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 extern u32 kvm_cpu_caps[NCAPINTS] __read_mostly;
  11 void kvm_set_cpu_caps(void);
  12
  13 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
  14 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
  15                                               u32 function, u32 index);
  16 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
  17                             struct kvm_cpuid_entry2 __user *entries,
  18                             unsigned int type);
  19 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
  20                              struct kvm_cpuid *cpuid,
  21                              struct kvm_cpuid_entry __user *entries);
  22 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
  23                               struct kvm_cpuid2 *cpuid,
  24                               struct kvm_cpuid_entry2 __user *entries);
  25 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
  26                               struct kvm_cpuid2 *cpuid,
  27                               struct kvm_cpuid_entry2 __user *entries);
  28 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
  29                u32 *ecx, u32 *edx, bool exact_only);
  30
  31 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
  32
  33 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
  34 {
  35         return vcpu->arch.maxphyaddr;
  36 }
  37
  38 static inline bool kvm_vcpu_is_illegal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
  39 {
  40         return (gpa >= BIT_ULL(cpuid_maxphyaddr(vcpu)));
  41 }
  42
  43 struct cpuid_reg {
  44         u32 function;
  45         u32 index;
  46         int reg;
  47 };
  48
  49 static const struct cpuid_reg reverse_cpuid[] = {
  50         [CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
  51         [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
  52         [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
  53         [CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
  54         [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
  55         [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
  56         [CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
  57         [CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
  58         [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
  59         [CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
  60         [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
  61         [CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
  62         [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
  63         [CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
  64         [CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
  65 };
  66
  67 /*
  68  * Reverse CPUID and its derivatives can only be used for hardware-defined
  69  * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
  70  * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
  71  * is nonsensical as the bit number/mask is an arbitrary software-defined value
  72  * and can't be used by KVM to query/control guest capabilities.  And obviously
  73  * the leaf being queried must have an entry in the lookup table.
  74  */
  75 static __always_inline void reverse_cpuid_check(unsigned int x86_leaf)
  76 {
  77         BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
  78         BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
  79         BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
  80         BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
  81         BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
  82         BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
  83 }
  84
  85 /*
  86  * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
  87  * the hardware defined bit number (stored in bits 4:0) and a software defined
  88  * "word" (stored in bits 31:5).  The word is used to index into arrays of
  89  * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
  90  */
  91 static __always_inline u32 __feature_bit(int x86_feature)
  92 {
  93         reverse_cpuid_check(x86_feature / 32);
  94         return 1 << (x86_feature & 31);
  95 }
  96
  97 #define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
  98
  99 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature)
 100 {
 101         unsigned int x86_leaf = x86_feature / 32;
 102
 103         reverse_cpuid_check(x86_leaf);
 104         return reverse_cpuid[x86_leaf];
 105 }
 106
 107 static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
 108                                                   u32 reg)
 109 {
 110         switch (reg) {
 111         case CPUID_EAX:
 112                 return &entry->eax;
 113         case CPUID_EBX:
 114                 return &entry->ebx;
 115         case CPUID_ECX:
 116                 return &entry->ecx;
 117         case CPUID_EDX:
 118                 return &entry->edx;
 119         default:
 120                 BUILD_BUG();
 121                 return NULL;
 122         }
 123 }
 124
 125 static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry,
 126                                                 unsigned int x86_feature)
 127 {
 128         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 129
 130         return __cpuid_entry_get_reg(entry, cpuid.reg);
 131 }
 132
 133 static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry,
 134                                            unsigned int x86_feature)
 135 {
 136         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 137
 138         return *reg & __feature_bit(x86_feature);
 139 }
 140
 141 static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry,
 142                                             unsigned int x86_feature)
 143 {
 144         return cpuid_entry_get(entry, x86_feature);
 145 }
 146
 147 static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry,
 148                                               unsigned int x86_feature)
 149 {
 150         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 151
 152         *reg &= ~__feature_bit(x86_feature);
 153 }
 154
 155 static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry,
 156                                             unsigned int x86_feature)
 157 {
 158         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 159
 160         *reg |= __feature_bit(x86_feature);
 161 }
 162
 163 static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry,
 164                                                unsigned int x86_feature,
 165                                                bool set)
 166 {
 167         u32 *reg = cpuid_entry_get_reg(entry, x86_feature);
 168
 169         /*
 170          * Open coded instead of using cpuid_entry_{clear,set}() to coerce the
 171          * compiler into using CMOV instead of Jcc when possible.
 172          */
 173         if (set)
 174                 *reg |= __feature_bit(x86_feature);
 175         else
 176                 *reg &= ~__feature_bit(x86_feature);
 177 }
 178
 179 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
 180                                                  enum cpuid_leafs leaf)
 181 {
 182         u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);
 183
 184         BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
 185         *reg = kvm_cpu_caps[leaf];
 186 }
 187
 188 static __always_inline u32 *guest_cpuid_get_register(struct kvm_vcpu *vcpu,
 189                                                      unsigned int x86_feature)
 190 {
 191         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 192         struct kvm_cpuid_entry2 *entry;
 193
 194         entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
 195         if (!entry)
 196                 return NULL;
 197
 198         return __cpuid_entry_get_reg(entry, cpuid.reg);
 199 }
 200
 201 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu,
 202                                             unsigned int x86_feature)
 203 {
 204         u32 *reg;
 205
 206         reg = guest_cpuid_get_register(vcpu, x86_feature);
 207         if (!reg)
 208                 return false;
 209
 210         return *reg & __feature_bit(x86_feature);
 211 }
 212
 213 static __always_inline void guest_cpuid_clear(struct kvm_vcpu *vcpu,
 214                                               unsigned int x86_feature)
 215 {
 216         u32 *reg;
 217
 218         reg = guest_cpuid_get_register(vcpu, x86_feature);
 219         if (reg)
 220                 *reg &= ~__feature_bit(x86_feature);
 221 }
 222
 223 static inline bool guest_cpuid_is_amd_or_hygon(struct kvm_vcpu *vcpu)
 224 {
 225         struct kvm_cpuid_entry2 *best;
 226
 227         best = kvm_find_cpuid_entry(vcpu, 0, 0);
 228         return best &&
 229                (is_guest_vendor_amd(best->ebx, best->ecx, best->edx) ||
 230                 is_guest_vendor_hygon(best->ebx, best->ecx, best->edx));
 231 }
 232
 233 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
 234 {
 235         struct kvm_cpuid_entry2 *best;
 236
 237         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 238         if (!best)
 239                 return -1;
 240
 241         return x86_family(best->eax);
 242 }
 243
 244 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
 245 {
 246         struct kvm_cpuid_entry2 *best;
 247
 248         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 249         if (!best)
 250                 return -1;
 251
 252         return x86_model(best->eax);
 253 }
 254
 255 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
 256 {
 257         struct kvm_cpuid_entry2 *best;
 258
 259         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 260         if (!best)
 261                 return -1;
 262
 263         return x86_stepping(best->eax);
 264 }
 265
 266 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
 267 {
 268         return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
 269 }
 270
 271 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
 272 {
 273         return vcpu->arch.msr_misc_features_enables &
 274                   MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
 275 }
 276
 277 static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature)
 278 {
 279         unsigned int x86_leaf = x86_feature / 32;
 280
 281         reverse_cpuid_check(x86_leaf);
 282         kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
 283 }
 284
 285 static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature)
 286 {
 287         unsigned int x86_leaf = x86_feature / 32;
 288
 289         reverse_cpuid_check(x86_leaf);
 290         kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
 291 }
 292
 293 static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
 294 {
 295         unsigned int x86_leaf = x86_feature / 32;
 296
 297         reverse_cpuid_check(x86_leaf);
 298         return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
 299 }
 300
 301 static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature)
 302 {
 303         return !!kvm_cpu_cap_get(x86_feature);
 304 }
 305
 306 static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature)
 307 {
 308         if (boot_cpu_has(x86_feature))
 309                 kvm_cpu_cap_set(x86_feature);
 310 }
 311
 312 static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
 313 {
 314         return PAGE_ALIGNED(gpa) && !(gpa >> cpuid_maxphyaddr(vcpu));
 315 }
 316
 317 static __always_inline bool guest_pv_has(struct kvm_vcpu *vcpu,
 318                                          unsigned int kvm_feature)
 319 {
 320         if (!vcpu->arch.pv_cpuid.enforce)
 321                 return true;
 322
 323         return vcpu->arch.pv_cpuid.features & (1u << kvm_feature);
 324 }
 325
 326 #endif