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 struct kvm_cpuid_entry2 *kvm_find_cpuid_entry2(struct kvm_cpuid_entry2 *entries, 15 int nent, u32 function, u64 index); 16 /* 17 * Magic value used by KVM when querying userspace-provided CPUID entries and 18 * doesn't care about the CPIUD index because the index of the function in 19 * question is not significant. Note, this magic value must have at least one 20 * bit set in bits[63:32] and must be consumed as a u64 by kvm_find_cpuid_entry2() 21 * to avoid false positives when processing guest CPUID input. 22 * 23 * KVM_CPUID_INDEX_NOT_SIGNIFICANT should never be used directly outside of 24 * kvm_find_cpuid_entry2() and kvm_find_cpuid_entry(). 25 */ 26 #define KVM_CPUID_INDEX_NOT_SIGNIFICANT -1ull 27 28 static inline struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu, 29 u32 function, u32 index) 30 { 31 return kvm_find_cpuid_entry2(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, 32 function, index); 33 } 34 35 static inline struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu, 36 u32 function) 37 { 38 return kvm_find_cpuid_entry2(vcpu->arch.cpuid_entries, vcpu->arch.cpuid_nent, 39 function, KVM_CPUID_INDEX_NOT_SIGNIFICANT); 40 } 41 42 int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid, 43 struct kvm_cpuid_entry2 __user *entries, 44 unsigned int type); 45 int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu, 46 struct kvm_cpuid *cpuid, 47 struct kvm_cpuid_entry __user *entries); 48 int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu, 49 struct kvm_cpuid2 *cpuid, 50 struct kvm_cpuid_entry2 __user *entries); 51 int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu, 52 struct kvm_cpuid2 *cpuid, 53 struct kvm_cpuid_entry2 __user *entries); 54 bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx, 55 u32 *ecx, u32 *edx, bool exact_only); 56 57 void __init kvm_init_xstate_sizes(void); 58 u32 xstate_required_size(u64 xstate_bv, bool compacted); 59 60 int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu); 61 int cpuid_query_maxguestphyaddr(struct kvm_vcpu *vcpu); 62 u64 kvm_vcpu_reserved_gpa_bits_raw(struct kvm_vcpu *vcpu); 63 64 static inline int cpuid_maxphyaddr(struct kvm_vcpu *vcpu) 65 { 66 return vcpu->arch.maxphyaddr; 67 } 68 69 static inline bool kvm_vcpu_is_legal_gpa(struct kvm_vcpu *vcpu, gpa_t gpa) 70 { 71 return !(gpa & vcpu->arch.reserved_gpa_bits); 72 } 73 74 static inline bool kvm_vcpu_is_legal_aligned_gpa(struct kvm_vcpu *vcpu, 75 gpa_t gpa, gpa_t alignment) 76 { 77 return IS_ALIGNED(gpa, alignment) && kvm_vcpu_is_legal_gpa(vcpu, gpa); 78 } 79 80 static inline bool page_address_valid(struct kvm_vcpu *vcpu, gpa_t gpa) 81 { 82 return kvm_vcpu_is_legal_aligned_gpa(vcpu, gpa, PAGE_SIZE); 83 } 84 85 static __always_inline void cpuid_entry_override(struct kvm_cpuid_entry2 *entry, 86 unsigned int leaf) 87 { 88 u32 *reg = cpuid_entry_get_reg(entry, leaf * 32); 89 90 BUILD_BUG_ON(leaf >= ARRAY_SIZE(kvm_cpu_caps)); 91 *reg = kvm_cpu_caps[leaf]; 92 } 93 94 static __always_inline bool guest_cpuid_has(struct kvm_vcpu *vcpu, 95 unsigned int x86_feature) 96 { 97 const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature); 98 struct kvm_cpuid_entry2 *entry; 99 u32 *reg; 100 101 /* 102 * XSAVES is a special snowflake. Due to lack of a dedicated intercept 103 * on SVM, KVM must assume that XSAVES (and thus XRSTORS) is usable by 104 * the guest if the host supports XSAVES and *XSAVE* is exposed to the 105 * guest. Because the guest can execute XSAVES and XRSTORS, i.e. can 106 * indirectly consume XSS, KVM must ensure XSS is zeroed when running 107 * the guest, i.e. must set XSAVES in vCPU capabilities. But to reject 108 * direct XSS reads and writes (to minimize the virtualization hole and 109 * honor userspace's CPUID), KVM needs to check the raw guest CPUID, 110 * not KVM's view of guest capabilities. 111 * 112 * For all other features, guest capabilities are accurate. Expand 113 * this allowlist with extreme vigilance. 114 */ 115 BUILD_BUG_ON(x86_feature != X86_FEATURE_XSAVES); 116 117 entry = kvm_find_cpuid_entry_index(vcpu, cpuid.function, cpuid.index); 118 if (!entry) 119 return NULL; 120 121 reg = __cpuid_entry_get_reg(entry, cpuid.reg); 122 if (!reg) 123 return false; 124 125 return *reg & __feature_bit(x86_feature); 126 } 127 128 static inline bool guest_cpuid_is_amd_compatible(struct kvm_vcpu *vcpu) 129 { 130 return vcpu->arch.is_amd_compatible; 131 } 132 133 static inline bool guest_cpuid_is_intel_compatible(struct kvm_vcpu *vcpu) 134 { 135 return !guest_cpuid_is_amd_compatible(vcpu); 136 } 137 138 static inline int guest_cpuid_family(struct kvm_vcpu *vcpu) 139 { 140 struct kvm_cpuid_entry2 *best; 141 142 best = kvm_find_cpuid_entry(vcpu, 0x1); 143 if (!best) 144 return -1; 145 146 return x86_family(best->eax); 147 } 148 149 static inline int guest_cpuid_model(struct kvm_vcpu *vcpu) 150 { 151 struct kvm_cpuid_entry2 *best; 152 153 best = kvm_find_cpuid_entry(vcpu, 0x1); 154 if (!best) 155 return -1; 156 157 return x86_model(best->eax); 158 } 159 160 static inline bool cpuid_model_is_consistent(struct kvm_vcpu *vcpu) 161 { 162 return boot_cpu_data.x86_model == guest_cpuid_model(vcpu); 163 } 164 165 static inline int guest_cpuid_stepping(struct kvm_vcpu *vcpu) 166 { 167 struct kvm_cpuid_entry2 *best; 168 169 best = kvm_find_cpuid_entry(vcpu, 0x1); 170 if (!best) 171 return -1; 172 173 return x86_stepping(best->eax); 174 } 175 176 static inline bool supports_cpuid_fault(struct kvm_vcpu *vcpu) 177 { 178 return vcpu->arch.msr_platform_info & MSR_PLATFORM_INFO_CPUID_FAULT; 179 } 180 181 static inline bool cpuid_fault_enabled(struct kvm_vcpu *vcpu) 182 { 183 return vcpu->arch.msr_misc_features_enables & 184 MSR_MISC_FEATURES_ENABLES_CPUID_FAULT; 185 } 186 187 static __always_inline void kvm_cpu_cap_clear(unsigned int x86_feature) 188 { 189 unsigned int x86_leaf = __feature_leaf(x86_feature); 190 191 kvm_cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature); 192 } 193 194 static __always_inline void kvm_cpu_cap_set(unsigned int x86_feature) 195 { 196 unsigned int x86_leaf = __feature_leaf(x86_feature); 197 198 kvm_cpu_caps[x86_leaf] |= __feature_bit(x86_feature); 199 } 200 201 static __always_inline u32 kvm_cpu_cap_get(unsigned int x86_feature) 202 { 203 unsigned int x86_leaf = __feature_leaf(x86_feature); 204 205 return kvm_cpu_caps[x86_leaf] & __feature_bit(x86_feature); 206 } 207 208 static __always_inline bool kvm_cpu_cap_has(unsigned int x86_feature) 209 { 210 return !!kvm_cpu_cap_get(x86_feature); 211 } 212 213 static __always_inline void kvm_cpu_cap_check_and_set(unsigned int x86_feature) 214 { 215 if (boot_cpu_has(x86_feature)) 216 kvm_cpu_cap_set(x86_feature); 217 } 218 219 static __always_inline bool guest_pv_has(struct kvm_vcpu *vcpu, 220 unsigned int kvm_feature) 221 { 222 if (!vcpu->arch.pv_cpuid.enforce) 223 return true; 224 225 return vcpu->arch.pv_cpuid.features & (1u << kvm_feature); 226 } 227 228 static __always_inline void guest_cpu_cap_set(struct kvm_vcpu *vcpu, 229 unsigned int x86_feature) 230 { 231 unsigned int x86_leaf = __feature_leaf(x86_feature); 232 233 vcpu->arch.cpu_caps[x86_leaf] |= __feature_bit(x86_feature); 234 } 235 236 static __always_inline void guest_cpu_cap_clear(struct kvm_vcpu *vcpu, 237 unsigned int x86_feature) 238 { 239 unsigned int x86_leaf = __feature_leaf(x86_feature); 240 241 vcpu->arch.cpu_caps[x86_leaf] &= ~__feature_bit(x86_feature); 242 } 243 244 static __always_inline void guest_cpu_cap_change(struct kvm_vcpu *vcpu, 245 unsigned int x86_feature, 246 bool guest_has_cap) 247 { 248 if (guest_has_cap) 249 guest_cpu_cap_set(vcpu, x86_feature); 250 else 251 guest_cpu_cap_clear(vcpu, x86_feature); 252 } 253 254 static __always_inline bool guest_cpu_cap_has(struct kvm_vcpu *vcpu, 255 unsigned int x86_feature) 256 { 257 unsigned int x86_leaf = __feature_leaf(x86_feature); 258 259 /* 260 * Except for MWAIT, querying dynamic feature bits is disallowed, so 261 * that KVM can defer runtime updates until the next CPUID emulation. 262 */ 263 BUILD_BUG_ON(x86_feature == X86_FEATURE_APIC || 264 x86_feature == X86_FEATURE_OSXSAVE || 265 x86_feature == X86_FEATURE_OSPKE); 266 267 return vcpu->arch.cpu_caps[x86_leaf] & __feature_bit(x86_feature); 268 } 269 270 static inline bool kvm_vcpu_is_legal_cr3(struct kvm_vcpu *vcpu, unsigned long cr3) 271 { 272 if (guest_cpu_cap_has(vcpu, X86_FEATURE_LAM)) 273 cr3 &= ~(X86_CR3_LAM_U48 | X86_CR3_LAM_U57); 274 275 return kvm_vcpu_is_legal_gpa(vcpu, cr3); 276 } 277 278 static inline bool guest_has_spec_ctrl_msr(struct kvm_vcpu *vcpu) 279 { 280 return (guest_cpu_cap_has(vcpu, X86_FEATURE_SPEC_CTRL) || 281 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_STIBP) || 282 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_IBRS) || 283 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_SSBD)); 284 } 285 286 static inline bool guest_has_pred_cmd_msr(struct kvm_vcpu *vcpu) 287 { 288 return (guest_cpu_cap_has(vcpu, X86_FEATURE_SPEC_CTRL) || 289 guest_cpu_cap_has(vcpu, X86_FEATURE_AMD_IBPB) || 290 guest_cpu_cap_has(vcpu, X86_FEATURE_SBPB)); 291 } 292 293 #endif 294