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/fpu/internal.h> /* For use_eager_fpu.  Ugh! */
  20 #include <asm/user.h>
  21 #include <asm/fpu/xstate.h>
  22 #include "cpuid.h"
  23 #include "lapic.h"
  24 #include "mmu.h"
  25 #include "trace.h"
  26 #include "pmu.h"
  27
  28 static u32 xstate_required_size(u64 xstate_bv, bool compacted)
  29 {
  30         int feature_bit = 0;
  31         u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
  32
  33         xstate_bv &= XFEATURE_MASK_EXTEND;
  34         while (xstate_bv) {
  35                 if (xstate_bv & 0x1) {
  36                         u32 eax, ebx, ecx, edx, offset;
  37                         cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
  38                         offset = compacted ? ret : ebx;
  39                         ret = max(ret, offset + eax);
  40                 }
  41
  42                 xstate_bv >>= 1;
  43                 feature_bit++;
  44         }
  45
  46         return ret;
  47 }
  48
  49 bool kvm_mpx_supported(void)
  50 {
  51         return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
  52                  && kvm_x86_ops->mpx_supported());
  53 }
  54 EXPORT_SYMBOL_GPL(kvm_mpx_supported);
  55
  56 u64 kvm_supported_xcr0(void)
  57 {
  58         u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
  59
  60         if (!kvm_mpx_supported())
  61                 xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
  62
  63         return xcr0;
  64 }
  65
  66 #define F(x) bit(X86_FEATURE_##x)
  67
  68 int kvm_update_cpuid(struct kvm_vcpu *vcpu)
  69 {
  70         struct kvm_cpuid_entry2 *best;
  71         struct kvm_lapic *apic = vcpu->arch.apic;
  72
  73         best = kvm_find_cpuid_entry(vcpu, 1, 0);
  74         if (!best)
  75                 return 0;
  76
  77         /* Update OSXSAVE bit */
  78         if (cpu_has_xsave && best->function == 0x1) {
  79                 best->ecx &= ~F(OSXSAVE);
  80                 if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
  81                         best->ecx |= F(OSXSAVE);
  82         }
  83
  84         if (apic) {
  85                 if (best->ecx & F(TSC_DEADLINE_TIMER))
  86                         apic->lapic_timer.timer_mode_mask = 3 << 17;
  87                 else
  88                         apic->lapic_timer.timer_mode_mask = 1 << 17;
  89         }
  90
  91         best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
  92         if (!best) {
  93                 vcpu->arch.guest_supported_xcr0 = 0;
  94                 vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
  95         } else {
  96                 vcpu->arch.guest_supported_xcr0 =
  97                         (best->eax | ((u64)best->edx << 32)) &
  98                         kvm_supported_xcr0();
  99                 vcpu->arch.guest_xstate_size = best->ebx =
 100                         xstate_required_size(vcpu->arch.xcr0, false);
 101         }
 102
 103         best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
 104         if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
 105                 best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
 106
 107         if (use_eager_fpu())
 108                 kvm_x86_ops->fpu_activate(vcpu);
 109
 110         /*
 111          * The existing code assumes virtual address is 48-bit in the canonical
 112          * address checks; exit if it is ever changed.
 113          */
 114         best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
 115         if (best && ((best->eax & 0xff00) >> 8) != 48 &&
 116                 ((best->eax & 0xff00) >> 8) != 0)
 117                 return -EINVAL;
 118
 119         /* Update physical-address width */
 120         vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
 121
 122         kvm_pmu_refresh(vcpu);
 123         return 0;
 124 }
 125
 126 static int is_efer_nx(void)
 127 {
 128         unsigned long long efer = 0;
 129
 130         rdmsrl_safe(MSR_EFER, &efer);
 131         return efer & EFER_NX;
 132 }
 133
 134 static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
 135 {
 136         int i;
 137         struct kvm_cpuid_entry2 *e, *entry;
 138
 139         entry = NULL;
 140         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
 141                 e = &vcpu->arch.cpuid_entries[i];
 142                 if (e->function == 0x80000001) {
 143                         entry = e;
 144                         break;
 145                 }
 146         }
 147         if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
 148                 entry->edx &= ~F(NX);
 149                 printk(KERN_INFO "kvm: guest NX capability removed\n");
 150         }
 151 }
 152
 153 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
 154 {
 155         struct kvm_cpuid_entry2 *best;
 156
 157         best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
 158         if (!best || best->eax < 0x80000008)
 159                 goto not_found;
 160         best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
 161         if (best)
 162                 return best->eax & 0xff;
 163 not_found:
 164         return 36;
 165 }
 166 EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
 167
 168 /* when an old userspace process fills a new kernel module */
 169 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
 170                              struct kvm_cpuid *cpuid,
 171                              struct kvm_cpuid_entry __user *entries)
 172 {
 173         int r, i;
 174         struct kvm_cpuid_entry *cpuid_entries;
 175
 176         r = -E2BIG;
 177         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 178                 goto out;
 179         r = -ENOMEM;
 180         cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) * cpuid->nent);
 181         if (!cpuid_entries)
 182                 goto out;
 183         r = -EFAULT;
 184         if (copy_from_user(cpuid_entries, entries,
 185                            cpuid->nent * sizeof(struct kvm_cpuid_entry)))
 186                 goto out_free;
 187         for (i = 0; i < cpuid->nent; i++) {
 188                 vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
 189                 vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
 190                 vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
 191                 vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
 192                 vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
 193                 vcpu->arch.cpuid_entries[i].index = 0;
 194                 vcpu->arch.cpuid_entries[i].flags = 0;
 195                 vcpu->arch.cpuid_entries[i].padding[0] = 0;
 196                 vcpu->arch.cpuid_entries[i].padding[1] = 0;
 197                 vcpu->arch.cpuid_entries[i].padding[2] = 0;
 198         }
 199         vcpu->arch.cpuid_nent = cpuid->nent;
 200         cpuid_fix_nx_cap(vcpu);
 201         kvm_apic_set_version(vcpu);
 202         kvm_x86_ops->cpuid_update(vcpu);
 203         r = kvm_update_cpuid(vcpu);
 204
 205 out_free:
 206         vfree(cpuid_entries);
 207 out:
 208         return r;
 209 }
 210
 211 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
 212                               struct kvm_cpuid2 *cpuid,
 213                               struct kvm_cpuid_entry2 __user *entries)
 214 {
 215         int r;
 216
 217         r = -E2BIG;
 218         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 219                 goto out;
 220         r = -EFAULT;
 221         if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
 222                            cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
 223                 goto out;
 224         vcpu->arch.cpuid_nent = cpuid->nent;
 225         kvm_apic_set_version(vcpu);
 226         kvm_x86_ops->cpuid_update(vcpu);
 227         r = kvm_update_cpuid(vcpu);
 228 out:
 229         return r;
 230 }
 231
 232 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
 233                               struct kvm_cpuid2 *cpuid,
 234                               struct kvm_cpuid_entry2 __user *entries)
 235 {
 236         int r;
 237
 238         r = -E2BIG;
 239         if (cpuid->nent < vcpu->arch.cpuid_nent)
 240                 goto out;
 241         r = -EFAULT;
 242         if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
 243                          vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
 244                 goto out;
 245         return 0;
 246
 247 out:
 248         cpuid->nent = vcpu->arch.cpuid_nent;
 249         return r;
 250 }
 251
 252 static void cpuid_mask(u32 *word, int wordnum)
 253 {
 254         *word &= boot_cpu_data.x86_capability[wordnum];
 255 }
 256
 257 static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 258                            u32 index)
 259 {
 260         entry->function = function;
 261         entry->index = index;
 262         cpuid_count(entry->function, entry->index,
 263                     &entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
 264         entry->flags = 0;
 265 }
 266
 267 static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
 268                                    u32 func, u32 index, int *nent, int maxnent)
 269 {
 270         switch (func) {
 271         case 0:
 272                 entry->eax = 1;         /* only one leaf currently */
 273                 ++*nent;
 274                 break;
 275         case 1:
 276                 entry->ecx = F(MOVBE);
 277                 ++*nent;
 278                 break;
 279         default:
 280                 break;
 281         }
 282
 283         entry->function = func;
 284         entry->index = index;
 285
 286         return 0;
 287 }
 288
 289 static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
 290                                  u32 index, int *nent, int maxnent)
 291 {
 292         int r;
 293         unsigned f_nx = is_efer_nx() ? F(NX) : 0;
 294 #ifdef CONFIG_X86_64
 295         unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
 296                                 ? F(GBPAGES) : 0;
 297         unsigned f_lm = F(LM);
 298 #else
 299         unsigned f_gbpages = 0;
 300         unsigned f_lm = 0;
 301 #endif
 302         unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
 303         unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
 304         unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
 305         unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
 306
 307         /* cpuid 1.edx */
 308         const u32 kvm_supported_word0_x86_features =
 309                 F(FPU) | F(VME) | F(DE) | F(PSE) |
 310                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
 311                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
 312                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 313                 F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
 314                 0 /* Reserved, DS, ACPI */ | F(MMX) |
 315                 F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
 316                 0 /* HTT, TM, Reserved, PBE */;
 317         /* cpuid 0x80000001.edx */
 318         const u32 kvm_supported_word1_x86_features =
 319                 F(FPU) | F(VME) | F(DE) | F(PSE) |
 320                 F(TSC) | F(MSR) | F(PAE) | F(MCE) |
 321                 F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
 322                 F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
 323                 F(PAT) | F(PSE36) | 0 /* Reserved */ |
 324                 f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
 325                 F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
 326                 0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
 327         /* cpuid 1.ecx */
 328         const u32 kvm_supported_word4_x86_features =
 329                 /* NOTE: MONITOR (and MWAIT) are emulated as NOP,
 330                  * but *not* advertised to guests via CPUID ! */
 331                 F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
 332                 0 /* DS-CPL, VMX, SMX, EST */ |
 333                 0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
 334                 F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
 335                 F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
 336                 F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
 337                 0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
 338                 F(F16C) | F(RDRAND);
 339         /* cpuid 0x80000001.ecx */
 340         const u32 kvm_supported_word6_x86_features =
 341                 F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
 342                 F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
 343                 F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
 344                 0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM);
 345
 346         /* cpuid 0xC0000001.edx */
 347         const u32 kvm_supported_word5_x86_features =
 348                 F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
 349                 F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
 350                 F(PMM) | F(PMM_EN);
 351
 352         /* cpuid 7.0.ebx */
 353         const u32 kvm_supported_word9_x86_features =
 354                 F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
 355                 F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
 356                 F(ADX) | F(SMAP) | F(AVX512F) | F(AVX512PF) | F(AVX512ER) |
 357                 F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(PCOMMIT);
 358
 359         /* cpuid 0xD.1.eax */
 360         const u32 kvm_supported_word10_x86_features =
 361                 F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
 362
 363         /* all calls to cpuid_count() should be made on the same cpu */
 364         get_cpu();
 365
 366         r = -E2BIG;
 367
 368         if (*nent >= maxnent)
 369                 goto out;
 370
 371         do_cpuid_1_ent(entry, function, index);
 372         ++*nent;
 373
 374         switch (function) {
 375         case 0:
 376                 entry->eax = min(entry->eax, (u32)0xd);
 377                 break;
 378         case 1:
 379                 entry->edx &= kvm_supported_word0_x86_features;
 380                 cpuid_mask(&entry->edx, 0);
 381                 entry->ecx &= kvm_supported_word4_x86_features;
 382                 cpuid_mask(&entry->ecx, 4);
 383                 /* we support x2apic emulation even if host does not support
 384                  * it since we emulate x2apic in software */
 385                 entry->ecx |= F(X2APIC);
 386                 break;
 387         /* function 2 entries are STATEFUL. That is, repeated cpuid commands
 388          * may return different values. This forces us to get_cpu() before
 389          * issuing the first command, and also to emulate this annoying behavior
 390          * in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
 391         case 2: {
 392                 int t, times = entry->eax & 0xff;
 393
 394                 entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
 395                 entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
 396                 for (t = 1; t < times; ++t) {
 397                         if (*nent >= maxnent)
 398                                 goto out;
 399
 400                         do_cpuid_1_ent(&entry[t], function, 0);
 401                         entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
 402                         ++*nent;
 403                 }
 404                 break;
 405         }
 406         /* function 4 has additional index. */
 407         case 4: {
 408                 int i, cache_type;
 409
 410                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 411                 /* read more entries until cache_type is zero */
 412                 for (i = 1; ; ++i) {
 413                         if (*nent >= maxnent)
 414                                 goto out;
 415
 416                         cache_type = entry[i - 1].eax & 0x1f;
 417                         if (!cache_type)
 418                                 break;
 419                         do_cpuid_1_ent(&entry[i], function, i);
 420                         entry[i].flags |=
 421                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 422                         ++*nent;
 423                 }
 424                 break;
 425         }
 426         case 6: /* Thermal management */
 427                 entry->eax = 0x4; /* allow ARAT */
 428                 entry->ebx = 0;
 429                 entry->ecx = 0;
 430                 entry->edx = 0;
 431                 break;
 432         case 7: {
 433                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 434                 /* Mask ebx against host capability word 9 */
 435                 if (index == 0) {
 436                         entry->ebx &= kvm_supported_word9_x86_features;
 437                         cpuid_mask(&entry->ebx, 9);
 438                         // TSC_ADJUST is emulated
 439                         entry->ebx |= F(TSC_ADJUST);
 440                 } else
 441                         entry->ebx = 0;
 442                 entry->eax = 0;
 443                 entry->ecx = 0;
 444                 entry->edx = 0;
 445                 break;
 446         }
 447         case 9:
 448                 break;
 449         case 0xa: { /* Architectural Performance Monitoring */
 450                 struct x86_pmu_capability cap;
 451                 union cpuid10_eax eax;
 452                 union cpuid10_edx edx;
 453
 454                 perf_get_x86_pmu_capability(&cap);
 455
 456                 /*
 457                  * Only support guest architectural pmu on a host
 458                  * with architectural pmu.
 459                  */
 460                 if (!cap.version)
 461                         memset(&cap, 0, sizeof(cap));
 462
 463                 eax.split.version_id = min(cap.version, 2);
 464                 eax.split.num_counters = cap.num_counters_gp;
 465                 eax.split.bit_width = cap.bit_width_gp;
 466                 eax.split.mask_length = cap.events_mask_len;
 467
 468                 edx.split.num_counters_fixed = cap.num_counters_fixed;
 469                 edx.split.bit_width_fixed = cap.bit_width_fixed;
 470                 edx.split.reserved = 0;
 471
 472                 entry->eax = eax.full;
 473                 entry->ebx = cap.events_mask;
 474                 entry->ecx = 0;
 475                 entry->edx = edx.full;
 476                 break;
 477         }
 478         /* function 0xb has additional index. */
 479         case 0xb: {
 480                 int i, level_type;
 481
 482                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 483                 /* read more entries until level_type is zero */
 484                 for (i = 1; ; ++i) {
 485                         if (*nent >= maxnent)
 486                                 goto out;
 487
 488                         level_type = entry[i - 1].ecx & 0xff00;
 489                         if (!level_type)
 490                                 break;
 491                         do_cpuid_1_ent(&entry[i], function, i);
 492                         entry[i].flags |=
 493                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 494                         ++*nent;
 495                 }
 496                 break;
 497         }
 498         case 0xd: {
 499                 int idx, i;
 500                 u64 supported = kvm_supported_xcr0();
 501
 502                 entry->eax &= supported;
 503                 entry->ebx = xstate_required_size(supported, false);
 504                 entry->ecx = entry->ebx;
 505                 entry->edx &= supported >> 32;
 506                 entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 507                 if (!supported)
 508                         break;
 509
 510                 for (idx = 1, i = 1; idx < 64; ++idx) {
 511                         u64 mask = ((u64)1 << idx);
 512                         if (*nent >= maxnent)
 513                                 goto out;
 514
 515                         do_cpuid_1_ent(&entry[i], function, idx);
 516                         if (idx == 1) {
 517                                 entry[i].eax &= kvm_supported_word10_x86_features;
 518                                 entry[i].ebx = 0;
 519                                 if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
 520                                         entry[i].ebx =
 521                                                 xstate_required_size(supported,
 522                                                                      true);
 523                         } else {
 524                                 if (entry[i].eax == 0 || !(supported & mask))
 525                                         continue;
 526                                 if (WARN_ON_ONCE(entry[i].ecx & 1))
 527                                         continue;
 528                         }
 529                         entry[i].ecx = 0;
 530                         entry[i].edx = 0;
 531                         entry[i].flags |=
 532                                KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
 533                         ++*nent;
 534                         ++i;
 535                 }
 536                 break;
 537         }
 538         case KVM_CPUID_SIGNATURE: {
 539                 static const char signature[12] = "KVMKVMKVM\0\0";
 540                 const u32 *sigptr = (const u32 *)signature;
 541                 entry->eax = KVM_CPUID_FEATURES;
 542                 entry->ebx = sigptr[0];
 543                 entry->ecx = sigptr[1];
 544                 entry->edx = sigptr[2];
 545                 break;
 546         }
 547         case KVM_CPUID_FEATURES:
 548                 entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
 549                              (1 << KVM_FEATURE_NOP_IO_DELAY) |
 550                              (1 << KVM_FEATURE_CLOCKSOURCE2) |
 551                              (1 << KVM_FEATURE_ASYNC_PF) |
 552                              (1 << KVM_FEATURE_PV_EOI) |
 553                              (1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
 554                              (1 << KVM_FEATURE_PV_UNHALT);
 555
 556                 if (sched_info_on())
 557                         entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
 558
 559                 entry->ebx = 0;
 560                 entry->ecx = 0;
 561                 entry->edx = 0;
 562                 break;
 563         case 0x80000000:
 564                 entry->eax = min(entry->eax, 0x8000001a);
 565                 break;
 566         case 0x80000001:
 567                 entry->edx &= kvm_supported_word1_x86_features;
 568                 cpuid_mask(&entry->edx, 1);
 569                 entry->ecx &= kvm_supported_word6_x86_features;
 570                 cpuid_mask(&entry->ecx, 6);
 571                 break;
 572         case 0x80000007: /* Advanced power management */
 573                 /* invariant TSC is CPUID.80000007H:EDX[8] */
 574                 entry->edx &= (1 << 8);
 575                 /* mask against host */
 576                 entry->edx &= boot_cpu_data.x86_power;
 577                 entry->eax = entry->ebx = entry->ecx = 0;
 578                 break;
 579         case 0x80000008: {
 580                 unsigned g_phys_as = (entry->eax >> 16) & 0xff;
 581                 unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
 582                 unsigned phys_as = entry->eax & 0xff;
 583
 584                 if (!g_phys_as)
 585                         g_phys_as = phys_as;
 586                 entry->eax = g_phys_as | (virt_as << 8);
 587                 entry->ebx = entry->edx = 0;
 588                 break;
 589         }
 590         case 0x80000019:
 591                 entry->ecx = entry->edx = 0;
 592                 break;
 593         case 0x8000001a:
 594                 break;
 595         case 0x8000001d:
 596                 break;
 597         /*Add support for Centaur's CPUID instruction*/
 598         case 0xC0000000:
 599                 /*Just support up to 0xC0000004 now*/
 600                 entry->eax = min(entry->eax, 0xC0000004);
 601                 break;
 602         case 0xC0000001:
 603                 entry->edx &= kvm_supported_word5_x86_features;
 604                 cpuid_mask(&entry->edx, 5);
 605                 break;
 606         case 3: /* Processor serial number */
 607         case 5: /* MONITOR/MWAIT */
 608         case 0xC0000002:
 609         case 0xC0000003:
 610         case 0xC0000004:
 611         default:
 612                 entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
 613                 break;
 614         }
 615
 616         kvm_x86_ops->set_supported_cpuid(function, entry);
 617
 618         r = 0;
 619
 620 out:
 621         put_cpu();
 622
 623         return r;
 624 }
 625
 626 static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
 627                         u32 idx, int *nent, int maxnent, unsigned int type)
 628 {
 629         if (type == KVM_GET_EMULATED_CPUID)
 630                 return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
 631
 632         return __do_cpuid_ent(entry, func, idx, nent, maxnent);
 633 }
 634
 635 #undef F
 636
 637 struct kvm_cpuid_param {
 638         u32 func;
 639         u32 idx;
 640         bool has_leaf_count;
 641         bool (*qualifier)(const struct kvm_cpuid_param *param);
 642 };
 643
 644 static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
 645 {
 646         return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
 647 }
 648
 649 static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
 650                                  __u32 num_entries, unsigned int ioctl_type)
 651 {
 652         int i;
 653         __u32 pad[3];
 654
 655         if (ioctl_type != KVM_GET_EMULATED_CPUID)
 656                 return false;
 657
 658         /*
 659          * We want to make sure that ->padding is being passed clean from
 660          * userspace in case we want to use it for something in the future.
 661          *
 662          * Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
 663          * have to give ourselves satisfied only with the emulated side. /me
 664          * sheds a tear.
 665          */
 666         for (i = 0; i < num_entries; i++) {
 667                 if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
 668                         return true;
 669
 670                 if (pad[0] || pad[1] || pad[2])
 671                         return true;
 672         }
 673         return false;
 674 }
 675
 676 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
 677                             struct kvm_cpuid_entry2 __user *entries,
 678                             unsigned int type)
 679 {
 680         struct kvm_cpuid_entry2 *cpuid_entries;
 681         int limit, nent = 0, r = -E2BIG, i;
 682         u32 func;
 683         static const struct kvm_cpuid_param param[] = {
 684                 { .func = 0, .has_leaf_count = true },
 685                 { .func = 0x80000000, .has_leaf_count = true },
 686                 { .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
 687                 { .func = KVM_CPUID_SIGNATURE },
 688                 { .func = KVM_CPUID_FEATURES },
 689         };
 690
 691         if (cpuid->nent < 1)
 692                 goto out;
 693         if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
 694                 cpuid->nent = KVM_MAX_CPUID_ENTRIES;
 695
 696         if (sanity_check_entries(entries, cpuid->nent, type))
 697                 return -EINVAL;
 698
 699         r = -ENOMEM;
 700         cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
 701         if (!cpuid_entries)
 702                 goto out;
 703
 704         r = 0;
 705         for (i = 0; i < ARRAY_SIZE(param); i++) {
 706                 const struct kvm_cpuid_param *ent = &param[i];
 707
 708                 if (ent->qualifier && !ent->qualifier(ent))
 709                         continue;
 710
 711                 r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
 712                                 &nent, cpuid->nent, type);
 713
 714                 if (r)
 715                         goto out_free;
 716
 717                 if (!ent->has_leaf_count)
 718                         continue;
 719
 720                 limit = cpuid_entries[nent - 1].eax;
 721                 for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
 722                         r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
 723                                      &nent, cpuid->nent, type);
 724
 725                 if (r)
 726                         goto out_free;
 727         }
 728
 729         r = -EFAULT;
 730         if (copy_to_user(entries, cpuid_entries,
 731                          nent * sizeof(struct kvm_cpuid_entry2)))
 732                 goto out_free;
 733         cpuid->nent = nent;
 734         r = 0;
 735
 736 out_free:
 737         vfree(cpuid_entries);
 738 out:
 739         return r;
 740 }
 741
 742 static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
 743 {
 744         struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
 745         int j, nent = vcpu->arch.cpuid_nent;
 746
 747         e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
 748         /* when no next entry is found, the current entry[i] is reselected */
 749         for (j = i + 1; ; j = (j + 1) % nent) {
 750                 struct kvm_cpuid_entry2 *ej = &vcpu->arch.cpuid_entries[j];
 751                 if (ej->function == e->function) {
 752                         ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
 753                         return j;
 754                 }
 755         }
 756         return 0; /* silence gcc, even though control never reaches here */
 757 }
 758
 759 /* find an entry with matching function, matching index (if needed), and that
 760  * should be read next (if it's stateful) */
 761 static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
 762         u32 function, u32 index)
 763 {
 764         if (e->function != function)
 765                 return 0;
 766         if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
 767                 return 0;
 768         if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
 769             !(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
 770                 return 0;
 771         return 1;
 772 }
 773
 774 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
 775                                               u32 function, u32 index)
 776 {
 777         int i;
 778         struct kvm_cpuid_entry2 *best = NULL;
 779
 780         for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
 781                 struct kvm_cpuid_entry2 *e;
 782
 783                 e = &vcpu->arch.cpuid_entries[i];
 784                 if (is_matching_cpuid_entry(e, function, index)) {
 785                         if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
 786                                 move_to_next_stateful_cpuid_entry(vcpu, i);
 787                         best = e;
 788                         break;
 789                 }
 790         }
 791         return best;
 792 }
 793 EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
 794
 795 /*
 796  * If no match is found, check whether we exceed the vCPU's limit
 797  * and return the content of the highest valid _standard_ leaf instead.
 798  * This is to satisfy the CPUID specification.
 799  */
 800 static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
 801                                                   u32 function, u32 index)
 802 {
 803         struct kvm_cpuid_entry2 *maxlevel;
 804
 805         maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
 806         if (!maxlevel || maxlevel->eax >= function)
 807                 return NULL;
 808         if (function & 0x80000000) {
 809                 maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
 810                 if (!maxlevel)
 811                         return NULL;
 812         }
 813         return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
 814 }
 815
 816 void kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, u32 *ecx, u32 *edx)
 817 {
 818         u32 function = *eax, index = *ecx;
 819         struct kvm_cpuid_entry2 *best;
 820
 821         best = kvm_find_cpuid_entry(vcpu, function, index);
 822
 823         if (!best)
 824                 best = check_cpuid_limit(vcpu, function, index);
 825
 826         /*
 827          * Perfmon not yet supported for L2 guest.
 828          */
 829         if (is_guest_mode(vcpu) && function == 0xa)
 830                 best = NULL;
 831
 832         if (best) {
 833                 *eax = best->eax;
 834                 *ebx = best->ebx;
 835                 *ecx = best->ecx;
 836                 *edx = best->edx;
 837         } else
 838                 *eax = *ebx = *ecx = *edx = 0;
 839         trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx);
 840 }
 841 EXPORT_SYMBOL_GPL(kvm_cpuid);
 842
 843 void kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
 844 {
 845         u32 function, eax, ebx, ecx, edx;
 846
 847         function = eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
 848         ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
 849         kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx);
 850         kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
 851         kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
 852         kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
 853         kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
 854         kvm_x86_ops->skip_emulated_instruction(vcpu);
 855 }
 856 EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);