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 int kvm_update_cpuid(struct kvm_vcpu *vcpu);
  10 bool kvm_mpx_supported(void);
  11 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
  12                                               u32 function, u32 index);
  13 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
  14                             struct kvm_cpuid_entry2 __user *entries,
  15                             unsigned int type);
  16 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
  17                              struct kvm_cpuid *cpuid,
  18                              struct kvm_cpuid_entry __user *entries);
  19 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
  20                               struct kvm_cpuid2 *cpuid,
  21                               struct kvm_cpuid_entry2 __user *entries);
  22 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
  23                               struct kvm_cpuid2 *cpuid,
  24                               struct kvm_cpuid_entry2 __user *entries);
  25 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
  26                u32 *ecx, u32 *edx, bool check_limit);
  27
  28 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
  29
  30 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
  31 {
  32         return vcpu->arch.maxphyaddr;
  33 }
  34
  35 struct cpuid_reg {
  36         u32 function;
  37         u32 index;
  38         int reg;
  39 };
  40
  41 static const struct cpuid_reg reverse_cpuid[] = {
  42         [CPUID_1_EDX]         = {         1, 0, CPUID_EDX},
  43         [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX},
  44         [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX},
  45         [CPUID_1_ECX]         = {         1, 0, CPUID_ECX},
  46         [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX},
  47         [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX},
  48         [CPUID_7_0_EBX]       = {         7, 0, CPUID_EBX},
  49         [CPUID_D_1_EAX]       = {       0xd, 1, CPUID_EAX},
  50         [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX},
  51         [CPUID_6_EAX]         = {         6, 0, CPUID_EAX},
  52         [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX},
  53         [CPUID_7_ECX]         = {         7, 0, CPUID_ECX},
  54         [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX},
  55         [CPUID_7_EDX]         = {         7, 0, CPUID_EDX},
  56         [CPUID_7_1_EAX]       = {         7, 1, CPUID_EAX},
  57 };
  58
  59 /*
  60  * Reverse CPUID and its derivatives can only be used for hardware-defined
  61  * feature words, i.e. words whose bits directly correspond to a CPUID leaf.
  62  * Retrieving a feature bit or masking guest CPUID from a Linux-defined word
  63  * is nonsensical as the bit number/mask is an arbitrary software-defined value
  64  * and can't be used by KVM to query/control guest capabilities.  And obviously
  65  * the leaf being queried must have an entry in the lookup table.
  66  */
  67 static __always_inline void reverse_cpuid_check(unsigned x86_leaf)
  68 {
  69         BUILD_BUG_ON(x86_leaf == CPUID_LNX_1);
  70         BUILD_BUG_ON(x86_leaf == CPUID_LNX_2);
  71         BUILD_BUG_ON(x86_leaf == CPUID_LNX_3);
  72         BUILD_BUG_ON(x86_leaf == CPUID_LNX_4);
  73         BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid));
  74         BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0);
  75 }
  76
  77 /*
  78  * Retrieve the bit mask from an X86_FEATURE_* definition.  Features contain
  79  * the hardware defined bit number (stored in bits 4:0) and a software defined
  80  * "word" (stored in bits 31:5).  The word is used to index into arrays of
  81  * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has().
  82  */
  83 static __always_inline u32 __feature_bit(int x86_feature)
  84 {
  85         reverse_cpuid_check(x86_feature / 32);
  86         return 1 << (x86_feature & 31);
  87 }
  88
  89 #define feature_bit(name)  __feature_bit(X86_FEATURE_##name)
  90
  91 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned x86_feature)
  92 {
  93         unsigned x86_leaf = x86_feature / 32;
  94
  95         reverse_cpuid_check(x86_leaf);
  96         return reverse_cpuid[x86_leaf];
  97 }
  98
  99 static __always_inline int *guest_cpuid_get_register(struct kvm_vcpu *vcpu, unsigned x86_feature)
 100 {
 101         struct kvm_cpuid_entry2 *entry;
 102         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
 103
 104         entry = kvm_find_cpuid_entry(vcpu, cpuid.function, cpuid.index);
 105         if (!entry)
 106                 return NULL;
 107
 108         switch (cpuid.reg) {
 109         case CPUID_EAX:
 110                 return &entry->eax;
 111         case CPUID_EBX:
 112                 return &entry->ebx;
 113         case CPUID_ECX:
 114                 return &entry->ecx;
 115         case CPUID_EDX:
 116                 return &entry->edx;
 117         default:
 118                 BUILD_BUG();
 119                 return NULL;
 120         }
 121 }
 122
 123 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu, unsigned x86_feature)
 124 {
 125         int *reg;
 126
 127         reg = guest_cpuid_get_register(vcpu, x86_feature);
 128         if (!reg)
 129                 return false;
 130
 131         return *reg & __feature_bit(x86_feature);
 132 }
 133
 134 static __always_inline void guest_cpuid_clear(struct kvm_vcpu *vcpu, unsigned x86_feature)
 135 {
 136         int *reg;
 137
 138         reg = guest_cpuid_get_register(vcpu, x86_feature);
 139         if (reg)
 140                 *reg &= ~__feature_bit(x86_feature);
 141 }
 142
 143 static inline bool guest_cpuid_is_amd(struct kvm_vcpu *vcpu)
 144 {
 145         struct kvm_cpuid_entry2 *best;
 146
 147         best = kvm_find_cpuid_entry(vcpu, 0, 0);
 148         return best && best->ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx;
 149 }
 150
 151 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
 152 {
 153         struct kvm_cpuid_entry2 *best;
 154
 155         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 156         if (!best)
 157                 return -1;
 158
 159         return x86_family(best->eax);
 160 }
 161
 162 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
 163 {
 164         struct kvm_cpuid_entry2 *best;
 165
 166         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 167         if (!best)
 168                 return -1;
 169
 170         return x86_model(best->eax);
 171 }
 172
 173 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
 174 {
 175         struct kvm_cpuid_entry2 *best;
 176
 177         best = kvm_find_cpuid_entry(vcpu, 0x1, 0);
 178         if (!best)
 179                 return -1;
 180
 181         return x86_stepping(best->eax);
 182 }
 183
 184 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
 185 {
 186         return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
 187 }
 188
 189 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
 190 {
 191         return vcpu->arch.msr_misc_features_enables &
 192                   MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
 193 }
 194
 195 #endif