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
   9 extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
  10 void kvm_set_cpu_caps(void);
  11
  12 int kvm_update_cpuid(struct kvm_vcpu *vcpu);
  13 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
  14                                               u32 function, u32 index);
  15 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
  16                             struct kvm_cpuid_entry2 __user *entries,
  17                             unsigned int type);
  18 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
  19                              struct kvm_cpuid *cpuid,
  20                              struct kvm_cpuid_entry __user *entries);
  21 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
  22                               struct kvm_cpuid2 *cpuid,
  23                               struct kvm_cpuid_entry2 __user *entries);
  24 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
  25                               struct kvm_cpuid2 *cpuid,
  26                               struct kvm_cpuid_entry2 __user *entries);
  27 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
  28                u32 *ecx, u32 *edx, bool exact_only);
  29
  30 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
  31
  32 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
  33 {
  34         return vcpu->arch.maxphyaddr;
  35 }
  36
  37 struct cpuid_reg {
  38         u32 function;
  39         u32 index;
  40         int reg;
  41 };
  42
  43 static const struct cpuid_reg reverse_cpuid[] = {
  44         [CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
  45         [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
  46         [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
  47         [CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
  48         [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
  49         [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
  50         [CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
  51         [CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
  52         [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
  53         [CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
  54         [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
  55         [CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
  56         [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
  57         [CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
  58         [CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
  59 };
  60
  61 /*
  62  * Reverse CPUID and its derivatives can only be used for hardware-defined
  63  * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
  64  * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
  65  * is nonsensical as the bit number/mask is an arbitrary software-defined value
  66  * and can't be used by KVM to query/control guest capabilities.  And obviously
  67  * the leaf being queried must have an entry in the lookup table.
  68  */
  69 static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
  70 {
  71         BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
  72         BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
  73         BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
  74         BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
  75         BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
  76         BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
  77 }
  78
  79 /*
  80  * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
  81  * the hardware defined bit number (stored in bits 4:0) and a software defined
  82  * "word" (stored in bits 31:5).  The word is used to index into arrays of
  83  * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
  84  */
  85 static __always_inline u32 __feature_bit(int x86_feature)
  86 {
  87         reverse_cpuid_check(x86_feature / 32);
  88         return 1 << (x86_feature & 31);
  89 }
  90
  91 #define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
  92
  93 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature)
  94 {
  95         unsigned int x86_leaf = x86_feature / 32;
  96
  97         reverse_cpuid_check(x86_leaf);
  98         return reverse_cpuid[x86_leaf];
  99 }
 100
 101 static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
 102                                                   u32 reg)
 103 {
 104         switch (reg) {
 105         case CPUID_EAX:
 106                 return &entry->eax;
 107         case CPUID_EBX:
 108                 return &entry->ebx;
 109         case CPUID_ECX:
 110                 return &entry->ecx;
 111         case CPUID_EDX:
 112                 return &entry->edx;
 113         default:
 114                 BUILD_BUG();
 115                 return NULL;
 116         }
 117 }
 118
 119 static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
 120                                                 unsigned int x86_feature)
 121 {
 122         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 123
 124         return __cpuid_entry_get_reg(entry, cpuid.reg);
 125 }
 126
 127 static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry,
 128                                            unsigned int x86_feature)
 129 {
 130         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 131
 132         return *reg & __feature_bit(x86_feature);
 133 }
 134
 135 static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry,
 136                                             unsigned int x86_feature)
 137 {
 138         return cpuid_entry_get(entry, x86_feature);
 139 }
 140
 141 static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry,
 142                                               unsigned int x86_feature)
 143 {
 144         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 145
 146         *reg &= ~__feature_bit(x86_feature);
 147 }
 148
 149 static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry,
 150                                             unsigned int x86_feature)
 151 {
 152         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 153
 154         *reg |= __feature_bit(x86_feature);
 155 }
 156
 157 static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
 158                                                unsigned int x86_feature,
 159                                                bool set)
 160 {
 161         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 162
 163         /*
 164          * Open coded instead of using cpuid_entry_{clear,set}() to coerce the
 165          * compiler into using CMOV instead of Jcc when possible.
 166          */
 167         if (set)
 168                 *reg |= __feature_bit(x86_feature);
 169         else
 170                 *reg &= ~__feature_bit(x86_feature);
 171 }
 172
 173 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
 174                                                  enum cpuid_leafs leaf)
 175 {
 176         u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);
 177
 178         BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
 179         *reg = kvm_cpu_caps[leaf];
 180 }
 181
 182 static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu,
 183                                                      unsigned int x86_feature)
 184 {
 185         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 186         struct kvm_cpuid_entry2 *entry;
 187
 188         entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
 189         if (!entry)
 190                 return NULL;
 191
 192         return __cpuid_entry_get_reg(entry, cpuid.reg);
 193 }
 194
 195 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu,
 196                                             unsigned int x86_feature)
 197 {
 198         u32 *reg;
 199
 200         reg = guest_cpuid_get_register(vcpu, x86_feature);
 201         if (!reg)
 202                 return false;
 203
 204         return *reg & __feature_bit(x86_feature);
 205 }
 206
 207 static __always_inline void guest_cpuid_clear(struct kvm_vcpu *vcpu,
 208                                               unsigned int x86_feature)
 209 {
 210         u32 *reg;
 211
 212         reg = guest_cpuid_get_register(vcpu, x86_feature);
 213         if (reg)
 214                 *reg &= ~__feature_bit(x86_feature);
 215 }
 216
 217 static inline bool guest_cpuid_is_amd_or_hygon(struct kvm_vcpu *vcpu)
 218 {
 219         struct kvm_cpuid_entry2 *best;
 220
 221         best = kvm_find_cpuid_entry(vcpu, 0, 0);
 222         return best &&
 223                (is_guest_vendor_amd(best->ebx, best->ecx, best->edx) ||
 224                 is_guest_vendor_hygon(best->ebx, best->ecx, best->edx));
 225 }
 226
 227 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
 228 {
 229         struct kvm_cpuid_entry2 *best;
 230
 231         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 232         if (!best)
 233                 return -1;
 234
 235         return x86_family(best->eax);
 236 }
 237
 238 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
 239 {
 240         struct kvm_cpuid_entry2 *best;
 241
 242         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 243         if (!best)
 244                 return -1;
 245
 246         return x86_model(best->eax);
 247 }
 248
 249 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
 250 {
 251         struct kvm_cpuid_entry2 *best;
 252
 253         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 254         if (!best)
 255                 return -1;
 256
 257         return x86_stepping(best->eax);
 258 }
 259
 260 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
 261 {
 262         return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
 263 }
 264
 265 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
 266 {
 267         return vcpu->arch.msr_misc_features_enables &
 268                   MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
 269 }
 270
 271 static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature)
 272 {
 273         unsigned int x86_leaf = x86_feature / 32;
 274
 275         reverse_cpuid_check(x86_leaf);
 276         kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
 277 }
 278
 279 static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature)
 280 {
 281         unsigned int x86_leaf = x86_feature / 32;
 282
 283         reverse_cpuid_check(x86_leaf);
 284         kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
 285 }
 286
 287 static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
 288 {
 289         unsigned int x86_leaf = x86_feature / 32;
 290
 291         reverse_cpuid_check(x86_leaf);
 292         return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
 293 }
 294
 295 static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature)
 296 {
 297         return !!kvm_cpu_cap_get(x86_feature);
 298 }
 299
 300 static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature)
 301 {
 302         if (boot_cpu_has(x86_feature))
 303                 kvm_cpu_cap_set(x86_feature);
 304 }
 305
 306 #endif