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 #include "qemu/osdep.h" 11 #include "qemu/error-report.h" 12 #include "tcg/tcg.h" 13 #include "tcg/tcg-op.h" 14 #include "exec/exec-all.h" 15 #include "exec/gen-icount.h" 16 #include "exec/log.h" 17 #include "exec/translator.h" 18 #include "exec/plugin-gen.h" 19 #include "sysemu/replay.h" 20 21 /* Pairs with tcg_clear_temp_count. 22 To be called by #TranslatorOps.{translate_insn,tb_stop} if 23 (1) the target is sufficiently clean to support reporting, 24 (2) as and when all temporaries are known to be consumed. 25 For most targets, (2) is at the end of translate_insn. */ 26 void translator_loop_temp_check(DisasContextBase *db) 27 { 28 if (tcg_check_temp_count()) { 29 qemu_log("warning: TCG temporary leaks before " 30 TARGET_FMT_lx "\n", db->pc_next); 31 } 32 } 33 34 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest) 35 { 36 /* Suppress goto_tb if requested. */ 37 if (tb_cflags(db->tb) & CF_NO_GOTO_TB) { 38 return false; 39 } 40 41 /* Check for the dest on the same page as the start of the TB. */ 42 return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0; 43 } 44 45 static inline void translator_page_protect(DisasContextBase *dcbase, 46 target_ulong pc) 47 { 48 #ifdef CONFIG_USER_ONLY 49 dcbase->page_protect_end = pc | ~TARGET_PAGE_MASK; 50 page_protect(pc); 51 #endif 52 } 53 54 void translator_loop(const TranslatorOps *ops, DisasContextBase *db, 55 CPUState *cpu, TranslationBlock *tb, int max_insns) 56 { 57 uint32_t cflags = tb_cflags(tb); 58 bool plugin_enabled; 59 60 /* Initialize DisasContext */ 61 db->tb = tb; 62 db->pc_first = tb->pc; 63 db->pc_next = db->pc_first; 64 db->is_jmp = DISAS_NEXT; 65 db->num_insns = 0; 66 db->max_insns = max_insns; 67 db->singlestep_enabled = cflags & CF_SINGLE_STEP; 68 translator_page_protect(db, db->pc_next); 69 70 ops->init_disas_context(db, cpu); 71 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 72 73 /* Reset the temp count so that we can identify leaks */ 74 tcg_clear_temp_count(); 75 76 /* Start translating. */ 77 gen_tb_start(db->tb); 78 ops->tb_start(db, cpu); 79 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 80 81 plugin_enabled = plugin_gen_tb_start(cpu, tb, cflags & CF_MEMI_ONLY); 82 83 while (true) { 84 db->num_insns++; 85 ops->insn_start(db, cpu); 86 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 87 88 if (plugin_enabled) { 89 plugin_gen_insn_start(cpu, db); 90 } 91 92 /* Disassemble one instruction. The translate_insn hook should 93 update db->pc_next and db->is_jmp to indicate what should be 94 done next -- either exiting this loop or locate the start of 95 the next instruction. */ 96 if (db->num_insns == db->max_insns && (cflags & CF_LAST_IO)) { 97 /* Accept I/O on the last instruction. */ 98 gen_io_start(); 99 ops->translate_insn(db, cpu); 100 } else { 101 /* we should only see CF_MEMI_ONLY for io_recompile */ 102 tcg_debug_assert(!(cflags & CF_MEMI_ONLY)); 103 ops->translate_insn(db, cpu); 104 } 105 106 /* Stop translation if translate_insn so indicated. */ 107 if (db->is_jmp != DISAS_NEXT) { 108 break; 109 } 110 111 /* 112 * We can't instrument after instructions that change control 113 * flow although this only really affects post-load operations. 114 */ 115 if (plugin_enabled) { 116 plugin_gen_insn_end(); 117 } 118 119 /* Stop translation if the output buffer is full, 120 or we have executed all of the allowed instructions. */ 121 if (tcg_op_buf_full() || db->num_insns >= db->max_insns) { 122 db->is_jmp = DISAS_TOO_MANY; 123 break; 124 } 125 } 126 127 /* Emit code to exit the TB, as indicated by db->is_jmp. */ 128 ops->tb_stop(db, cpu); 129 gen_tb_end(db->tb, db->num_insns); 130 131 if (plugin_enabled) { 132 plugin_gen_tb_end(cpu); 133 } 134 135 /* The disas_log hook may use these values rather than recompute. */ 136 tb->size = db->pc_next - db->pc_first; 137 tb->icount = db->num_insns; 138 139 #ifdef DEBUG_DISAS 140 if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) 141 && qemu_log_in_addr_range(db->pc_first)) { 142 FILE *logfile = qemu_log_lock(); 143 qemu_log("----------------\n"); 144 ops->disas_log(db, cpu); 145 qemu_log("\n"); 146 qemu_log_unlock(logfile); 147 } 148 #endif 149 } 150 151 static inline void translator_maybe_page_protect(DisasContextBase *dcbase, 152 target_ulong pc, size_t len) 153 { 154 #ifdef CONFIG_USER_ONLY 155 target_ulong end = pc + len - 1; 156 157 if (end > dcbase->page_protect_end) { 158 translator_page_protect(dcbase, end); 159 } 160 #endif 161 } 162 163 #define GEN_TRANSLATOR_LD(fullname, type, load_fn, swap_fn) \ 164 type fullname ## _swap(CPUArchState *env, DisasContextBase *dcbase, \ 165 abi_ptr pc, bool do_swap) \ 166 { \ 167 translator_maybe_page_protect(dcbase, pc, sizeof(type)); \ 168 type ret = load_fn(env, pc); \ 169 if (do_swap) { \ 170 ret = swap_fn(ret); \ 171 } \ 172 plugin_insn_append(pc, &ret, sizeof(ret)); \ 173 return ret; \ 174 } 175 176 FOR_EACH_TRANSLATOR_LD(GEN_TRANSLATOR_LD) 177 178 #undef GEN_TRANSLATOR_LD 179