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 "cpu.h" 13 #include "tcg/tcg.h" 14 #include "tcg/tcg-op.h" 15 #include "exec/exec-all.h" 16 #include "exec/gen-icount.h" 17 #include "exec/log.h" 18 #include "exec/translator.h" 19 #include "exec/plugin-gen.h" 20 #include "sysemu/replay.h" 21 22 /* Pairs with tcg_clear_temp_count. 23 To be called by #TranslatorOps.{translate_insn,tb_stop} if 24 (1) the target is sufficiently clean to support reporting, 25 (2) as and when all temporaries are known to be consumed. 26 For most targets, (2) is at the end of translate_insn. */ 27 void translator_loop_temp_check(DisasContextBase *db) 28 { 29 if (tcg_check_temp_count()) { 30 qemu_log("warning: TCG temporary leaks before " 31 TARGET_FMT_lx "\n", db->pc_next); 32 } 33 } 34 35 void translator_loop(const TranslatorOps *ops, DisasContextBase *db, 36 CPUState *cpu, TranslationBlock *tb, int max_insns) 37 { 38 int bp_insn = 0; 39 bool plugin_enabled; 40 41 /* Initialize DisasContext */ 42 db->tb = tb; 43 db->pc_first = tb->pc; 44 db->pc_next = db->pc_first; 45 db->is_jmp = DISAS_NEXT; 46 db->num_insns = 0; 47 db->max_insns = max_insns; 48 db->singlestep_enabled = cpu->singlestep_enabled; 49 50 ops->init_disas_context(db, cpu); 51 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 52 53 /* Reset the temp count so that we can identify leaks */ 54 tcg_clear_temp_count(); 55 56 /* Start translating. */ 57 gen_tb_start(db->tb); 58 ops->tb_start(db, cpu); 59 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 60 61 plugin_enabled = plugin_gen_tb_start(cpu, tb, 62 tb_cflags(db->tb) & CF_MEMI_ONLY); 63 64 while (true) { 65 db->num_insns++; 66 ops->insn_start(db, cpu); 67 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 68 69 if (plugin_enabled) { 70 plugin_gen_insn_start(cpu, db); 71 } 72 73 /* Pass breakpoint hits to target for further processing */ 74 if (!db->singlestep_enabled 75 && unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) { 76 CPUBreakpoint *bp; 77 QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) { 78 if (bp->pc == db->pc_next) { 79 if (ops->breakpoint_check(db, cpu, bp)) { 80 bp_insn = 1; 81 break; 82 } 83 } 84 } 85 /* The breakpoint_check hook may use DISAS_TOO_MANY to indicate 86 that only one more instruction is to be executed. Otherwise 87 it should use DISAS_NORETURN when generating an exception, 88 but may use a DISAS_TARGET_* value for Something Else. */ 89 if (db->is_jmp > DISAS_TOO_MANY) { 90 break; 91 } 92 } 93 94 /* Disassemble one instruction. The translate_insn hook should 95 update db->pc_next and db->is_jmp to indicate what should be 96 done next -- either exiting this loop or locate the start of 97 the next instruction. */ 98 if (db->num_insns == db->max_insns 99 && (tb_cflags(db->tb) & CF_LAST_IO)) { 100 /* Accept I/O on the last instruction. */ 101 gen_io_start(); 102 ops->translate_insn(db, cpu); 103 } else { 104 /* we should only see CF_MEMI_ONLY for io_recompile */ 105 tcg_debug_assert(!(tb_cflags(db->tb) & CF_MEMI_ONLY)); 106 ops->translate_insn(db, cpu); 107 } 108 109 /* Stop translation if translate_insn so indicated. */ 110 if (db->is_jmp != DISAS_NEXT) { 111 break; 112 } 113 114 /* 115 * We can't instrument after instructions that change control 116 * flow although this only really affects post-load operations. 117 */ 118 if (plugin_enabled) { 119 plugin_gen_insn_end(); 120 } 121 122 /* Stop translation if the output buffer is full, 123 or we have executed all of the allowed instructions. */ 124 if (tcg_op_buf_full() || db->num_insns >= db->max_insns) { 125 db->is_jmp = DISAS_TOO_MANY; 126 break; 127 } 128 } 129 130 /* Emit code to exit the TB, as indicated by db->is_jmp. */ 131 ops->tb_stop(db, cpu); 132 gen_tb_end(db->tb, db->num_insns - bp_insn); 133 134 if (plugin_enabled) { 135 plugin_gen_tb_end(cpu); 136 } 137 138 /* The disas_log hook may use these values rather than recompute. */ 139 tb->size = db->pc_next - db->pc_first; 140 tb->icount = db->num_insns; 141 142 #ifdef DEBUG_DISAS 143 if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) 144 && qemu_log_in_addr_range(db->pc_first)) { 145 FILE *logfile = qemu_log_lock(); 146 qemu_log("----------------\n"); 147 ops->disas_log(db, cpu); 148 qemu_log("\n"); 149 qemu_log_unlock(logfile); 150 } 151 #endif 152 } 153