1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef ARCH_X86_KVM_REVERSE_CPUID_H 3 #define ARCH_X86_KVM_REVERSE_CPUID_H 4 5 #include <uapi/asm/kvm.h> 6 #include <asm/cpufeature.h> 7 #include <asm/cpufeatures.h> 8 9 /* 10 * Define a KVM-only feature flag. 11 * 12 * For features that are scattered by cpufeatures.h, __feature_translate() also 13 * needs to be updated to translate the kernel-defined feature into the 14 * KVM-defined feature. 15 * 16 * For features that are 100% KVM-only, i.e. not defined by cpufeatures.h, 17 * forego the intermediate KVM_X86_FEATURE and directly define X86_FEATURE_* so 18 * that X86_FEATURE_* can be used in KVM. No __feature_translate() handling is 19 * needed in this case. 20 */ 21 #define KVM_X86_FEATURE(w, f) ((w)*32 + (f)) 22 23 /* Intel-defined SGX sub-features, CPUID level 0x12 (EAX). */ 24 #define KVM_X86_FEATURE_SGX1 KVM_X86_FEATURE(CPUID_12_EAX, 0) 25 #define KVM_X86_FEATURE_SGX2 KVM_X86_FEATURE(CPUID_12_EAX, 1) 26 #define KVM_X86_FEATURE_SGX_EDECCSSA KVM_X86_FEATURE(CPUID_12_EAX, 11) 27 28 /* Intel-defined sub-features, CPUID level 0x00000007:1 (EDX) */ 29 #define X86_FEATURE_AVX_VNNI_INT8 KVM_X86_FEATURE(CPUID_7_1_EDX, 4) 30 #define X86_FEATURE_AVX_NE_CONVERT KVM_X86_FEATURE(CPUID_7_1_EDX, 5) 31 #define X86_FEATURE_AMX_COMPLEX KVM_X86_FEATURE(CPUID_7_1_EDX, 8) 32 #define X86_FEATURE_AVX_VNNI_INT16 KVM_X86_FEATURE(CPUID_7_1_EDX, 10) 33 #define X86_FEATURE_PREFETCHITI KVM_X86_FEATURE(CPUID_7_1_EDX, 14) 34 #define X86_FEATURE_AVX10 KVM_X86_FEATURE(CPUID_7_1_EDX, 19) 35 36 /* Intel-defined sub-features, CPUID level 0x00000007:2 (EDX) */ 37 #define X86_FEATURE_INTEL_PSFD KVM_X86_FEATURE(CPUID_7_2_EDX, 0) 38 #define X86_FEATURE_IPRED_CTRL KVM_X86_FEATURE(CPUID_7_2_EDX, 1) 39 #define KVM_X86_FEATURE_RRSBA_CTRL KVM_X86_FEATURE(CPUID_7_2_EDX, 2) 40 #define X86_FEATURE_DDPD_U KVM_X86_FEATURE(CPUID_7_2_EDX, 3) 41 #define KVM_X86_FEATURE_BHI_CTRL KVM_X86_FEATURE(CPUID_7_2_EDX, 4) 42 #define X86_FEATURE_MCDT_NO KVM_X86_FEATURE(CPUID_7_2_EDX, 5) 43 44 /* Intel-defined sub-features, CPUID level 0x00000024:0 (EBX) */ 45 #define X86_FEATURE_AVX10_128 KVM_X86_FEATURE(CPUID_24_0_EBX, 16) 46 #define X86_FEATURE_AVX10_256 KVM_X86_FEATURE(CPUID_24_0_EBX, 17) 47 #define X86_FEATURE_AVX10_512 KVM_X86_FEATURE(CPUID_24_0_EBX, 18) 48 49 /* CPUID level 0x80000007 (EDX). */ 50 #define KVM_X86_FEATURE_CONSTANT_TSC KVM_X86_FEATURE(CPUID_8000_0007_EDX, 8) 51 52 /* CPUID level 0x80000022 (EAX) */ 53 #define KVM_X86_FEATURE_PERFMON_V2 KVM_X86_FEATURE(CPUID_8000_0022_EAX, 0) 54 55 /* CPUID level 0x80000021 (ECX) */ 56 #define KVM_X86_FEATURE_TSA_SQ_NO KVM_X86_FEATURE(CPUID_8000_0021_ECX, 1) 57 #define KVM_X86_FEATURE_TSA_L1_NO KVM_X86_FEATURE(CPUID_8000_0021_ECX, 2) 58 59 struct cpuid_reg { 60 u32 function; 61 u32 index; 62 int reg; 63 }; 64 65 static const struct cpuid_reg reverse_cpuid[] = { 66 [CPUID_1_EDX] = { 1, 0, CPUID_EDX}, 67 [CPUID_8000_0001_EDX] = {0x80000001, 0, CPUID_EDX}, 68 [CPUID_8086_0001_EDX] = {0x80860001, 0, CPUID_EDX}, 69 [CPUID_1_ECX] = { 1, 0, CPUID_ECX}, 70 [CPUID_C000_0001_EDX] = {0xc0000001, 0, CPUID_EDX}, 71 [CPUID_8000_0001_ECX] = {0x80000001, 0, CPUID_ECX}, 72 [CPUID_7_0_EBX] = { 7, 0, CPUID_EBX}, 73 [CPUID_D_1_EAX] = { 0xd, 1, CPUID_EAX}, 74 [CPUID_8000_0008_EBX] = {0x80000008, 0, CPUID_EBX}, 75 [CPUID_6_EAX] = { 6, 0, CPUID_EAX}, 76 [CPUID_8000_000A_EDX] = {0x8000000a, 0, CPUID_EDX}, 77 [CPUID_7_ECX] = { 7, 0, CPUID_ECX}, 78 [CPUID_8000_0007_EBX] = {0x80000007, 0, CPUID_EBX}, 79 [CPUID_7_EDX] = { 7, 0, CPUID_EDX}, 80 [CPUID_7_1_EAX] = { 7, 1, CPUID_EAX}, 81 [CPUID_12_EAX] = {0x00000012, 0, CPUID_EAX}, 82 [CPUID_8000_001F_EAX] = {0x8000001f, 0, CPUID_EAX}, 83 [CPUID_7_1_EDX] = { 7, 1, CPUID_EDX}, 84 [CPUID_8000_0007_EDX] = {0x80000007, 0, CPUID_EDX}, 85 [CPUID_8000_0021_EAX] = {0x80000021, 0, CPUID_EAX}, 86 [CPUID_8000_0022_EAX] = {0x80000022, 0, CPUID_EAX}, 87 [CPUID_7_2_EDX] = { 7, 2, CPUID_EDX}, 88 [CPUID_24_0_EBX] = { 0x24, 0, CPUID_EBX}, 89 [CPUID_8000_0021_ECX] = {0x80000021, 0, CPUID_ECX}, 90 }; 91 92 /* 93 * Reverse CPUID and its derivatives can only be used for hardware-defined 94 * feature words, i.e. words whose bits directly correspond to a CPUID leaf. 95 * Retrieving a feature bit or masking guest CPUID from a Linux-defined word 96 * is nonsensical as the bit number/mask is an arbitrary software-defined value 97 * and can't be used by KVM to query/control guest capabilities. And obviously 98 * the leaf being queried must have an entry in the lookup table. 99 */ 100 static __always_inline void reverse_cpuid_check(unsigned int x86_leaf) 101 { 102 BUILD_BUG_ON(NR_CPUID_WORDS != NCAPINTS); 103 BUILD_BUG_ON(x86_leaf == CPUID_LNX_1); 104 BUILD_BUG_ON(x86_leaf == CPUID_LNX_2); 105 BUILD_BUG_ON(x86_leaf == CPUID_LNX_3); 106 BUILD_BUG_ON(x86_leaf == CPUID_LNX_4); 107 BUILD_BUG_ON(x86_leaf == CPUID_LNX_5); 108 BUILD_BUG_ON(x86_leaf >= ARRAY_SIZE(reverse_cpuid)); 109 BUILD_BUG_ON(reverse_cpuid[x86_leaf].function == 0); 110 } 111 112 /* 113 * Translate feature bits that are scattered in the kernel's cpufeatures word 114 * into KVM feature words that align with hardware's definitions. 115 */ 116 static __always_inline u32 __feature_translate(int x86_feature) 117 { 118 #define KVM_X86_TRANSLATE_FEATURE(f) \ 119 case X86_FEATURE_##f: return KVM_X86_FEATURE_##f 120 121 switch (x86_feature) { 122 KVM_X86_TRANSLATE_FEATURE(SGX1); 123 KVM_X86_TRANSLATE_FEATURE(SGX2); 124 KVM_X86_TRANSLATE_FEATURE(SGX_EDECCSSA); 125 KVM_X86_TRANSLATE_FEATURE(CONSTANT_TSC); 126 KVM_X86_TRANSLATE_FEATURE(PERFMON_V2); 127 KVM_X86_TRANSLATE_FEATURE(RRSBA_CTRL); 128 KVM_X86_TRANSLATE_FEATURE(BHI_CTRL); 129 KVM_X86_TRANSLATE_FEATURE(TSA_SQ_NO); 130 KVM_X86_TRANSLATE_FEATURE(TSA_L1_NO); 131 default: 132 return x86_feature; 133 } 134 } 135 136 static __always_inline u32 __feature_leaf(int x86_feature) 137 { 138 u32 x86_leaf = __feature_translate(x86_feature) / 32; 139 140 reverse_cpuid_check(x86_leaf); 141 return x86_leaf; 142 } 143 144 /* 145 * Retrieve the bit mask from an X86_FEATURE_* definition. Features contain 146 * the hardware defined bit number (stored in bits 4:0) and a software defined 147 * "word" (stored in bits 31:5). The word is used to index into arrays of 148 * bit masks that hold the per-cpu feature capabilities, e.g. this_cpu_has(). 149 */ 150 static __always_inline u32 __feature_bit(int x86_feature) 151 { 152 x86_feature = __feature_translate(x86_feature); 153 154 reverse_cpuid_check(x86_feature / 32); 155 return 1 << (x86_feature & 31); 156 } 157 158 #define feature_bit(name) __feature_bit(X86_FEATURE_##name) 159 160 static __always_inline struct cpuid_reg x86_feature_cpuid(unsigned int x86_feature) 161 { 162 unsigned int x86_leaf = __feature_leaf(x86_feature); 163 164 return reverse_cpuid[x86_leaf]; 165 } 166 167 static __always_inline u32 *__cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, 168 u32 reg) 169 { 170 switch (reg) { 171 case CPUID_EAX: 172 return &entry->eax; 173 case CPUID_EBX: 174 return &entry->ebx; 175 case CPUID_ECX: 176 return &entry->ecx; 177 case CPUID_EDX: 178 return &entry->edx; 179 default: 180 BUILD_BUG(); 181 return NULL; 182 } 183 } 184 185 static __always_inline u32 *cpuid_entry_get_reg(struct kvm_cpuid_entry2 *entry, 186 unsigned int x86_feature) 187 { 188 const struct cpuid_reg cpuid = x86_feature_cpuid(x86_feature); 189 190 return __cpuid_entry_get_reg(entry, cpuid.reg); 191 } 192 193 static __always_inline u32 cpuid_entry_get(struct kvm_cpuid_entry2 *entry, 194 unsigned int x86_feature) 195 { 196 u32 *reg = cpuid_entry_get_reg(entry, x86_feature); 197 198 return *reg & __feature_bit(x86_feature); 199 } 200 201 static __always_inline bool cpuid_entry_has(struct kvm_cpuid_entry2 *entry, 202 unsigned int x86_feature) 203 { 204 return cpuid_entry_get(entry, x86_feature); 205 } 206 207 static __always_inline void cpuid_entry_clear(struct kvm_cpuid_entry2 *entry, 208 unsigned int x86_feature) 209 { 210 u32 *reg = cpuid_entry_get_reg(entry, x86_feature); 211 212 *reg &= ~__feature_bit(x86_feature); 213 } 214 215 static __always_inline void cpuid_entry_set(struct kvm_cpuid_entry2 *entry, 216 unsigned int x86_feature) 217 { 218 u32 *reg = cpuid_entry_get_reg(entry, x86_feature); 219 220 *reg |= __feature_bit(x86_feature); 221 } 222 223 static __always_inline void cpuid_entry_change(struct kvm_cpuid_entry2 *entry, 224 unsigned int x86_feature, 225 bool set) 226 { 227 u32 *reg = cpuid_entry_get_reg(entry, x86_feature); 228 229 /* 230 * Open coded instead of using cpuid_entry_{clear,set}() to coerce the 231 * compiler into using CMOV instead of Jcc when possible. 232 */ 233 if (set) 234 *reg |= __feature_bit(x86_feature); 235 else 236 *reg &= ~__feature_bit(x86_feature); 237 } 238 239 #endif /* ARCH_X86_KVM_REVERSE_CPUID_H */ 240