1 #ifndef _X86_DESC_H_ 2 #define _X86_DESC_H_ 3 4 /* 5 * selector 32-bit 64-bit 6 * 0x00 NULL descriptor NULL descriptor 7 * 0x08 ring-0 code segment (32-bit) ring-0 code segment (64-bit) 8 * 0x10 ring-0 data segment (32-bit) ring-0 data segment (32/64-bit) 9 * 0x18 ring-0 code segment (P=0) ring-0 code segment (64-bit, P=0) 10 * 0x20 intr_alt_stack TSS ring-0 code segment (32-bit) 11 * 0x28 ring-0 code segment (16-bit) same 12 * 0x30 ring-0 data segment (16-bit) same 13 * 0x38 (0x3b) ring-3 code segment (32-bit) same 14 * 0x40 (0x43) ring-3 data segment (32-bit) ring-3 data segment (32/64-bit) 15 * 0x48 (0x4b) **unused** ring-3 code segment (64-bit) 16 * 0x50-0x78 free to use for test cases same 17 * 0x80-0x870 primary TSS (CPU 0..254) same 18 * 0x878-0x1068 percpu area (CPU 0..254) not used 19 * 20 * Note that the same segment can be used for 32-bit and 64-bit data segments 21 * (the L bit is only defined for code segments) 22 * 23 * Selectors 0x08-0x10 and 0x3b-0x4b are set up for use with the SYSCALL 24 * and SYSRET instructions. 25 */ 26 27 #define KERNEL_CS 0x08 28 #define KERNEL_DS 0x10 29 #define NP_SEL 0x18 30 #ifdef __x86_64__ 31 #define KERNEL_CS32 0x20 32 #else 33 #define TSS_INTR 0x20 34 #endif 35 #define KERNEL_CS16 0x28 36 #define KERNEL_DS16 0x30 37 #define USER_CS32 0x3b 38 #define USER_DS 0x43 39 #ifdef __x86_64__ 40 #define USER_CS64 0x4b 41 #endif 42 43 /* Synonyms */ 44 #define KERNEL_DS32 KERNEL_DS 45 #define USER_DS32 USER_DS 46 47 #ifdef __x86_64__ 48 #define KERNEL_CS64 KERNEL_CS 49 #define USER_CS USER_CS64 50 #define KERNEL_DS64 KERNEL_DS 51 #define USER_DS64 USER_DS 52 #else 53 #define KERNEL_CS32 KERNEL_CS 54 #define USER_CS USER_CS32 55 #endif 56 57 #define FIRST_SPARE_SEL 0x50 58 #define TSS_MAIN 0x80 59 60 #ifdef __ASSEMBLER__ 61 #define __ASM_FORM(x, ...) x,## __VA_ARGS__ 62 #else 63 #define __ASM_FORM(x, ...) " " xstr(x,##__VA_ARGS__) " " 64 #endif 65 66 #ifndef __x86_64__ 67 #define __ASM_SEL(a,b) __ASM_FORM(a) 68 #else 69 #define __ASM_SEL(a,b) __ASM_FORM(b) 70 #endif 71 72 #ifndef __ASSEMBLER__ 73 74 #include <setjmp.h> 75 76 void setup_idt(void); 77 void load_idt(void); 78 void setup_alt_stack(void); 79 80 struct ex_regs { 81 unsigned long rax, rcx, rdx, rbx; 82 unsigned long dummy, rbp, rsi, rdi; 83 #ifdef __x86_64__ 84 unsigned long r8, r9, r10, r11; 85 unsigned long r12, r13, r14, r15; 86 #endif 87 unsigned long vector; 88 unsigned long error_code; 89 unsigned long rip; 90 unsigned long cs; 91 unsigned long rflags; 92 #ifdef __x86_64__ 93 unsigned long rsp; 94 unsigned long ss; 95 #endif 96 }; 97 98 typedef void (*handler)(struct ex_regs *regs); 99 100 typedef struct { 101 u16 prev; 102 u16 res1; 103 u32 esp0; 104 u16 ss0; 105 u16 res2; 106 u32 esp1; 107 u16 ss1; 108 u16 res3; 109 u32 esp2; 110 u16 ss2; 111 u16 res4; 112 u32 cr3; 113 u32 eip; 114 u32 eflags; 115 u32 eax, ecx, edx, ebx, esp, ebp, esi, edi; 116 u16 es; 117 u16 res5; 118 u16 cs; 119 u16 res6; 120 u16 ss; 121 u16 res7; 122 u16 ds; 123 u16 res8; 124 u16 fs; 125 u16 res9; 126 u16 gs; 127 u16 res10; 128 u16 ldt; 129 u16 res11; 130 u16 t:1; 131 u16 res12:15; 132 u16 iomap_base; 133 } tss32_t; 134 135 typedef struct __attribute__((packed)) { 136 u32 res1; 137 u64 rsp0; 138 u64 rsp1; 139 u64 rsp2; 140 u64 res2; 141 u64 ist1; 142 u64 ist2; 143 u64 ist3; 144 u64 ist4; 145 u64 ist5; 146 u64 ist6; 147 u64 ist7; 148 u64 res3; 149 u16 res4; 150 u16 iomap_base; 151 } tss64_t; 152 153 #define __ASM_TRY(prefix, catch) \ 154 "movl $0, %%gs:4\n\t" \ 155 ".pushsection .data.ex\n\t" \ 156 __ASM_SEL(.long, .quad) " 1111f, " catch "\n\t" \ 157 ".popsection \n\t" \ 158 prefix "\n\t" \ 159 "1111:" 160 161 #define ASM_TRY(catch) __ASM_TRY("", catch) 162 163 /* Forced emulation prefix, used to invoke the emulator unconditionally. */ 164 #define KVM_FEP "ud2; .byte 'k', 'v', 'm';" 165 #define ASM_TRY_FEP(catch) __ASM_TRY(KVM_FEP, catch) 166 167 extern bool is_fep_available; 168 169 typedef struct { 170 unsigned short offset0; 171 unsigned short selector; 172 unsigned short ist : 3; 173 unsigned short : 5; 174 unsigned short type : 4; 175 unsigned short : 1; 176 unsigned short dpl : 2; 177 unsigned short p : 1; 178 unsigned short offset1; 179 #ifdef __x86_64__ 180 unsigned offset2; 181 unsigned reserved; 182 #endif 183 } idt_entry_t; 184 185 typedef struct { 186 uint16_t limit1; 187 uint16_t base1; 188 uint8_t base2; 189 union { 190 uint16_t type_limit_flags; /* Type and limit flags */ 191 struct { 192 uint16_t type:4; 193 uint16_t s:1; 194 uint16_t dpl:2; 195 uint16_t p:1; 196 uint16_t limit2:4; 197 uint16_t avl:1; 198 uint16_t l:1; 199 uint16_t db:1; 200 uint16_t g:1; 201 } __attribute__((__packed__)); 202 } __attribute__((__packed__)); 203 uint8_t base3; 204 } __attribute__((__packed__)) gdt_entry_t; 205 206 #ifdef __x86_64__ 207 struct system_desc64 { 208 gdt_entry_t common; 209 uint32_t base4; 210 uint32_t zero; 211 } __attribute__((__packed__)); 212 #endif 213 214 #define DESC_BUSY 2 215 216 extern idt_entry_t boot_idt[256]; 217 218 #ifndef __x86_64__ 219 extern tss32_t tss[]; 220 extern tss32_t tss_intr; 221 void set_gdt_task_gate(u16 tss_sel, u16 sel); 222 void set_idt_task_gate(int vec, u16 sel); 223 void set_intr_task_gate(int vec, void *fn); 224 void setup_tss32(void); 225 #else 226 extern tss64_t tss[]; 227 #endif 228 extern gdt_entry_t gdt[]; 229 230 unsigned exception_vector(void); 231 unsigned exception_error_code(void); 232 bool exception_rflags_rf(void); 233 void set_desc_entry(idt_entry_t *e, size_t e_sz, void *addr, 234 u16 sel, u16 type, u16 dpl); 235 void set_idt_entry(int vec, void *addr, int dpl); 236 void set_idt_sel(int vec, u16 sel); 237 void set_idt_dpl(int vec, u16 dpl); 238 void set_gdt_entry(int sel, unsigned long base, u32 limit, u8 access, u8 gran); 239 void set_gdt_entry_base(int sel, unsigned long base); 240 void clear_tss_busy(int sel); 241 void load_gdt_tss(size_t tss_offset); 242 void set_intr_alt_stack(int e, void *fn); 243 void print_current_tss_info(void); 244 handler handle_exception(u8 v, handler fn); 245 void unhandled_exception(struct ex_regs *regs, bool cpu); 246 const char* exception_mnemonic(int vector); 247 248 bool test_for_exception(unsigned int ex, void (*trigger_func)(void *data), 249 void *data); 250 void __set_exception_jmpbuf(jmp_buf *addr); 251 #define set_exception_jmpbuf(jmpbuf) \ 252 (setjmp(jmpbuf) ? : (__set_exception_jmpbuf(&(jmpbuf)), 0)) 253 get_idt_addr(idt_entry_t * entry)254 static inline void *get_idt_addr(idt_entry_t *entry) 255 { 256 uintptr_t addr = entry->offset0 | ((u32)entry->offset1 << 16); 257 #ifdef __x86_64__ 258 addr |= (u64)entry->offset2 << 32; 259 #endif 260 return (void *)addr; 261 } 262 263 extern gdt_entry_t *get_gdt_entry(u16 sel); 264 extern gdt_entry_t *get_tss_descr(void); 265 gdt_entry_t *get_ldt_descr(void); 266 267 extern unsigned long get_gdt_entry_base(gdt_entry_t *entry); 268 extern unsigned long get_gdt_entry_limit(gdt_entry_t *entry); 269 270 #define __asm_safe(fep, insn, inputs...) \ 271 ({ \ 272 asm volatile(__ASM_TRY(fep, "1f") \ 273 insn "\n\t" \ 274 "1:\n\t" \ 275 : \ 276 : inputs \ 277 : "memory"); \ 278 exception_vector(); \ 279 }) 280 281 #define asm_safe(insn, inputs...) \ 282 __asm_safe("", insn, inputs) 283 284 #define asm_fep_safe(insn, inputs...) \ 285 __asm_safe_out1(KVM_FEP, insn,, inputs) 286 287 #define __asm_safe_out1(fep, insn, output, inputs...) \ 288 ({ \ 289 asm volatile(__ASM_TRY(fep, "1f") \ 290 insn "\n\t" \ 291 "1:\n\t" \ 292 : output \ 293 : inputs \ 294 : "memory"); \ 295 exception_vector(); \ 296 }) 297 298 #define asm_safe_out1(insn, output, inputs...) \ 299 __asm_safe_out1("", insn, output, inputs) 300 301 #define asm_fep_safe_out1(insn, output, inputs...) \ 302 __asm_safe_out1(KVM_FEP, insn, output, inputs) 303 304 #define __asm_safe_out2(fep, insn, output1, output2, inputs...) \ 305 ({ \ 306 asm volatile(__ASM_TRY(fep, "1f") \ 307 insn "\n\t" \ 308 "1:\n\t" \ 309 : output1, output2 \ 310 : inputs \ 311 : "memory"); \ 312 exception_vector(); \ 313 }) 314 315 #define asm_safe_out2(fep, insn, output1, output2, inputs...) \ 316 __asm_safe_out2("", insn, output1, output2, inputs) 317 318 #define asm_fep_safe_out2(insn, output1, output2, inputs...) \ 319 __asm_safe_out2(KVM_FEP, insn, output1, output2, inputs) 320 321 #define __asm_safe_report(want, insn, inputs...) \ 322 do { \ 323 int vector = asm_safe(insn, inputs); \ 324 \ 325 report(vector == want, "Expected %s on '%s', got %s", \ 326 want ? exception_mnemonic(want) : "SUCCESS", \ 327 insn, \ 328 vector ? exception_mnemonic(vector) : "SUCCESS"); \ 329 } while (0) 330 331 #define asm_safe_report(insn, inputs...) \ 332 __asm_safe_report(0, insn, inputs) 333 334 #define asm_safe_report_ex __asm_safe_report 335 336 337 #endif /* __ASSEMBLER__ */ 338 339 #endif /* _X86_DESC_H_ */ 340