdmsrl_safe(MSR_EFER, &efer);
 116         return efer & EFER_NX;
 117 }
 118
 119 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
 120 {
 121         int i;
 122         struct kvm_cpuid_entry2 *e, *entry;
 123
 124         entry = NULL;
 125         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
 126                 e = &vcpu->arch.cpuid_entries[i];
 127                 if (e->function == 0x80000001) {
 128                         entry = e;
 129                         break;
 130                 }
 131         }
 132         if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
 133                 entry->edx &= ~F(NX);
 134                 printk(KERN_INFO "kvm: guest NX capability removed\n");
 135         }
 136 }
 137
 138 /* when an old userspace process fills a new kernel module */
 139 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 140                              struct kvm_cpuid *cpuid,
 141                              struct kvm_cpuid_entry __user *entries)
 142 {
 143         int r, i;
 144         struct kvm_cpuid_entry *cpuid_entries;
 145
 146         r = -E2BIG;
 147         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 148                 goto out;
 149         r = -ENOMEM;
 150         cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
 151         if (!cpuid_entries)
 152                 goto out;
 153         r = -EFAULT;
 154         if (copy_from_user(cpuid_entries, entries,
 155                            cpuid->nent * sizeof(struct kvm_cpuid_entry)))
 156                 goto out_free;
 157         for (i = 0; i < cpuid->nent; i++) {
 158                 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
 159                 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
 160                 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
 161                 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
 162                 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
 163                 vcpu->arch.cpuid_entries[i].index = 0;
 164                 vcpu->arch.cpuid_entries[i].flags = 0;
 165                 vcpu->arch.cpuid_entries[i].padding[0] = 0;
 166                 vcpu->arch.cpuid_entries[i].padding[1] = 0;
 167                 vcpu->arch.cpuid_entries[i].padding[2] = 0;
 168         }
 169         vcpu->arch.cpuid_nent = cpuid->nent;
 170         cpuid_fix_nx_cap(vcpu);
 171         kvm_apic_set_version(vcpu);
 172         kvm_x86_ops->cpuid_update(vcpu);
 173         r = kvm_update_cpuid(vcpu);
 174
 175 out_free:
 176         vfree(cpuid_entries);
 177 out:
 178         return r;
 179 }
 180
 181 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
 182                               struct kvm_cpuid2 *cpuid,
 183                               struct kvm_cpuid_entry2 __user *entries)
 184 {
 185         int r;
 186
 187         r = -E2BIG;
 188         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 189                 goto out;
 190         r = -EFAULT;
 191         if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
 192                            cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
 193                 goto out;
 194         vcpu->arch.cpuid_nent = cpuid->nent;
 195         kvm_apic_set_version(vcpu);
 196         kvm_x86_ops->cpuid_update(vcpu);
 197         r = kvm_update_cpuid(vcpu);
 198 out:
 199         return r;
 200 }
 201
 202 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
 203                               struct kvm_cpuid2 *cpuid,
 204                               struct kvm_cpuid_entry2 __user *entries)
 205 {
 206         int r;
 207
 208         r = -E2BIG;
 209         if (cpuid->nent < vcpu->arch.cpuid_nent)
 210                 goto out;
 211         r = -EFAULT;
 212         if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
 213                          vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
 214                 goto out;
 215         return 0;
 216
 217 out:
 218         cpuid->nent = vcpu->arch.cpuid_nent;
 219         return r;
 220 }
 221
 222 static void cpuid_mask(u32 *word, int wordnum)
 223 {
 224         *word &= boot_cpu_data.x86_capability[wordnum];
 225 }
 226
 227 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 228                            u32 index)
 229 {
 230         entry->function = function;
 231         entry->index = index;
 232         cpuid_count(entry->function, entry->index,
 233                     &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
 234         entry->flags = 0;
 235 }
 236
 237 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
 238                                    u32 func, u32 index, int *nent, int maxnent)
 239 {
 240         switch (func) {
 241         case 0:
 242                 entry->eax = 1;         /* only one leaf currently */
 243                 ++*nent;
 244                 break;
 245         case 1:
 246                 entry->ecx = F(MOVBE);
 247                 ++*nent;
 248                 break;
 249         default:
 250                 break;
 251         }
 252
 253         entry->function = func;
 254         entry->index = index;
 255
 256         return 0;
 257 }
 258
 259 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 260                                  u32 index, int *nent, int maxnent)
 261 {
 262         int r;
 263         unsigned f_nx = is_efer_nx() ? F(NX) : 0;
 264 #ifdef CONFIG_X86_64
 265         unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
 266                                 ? F(GBPAGES) : 0;
 267         unsigned f_lm = F(LM);
 268 #else
 269         unsigned f_gbpages = 0;
 270         unsigned f_lm = 0;
 271 #endif
 272         unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
 273         unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
 274         unsigned f_mpx = kvm_x86_ops->mpx_supported() ? F(MPX) : 0;
 275         unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
 276
 277         /* cpuid 1.edx */
 278         const u32 kvm_supported_word0_x86_features =
 279                 F(FPU) | F(VME) | F(DE) | F(PSE) |
 280                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
 281                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
 282                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 283                 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
 284                 0 /* Reserved, DS, ACPI */ | F(MMX) |
 285                 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
 286                 0 /* HTT, TM, Reserved, PBE */;
 287         /* cpuid 0x80000001.edx */
 288         const u32 kvm_supported_word1_x86_features =
 289                 F(FPU) | F(VME) | F(DE) | F(PSE) |
 290                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
 291                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
 292                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 293                 F(PAT) | F(PSE36) | 0 /* Reserved */ |
 294                 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
 295                 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
 296                 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
 297         /* cpuid 1.ecx */
 298         const u32 kvm_supported_word4_x86_features =
 299                 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
 300                  * but *not* advertised to guests via CPUID ! */
 301                 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
 302                 0 /* DS-CPL, VMX, SMX, EST */ |
 303                 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
 304                 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
 305                 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
 306                 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
 307                 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
 308                 F(F16C) | F(RDRAND);
 309         /* cpuid 0x80000001.ecx */
 310         const u32 kvm_supported_word6_x86_features =
 311                 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
 312                 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
 313                 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
 314                 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
 315
 316         /* cpuid 0xC0000001.edx */
 317         const u32 kvm_supported_word5_x86_features =
 318                 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
 319                 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
 320                 F(PMM) | F(PMM_EN);
 321
 322         /* cpuid 7.0.ebx */
 323         const u32 kvm_supported_word9_x86_features =
 324                 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
 325                 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
 326                 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
 327                 F(AVX512CD);
 328
 329         /* cpuid 0xD.1.eax */
 330         const u32 kvm_supported_word10_x86_features =
 331                 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
 332
 333         /* all calls to cpuid_count() should be made on the same cpu */
 334         get_cpu();
 335
 336         r = -E2BIG;
 337
 338         if (*nent >= maxnent)
 339                 goto out;
 340
 341         do_cpuid_1_ent(entry, function, index);
 342         ++*nent;
 343
 344         switch (function) {
 345         case 0:
 346                 entry->eax = min(entry->eax, (u32)0xd);
 347                 break;
 348         case 1:
 349                 entry->edx &= kvm_supported_word0_x86_features;
 350                 cpuid_mask(&entry->edx, 0);
 351                 entry->ecx &= kvm_supported_word4_x86_features;
 352                 cpuid_mask(&entry->ecx, 4);
 353                 /* we support x2apic emulation even if host does not support
 354                  * it since we emulate x2apic in software */
 355                 entry->ecx |= F(X2APIC);
 356                 break;
 357         /* function 2 entries are STATEFUL. That is, repeated cpuid commands
 358          * may return different values. This forces us to get_cpu() before
 359          * issuing the first command, and also to emulate this annoying behavior
 360          * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
 361         case 2: {
 362                 int t, times = entry->eax & 0xff;
 363
 364                 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
 365                 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
 366                 for (t = 1; t < times; ++t) {
 367                         if (*nent >= maxnent)
 368                                 goto out;
 369
 370                         do_cpuid_1_ent(&entry[t], function, 0);
 371                         entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
 372                         ++*nent;
 373                 }
 374                 break;
 375         }
 376         /* function 4 has additional index. */
 377         case 4: {
 378                 int i, cache_type;
 379
 380                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 381                 /* read more entries until cache_type is zero */
 382                 for (i = 1; ; ++i) {
 383                         if (*nent >= maxnent)
 384                                 goto out;
 385
 386                         cache_type = entry[i - 1].eax & 0x1f;
 387                         if (!cache_type)
 388                                 break;
 389                         do_cpuid_1_ent(&entry[i], function, i);
 390                         entry[i].flags |=
 391                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 392                         ++*nent;
 393                 }
 394                 break;
 395         }
 396         case 7: {
 397                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 398                 /* Mask ebx against host capability word 9 */
 399                 if (index == 0) {
 400                         entry->ebx &= kvm_supported_word9_x86_features;
 401                         cpuid_mask(&entry->ebx, 9);
 402                         // TSC_ADJUST is emulated
 403                         entry->ebx |= F(TSC_ADJUST);
 404                 } else
 405                         entry->ebx = 0;
 406                 entry->eax = 0;
 407                 entry->ecx = 0;
 408                 entry->edx = 0;
 409                 break;
 410         }
 411         case 9:
 412                 break;
 413         case 0xa: { /* Architectural Performance Monitoring */
 414                 struct x86_pmu_capability cap;
 415                 union cpuid10_eax eax;
 416                 union cpuid10_edx edx;
 417
 418                 perf_get_x86_pmu_capability(&cap);
 419
 420                 /*
 421                  * Only support guest architectural pmu on a host
 422                  * with architectural pmu.
 423                  */
 424                 if (!cap.version)
 425                         memset(&cap, 0, sizeof(cap));
 426
 427                 eax.split.version_id = min(cap.version, 2);
 428                 eax.split.num_counters = cap.num_counters_gp;
 429                 eax.split.bit_width = cap.bit_width_gp;
 430                 eax.split.mask_length = cap.events_mask_len;
 431
 432                 edx.split.num_counters_fixed = cap.num_counters_fixed;
 433                 edx.split.bit_width_fixed = cap.bit_width_fixed;
 434                 edx.split.reserved = 0;
 435
 436                 entry->eax = eax.full;
 437                 entry->ebx = cap.events_mask;
 438                 entry->ecx = 0;
 439                 entry->edx = edx.full;
 440                 break;
 441         }
 442         /* function 0xb has additional index. */
 443         case 0xb: {
 444                 int i, level_type;
 445
 446                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 447                 /* read more entries until level_type is zero */
 448                 for (i = 1; ; ++i) {
 449                         if (*nent >= maxnent)
 450                                 goto out;
 451
 452                         level_type = entry[i - 1].ecx & 0xff00;
 453                         if (!level_type)
 454                                 break;
 455                         do_cpuid_1_ent(&entry[i], function, i);
 456                         entry[i].flags |=
 457                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 458                         ++*nent;
 459                 }
 460                 break;
 461         }
 462         case 0xd: {
 463                 int idx, i;
 464                 u64 supported = kvm_supported_xcr0();
 465
 466                 entry->eax &= supported;
 467                 entry->ebx = xstate_required_size(supported, false);
 468                 entry->ecx = entry->ebx;
 469                 entry->edx &= supported >> 32;
 470                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 471                 if (!supported)
 472                         break;
 473
 474                 for (idx = 1, i = 1; idx < 64; ++idx) {
 475                         u64 mask = ((u64)1 << idx);
 476                         if (*nent >= maxnent)
 477                                 goto out;
 478
 479                         do_cpuid_1_ent(&entry[i], function, idx);
 480                         if (idx == 1) {
 481                                 entry[i].eax &= kvm_supported_word10_x86_features;
 482                                 entry[i].ebx = 0;
 483                                 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
 484                                         entry[i].ebx =
 485                                                 xstate_required_size(supported,
 486                                                                      true);
 487                         } else {
 488                                 if (entry[i].eax == 0 || !(supported & mask))
 489                                         continue;
 490                                 if (WARN_ON_ONCE(entry[i].ecx & 1))
 491                                         continue;
 492                         }
 493                         entry[i].ecx = 0;
 494                         entry[i].edx = 0;
 495                         entry[i].flags |=
 496                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 497                         ++*nent;
 498                         ++i;
 499                 }
 500                 break;
 501         }
 502         case KVM_CPUID_SIGNATURE: {
 503                 static const char signature[12] = "KVMKVMKVM\0\0";
 504                 const u32 *sigptr = (const u32 *)signature;
 505                 entry->eax = KVM_CPUID_FEATURES;
 506                 entry->ebx = sigptr[0];
 507                 entry->ecx = sigptr[1];
 508                 entry->edx = sigptr[2];
 509                 break;
 510         }
 511         case KVM_CPUID_FEATURES:
 512                 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
 513                              (1 << KVM_FEATURE_NOP_IO_DELAY) |
 514                              (1 << KVM_FEATURE_CLOCKSOURCE2) |
 515                              (1 << KVM_FEATURE_ASYNC_PF) |
 516                              (1 << KVM_FEATURE_PV_EOI) |
 517                              (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
 518                              (1 << KVM_FEATURE_PV_UNHALT);
 519
 520                 if (sched_info_on())
 521                         entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
 522
 523                 entry->ebx = 0;
 524                 entry->ecx = 0;
 525                 entry->edx = 0;
 526                 break;
 527         case 0x80000000:
 528                 entry->eax = min(entry->eax, 0x8000001a);
 529                 break;
 530         case 0x80000001:
 531                 entry->edx &= kvm_supported_word1_x86_features;
 532                 cpuid_mask(&entry->edx, 1);
 533                 entry->ecx &= kvm_supported_word6_x86_features;
 534                 cpuid_mask(&entry->ecx, 6);
 535                 break;
 536         case 0x80000007: /* Advanced power management */
 537                 /* invariant TSC is CPUID.80000007H:EDX[8] */
 538                 entry->edx &= (1 << 8);
 539                 /* mask against host */
 540                 entry->edx &= boot_cpu_data.x86_power;
 541                 entry->eax = entry->ebx = entry->ecx = 0;
 542                 break;
 543         case 0x80000008: {
 544                 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
 545                 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
 546                 unsigned phys_as = entry->eax & 0xff;
 547
 548                 if (!g_phys_as)
 549                         g_phys_as = phys_as;
 550                 entry->eax = g_phys_as | (virt_as << 8);
 551                 entry->ebx = entry->edx = 0;
 552                 break;
 553         }
 554         case 0x80000019:
 555                 entry->ecx = entry->edx = 0;
 556                 break;
 557         case 0x8000001a:
 558                 break;
 559         case 0x8000001d:
 560                 break;
 561         /*Add support for Centaur's CPUID instruction*/
 562         case 0xC0000000:
 563                 /*Just support up to 0xC0000004 now*/
 564                 entry->eax = min(entry->eax, 0xC0000004);
 565                 break;
 566         case 0xC0000001:
 567                 entry->edx &= kvm_supported_word5_x86_features;
 568                 cpuid_mask(&entry->edx, 5);
 569                 break;
 570         case 3: /* Processor serial number */
 571         case 5: /* MONITOR/MWAIT */
 572         case 6: /* Thermal management */
 573         case 0xC0000002:
 574         case 0xC0000003:
 575         case 0xC0000004:
 576         default:
 577                 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
 578                 break;
 579         }
 580
 581         kvm_x86_ops->set_supported_cpuid(function, entry);
 582
 583         r = 0;
 584
 585 out:
 586         put_cpu();
 587
 588         return r;
 589 }
 590
 591 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
 592                         u32 idx, int *nent, int maxnent, unsigned int type)
 593 {
 594         if (type == KVM_GET_EMULATED_CPUID)
 595                 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
 596
 597         return __do_cpuid_ent(entry, func, idx, nent, maxnent);
 598 }
 599
 600 #undef F
 601
 602 struct kvm_cpuid_param {
 603         u32 func;
 604         u32 idx;
 605         bool has_leaf_count;
 606         bool (*qualifier)(const struct kvm_cpuid_param *param);
 607 };
 608
 609 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
 610 {
 611         return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
 612 }
 613
 614 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
 615                                  __u32 num_entries, unsigned int ioctl_type)
 616 {
 617         int i;
 618         __u32 pad[3];
 619
 620         if (ioctl_type != KVM_GET_EMULATED_CPUID)
 621                 return false;
 622
 623         /*
 624          * We want to make sure that ->padding is being passed clean from
 625          * userspace in case we want to use it for something in the future.
 626          *
 627          * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
 628          * have to give ourselves satisfied only with the emulated side. /me
 629          * sheds a tear.
 630          */
 631         for (i = 0; i < num_entries; i++) {
 632                 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
 633                         return true;
 634
 635                 if (pad[0] || pad[1] || pad[2])
 636                         return true;
 637         }
 638         return false;
 639 }
 640
 641 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
 642                             struct kvm_cpuid_entry2 __user *entries,
 643                             unsigned int type)
 644 {
 645         struct kvm_cpuid_entry2 *cpuid_entries;
 646         int limit, nent = 0, r = -E2BIG, i;
 647         u32 func;
 648         static const struct kvm_cpuid_param param[] = {
 649                 { .func = 0, .has_leaf_count = true },
 650                 { .func = 0x80000000, .has_leaf_count = true },
 651                 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
 652                 { .func = KVM_CPUID_SIGNATURE },
 653                 { .func = KVM_CPUID_FEATURES },
 654         };
 655
 656         if (cpuid->nent < 1)
 657                 goto out;
 658         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 659                 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
 660
 661         if (sanity_check_entries(entries, cpuid->nent, type))
 662                 return -EINVAL;
 663
 664         r = -ENOMEM;
 665         cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
 666         if (!cpuid_entries)
 667                 goto out;
 668
 669         r = 0;
 670         for (i = 0; i < ARRAY_SIZE(param); i++) {
 671                 const struct kvm_cpuid_param *ent = &param[i];
 672
 673                 if (ent->qualifier && !ent->qualifier(ent))
 674                         continue;
 675
 676                 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
 677                                 &nent, cpuid->nent, type);
 678
 679                 if (r)
 680                         goto out_free;
 681
 682                 if (!ent->has_leaf_count)
 683                         continue;
 684
 685                 limit = cpuid_entries[nent - 1].eax;
 686                 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
 687                         r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
 688                                      &nent, cpuid->nent, type);
 689
 690                 if (r)
 691                         goto out_free;
 692         }
 693
 694         r = -EFAULT;
 695         if (copy_to_user(entries, cpuid_entries,
 696                          nent * sizeof(struct kvm_cpuid_entry2)))
 697                 goto out_free;
 698         cpuid->nent = nent;
 699         r = 0;
 700
 701 out_free:
 702         vfree(cpuid_entries);
 703 out:
 704         return r;
 705 }
 706
 707 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
 708 {
 709         struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
 710         int j, nent = vcpu->arch.cpuid_nent;
 711
 712         e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
 713         /* when no next entry is found, the current entry[i] is reselected */
 714         for (j = i + 1; ; j = (j + 1) % nent) {
 715                 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
 716                 if (ej->function == e->function) {
 717                         ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
 718                         return j;
 719                 }
 720         }
 721         return 0; /* silence gcc, even though control never reaches here */
 722 }
 723
 724 /* find an entry with matching function, matching index (if needed), and that
 725  * should be read next (if it's stateful) */
 726 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
 727         u32 function, u32 index)
 728 {
 729         if (e->function != function)
 730                 return 0;
 731         if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
 732                 return 0;
 733         if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
 734             !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
 735                 return 0;
 736         return 1;
 737 }
 738
 739 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
 740                                               u32 function, u32 index)
 741 {
 742         int i;
 743         struct kvm_cpuid_entry2 *best = NULL;
 744
 745         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
 746                 struct kvm_cpuid_entry2 *e;
 747
 748                 e = &vcpu->arch.cpuid_entries[i];
 749                 if (is_matching_cpuid_entry(e, function, index)) {
 750                         if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
 751                                 move_to_next_stateful_cpuid_entry(vcpu, i);
 752                         best = e;
 753                         break;
 754                 }
 755         }
 756         return best;
 757 }
 758 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
 759
 760 int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
 761 {
 762         struct kvm_cpuid_entry2 *best;
 763
 764         best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
 765         if (!best || best->eax < 0x80000008)
 766                 goto not_found;
 767         best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
 768         if (best)
 769                 return best->eax & 0xff;
 770 not_found:
 771         return 36;
 772 }
 773 EXPORT_SYMBOL_GPL(cpuid_maxphyaddr);
 774
 775 /*
 776  * If no match is found, check whether we exceed the vCPU's limit
 777  * and return the content of the highest valid _standard_ leaf instead.
 778  * This is to satisfy the CPUID specification.
 779  */
 780 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
 781                                                   u32 function, u32 index)
 782 {
 783         struct kvm_cpuid_entry2 *maxlevel;
 784
 785         maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
 786         if (!maxlevel || maxlevel->eax >= function)
 787                 return NULL;
 788         if (function & 0x80000000) {
 789                 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
 790                 if (!maxlevel)
 791                         return NULL;
 792         }
 793         return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
 794 }
 795
 796 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
 797 {
 798         u32 function = *eax, index = *ecx;
 799         struct kvm_cpuid_entry2 *best;
 800
 801         best = kvm_find_cpuid_entry(vcpu, function, index);
 802
 803         if (!best)
 804                 best = check_cpuid_limit(vcpu, function, index);
 805
 806         /*
 807          * Perfmon not yet supported for L2 guest.
 808          */
 809         if (is_guest_mode(vcpu) && function == 0xa)
 810                 best = NULL;
 811
 812         if (best) {
 813                 *eax = best->eax;
 814                 *ebx = best->ebx;
 815                 *ecx = best->ecx;
 816                 *edx = best->edx;
 817         } else
 818                 *eax = *ebx = *ecx = *edx = 0;
 819         trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
 820 }
 821 EXPORT_SYMBOL_GPL(kvm_cpuid);
 822
 823 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
 824 {
 825         u32 function, eax, ebx, ecx, edx;
 826
 827         function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
 828         ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
 829         kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
 830         kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
 831         kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
 832         kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
 833         kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
 834         kvm_x86_ops->skip_emulated_instruction(vcpu);
 835 }
 836 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);