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 63 while (true) { 64 db->num_insns++; 65 ops->insn_start(db, cpu); 66 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 67 68 if (plugin_enabled) { 69 plugin_gen_insn_start(cpu, db); 70 } 71 72 /* Pass breakpoint hits to target for further processing */ 73 if (!db->singlestep_enabled 74 && unlikely(!QTAILQ_EMPTY(&cpu->breakpoints))) { 75 CPUBreakpoint *bp; 76 QTAILQ_FOREACH(bp, &cpu->breakpoints, entry) { 77 if (bp->pc == db->pc_next) { 78 if (ops->breakpoint_check(db, cpu, bp)) { 79 bp_insn = 1; 80 break; 81 } 82 } 83 } 84 /* The breakpoint_check hook may use DISAS_TOO_MANY to indicate 85 that only one more instruction is to be executed. Otherwise 86 it should use DISAS_NORETURN when generating an exception, 87 but may use a DISAS_TARGET_* value for Something Else. */ 88 if (db->is_jmp > DISAS_TOO_MANY) { 89 break; 90 } 91 } 92 93 /* Disassemble one instruction. The translate_insn hook should 94 update db->pc_next and db->is_jmp to indicate what should be 95 done next -- either exiting this loop or locate the start of 96 the next instruction. */ 97 if (db->num_insns == db->max_insns 98 && (tb_cflags(db->tb) & CF_LAST_IO)) { 99 /* Accept I/O on the last instruction. */ 100 gen_io_start(); 101 ops->translate_insn(db, cpu); 102 } else { 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 - bp_insn); 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 db->tb->size = db->pc_next - db->pc_first; 137 db->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