arch/x86/kvm/cpuid.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef ARCH_X86_KVM_CPUID_H
   3 #define ARCH_X86_KVM_CPUID_H
   4
   5 #include "x86.h"
   6 #include <asm/cpu.h>
   7 #include <asm/processor.h>
   8 #include <uapi/asm/kvm_para.h>
   9
  10 /*
  11  * Hardware-defined CPUID leafs that are scattered in the kernel, but need to
  12  * be directly used by KVM.  Note, these word values conflict with the kernel's
  13  * "bug" caps, but KVM doesn't use those.
  14  */
  15 enum kvm_only_cpuid_leafs {
  16         CPUID_12_EAX     = NCAPINTS,
  17         NR_KVM_CPU_CAPS,
  18
  19         NKVMCAPINTS = NR_KVM_CPU_CAPS - NCAPINTS,
  20 };
  21
  22 #define KVM_X86_FEATURE(w, f)           ((w)*32 + (f))
  23
  24 /* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */
  25 #define KVM_X86_FEATURE_SGX1            KVM_X86_FEATURE(CPUID_12_EAX, 0)
  26 #define KVM_X86_FEATURE_SGX2            KVM_X86_FEATURE(CPUID_12_EAX, 1)
  27
  28 extern u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly;
  29 void kvm_set_cpu_caps(void);
  30
  31 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
  32 void kvm_update_pv_runtime(struct kvm_vcpu *vcpu);
  33 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
  34                                               u32 function, u32 index);
  35 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
  36                             struct kvm_cpuid_entry2 __user *entries,
  37                             unsigned int type);
  38 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
  39                              struct kvm_cpuid *cpuid,
  40                              struct kvm_cpuid_entry __user *entries);
  41 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
  42                               struct kvm_cpuid2 *cpuid,
  43                               struct kvm_cpuid_entry2 __user *entries);
  44 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
  45                               struct kvm_cpuid2 *cpuid,
  46                               struct kvm_cpuid_entry2 __user *entries);
  47 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
  48                u32 *ecx, u32 *edx, bool exact_only);
  49
  50 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
  51 u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu);
  52
  53 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
  54 {
  55         return vcpu->arch.maxphyaddr;
  56 }
  57
  58 static inline bool kvm_vcpu_is_legal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
  59 {
  60         return !(gpa & vcpu->arch.reserved_gpa_bits);
  61 }
  62
  63 static inline bool kvm_vcpu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
  64 {
  65         return !kvm_vcpu_is_legal_gpa(vcpu, gpa);
  66 }
  67
  68 static inline bool kvm_vcpu_is_legal_aligned_gpa(struct kvm_vcpu *vcpu,
  69                                                  gpa_t gpa, gpa_t alignment)
  70 {
  71         return IS_ALIGNED(gpa, alignment) && kvm_vcpu_is_legal_gpa(vcpu, gpa);
  72 }
  73
  74 static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
  75 {
  76         return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE);
  77 }
  78
  79 struct cpuid_reg {
  80         u32 function;
  81         u32 index;
  82         int reg;
  83 };
  84
  85 static const struct cpuid_reg reverse_cpuid[] = {
  86         [CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
  87         [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
  88         [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
  89         [CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
  90         [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
  91         [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
  92         [CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
  93         [CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
  94         [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
  95         [CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
  96         [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
  97         [CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
  98         [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
  99         [CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
 100         [CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
 101         [CPUID_12_EAX]        = {0x00000012, 0, CPUID_EAX},
 102 };
 103
 104 /*
 105  * Reverse CPUID and its derivatives can only be used for hardware-defined
 106  * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
 107  * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
 108  * is nonsensical as the bit number/mask is an arbitrary software-defined value
 109  * and can't be used by KVM to query/control guest capabilities.  And obviously
 110  * the leaf being queried must have an entry in the lookup table.
 111  */
 112 static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
 113 {
 114         BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
 115         BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
 116         BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
 117         BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
 118         BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
 119         BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
 120 }
 121
 122 /*
 123  * Translate feature bits that are scattered in the kernel's cpufeatures word
 124  * into KVM feature words that align with hardware's definitions.
 125  */
 126 static __always_inline u32 __feature_translate(int x86_feature)
 127 {
 128         if (x86_feature == X86_FEATURE_SGX1)
 129                 return KVM_X86_FEATURE_SGX1;
 130         else if (x86_feature == X86_FEATURE_SGX2)
 131                 return KVM_X86_FEATURE_SGX2;
 132
 133         return x86_feature;
 134 }
 135
 136 static __always_inline u32 __feature_leaf(int x86_feature)
 137 {
 138         return __feature_translate(x86_feature) / 32;
 139 }
 140
 141 /*
 142  * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
 143  * the hardware defined bit number (stored in bits 4:0) and a software defined
 144  * "word" (stored in bits 31:5).  The word is used to index into arrays of
 145  * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
 146  */
 147 static __always_inline u32 __feature_bit(int x86_feature)
 148 {
 149         x86_feature = __feature_translate(x86_feature);
 150
 151         reverse_cpuid_check(x86_feature / 32);
 152         return 1 << (x86_feature & 31);
 153 }
 154
 155 #define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
 156
 157 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature)
 158 {
 159         unsigned int x86_leaf = __feature_leaf(x86_feature);
 160
 161         reverse_cpuid_check(x86_leaf);
 162         return reverse_cpuid[x86_leaf];
 163 }
 164
 165 static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
 166                                                   u32 reg)
 167 {
 168         switch (reg) {
 169         case CPUID_EAX:
 170                 return &entry->eax;
 171         case CPUID_EBX:
 172                 return &entry->ebx;
 173         case CPUID_ECX:
 174                 return &entry->ecx;
 175         case CPUID_EDX:
 176                 return &entry->edx;
 177         default:
 178                 BUILD_BUG();
 179                 return NULL;
 180         }
 181 }
 182
 183 static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
 184                                                 unsigned int x86_feature)
 185 {
 186         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 187
 188         return __cpuid_entry_get_reg(entry, cpuid.reg);
 189 }
 190
 191 static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry,
 192                                            unsigned int x86_feature)
 193 {
 194         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 195
 196         return *reg & __feature_bit(x86_feature);
 197 }
 198
 199 static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry,
 200                                             unsigned int x86_feature)
 201 {
 202         return cpuid_entry_get(entry, x86_feature);
 203 }
 204
 205 static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry,
 206                                               unsigned int x86_feature)
 207 {
 208         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 209
 210         *reg &= ~__feature_bit(x86_feature);
 211 }
 212
 213 static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry,
 214                                             unsigned int x86_feature)
 215 {
 216         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 217
 218         *reg |= __feature_bit(x86_feature);
 219 }
 220
 221 static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
 222                                                unsigned int x86_feature,
 223                                                bool set)
 224 {
 225         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 226
 227         /*
 228          * Open coded instead of using cpuid_entry_{clear,set}() to coerce the
 229          * compiler into using CMOV instead of Jcc when possible.
 230          */
 231         if (set)
 232                 *reg |= __feature_bit(x86_feature);
 233         else
 234                 *reg &= ~__feature_bit(x86_feature);
 235 }
 236
 237 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
 238                                                  unsigned int leaf)
 239 {
 240         u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);
 241
 242         BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
 243         *reg = kvm_cpu_caps[leaf];
 244 }
 245
 246 static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu,
 247                                                      unsigned int x86_feature)
 248 {
 249         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 250         struct kvm_cpuid_entry2 *entry;
 251
 252         entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
 253         if (!entry)
 254                 return NULL;
 255
 256         return __cpuid_entry_get_reg(entry, cpuid.reg);
 257 }
 258
 259 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu,
 260                                             unsigned int x86_feature)
 261 {
 262         u32 *reg;
 263
 264         reg = guest_cpuid_get_register(vcpu, x86_feature);
 265         if (!reg)
 266                 return false;
 267
 268         return *reg & __feature_bit(x86_feature);
 269 }
 270
 271 static __always_inline void guest_cpuid_clear(struct kvm_vcpu *vcpu,
 272                                               unsigned int x86_feature)
 273 {
 274         u32 *reg;
 275
 276         reg = guest_cpuid_get_register(vcpu, x86_feature);
 277         if (reg)
 278                 *reg &= ~__feature_bit(x86_feature);
 279 }
 280
 281 static inline bool guest_cpuid_is_amd_or_hygon(struct kvm_vcpu *vcpu)
 282 {
 283         struct kvm_cpuid_entry2 *best;
 284
 285         best = kvm_find_cpuid_entry(vcpu, 0, 0);
 286         return best &&
 287                (is_guest_vendor_amd(best->ebx, best->ecx, best->edx) ||
 288                 is_guest_vendor_hygon(best->ebx, best->ecx, best->edx));
 289 }
 290
 291 static inline bool guest_cpuid_is_intel(struct kvm_vcpu *vcpu)
 292 {
 293         struct kvm_cpuid_entry2 *best;
 294
 295         best = kvm_find_cpuid_entry(vcpu, 0, 0);
 296         return best && is_guest_vendor_intel(best->ebx, best->ecx, best->edx);
 297 }
 298
 299 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
 300 {
 301         struct kvm_cpuid_entry2 *best;
 302
 303         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 304         if (!best)
 305                 return -1;
 306
 307         return x86_family(best->eax);
 308 }
 309
 310 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
 311 {
 312         struct kvm_cpuid_entry2 *best;
 313
 314         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 315         if (!best)
 316                 return -1;
 317
 318         return x86_model(best->eax);
 319 }
 320
 321 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
 322 {
 323         struct kvm_cpuid_entry2 *best;
 324
 325         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 326         if (!best)
 327                 return -1;
 328
 329         return x86_stepping(best->eax);
 330 }
 331
 332 static inline bool guest_has_spec_ctrl_msr(struct kvm_vcpu *vcpu)
 333 {
 334         return (guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
 335                 guest_cpuid_has(vcpu, X86_FEATURE_AMD_STIBP) ||
 336                 guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBRS) ||
 337                 guest_cpuid_has(vcpu, X86_FEATURE_AMD_SSBD));
 338 }
 339
 340 static inline bool guest_has_pred_cmd_msr(struct kvm_vcpu *vcpu)
 341 {
 342         return (guest_cpuid_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
 343                 guest_cpuid_has(vcpu, X86_FEATURE_AMD_IBPB));
 344 }
 345
 346 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
 347 {
 348         return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
 349 }
 350
 351 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
 352 {
 353         return vcpu->arch.msr_misc_features_enables &
 354                   MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
 355 }
 356
 357 static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature)
 358 {
 359         unsigned int x86_leaf = __feature_leaf(x86_feature);
 360
 361         reverse_cpuid_check(x86_leaf);
 362         kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
 363 }
 364
 365 static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature)
 366 {
 367         unsigned int x86_leaf = __feature_leaf(x86_feature);
 368
 369         reverse_cpuid_check(x86_leaf);
 370         kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
 371 }
 372
 373 static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
 374 {
 375         unsigned int x86_leaf = __feature_leaf(x86_feature);
 376
 377         reverse_cpuid_check(x86_leaf);
 378         return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
 379 }
 380
 381 static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature)
 382 {
 383         return !!kvm_cpu_cap_get(x86_feature);
 384 }
 385
 386 static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature)
 387 {
 388         if (boot_cpu_has(x86_feature))
 389                 kvm_cpu_cap_set(x86_feature);
 390 }
 391
 392 static __always_inline bool guest_pv_has(struct kvm_vcpu *vcpu,
 393                                          unsigned int kvm_feature)
 394 {
 395         if (!vcpu->arch.pv_cpuid.enforce)
 396                 return true;
 397
 398         return vcpu->arch.pv_cpuid.features & (1u << kvm_feature);
 399 }
 400
 401 #endif