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