kvm_emulate.h (17448B)
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#include "fpu.h" 17 18struct x86_emulate_ctxt; 19enum x86_intercept; 20enum x86_intercept_stage; 21 22struct x86_exception { 23 u8 vector; 24 bool error_code_valid; 25 u16 error_code; 26 bool nested_page_fault; 27 u64 address; /* cr2 or nested page fault gpa */ 28 u8 async_page_fault; 29}; 30 31/* 32 * This struct is used to carry enough information from the instruction 33 * decoder to main KVM so that a decision can be made whether the 34 * instruction needs to be intercepted or not. 35 */ 36struct x86_instruction_info { 37 u8 intercept; /* which intercept */ 38 u8 rep_prefix; /* rep prefix? */ 39 u8 modrm_mod; /* mod part of modrm */ 40 u8 modrm_reg; /* index of register used */ 41 u8 modrm_rm; /* rm part of modrm */ 42 u64 src_val; /* value of source operand */ 43 u64 dst_val; /* value of destination operand */ 44 u8 src_bytes; /* size of source operand */ 45 u8 dst_bytes; /* size of destination operand */ 46 u8 ad_bytes; /* size of src/dst address */ 47 u64 next_rip; /* rip following the instruction */ 48}; 49 50/* 51 * x86_emulate_ops: 52 * 53 * These operations represent the instruction emulator's interface to memory. 54 * There are two categories of operation: those that act on ordinary memory 55 * regions (*_std), and those that act on memory regions known to require 56 * special treatment or emulation (*_emulated). 57 * 58 * The emulator assumes that an instruction accesses only one 'emulated memory' 59 * location, that this location is the given linear faulting address (cr2), and 60 * that this is one of the instruction's data operands. Instruction fetches and 61 * stack operations are assumed never to access emulated memory. The emulator 62 * automatically deduces which operand of a string-move operation is accessing 63 * emulated memory, and assumes that the other operand accesses normal memory. 64 * 65 * NOTES: 66 * 1. The emulator isn't very smart about emulated vs. standard memory. 67 * 'Emulated memory' access addresses should be checked for sanity. 68 * 'Normal memory' accesses may fault, and the caller must arrange to 69 * detect and handle reentrancy into the emulator via recursive faults. 70 * Accesses may be unaligned and may cross page boundaries. 71 * 2. If the access fails (cannot emulate, or a standard access faults) then 72 * it is up to the memop to propagate the fault to the guest VM via 73 * some out-of-band mechanism, unknown to the emulator. The memop signals 74 * failure by returning X86EMUL_PROPAGATE_FAULT to the emulator, which will 75 * then immediately bail. 76 * 3. Valid access sizes are 1, 2, 4 and 8 bytes. On x86/32 systems only 77 * cmpxchg8b_emulated need support 8-byte accesses. 78 * 4. The emulator cannot handle 64-bit mode emulation on an x86/32 system. 79 */ 80/* Access completed successfully: continue emulation as normal. */ 81#define X86EMUL_CONTINUE 0 82/* Access is unhandleable: bail from emulation and return error to caller. */ 83#define X86EMUL_UNHANDLEABLE 1 84/* Terminate emulation but return success to the caller. */ 85#define X86EMUL_PROPAGATE_FAULT 2 /* propagate a generated fault to guest */ 86#define X86EMUL_RETRY_INSTR 3 /* retry the instruction for some reason */ 87#define X86EMUL_CMPXCHG_FAILED 4 /* cmpxchg did not see expected value */ 88#define X86EMUL_IO_NEEDED 5 /* IO is needed to complete emulation */ 89#define X86EMUL_INTERCEPTED 6 /* Intercepted by nested VMCB/VMCS */ 90 91struct x86_emulate_ops { 92 /* 93 * read_gpr: read a general purpose register (rax - r15) 94 * 95 * @reg: gpr number. 96 */ 97 ulong (*read_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg); 98 /* 99 * write_gpr: write a general purpose register (rax - r15) 100 * 101 * @reg: gpr number. 102 * @val: value to write. 103 */ 104 void (*write_gpr)(struct x86_emulate_ctxt *ctxt, unsigned reg, ulong val); 105 /* 106 * read_std: Read bytes of standard (non-emulated/special) memory. 107 * Used for descriptor reading. 108 * @addr: [IN ] Linear address from which to read. 109 * @val: [OUT] Value read from memory, zero-extended to 'u_long'. 110 * @bytes: [IN ] Number of bytes to read from memory. 111 * @system:[IN ] Whether the access is forced to be at CPL0. 112 */ 113 int (*read_std)(struct x86_emulate_ctxt *ctxt, 114 unsigned long addr, void *val, 115 unsigned int bytes, 116 struct x86_exception *fault, bool system); 117 118 /* 119 * read_phys: Read bytes of standard (non-emulated/special) memory. 120 * Used for descriptor reading. 121 * @addr: [IN ] Physical address from which to read. 122 * @val: [OUT] Value read from memory. 123 * @bytes: [IN ] Number of bytes to read from memory. 124 */ 125 int (*read_phys)(struct x86_emulate_ctxt *ctxt, unsigned long addr, 126 void *val, unsigned int bytes); 127 128 /* 129 * write_std: Write bytes of standard (non-emulated/special) memory. 130 * Used for descriptor writing. 131 * @addr: [IN ] Linear address to which to write. 132 * @val: [OUT] Value write to memory, zero-extended to 'u_long'. 133 * @bytes: [IN ] Number of bytes to write to memory. 134 * @system:[IN ] Whether the access is forced to be at CPL0. 135 */ 136 int (*write_std)(struct x86_emulate_ctxt *ctxt, 137 unsigned long addr, void *val, unsigned int bytes, 138 struct x86_exception *fault, bool system); 139 /* 140 * fetch: Read bytes of standard (non-emulated/special) memory. 141 * Used for instruction fetch. 142 * @addr: [IN ] Linear address from which to read. 143 * @val: [OUT] Value read from memory, zero-extended to 'u_long'. 144 * @bytes: [IN ] Number of bytes to read from memory. 145 */ 146 int (*fetch)(struct x86_emulate_ctxt *ctxt, 147 unsigned long addr, void *val, unsigned int bytes, 148 struct x86_exception *fault); 149 150 /* 151 * read_emulated: Read bytes from emulated/special memory area. 152 * @addr: [IN ] Linear address from which to read. 153 * @val: [OUT] Value read from memory, zero-extended to 'u_long'. 154 * @bytes: [IN ] Number of bytes to read from memory. 155 */ 156 int (*read_emulated)(struct x86_emulate_ctxt *ctxt, 157 unsigned long addr, void *val, unsigned int bytes, 158 struct x86_exception *fault); 159 160 /* 161 * write_emulated: Write bytes to emulated/special memory area. 162 * @addr: [IN ] Linear address to which to write. 163 * @val: [IN ] Value to write to memory (low-order bytes used as 164 * required). 165 * @bytes: [IN ] Number of bytes to write to memory. 166 */ 167 int (*write_emulated)(struct x86_emulate_ctxt *ctxt, 168 unsigned long addr, const void *val, 169 unsigned int bytes, 170 struct x86_exception *fault); 171 172 /* 173 * cmpxchg_emulated: Emulate an atomic (LOCKed) CMPXCHG operation on an 174 * emulated/special memory area. 175 * @addr: [IN ] Linear address to access. 176 * @old: [IN ] Value expected to be current at @addr. 177 * @new: [IN ] Value to write to @addr. 178 * @bytes: [IN ] Number of bytes to access using CMPXCHG. 179 */ 180 int (*cmpxchg_emulated)(struct x86_emulate_ctxt *ctxt, 181 unsigned long addr, 182 const void *old, 183 const void *new, 184 unsigned int bytes, 185 struct x86_exception *fault); 186 void (*invlpg)(struct x86_emulate_ctxt *ctxt, ulong addr); 187 188 int (*pio_in_emulated)(struct x86_emulate_ctxt *ctxt, 189 int size, unsigned short port, void *val, 190 unsigned int count); 191 192 int (*pio_out_emulated)(struct x86_emulate_ctxt *ctxt, 193 int size, unsigned short port, const void *val, 194 unsigned int count); 195 196 bool (*get_segment)(struct x86_emulate_ctxt *ctxt, u16 *selector, 197 struct desc_struct *desc, u32 *base3, int seg); 198 void (*set_segment)(struct x86_emulate_ctxt *ctxt, u16 selector, 199 struct desc_struct *desc, u32 base3, int seg); 200 unsigned long (*get_cached_segment_base)(struct x86_emulate_ctxt *ctxt, 201 int seg); 202 void (*get_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 203 void (*get_idt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 204 void (*set_gdt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 205 void (*set_idt)(struct x86_emulate_ctxt *ctxt, struct desc_ptr *dt); 206 ulong (*get_cr)(struct x86_emulate_ctxt *ctxt, int cr); 207 int (*set_cr)(struct x86_emulate_ctxt *ctxt, int cr, ulong val); 208 int (*cpl)(struct x86_emulate_ctxt *ctxt); 209 void (*get_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong *dest); 210 int (*set_dr)(struct x86_emulate_ctxt *ctxt, int dr, ulong value); 211 u64 (*get_smbase)(struct x86_emulate_ctxt *ctxt); 212 void (*set_smbase)(struct x86_emulate_ctxt *ctxt, u64 smbase); 213 int (*set_msr_with_filter)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data); 214 int (*get_msr_with_filter)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata); 215 int (*set_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 data); 216 int (*get_msr)(struct x86_emulate_ctxt *ctxt, u32 msr_index, u64 *pdata); 217 int (*check_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc); 218 int (*read_pmc)(struct x86_emulate_ctxt *ctxt, u32 pmc, u64 *pdata); 219 void (*halt)(struct x86_emulate_ctxt *ctxt); 220 void (*wbinvd)(struct x86_emulate_ctxt *ctxt); 221 int (*fix_hypercall)(struct x86_emulate_ctxt *ctxt); 222 int (*intercept)(struct x86_emulate_ctxt *ctxt, 223 struct x86_instruction_info *info, 224 enum x86_intercept_stage stage); 225 226 bool (*get_cpuid)(struct x86_emulate_ctxt *ctxt, u32 *eax, u32 *ebx, 227 u32 *ecx, u32 *edx, bool exact_only); 228 bool (*guest_has_long_mode)(struct x86_emulate_ctxt *ctxt); 229 bool (*guest_has_movbe)(struct x86_emulate_ctxt *ctxt); 230 bool (*guest_has_fxsr)(struct x86_emulate_ctxt *ctxt); 231 bool (*guest_has_rdpid)(struct x86_emulate_ctxt *ctxt); 232 233 void (*set_nmi_mask)(struct x86_emulate_ctxt *ctxt, bool masked); 234 235 unsigned (*get_hflags)(struct x86_emulate_ctxt *ctxt); 236 void (*exiting_smm)(struct x86_emulate_ctxt *ctxt); 237 int (*leave_smm)(struct x86_emulate_ctxt *ctxt, const char *smstate); 238 void (*triple_fault)(struct x86_emulate_ctxt *ctxt); 239 int (*set_xcr)(struct x86_emulate_ctxt *ctxt, u32 index, u64 xcr); 240}; 241 242/* Type, address-of, and value of an instruction's operand. */ 243struct operand { 244 enum { OP_REG, OP_MEM, OP_MEM_STR, OP_IMM, OP_XMM, OP_MM, OP_NONE } type; 245 unsigned int bytes; 246 unsigned int count; 247 union { 248 unsigned long orig_val; 249 u64 orig_val64; 250 }; 251 union { 252 unsigned long *reg; 253 struct segmented_address { 254 ulong ea; 255 unsigned seg; 256 } mem; 257 unsigned xmm; 258 unsigned mm; 259 } addr; 260 union { 261 unsigned long val; 262 u64 val64; 263 char valptr[sizeof(sse128_t)]; 264 sse128_t vec_val; 265 u64 mm_val; 266 void *data; 267 }; 268}; 269 270struct fetch_cache { 271 u8 data[15]; 272 u8 *ptr; 273 u8 *end; 274}; 275 276struct read_cache { 277 u8 data[1024]; 278 unsigned long pos; 279 unsigned long end; 280}; 281 282/* Execution mode, passed to the emulator. */ 283enum x86emul_mode { 284 X86EMUL_MODE_REAL, /* Real mode. */ 285 X86EMUL_MODE_VM86, /* Virtual 8086 mode. */ 286 X86EMUL_MODE_PROT16, /* 16-bit protected mode. */ 287 X86EMUL_MODE_PROT32, /* 32-bit protected mode. */ 288 X86EMUL_MODE_PROT64, /* 64-bit (long) mode. */ 289}; 290 291/* These match some of the HF_* flags defined in kvm_host.h */ 292#define X86EMUL_GUEST_MASK (1 << 5) /* VCPU is in guest-mode */ 293#define X86EMUL_SMM_MASK (1 << 6) 294#define X86EMUL_SMM_INSIDE_NMI_MASK (1 << 7) 295 296/* 297 * fastop functions are declared as taking a never-defined fastop parameter, 298 * so they can't be called from C directly. 299 */ 300struct fastop; 301 302typedef void (*fastop_t)(struct fastop *); 303 304struct x86_emulate_ctxt { 305 void *vcpu; 306 const struct x86_emulate_ops *ops; 307 308 /* Register state before/after emulation. */ 309 unsigned long eflags; 310 unsigned long eip; /* eip before instruction emulation */ 311 /* Emulated execution mode, represented by an X86EMUL_MODE value. */ 312 enum x86emul_mode mode; 313 314 /* interruptibility state, as a result of execution of STI or MOV SS */ 315 int interruptibility; 316 317 bool perm_ok; /* do not check permissions if true */ 318 bool tf; /* TF value before instruction (after for syscall/sysret) */ 319 320 bool have_exception; 321 struct x86_exception exception; 322 323 /* GPA available */ 324 bool gpa_available; 325 gpa_t gpa_val; 326 327 /* 328 * decode cache 329 */ 330 331 /* current opcode length in bytes */ 332 u8 opcode_len; 333 u8 b; 334 u8 intercept; 335 u8 op_bytes; 336 u8 ad_bytes; 337 union { 338 int (*execute)(struct x86_emulate_ctxt *ctxt); 339 fastop_t fop; 340 }; 341 int (*check_perm)(struct x86_emulate_ctxt *ctxt); 342 343 bool rip_relative; 344 u8 rex_prefix; 345 u8 lock_prefix; 346 u8 rep_prefix; 347 /* bitmaps of registers in _regs[] that can be read */ 348 u32 regs_valid; 349 /* bitmaps of registers in _regs[] that have been written */ 350 u32 regs_dirty; 351 /* modrm */ 352 u8 modrm; 353 u8 modrm_mod; 354 u8 modrm_reg; 355 u8 modrm_rm; 356 u8 modrm_seg; 357 u8 seg_override; 358 u64 d; 359 unsigned long _eip; 360 361 /* Here begins the usercopy section. */ 362 struct operand src; 363 struct operand src2; 364 struct operand dst; 365 struct operand memop; 366 unsigned long _regs[NR_VCPU_REGS]; 367 struct operand *memopp; 368 struct fetch_cache fetch; 369 struct read_cache io_read; 370 struct read_cache mem_read; 371 bool is_branch; 372}; 373 374/* Repeat String Operation Prefix */ 375#define REPE_PREFIX 0xf3 376#define REPNE_PREFIX 0xf2 377 378/* CPUID vendors */ 379#define X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx 0x68747541 380#define X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx 0x444d4163 381#define X86EMUL_CPUID_VENDOR_AuthenticAMD_edx 0x69746e65 382 383#define X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx 0x69444d41 384#define X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx 0x21726574 385#define X86EMUL_CPUID_VENDOR_AMDisbetterI_edx 0x74656273 386 387#define X86EMUL_CPUID_VENDOR_HygonGenuine_ebx 0x6f677948 388#define X86EMUL_CPUID_VENDOR_HygonGenuine_ecx 0x656e6975 389#define X86EMUL_CPUID_VENDOR_HygonGenuine_edx 0x6e65476e 390 391#define X86EMUL_CPUID_VENDOR_GenuineIntel_ebx 0x756e6547 392#define X86EMUL_CPUID_VENDOR_GenuineIntel_ecx 0x6c65746e 393#define X86EMUL_CPUID_VENDOR_GenuineIntel_edx 0x49656e69 394 395#define X86EMUL_CPUID_VENDOR_CentaurHauls_ebx 0x746e6543 396#define X86EMUL_CPUID_VENDOR_CentaurHauls_ecx 0x736c7561 397#define X86EMUL_CPUID_VENDOR_CentaurHauls_edx 0x48727561 398 399static inline bool is_guest_vendor_intel(u32 ebx, u32 ecx, u32 edx) 400{ 401 return ebx == X86EMUL_CPUID_VENDOR_GenuineIntel_ebx && 402 ecx == X86EMUL_CPUID_VENDOR_GenuineIntel_ecx && 403 edx == X86EMUL_CPUID_VENDOR_GenuineIntel_edx; 404} 405 406static inline bool is_guest_vendor_amd(u32 ebx, u32 ecx, u32 edx) 407{ 408 return (ebx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ebx && 409 ecx == X86EMUL_CPUID_VENDOR_AuthenticAMD_ecx && 410 edx == X86EMUL_CPUID_VENDOR_AuthenticAMD_edx) || 411 (ebx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ebx && 412 ecx == X86EMUL_CPUID_VENDOR_AMDisbetterI_ecx && 413 edx == X86EMUL_CPUID_VENDOR_AMDisbetterI_edx); 414} 415 416static inline bool is_guest_vendor_hygon(u32 ebx, u32 ecx, u32 edx) 417{ 418 return ebx == X86EMUL_CPUID_VENDOR_HygonGenuine_ebx && 419 ecx == X86EMUL_CPUID_VENDOR_HygonGenuine_ecx && 420 edx == X86EMUL_CPUID_VENDOR_HygonGenuine_edx; 421} 422 423enum x86_intercept_stage { 424 X86_ICTP_NONE = 0, /* Allow zero-init to not match anything */ 425 X86_ICPT_PRE_EXCEPT, 426 X86_ICPT_POST_EXCEPT, 427 X86_ICPT_POST_MEMACCESS, 428}; 429 430enum x86_intercept { 431 x86_intercept_none, 432 x86_intercept_cr_read, 433 x86_intercept_cr_write, 434 x86_intercept_clts, 435 x86_intercept_lmsw, 436 x86_intercept_smsw, 437 x86_intercept_dr_read, 438 x86_intercept_dr_write, 439 x86_intercept_lidt, 440 x86_intercept_sidt, 441 x86_intercept_lgdt, 442 x86_intercept_sgdt, 443 x86_intercept_lldt, 444 x86_intercept_sldt, 445 x86_intercept_ltr, 446 x86_intercept_str, 447 x86_intercept_rdtsc, 448 x86_intercept_rdpmc, 449 x86_intercept_pushf, 450 x86_intercept_popf, 451 x86_intercept_cpuid, 452 x86_intercept_rsm, 453 x86_intercept_iret, 454 x86_intercept_intn, 455 x86_intercept_invd, 456 x86_intercept_pause, 457 x86_intercept_hlt, 458 x86_intercept_invlpg, 459 x86_intercept_invlpga, 460 x86_intercept_vmrun, 461 x86_intercept_vmload, 462 x86_intercept_vmsave, 463 x86_intercept_vmmcall, 464 x86_intercept_stgi, 465 x86_intercept_clgi, 466 x86_intercept_skinit, 467 x86_intercept_rdtscp, 468 x86_intercept_rdpid, 469 x86_intercept_icebp, 470 x86_intercept_wbinvd, 471 x86_intercept_monitor, 472 x86_intercept_mwait, 473 x86_intercept_rdmsr, 474 x86_intercept_wrmsr, 475 x86_intercept_in, 476 x86_intercept_ins, 477 x86_intercept_out, 478 x86_intercept_outs, 479 x86_intercept_xsetbv, 480 481 nr_x86_intercepts 482}; 483 484/* Host execution mode. */ 485#if defined(CONFIG_X86_32) 486#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32 487#elif defined(CONFIG_X86_64) 488#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT64 489#endif 490 491int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len, int emulation_type); 492bool x86_page_table_writing_insn(struct x86_emulate_ctxt *ctxt); 493#define EMULATION_FAILED -1 494#define EMULATION_OK 0 495#define EMULATION_RESTART 1 496#define EMULATION_INTERCEPTED 2 497void init_decode_cache(struct x86_emulate_ctxt *ctxt); 498int x86_emulate_insn(struct x86_emulate_ctxt *ctxt); 499int emulator_task_switch(struct x86_emulate_ctxt *ctxt, 500 u16 tss_selector, int idt_index, int reason, 501 bool has_error_code, u32 error_code); 502int emulate_int_real(struct x86_emulate_ctxt *ctxt, int irq); 503void emulator_invalidate_register_cache(struct x86_emulate_ctxt *ctxt); 504void emulator_writeback_register_cache(struct x86_emulate_ctxt *ctxt); 505bool emulator_can_use_gpa(struct x86_emulate_ctxt *ctxt); 506 507#endif /* _ASM_X86_KVM_X86_EMULATE_H */