1 /* SPDX-License-Identifier: GPL-2.0 */ 2 /****************************************************************************** 3 * x86_emulate.h 4 * 5 * Generic x86 (32-bit and 64-bit) instruction decoder and emulator. 6 * 7 * Copyright (c) 2005 Keir Fraser 8 * 9 * From: xen-unstable 10676:af9809f51f81a3c43f276f00c81a52ef558afda4 10 */ 11 12 #ifndef _ASM_X86_KVM_X86_EMULATE_H 13 #define _ASM_X86_KVM_X86_EMULATE_H 14 15 #include <asm/desc_defs.h> 16 17 struct x86_emulate_ctxt; 18 enum x86_intercept; 19 enum x86_intercept_stage; 20 21 struct x86_exception { 22 u8 vector; 23 bool error_code_valid; 24 u16 error_code; 25 bool nested_page_fault; 26 u64 address; /* cr2 or nested page fault gpa */ 27 u8 async_page_fault; 28 }; 29 30 /* 31 * This struct is used to carry enough information from the instruction 32 * decoder to main KVM so that a decision can be made whether the 33 * instruction needs to be intercepted or not. 34 */ 35 struct x86_instruction_info { 36 u8 intercept; /* which intercept */ 37 u8 rep_prefix; /* rep prefix? */ 38 u8 modrm_mod; /* mod part of modrm */ 39 u8 modrm_reg; /* index of register used */ 40 u8 modrm_rm; /* rm part of modrm */ 41 u64 src_val; /* value of source operand */ 42 u64 dst_val; /* value of destination operand */ 43 u8 src_bytes; /* size of source operand */ 44 u8 dst_bytes; /* size of destination operand */ 45 u8 ad_bytes; /* size of src/dst address */ 46 u64 next_rip; /* rip following the instruction */ 47 }; 48 49 /* 50 * x86_emulate_ops: 51 * 52 * These operations represent the instruction emulator's interface to memory. 53 * There are two categories of operation: those that act on ordinary memory 54 * regions (*_std), and those that act on memory regions known to require 55 * special treatment or emulation (*_emulated). 56 * 57 * The emulator assumes that an instruction accesses only one 'emulated memory' 58 * location, that this location is the given linear faulting address (cr2), and 59 * that this is one of the instruction's data operands. Instruction fetches and 60 * stack operations are assumed never to access emulated memory. The emulator 61 * automatically deduces which operand of a string-move operation is accessing 62 * emulated memory, and assumes that the other operand accesses normal memory. 63 * 64 * NOTES: 65 * 1. The emulator isn't very smart about emulated vs. standard memory. 66 * 'Emulated memory' access addresses should be checked for sanity. 67 * 'Normal memory' accesses may fault, and the caller must arrange to 68 * detect and handle reentrancy into the emulator via recursive faults. 69 * Accesses may be unaligned and may cross page boundaries. 70 * 2. If the access fails (cannot emulate, or a standard access faults) then 71 * it is up to the memop to propagate the fault to the guest VM via 72 * some out-of-band mechanism, unknown to the emulator. The memop signals 73 * failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will 74 * then immediately bail. 75 * 3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only 76 * cmpxchg8b_emulated need support 8-byte accesses. 77 * 4. The emulator cannot handle 64-bit mode emulation on an x86/32 system. 78 */ 79 /* Access completed successfully: continue emulation as normal. */ 80 #define X86EMUL_CONTINUE 0 81 /* Access is unhandleable: bail from emulation and return error to caller. */ 82 #define X86EMUL_UNHANDLEABLE 1 83 /* Terminate emulation but return success to the caller. */ 84 #define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */ 85 #define X86EMUL_RETRY_INSTR 3 /* retry the instruction for some reason */ 86 #define X86EMUL_CMPXCHG_FAILED 4 /* cmpxchg did not see expected value */ 87 #define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */ 88 #define X86EMUL_INTERCEPTED 6 /* Intercepted by nested VMCB/VMCS */ 89 90 struct x86_emulate_ops { 91 /* 92 * read_gpr: read a general purpose register (rax - r15) 93 * 94 * @reg: gpr number. 95 */ 96 ulong (*read_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg); 97 /* 98 * write_gpr: write a general purpose register (rax - r15) 99 * 100 * @reg: gpr number. 101 * @val: value to write. 102 */ 103 void (*write_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val); 104 /* 105 * read_std: Read bytes of standard (non-emulated/special) memory. 106 * Used for descriptor reading. 107 * @addr: [IN ] Linear address from which to read. 108 * @val: [OUT] Value read from memory, zero-extended to 'u_long'. 109 * @bytes: [IN ] Number of bytes to read from memory. 110 * @system:[IN ] Whether the access is forced to be at CPL0. 111 */ 112 int (*read_std)(struct x86_emulate_ctxt *ctxt, 113 unsigned long addr, void *val, 114 unsigned int bytes, 115 struct x86_exception *fault, bool system); 116 117 /* 118 * read_phys: Read bytes of standard (non-emulated/special) memory. 119 * Used for descriptor reading. 120 * @addr: [IN ] Physical address from which to read. 121 * @val: [OUT] Value read from memory. 122 * @bytes: [IN ] Number of bytes to read from memory. 123 */ 124 int (*read_phys)(struct x86_emulate_ctxt *ctxt, unsigned long addr, 125 void *val, unsigned int bytes); 126 127 /* 128 * write_std: Write bytes of standard (non-emulated/special) memory. 129 * Used for descriptor writing. 130 * @addr: [IN ] Linear address to which to write. 131 * @val: [OUT] Value write to memory, zero-extended to 'u_long'. 132 * @bytes: [IN ] Number of bytes to write to memory. 133 * @system:[IN ] Whether the access is forced to be at CPL0. 134 */ 135 int (*write_std)(struct x86_emulate_ctxt *ctxt, 136 unsigned long addr, void *val, unsigned int bytes, 137 struct x86_exception *fault, bool system); 138 /* 139 * fetch: Read bytes of standard (non-emulated/special) memory. 140 * Used for instruction fetch. 141 * @addr: [IN ] Linear address from which to read. 142 * @val: [OUT] Value read from memory, zero-extended to 'u_long'. 143 * @bytes: [IN ] Number of bytes to read from memory. 144 */ 145 int (*fetch)(struct x86_emulate_ctxt *ctxt, 146 unsigned long addr, void *val, unsigned int bytes, 147 struct x86_exception *fault); 148 149 /* 150 * read_emulated: Read bytes from emulated/special memory area. 151 * @addr: [IN ] Linear address from which to read. 152 * @val: [OUT] Value read from memory, zero-extended to 'u_long'. 153 * @bytes: [IN ] Number of bytes to read from memory. 154 */ 155 int (*read_emulated)(struct x86_emulate_ctxt *ctxt, 156 unsigned long addr, void *val, unsigned int bytes, 157 struct x86_exception *fault); 158 159 /* 160 * write_emulated: Write bytes to emulated/special memory area. 161 * @addr: [IN ] Linear address to which to write. 162 * @val: [IN ] Value to write to memory (low-order bytes used as 163 * required). 164 * @bytes: [IN ] Number of bytes to write to memory. 165 */ 166 int (*write_emulated)(struct x86_emulate_ctxt *ctxt, 167 unsigned long addr, const void *val, 168 unsigned int bytes, 169 struct x86_exception *fault); 170 171 /* 172 * cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an 173 * emulated/special memory area. 174 * @addr: [IN ] Linear address to access. 175 * @old: [IN ] Value expected to be current at @addr. 176 * @new: [IN ] Value to write to @addr. 177 * @bytes: [IN ] Number of bytes to access using CMPXCHG. 178 */ 179 int (*cmpxchg_emulated)(struct x86_emulate_ctxt *ctxt, 180 unsigned long addr, 181 const void *old, 182 const void *new, 183 unsigned int bytes, 184 struct x86_exception *fault); 185 void (*invlpg)(struct x86_emulate_ctxt *ctxt, ulong addr); 186 187 int (*pio_in_emulated)(struct x86_emulate_ctxt *ctxt, 188 int size, unsigned short port, void *val, 189 unsigned int count); 190 191 int (*pio_out_emulated)(struct x86_emulate_ctxt *ctxt, 192 int size, unsigned short port, const void *val, 193 unsigned int count); 194 195 bool (*get_segment)(struct x86_emulate_ctxt *ctxt, u16 *selector, 196 struct desc_struct *desc, u32 *base3, int seg); 197 void (*set_segment)(struct x86_emulate_ctxt *ctxt, u16 selector, 198 struct desc_struct *desc, u32 base3, int seg); 199 unsigned long (*get_cached_segment_base)(struct x86_emulate_ctxt *ctxt, 200 int seg); 201 void (*get_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 202 void (*get_idt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 203 void (*set_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 204 void (*set_idt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 205 ulong (*get_cr)(struct x86_emulate_ctxt *ctxt, int cr); 206 int (*set_cr)(struct x86_emulate_ctxt *ctxt, int cr, ulong val); 207 int (*cpl)(struct x86_emulate_ctxt *ctxt); 208 int (*get_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong *dest); 209 int (*set_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong value); 210 u64 (*get_smbase)(struct x86_emulate_ctxt *ctxt); 211 void (*set_smbase)(struct x86_emulate_ctxt *ctxt, u64 smbase); 212 int (*set_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data); 213 int (*get_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata); 214 int (*check_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc); 215 int (*read_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc, u64 *pdata); 216 void (*halt)(struct x86_emulate_ctxt *ctxt); 217 void (*wbinvd)(struct x86_emulate_ctxt *ctxt); 218 int (*fix_hypercall)(struct x86_emulate_ctxt *ctxt); 219 int (*intercept)(struct x86_emulate_ctxt *ctxt, 220 struct x86_instruction_info *info, 221 enum x86_intercept_stage stage); 222 223 bool (*get_cpuid)(struct x86_emulate_ctxt *ctxt, u32 *eax, u32 *ebx, 224 u32 *ecx, u32 *edx, bool check_limit); 225 void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); 226 227 unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt); 228 void (*set_hflags)(struct x86_emulate_ctxt *ctxt, unsigned hflags); 229 int (*pre_leave_smm)(struct x86_emulate_ctxt *ctxt, 230 const char *smstate); 231 void (*post_leave_smm)(struct x86_emulate_ctxt *ctxt); 232 int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); 233 }; 234 235 typedef u32 __attribute__((vector_size(16))) sse128_t; 236 237 /* Type, address-of, and value of an instruction's operand. */ 238 struct operand { 239 enum { OP_REG, OP_MEM, OP_MEM_STR, OP_IMM, OP_XMM, OP_MM, OP_NONE } type; 240 unsigned int bytes; 241 unsigned int count; 242 union { 243 unsigned long orig_val; 244 u64 orig_val64; 245 }; 246 union { 247 unsigned long *reg; 248 struct segmented_address { 249 ulong ea; 250 unsigned seg; 251 } mem; 252 unsigned xmm; 253 unsigned mm; 254 } addr; 255 union { 256 unsigned long val; 257 u64 val64; 258 char valptr[sizeof(sse128_t)]; 259 sse128_t vec_val; 260 u64 mm_val; 261 void *data; 262 }; 263 }; 264 265 struct fetch_cache { 266 u8 data[15]; 267 u8 *ptr; 268 u8 *end; 269 }; 270 271 struct read_cache { 272 u8 data[1024]; 273 unsigned long pos; 274 unsigned long end; 275 }; 276 277 /* Execution mode, passed to the emulator. */ 278 enum x86emul_mode { 279 X86EMUL_MODE_REAL, /* Real mode. */ 280 X86EMUL_MODE_VM86, /* Virtual 8086 mode. */ 281 X86EMUL_MODE_PROT16, /* 16-bit protected mode. */ 282 X86EMUL_MODE_PROT32, /* 32-bit protected mode. */ 283 X86EMUL_MODE_PROT64, /* 64-bit (long) mode. */ 284 }; 285 286 /* These match some of the HF_* flags defined in kvm_host.h */ 287 #define X86EMUL_GUEST_MASK (1 << 5) /* VCPU is in guest-mode */ 288 #define X86EMUL_SMM_MASK (1 << 6) 289 #define X86EMUL_SMM_INSIDE_NMI_MASK (1 << 7) 290 291 struct x86_emulate_ctxt { 292 const struct x86_emulate_ops *ops; 293 294 /* Register state before/after emulation. */ 295 unsigned long eflags; 296 unsigned long eip; /* eip before instruction emulation */ 297 /* Emulated execution mode, represented by an X86EMUL_MODE value. */ 298 enum x86emul_mode mode; 299 300 /* interruptibility state, as a result of execution of STI or MOV SS */ 301 int interruptibility; 302 303 bool perm_ok; /* do not check permissions if true */ 304 bool ud; /* inject an #UD if host doesn't support insn */ 305 bool tf; /* TF value before instruction (after for syscall/sysret) */ 306 307 bool have_exception; 308 struct x86_exception exception; 309 310 /* 311 * decode cache 312 */ 313 314 /* current opcode length in bytes */ 315 u8 opcode_len; 316 u8 b; 317 u8 intercept; 318 u8 op_bytes; 319 u8 ad_bytes; 320 struct operand src; 321 struct operand src2; 322 struct operand dst; 323 int (*execute)(struct x86_emulate_ctxt *ctxt); 324 int (*check_perm)(struct x86_emulate_ctxt *ctxt); 325 /* 326 * The following six fields are cleared together, 327 * the rest are initialized unconditionally in x86_decode_insn 328 * or elsewhere 329 */ 330 bool rip_relative; 331 u8 rex_prefix; 332 u8 lock_prefix; 333 u8 rep_prefix; 334 /* bitmaps of registers in _regs[] that can be read */ 335 u32 regs_valid; 336 /* bitmaps of registers in _regs[] that have been written */ 337 u32 regs_dirty; 338 /* modrm */ 339 u8 modrm; 340 u8 modrm_mod; 341 u8 modrm_reg; 342 u8 modrm_rm; 343 u8 modrm_seg; 344 u8 seg_override; 345 u64 d; 346 unsigned long _eip; 347 struct operand memop; 348 /* Fields above regs are cleared together. */ 349 unsigned long _regs[NR_VCPU_REGS]; 350 struct operand *memopp; 351 struct fetch_cache fetch; 352 struct read_cache io_read; 353 struct read_cache mem_read; 354 }; 355 356 /* Repeat String Operation Prefix */ 357 #define REPE_PREFIX 0xf3 358 #define REPNE_PREFIX 0xf2 359 360 /* CPUID vendors */ 361 #define X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx 0x68747541 362 #define X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx 0x444d4163 363 #define X86EMUL_CPUID_VENDOR_AuthenticAMD_edx 0x69746e65 364 365 #define X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx 0x69444d41 366 #define X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx 0x21726574 367 #define X86EMUL_CPUID_VENDOR_AMDisbetterI_edx 0x74656273 368 369 #define X86EMUL_CPUID_VENDOR_HygonGenuine_ebx 0x6f677948 370 #define X86EMUL_CPUID_VENDOR_HygonGenuine_ecx 0x656e6975 371 #define X86EMUL_CPUID_VENDOR_HygonGenuine_edx 0x6e65476e 372 373 #define X86EMUL_CPUID_VENDOR_GenuineIntel_ebx 0x756e6547 374 #define X86EMUL_CPUID_VENDOR_GenuineIntel_ecx 0x6c65746e 375 #define X86EMUL_CPUID_VENDOR_GenuineIntel_edx 0x49656e69 376 377 enum x86_intercept_stage { 378 X86_ICTP_NONE = 0, /* Allow zero-init to not match anything */ 379 X86_ICPT_PRE_EXCEPT, 380 X86_ICPT_POST_EXCEPT, 381 X86_ICPT_POST_MEMACCESS, 382 }; 383 384 enum x86_intercept { 385 x86_intercept_none, 386 x86_intercept_cr_read, 387 x86_intercept_cr_write, 388 x86_intercept_clts, 389 x86_intercept_lmsw, 390 x86_intercept_smsw, 391 x86_intercept_dr_read, 392 x86_intercept_dr_write, 393 x86_intercept_lidt, 394 x86_intercept_sidt, 395 x86_intercept_lgdt, 396 x86_intercept_sgdt, 397 x86_intercept_lldt, 398 x86_intercept_sldt, 399 x86_intercept_ltr, 400 x86_intercept_str, 401 x86_intercept_rdtsc, 402 x86_intercept_rdpmc, 403 x86_intercept_pushf, 404 x86_intercept_popf, 405 x86_intercept_cpuid, 406 x86_intercept_rsm, 407 x86_intercept_iret, 408 x86_intercept_intn, 409 x86_intercept_invd, 410 x86_intercept_pause, 411 x86_intercept_hlt, 412 x86_intercept_invlpg, 413 x86_intercept_invlpga, 414 x86_intercept_vmrun, 415 x86_intercept_vmload, 416 x86_intercept_vmsave, 417 x86_intercept_vmmcall, 418 x86_intercept_stgi, 419 x86_intercept_clgi, 420 x86_intercept_skinit, 421 x86_intercept_rdtscp, 422 x86_intercept_icebp, 423 x86_intercept_wbinvd, 424 x86_intercept_monitor, 425 x86_intercept_mwait, 426 x86_intercept_rdmsr, 427 x86_intercept_wrmsr, 428 x86_intercept_in, 429 x86_intercept_ins, 430 x86_intercept_out, 431 x86_intercept_outs, 432 x86_intercept_xsetbv, 433 434 nr_x86_intercepts 435 }; 436 437 /* Host execution mode. */ 438 #if defined(CONFIG_X86_32) 439 #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32 440 #elif defined(CONFIG_X86_64) 441 #define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64 442 #endif 443 444 int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len); 445 bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt); 446 #define EMULATION_FAILED -1 447 #define EMULATION_OK 0 448 #define EMULATION_RESTART 1 449 #define EMULATION_INTERCEPTED 2 450 void init_decode_cache(struct x86_emulate_ctxt *ctxt); 451 int x86_emulate_insn(struct x86_emulate_ctxt *ctxt); 452 int emulator_task_switch(struct x86_emulate_ctxt *ctxt, 453 u16 tss_selector, int idt_index, int reason, 454 bool has_error_code, u32 error_code); 455 int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq); 456 void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt); 457 void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt); 458 bool emulator_can_use_gpa(struct x86_emulate_ctxt *ctxt); 459 460 #endif /* _ASM_X86_KVM_X86_EMULATE_H */ 461