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 "reverse_cpuid.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[NR_KVM_CPU_CAPS] __read_mostly;
  11 void kvm_set_cpu_caps(void);
  12
  13 void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu);
  14 void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
  15 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu,
  16                                                     u32 function, u32 index);
  17 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
  18                                               u32 function);
  19 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
  20                             struct kvm_cpuid_entry2 __user *entries,
  21                             unsigned int type);
  22 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
  23                              struct kvm_cpuid *cpuid,
  24                              struct kvm_cpuid_entry __user *entries);
  25 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
  26                               struct kvm_cpuid2 *cpuid,
  27                               struct kvm_cpuid_entry2 __user *entries);
  28 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
  29                               struct kvm_cpuid2 *cpuid,
  30                               struct kvm_cpuid_entry2 __user *entries);
  31 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
  32                u32 *ecx, u32 *edx, bool exact_only);
  33
  34 void __init kvm_init_xstate_sizes(void);
  35 u32 xstate_required_size(u64 xstate_bv, bool compacted);
  36
  37 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu);
  38 u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu);
  39
  40 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu)
  41 {
  42         return vcpu->arch.maxphyaddr;
  43 }
  44
  45 static inline bool kvm_vcpu_is_legal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa)
  46 {
  47         return !(gpa & vcpu->arch.reserved_gpa_bits);
  48 }
  49
  50 static inline bool kvm_vcpu_is_legal_aligned_gpa(struct kvm_vcpu *vcpu,
  51                                                  gpa_t gpa, gpa_t alignment)
  52 {
  53         return IS_ALIGNED(gpa, alignment) && kvm_vcpu_is_legal_gpa(vcpu, gpa);
  54 }
  55
  56 static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa)
  57 {
  58         return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE);
  59 }
  60
  61 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry,
  62                                                  unsigned int leaf)
  63 {
  64         u32 *reg = cpuid_entry_get_reg(entry, leaf * 32);
  65
  66         BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps));
  67         *reg = kvm_cpu_caps[leaf];
  68 }
  69
  70 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu,
  71                                             unsigned int x86_feature)
  72 {
  73         const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature);
  74         struct kvm_cpuid_entry2 *entry;
  75         u32 *reg;
  76
  77         /*
  78          * XSAVES is a special snowflake.  Due to lack of a dedicated intercept
  79          * on SVM, KVM must assume that XSAVES (and thus XRSTORS) is usable by
  80          * the guest if the host supports XSAVES and *XSAVE* is exposed to the
  81          * guest.  Because the guest can execute XSAVES and XRSTORS, i.e. can
  82          * indirectly consume XSS, KVM must ensure XSS is zeroed when running
  83          * the guest, i.e. must set XSAVES in vCPU capabilities.  But to reject
  84          * direct XSS reads and writes (to minimize the virtualization hole and
  85          * honor userspace's CPUID), KVM needs to check the raw guest CPUID,
  86          * not KVM's view of guest capabilities.
  87          *
  88          * For all other features, guest capabilities are accurate.  Expand
  89          * this allowlist with extreme vigilance.
  90          */
  91         BUILD_BUG_ON(x86_feature != X86_FEATURE_XSAVES);
  92
  93         entry = kvm_find_cpuid_entry_index(vcpu, cpuid.function, cpuid.index);
  94         if (!entry)
  95                 return NULL;
  96
  97         reg = __cpuid_entry_get_reg(entry, cpuid.reg);
  98         if (!reg)
  99                 return false;
 100
 101         return *reg & __feature_bit(x86_feature);
 102 }
 103
 104 static inline bool guest_cpuid_is_amd_compatible(struct kvm_vcpu *vcpu)
 105 {
 106         return vcpu->arch.is_amd_compatible;
 107 }
 108
 109 static inline bool guest_cpuid_is_intel_compatible(struct kvm_vcpu *vcpu)
 110 {
 111         return !guest_cpuid_is_amd_compatible(vcpu);
 112 }
 113
 114 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu)
 115 {
 116         struct kvm_cpuid_entry2 *best;
 117
 118         best = kvm_find_cpuid_entry(vcpu, 0x1);
 119         if (!best)
 120                 return -1;
 121
 122         return x86_family(best->eax);
 123 }
 124
 125 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu)
 126 {
 127         struct kvm_cpuid_entry2 *best;
 128
 129         best = kvm_find_cpuid_entry(vcpu, 0x1);
 130         if (!best)
 131                 return -1;
 132
 133         return x86_model(best->eax);
 134 }
 135
 136 static inline bool cpuid_model_is_consistent(struct kvm_vcpu *vcpu)
 137 {
 138         return boot_cpu_data.x86_model == guest_cpuid_model(vcpu);
 139 }
 140
 141 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu)
 142 {
 143         struct kvm_cpuid_entry2 *best;
 144
 145         best = kvm_find_cpuid_entry(vcpu, 0x1);
 146         if (!best)
 147                 return -1;
 148
 149         return x86_stepping(best->eax);
 150 }
 151
 152 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu)
 153 {
 154         return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT;
 155 }
 156
 157 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu)
 158 {
 159         return vcpu->arch.msr_misc_features_enables &
 160                   MSR_MISC_FEATURES_ENABLES_CPUID_FAULT;
 161 }
 162
 163 static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature)
 164 {
 165         unsigned int x86_leaf = __feature_leaf(x86_feature);
 166
 167         kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
 168 }
 169
 170 static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature)
 171 {
 172         unsigned int x86_leaf = __feature_leaf(x86_feature);
 173
 174         kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
 175 }
 176
 177 static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature)
 178 {
 179         unsigned int x86_leaf = __feature_leaf(x86_feature);
 180
 181         return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature);
 182 }
 183
 184 static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature)
 185 {
 186         return !!kvm_cpu_cap_get(x86_feature);
 187 }
 188
 189 static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature)
 190 {
 191         if (boot_cpu_has(x86_feature))
 192                 kvm_cpu_cap_set(x86_feature);
 193 }
 194
 195 static __always_inline bool guest_pv_has(struct kvm_vcpu *vcpu,
 196                                          unsigned int kvm_feature)
 197 {
 198         if (!vcpu->arch.pv_cpuid.enforce)
 199                 return true;
 200
 201         return vcpu->arch.pv_cpuid.features & (1u << kvm_feature);
 202 }
 203
 204 static __always_inline void guest_cpu_cap_set(struct kvm_vcpu *vcpu,
 205                                               unsigned int x86_feature)
 206 {
 207         unsigned int x86_leaf = __feature_leaf(x86_feature);
 208
 209         vcpu->arch.cpu_caps[x86_leaf] |= __feature_bit(x86_feature);
 210 }
 211
 212 static __always_inline void guest_cpu_cap_clear(struct kvm_vcpu *vcpu,
 213                                                 unsigned int x86_feature)
 214 {
 215         unsigned int x86_leaf = __feature_leaf(x86_feature);
 216
 217         vcpu->arch.cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature);
 218 }
 219
 220 static __always_inline void guest_cpu_cap_change(struct kvm_vcpu *vcpu,
 221                                                  unsigned int x86_feature,
 222                                                  bool guest_has_cap)
 223 {
 224         if (guest_has_cap)
 225                 guest_cpu_cap_set(vcpu, x86_feature);
 226         else
 227                 guest_cpu_cap_clear(vcpu, x86_feature);
 228 }
 229
 230 static __always_inline bool guest_cpu_cap_has(struct kvm_vcpu *vcpu,
 231                                               unsigned int x86_feature)
 232 {
 233         unsigned int x86_leaf = __feature_leaf(x86_feature);
 234
 235         return vcpu->arch.cpu_caps[x86_leaf] & __feature_bit(x86_feature);
 236 }
 237
 238 static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
 239 {
 240         if (guest_cpu_cap_has(vcpu, X86_FEATURE_LAM))
 241                 cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57);
 242
 243         return kvm_vcpu_is_legal_gpa(vcpu, cr3);
 244 }
 245
 246 static inline bool guest_has_spec_ctrl_msr(struct kvm_vcpu *vcpu)
 247 {
 248         return (guest_cpu_cap_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
 249                 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_STIBP) ||
 250                 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_IBRS) ||
 251                 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_SSBD));
 252 }
 253
 254 static inline bool guest_has_pred_cmd_msr(struct kvm_vcpu *vcpu)
 255 {
 256         return (guest_cpu_cap_has(vcpu, X86_FEATURE_SPEC_CTRL) ||
 257                 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_IBPB) ||
 258                 guest_cpu_cap_has(vcpu, X86_FEATURE_SBPB));
 259 }
 260
 261 #endif