include/exec/translator.h

   1 /*
   2  * Generic intermediate code generation.
   3  *
   4  * Copyright (C) 2016-2017 Lluís Vilanova <vilanova@ac.upc.edu>
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  */
   9
  10 #ifndef EXEC__TRANSLATOR_H
  11 #define EXEC__TRANSLATOR_H
  12
  13 /*
  14  * Include this header from a target-specific file, and add a
  15  *
  16  *     DisasContextBase base;
  17  *
  18  * member in your target-specific DisasContext.
  19  */
  20
  21
  22 #include "qemu/bswap.h"
  23 #include "exec/exec-all.h"
  24 #include "exec/cpu_ldst.h"
  25 #include "exec/plugin-gen.h"
  26 #include "exec/translate-all.h"
  27 #include "tcg/tcg.h"
  28
  29
  30 /**
  31  * DisasJumpType:
  32  * @DISAS_NEXT: Next instruction in program order.
  33  * @DISAS_TOO_MANY: Too many instructions translated.
  34  * @DISAS_NORETURN: Following code is dead.
  35  * @DISAS_TARGET_*: Start of target-specific conditions.
  36  *
  37  * What instruction to disassemble next.
  38  */
  39 typedef enum DisasJumpType {
  40     DISAS_NEXT,
  41     DISAS_TOO_MANY,
  42     DISAS_NORETURN,
  43     DISAS_TARGET_0,
  44     DISAS_TARGET_1,
  45     DISAS_TARGET_2,
  46     DISAS_TARGET_3,
  47     DISAS_TARGET_4,
  48     DISAS_TARGET_5,
  49     DISAS_TARGET_6,
  50     DISAS_TARGET_7,
  51     DISAS_TARGET_8,
  52     DISAS_TARGET_9,
  53     DISAS_TARGET_10,
  54     DISAS_TARGET_11,
  55 } DisasJumpType;
  56
  57 /**
  58  * DisasContextBase:
  59  * @tb: Translation block for this disassembly.
  60  * @pc_first: Address of first guest instruction in this TB.
  61  * @pc_next: Address of next guest instruction in this TB (current during
  62  *           disassembly).
  63  * @is_jmp: What instruction to disassemble next.
  64  * @num_insns: Number of translated instructions (including current).
  65  * @max_insns: Maximum number of instructions to be translated in this TB.
  66  * @singlestep_enabled: "Hardware" single stepping enabled.
  67  *
  68  * Architecture-agnostic disassembly context.
  69  */
  70 typedef struct DisasContextBase {
  71     const TranslationBlock *tb;
  72     target_ulong pc_first;
  73     target_ulong pc_next;
  74     DisasJumpType is_jmp;
  75     int num_insns;
  76     int max_insns;
  77     bool singlestep_enabled;
  78 #ifdef CONFIG_USER_ONLY
  79     /*
  80      * Guest address of the last byte of the last protected page.
  81      *
  82      * Pages containing the translated instructions are made non-writable in
  83      * order to achieve consistency in case another thread is modifying the
  84      * code while translate_insn() fetches the instruction bytes piecemeal.
  85      * Such writer threads are blocked on mmap_lock() in page_unprotect().
  86      */
  87     target_ulong page_protect_end;
  88 #endif
  89 } DisasContextBase;
  90
  91 /**
  92  * TranslatorOps:
  93  * @init_disas_context:
  94  *      Initialize the target-specific portions of DisasContext struct.
  95  *      The generic DisasContextBase has already been initialized.
  96  *
  97  * @tb_start:
  98  *      Emit any code required before the start of the main loop,
  99  *      after the generic gen_tb_start().
 100  *
 101  * @insn_start:
 102  *      Emit the tcg_gen_insn_start opcode.
 103  *
 104  * @translate_insn:
 105  *      Disassemble one instruction and set db->pc_next for the start
 106  *      of the following instruction.  Set db->is_jmp as necessary to
 107  *      terminate the main loop.
 108  *
 109  * @tb_stop:
 110  *      Emit any opcodes required to exit the TB, based on db->is_jmp.
 111  *
 112  * @disas_log:
 113  *      Print instruction disassembly to log.
 114  */
 115 typedef struct TranslatorOps {
 116     void (*init_disas_context)(DisasContextBase *db, CPUState *cpu);
 117     void (*tb_start)(DisasContextBase *db, CPUState *cpu);
 118     void (*insn_start)(DisasContextBase *db, CPUState *cpu);
 119     void (*translate_insn)(DisasContextBase *db, CPUState *cpu);
 120     void (*tb_stop)(DisasContextBase *db, CPUState *cpu);
 121     void (*disas_log)(const DisasContextBase *db, CPUState *cpu);
 122 } TranslatorOps;
 123
 124 /**
 125  * translator_loop:
 126  * @ops: Target-specific operations.
 127  * @db: Disassembly context.
 128  * @cpu: Target vCPU.
 129  * @tb: Translation block.
 130  * @max_insns: Maximum number of insns to translate.
 131  *
 132  * Generic translator loop.
 133  *
 134  * Translation will stop in the following cases (in order):
 135  * - When is_jmp set by #TranslatorOps::breakpoint_check.
 136  *   - set to DISAS_TOO_MANY exits after translating one more insn
 137  *   - set to any other value than DISAS_NEXT exits immediately.
 138  * - When is_jmp set by #TranslatorOps::translate_insn.
 139  *   - set to any value other than DISAS_NEXT exits immediately.
 140  * - When the TCG operation buffer is full.
 141  * - When single-stepping is enabled (system-wide or on the current vCPU).
 142  * - When too many instructions have been translated.
 143  */
 144 void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
 145                      CPUState *cpu, TranslationBlock *tb, int max_insns);
 146
 147 void translator_loop_temp_check(DisasContextBase *db);
 148
 149 /**
 150  * translator_use_goto_tb
 151  * @db: Disassembly context
 152  * @dest: target pc of the goto
 153  *
 154  * Return true if goto_tb is allowed between the current TB
 155  * and the destination PC.
 156  */
 157 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest);
 158
 159 /*
 160  * Translator Load Functions
 161  *
 162  * These are intended to replace the direct usage of the cpu_ld*_code
 163  * functions and are mandatory for front-ends that have been migrated
 164  * to the common translator_loop. These functions are only intended
 165  * to be called from the translation stage and should not be called
 166  * from helper functions. Those functions should be converted to encode
 167  * the relevant information at translation time.
 168  */
 169
 170 #define GEN_TRANSLATOR_LD(fullname, type, load_fn, swap_fn)             \
 171     type fullname ## _swap(CPUArchState *env, DisasContextBase *dcbase, \
 172                            abi_ptr pc, bool do_swap);                   \
 173     static inline type fullname(CPUArchState *env,                      \
 174                                 DisasContextBase *dcbase, abi_ptr pc)   \
 175     {                                                                   \
 176         return fullname ## _swap(env, dcbase, pc, false);               \
 177     }
 178
 179 #define FOR_EACH_TRANSLATOR_LD(F)                                       \
 180     F(translator_ldub, uint8_t, cpu_ldub_code, /* no swap */)           \
 181     F(translator_ldsw, int16_t, cpu_ldsw_code, bswap16)                 \
 182     F(translator_lduw, uint16_t, cpu_lduw_code, bswap16)                \
 183     F(translator_ldl, uint32_t, cpu_ldl_code, bswap32)                  \
 184     F(translator_ldq, uint64_t, cpu_ldq_code, bswap64)
 185
 186 FOR_EACH_TRANSLATOR_LD(GEN_TRANSLATOR_LD)
 187
 188 #undef GEN_TRANSLATOR_LD
 189
 190 #endif  /* EXEC__TRANSLATOR_H */