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 "exec/replay-core.h" 20 21 bool translator_use_goto_tb(DisasContextBase *db, target_ulong dest) 22 { 23 /* Suppress goto_tb if requested. */ 24 if (tb_cflags(db->tb) & CF_NO_GOTO_TB) { 25 return false; 26 } 27 28 /* Check for the dest on the same page as the start of the TB. */ 29 return ((db->pc_first ^ dest) & TARGET_PAGE_MASK) == 0; 30 } 31 32 void translator_loop(CPUState *cpu, TranslationBlock *tb, int *max_insns, 33 target_ulong pc, void *host_pc, 34 const TranslatorOps *ops, DisasContextBase *db) 35 { 36 uint32_t cflags = tb_cflags(tb); 37 bool plugin_enabled; 38 39 /* Initialize DisasContext */ 40 db->tb = tb; 41 db->pc_first = pc; 42 db->pc_next = pc; 43 db->is_jmp = DISAS_NEXT; 44 db->num_insns = 0; 45 db->max_insns = *max_insns; 46 db->singlestep_enabled = cflags & CF_SINGLE_STEP; 47 db->host_addr[0] = host_pc; 48 db->host_addr[1] = NULL; 49 50 #ifdef CONFIG_USER_ONLY 51 page_protect(pc); 52 #endif 53 54 ops->init_disas_context(db, cpu); 55 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 56 57 /* Start translating. */ 58 gen_tb_start(db->tb); 59 ops->tb_start(db, cpu); 60 tcg_debug_assert(db->is_jmp == DISAS_NEXT); /* no early exit */ 61 62 plugin_enabled = plugin_gen_tb_start(cpu, db, cflags & CF_MEMI_ONLY); 63 64 while (true) { 65 *max_insns = ++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 /* Disassemble one instruction. The translate_insn hook should 74 update db->pc_next and db->is_jmp to indicate what should be 75 done next -- either exiting this loop or locate the start of 76 the next instruction. */ 77 if (db->num_insns == db->max_insns && (cflags & CF_LAST_IO)) { 78 /* Accept I/O on the last instruction. */ 79 gen_io_start(); 80 ops->translate_insn(db, cpu); 81 } else { 82 /* we should only see CF_MEMI_ONLY for io_recompile */ 83 tcg_debug_assert(!(cflags & CF_MEMI_ONLY)); 84 ops->translate_insn(db, cpu); 85 } 86 87 /* 88 * We can't instrument after instructions that change control 89 * flow although this only really affects post-load operations. 90 * 91 * Calling plugin_gen_insn_end() before we possibly stop translation 92 * is important. Even if this ends up as dead code, plugin generation 93 * needs to see a matching plugin_gen_insn_{start,end}() pair in order 94 * to accurately track instrumented helpers that might access memory. 95 */ 96 if (plugin_enabled) { 97 plugin_gen_insn_end(); 98 } 99 100 /* Stop translation if translate_insn so indicated. */ 101 if (db->is_jmp != DISAS_NEXT) { 102 break; 103 } 104 105 /* Stop translation if the output buffer is full, 106 or we have executed all of the allowed instructions. */ 107 if (tcg_op_buf_full() || db->num_insns >= db->max_insns) { 108 db->is_jmp = DISAS_TOO_MANY; 109 break; 110 } 111 } 112 113 /* Emit code to exit the TB, as indicated by db->is_jmp. */ 114 ops->tb_stop(db, cpu); 115 gen_tb_end(db->tb, db->num_insns); 116 117 if (plugin_enabled) { 118 plugin_gen_tb_end(cpu); 119 } 120 121 /* The disas_log hook may use these values rather than recompute. */ 122 tb->size = db->pc_next - db->pc_first; 123 tb->icount = db->num_insns; 124 125 #ifdef DEBUG_DISAS 126 if (qemu_loglevel_mask(CPU_LOG_TB_IN_ASM) 127 && qemu_log_in_addr_range(db->pc_first)) { 128 FILE *logfile = qemu_log_trylock(); 129 if (logfile) { 130 fprintf(logfile, "----------------\n"); 131 ops->disas_log(db, cpu, logfile); 132 fprintf(logfile, "\n"); 133 qemu_log_unlock(logfile); 134 } 135 } 136 #endif 137 } 138 139 static void *translator_access(CPUArchState *env, DisasContextBase *db, 140 target_ulong pc, size_t len) 141 { 142 void *host; 143 target_ulong base, end; 144 TranslationBlock *tb; 145 146 tb = db->tb; 147 148 /* Use slow path if first page is MMIO. */ 149 if (unlikely(tb_page_addr0(tb) == -1)) { 150 return NULL; 151 } 152 153 end = pc + len - 1; 154 if (likely(is_same_page(db, end))) { 155 host = db->host_addr[0]; 156 base = db->pc_first; 157 } else { 158 host = db->host_addr[1]; 159 base = TARGET_PAGE_ALIGN(db->pc_first); 160 if (host == NULL) { 161 tb_page_addr_t phys_page = 162 get_page_addr_code_hostp(env, base, &db->host_addr[1]); 163 164 /* 165 * If the second page is MMIO, treat as if the first page 166 * was MMIO as well, so that we do not cache the TB. 167 */ 168 if (unlikely(phys_page == -1)) { 169 tb_set_page_addr0(tb, -1); 170 return NULL; 171 } 172 173 tb_set_page_addr1(tb, phys_page); 174 #ifdef CONFIG_USER_ONLY 175 page_protect(end); 176 #endif 177 host = db->host_addr[1]; 178 } 179 180 /* Use slow path when crossing pages. */ 181 if (is_same_page(db, pc)) { 182 return NULL; 183 } 184 } 185 186 tcg_debug_assert(pc >= base); 187 return host + (pc - base); 188 } 189 190 uint8_t translator_ldub(CPUArchState *env, DisasContextBase *db, abi_ptr pc) 191 { 192 uint8_t ret; 193 void *p = translator_access(env, db, pc, sizeof(ret)); 194 195 if (p) { 196 plugin_insn_append(pc, p, sizeof(ret)); 197 return ldub_p(p); 198 } 199 ret = cpu_ldub_code(env, pc); 200 plugin_insn_append(pc, &ret, sizeof(ret)); 201 return ret; 202 } 203 204 uint16_t translator_lduw(CPUArchState *env, DisasContextBase *db, abi_ptr pc) 205 { 206 uint16_t ret, plug; 207 void *p = translator_access(env, db, pc, sizeof(ret)); 208 209 if (p) { 210 plugin_insn_append(pc, p, sizeof(ret)); 211 return lduw_p(p); 212 } 213 ret = cpu_lduw_code(env, pc); 214 plug = tswap16(ret); 215 plugin_insn_append(pc, &plug, sizeof(ret)); 216 return ret; 217 } 218 219 uint32_t translator_ldl(CPUArchState *env, DisasContextBase *db, abi_ptr pc) 220 { 221 uint32_t ret, plug; 222 void *p = translator_access(env, db, pc, sizeof(ret)); 223 224 if (p) { 225 plugin_insn_append(pc, p, sizeof(ret)); 226 return ldl_p(p); 227 } 228 ret = cpu_ldl_code(env, pc); 229 plug = tswap32(ret); 230 plugin_insn_append(pc, &plug, sizeof(ret)); 231 return ret; 232 } 233 234 uint64_t translator_ldq(CPUArchState *env, DisasContextBase *db, abi_ptr pc) 235 { 236 uint64_t ret, plug; 237 void *p = translator_access(env, db, pc, sizeof(ret)); 238 239 if (p) { 240 plugin_insn_append(pc, p, sizeof(ret)); 241 return ldq_p(p); 242 } 243 ret = cpu_ldq_code(env, pc); 244 plug = tswap64(ret); 245 plugin_insn_append(pc, &plug, sizeof(ret)); 246 return ret; 247 } 248