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