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 "tcg/tcg.h"
  27
  28
  29 /**
  30  * DisasJumpType:
  31  * @DISAS_NEXT: Next instruction in program order.
  32  * @DISAS_TOO_MANY: Too many instructions translated.
  33  * @DISAS_NORETURN: Following code is dead.
  34  * @DISAS_TARGET_*: Start of target-specific conditions.
  35  *
  36  * What instruction to disassemble next.
  37  */
  38 typedef enum DisasJumpType {
  39     DISAS_NEXT,
  40     DISAS_TOO_MANY,
  41     DISAS_NORETURN,
  42     DISAS_TARGET_0,
  43     DISAS_TARGET_1,
  44     DISAS_TARGET_2,
  45     DISAS_TARGET_3,
  46     DISAS_TARGET_4,
  47     DISAS_TARGET_5,
  48     DISAS_TARGET_6,
  49     DISAS_TARGET_7,
  50     DISAS_TARGET_8,
  51     DISAS_TARGET_9,
  52     DISAS_TARGET_10,
  53     DISAS_TARGET_11,
  54 } DisasJumpType;
  55
  56 /**
  57  * DisasContextBase:
  58  * @tb: Translation block for this disassembly.
  59  * @pc_first: Address of first guest instruction in this TB.
  60  * @pc_next: Address of next guest instruction in this TB (current during
  61  *           disassembly).
  62  * @is_jmp: What instruction to disassemble next.
  63  * @num_insns: Number of translated instructions (including current).
  64  * @max_insns: Maximum number of instructions to be translated in this TB.
  65  * @singlestep_enabled: "Hardware" single stepping enabled.
  66  *
  67  * Architecture-agnostic disassembly context.
  68  */
  69 typedef struct DisasContextBase {
  70     const TranslationBlock *tb;
  71     target_ulong pc_first;
  72     target_ulong pc_next;
  73     DisasJumpType is_jmp;
  74     int num_insns;
  75     int max_insns;
  76     bool singlestep_enabled;
  77 } DisasContextBase;
  78
  79 /**
  80  * TranslatorOps:
  81  * @init_disas_context:
  82  *      Initialize the target-specific portions of DisasContext struct.
  83  *      The generic DisasContextBase has already been initialized.
  84  *
  85  * @tb_start:
  86  *      Emit any code required before the start of the main loop,
  87  *      after the generic gen_tb_start().
  88  *
  89  * @insn_start:
  90  *      Emit the tcg_gen_insn_start opcode.
  91  *
  92  * @translate_insn:
  93  *      Disassemble one instruction and set db->pc_next for the start
  94  *      of the following instruction.  Set db->is_jmp as necessary to
  95  *      terminate the main loop.
  96  *
  97  * @tb_stop:
  98  *      Emit any opcodes required to exit the TB, based on db->is_jmp.
  99  *
 100  * @disas_log:
 101  *      Print instruction disassembly to log.
 102  */
 103 typedef struct TranslatorOps {
 104     void (*init_disas_context)(DisasContextBase *db, CPUState *cpu);
 105     void (*tb_start)(DisasContextBase *db, CPUState *cpu);
 106     void (*insn_start)(DisasContextBase *db, CPUState *cpu);
 107     void (*translate_insn)(DisasContextBase *db, CPUState *cpu);
 108     void (*tb_stop)(DisasContextBase *db, CPUState *cpu);
 109     void (*disas_log)(const DisasContextBase *db, CPUState *cpu);
 110 } TranslatorOps;
 111
 112 /**
 113  * translator_loop:
 114  * @ops: Target-specific operations.
 115  * @db: Disassembly context.
 116  * @cpu: Target vCPU.
 117  * @tb: Translation block.
 118  * @max_insns: Maximum number of insns to translate.
 119  *
 120  * Generic translator loop.
 121  *
 122  * Translation will stop in the following cases (in order):
 123  * - When is_jmp set by #TranslatorOps::breakpoint_check.
 124  *   - set to DISAS_TOO_MANY exits after translating one more insn
 125  *   - set to any other value than DISAS_NEXT exits immediately.
 126  * - When is_jmp set by #TranslatorOps::translate_insn.
 127  *   - set to any value other than DISAS_NEXT exits immediately.
 128  * - When the TCG operation buffer is full.
 129  * - When single-stepping is enabled (system-wide or on the current vCPU).
 130  * - When too many instructions have been translated.
 131  */
 132 void translator_loop(const TranslatorOps *ops, DisasContextBase *db,
 133                      CPUState *cpu, TranslationBlock *tb, int max_insns);
 134
 135 void translator_loop_temp_check(DisasContextBase *db);
 136
 137 /**
 138  * translator_use_goto_tb
 139  * @db: Disassembly context
 140  * @dest: target pc of the goto
 141  *
 142  * Return true if goto_tb is allowed between the current TB
 143  * and the destination PC.
 144  */
 145 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest);
 146
 147 /*
 148  * Translator Load Functions
 149  *
 150  * These are intended to replace the direct usage of the cpu_ld*_code
 151  * functions and are mandatory for front-ends that have been migrated
 152  * to the common translator_loop. These functions are only intended
 153  * to be called from the translation stage and should not be called
 154  * from helper functions. Those functions should be converted to encode
 155  * the relevant information at translation time.
 156  */
 157
 158 #define GEN_TRANSLATOR_LD(fullname, type, load_fn, swap_fn)             \
 159     static inline type                                                  \
 160     fullname ## _swap(CPUArchState *env, abi_ptr pc, bool do_swap)      \
 161     {                                                                   \
 162         type ret = load_fn(env, pc);                                    \
 163         if (do_swap) {                                                  \
 164             ret = swap_fn(ret);                                         \
 165         }                                                               \
 166         plugin_insn_append(&ret, sizeof(ret));                          \
 167         return ret;                                                     \
 168     }                                                                   \
 169                                                                         \
 170     static inline type fullname(CPUArchState *env, abi_ptr pc)          \
 171     {                                                                   \
 172         return fullname ## _swap(env, pc, false);                       \
 173     }
 174
 175 GEN_TRANSLATOR_LD(translator_ldub, uint8_t, cpu_ldub_code, /* no swap */)
 176 GEN_TRANSLATOR_LD(translator_ldsw, int16_t, cpu_ldsw_code, bswap16)
 177 GEN_TRANSLATOR_LD(translator_lduw, uint16_t, cpu_lduw_code, bswap16)
 178 GEN_TRANSLATOR_LD(translator_ldl, uint32_t, cpu_ldl_code, bswap32)
 179 GEN_TRANSLATOR_LD(translator_ldq, uint64_t, cpu_ldq_code, bswap64)
 180 #undef GEN_TRANSLATOR_LD
 181
 182 #endif  /* EXEC__TRANSLATOR_H */