1 /* 2 * QEMU System Emulator, accelerator interfaces 3 * 4 * Copyright (c) 2003-2008 Fabrice Bellard 5 * Copyright (c) 2014 Red Hat Inc. 6 * 7 * Permission is hereby granted, free of charge, to any person obtaining a copy 8 * of this software and associated documentation files (the "Software"), to deal 9 * in the Software without restriction, including without limitation the rights 10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell 11 * copies of the Software, and to permit persons to whom the Software is 12 * furnished to do so, subject to the following conditions: 13 * 14 * The above copyright notice and this permission notice shall be included in 15 * all copies or substantial portions of the Software. 16 * 17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR 18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, 19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL 20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER 21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, 22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN 23 * THE SOFTWARE. 24 */ 25 26 #include "qemu/osdep.h" 27 #include "sysemu/tcg.h" 28 #include "sysemu/cpu-timers.h" 29 #include "tcg/tcg.h" 30 #include "qapi/error.h" 31 #include "qemu/error-report.h" 32 #include "qemu/accel.h" 33 #include "qapi/qapi-builtin-visit.h" 34 #include "qemu/units.h" 35 #if !defined(CONFIG_USER_ONLY) 36 #include "hw/boards.h" 37 #endif 38 #include "internal.h" 39 40 struct TCGState { 41 AccelState parent_obj; 42 43 bool mttcg_enabled; 44 int splitwx_enabled; 45 unsigned long tb_size; 46 }; 47 typedef struct TCGState TCGState; 48 49 #define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg") 50 51 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE, 52 TYPE_TCG_ACCEL) 53 54 /* 55 * We default to false if we know other options have been enabled 56 * which are currently incompatible with MTTCG. Otherwise when each 57 * guest (target) has been updated to support: 58 * - atomic instructions 59 * - memory ordering primitives (barriers) 60 * they can set the appropriate CONFIG flags in ${target}-softmmu.mak 61 * 62 * Once a guest architecture has been converted to the new primitives 63 * there are two remaining limitations to check. 64 * 65 * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host) 66 * - The host must have a stronger memory order than the guest 67 * 68 * It may be possible in future to support strong guests on weak hosts 69 * but that will require tagging all load/stores in a guest with their 70 * implicit memory order requirements which would likely slow things 71 * down a lot. 72 */ 73 74 static bool check_tcg_memory_orders_compatible(void) 75 { 76 #if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO) 77 return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0; 78 #else 79 return false; 80 #endif 81 } 82 83 static bool default_mttcg_enabled(void) 84 { 85 if (icount_enabled() || TCG_OVERSIZED_GUEST) { 86 return false; 87 } else { 88 #ifdef TARGET_SUPPORTS_MTTCG 89 return check_tcg_memory_orders_compatible(); 90 #else 91 return false; 92 #endif 93 } 94 } 95 96 static void tcg_accel_instance_init(Object *obj) 97 { 98 TCGState *s = TCG_STATE(obj); 99 100 s->mttcg_enabled = default_mttcg_enabled(); 101 102 /* If debugging enabled, default "auto on", otherwise off. */ 103 #if defined(CONFIG_DEBUG_TCG) && !defined(CONFIG_USER_ONLY) 104 s->splitwx_enabled = -1; 105 #else 106 s->splitwx_enabled = 0; 107 #endif 108 } 109 110 bool mttcg_enabled; 111 112 static int tcg_init_machine(MachineState *ms) 113 { 114 TCGState *s = TCG_STATE(current_accel()); 115 #ifdef CONFIG_USER_ONLY 116 unsigned max_cpus = 1; 117 #else 118 unsigned max_cpus = ms->smp.max_cpus; 119 #endif 120 121 tcg_allowed = true; 122 mttcg_enabled = s->mttcg_enabled; 123 124 page_init(); 125 tb_htable_init(); 126 tcg_init(s->tb_size * MiB, s->splitwx_enabled, max_cpus); 127 128 #if defined(CONFIG_SOFTMMU) 129 /* 130 * There's no guest base to take into account, so go ahead and 131 * initialize the prologue now. 132 */ 133 tcg_prologue_init(tcg_ctx); 134 #endif 135 136 return 0; 137 } 138 139 static char *tcg_get_thread(Object *obj, Error **errp) 140 { 141 TCGState *s = TCG_STATE(obj); 142 143 return g_strdup(s->mttcg_enabled ? "multi" : "single"); 144 } 145 146 static void tcg_set_thread(Object *obj, const char *value, Error **errp) 147 { 148 TCGState *s = TCG_STATE(obj); 149 150 if (strcmp(value, "multi") == 0) { 151 if (TCG_OVERSIZED_GUEST) { 152 error_setg(errp, "No MTTCG when guest word size > hosts"); 153 } else if (icount_enabled()) { 154 error_setg(errp, "No MTTCG when icount is enabled"); 155 } else { 156 #ifndef TARGET_SUPPORTS_MTTCG 157 warn_report("Guest not yet converted to MTTCG - " 158 "you may get unexpected results"); 159 #endif 160 if (!check_tcg_memory_orders_compatible()) { 161 warn_report("Guest expects a stronger memory ordering " 162 "than the host provides"); 163 error_printf("This may cause strange/hard to debug errors\n"); 164 } 165 s->mttcg_enabled = true; 166 } 167 } else if (strcmp(value, "single") == 0) { 168 s->mttcg_enabled = false; 169 } else { 170 error_setg(errp, "Invalid 'thread' setting %s", value); 171 } 172 } 173 174 static void tcg_get_tb_size(Object *obj, Visitor *v, 175 const char *name, void *opaque, 176 Error **errp) 177 { 178 TCGState *s = TCG_STATE(obj); 179 uint32_t value = s->tb_size; 180 181 visit_type_uint32(v, name, &value, errp); 182 } 183 184 static void tcg_set_tb_size(Object *obj, Visitor *v, 185 const char *name, void *opaque, 186 Error **errp) 187 { 188 TCGState *s = TCG_STATE(obj); 189 uint32_t value; 190 191 if (!visit_type_uint32(v, name, &value, errp)) { 192 return; 193 } 194 195 s->tb_size = value; 196 } 197 198 static bool tcg_get_splitwx(Object *obj, Error **errp) 199 { 200 TCGState *s = TCG_STATE(obj); 201 return s->splitwx_enabled; 202 } 203 204 static void tcg_set_splitwx(Object *obj, bool value, Error **errp) 205 { 206 TCGState *s = TCG_STATE(obj); 207 s->splitwx_enabled = value; 208 } 209 210 static void tcg_accel_class_init(ObjectClass *oc, void *data) 211 { 212 AccelClass *ac = ACCEL_CLASS(oc); 213 ac->name = "tcg"; 214 ac->init_machine = tcg_init_machine; 215 ac->allowed = &tcg_allowed; 216 217 object_class_property_add_str(oc, "thread", 218 tcg_get_thread, 219 tcg_set_thread); 220 221 object_class_property_add(oc, "tb-size", "int", 222 tcg_get_tb_size, tcg_set_tb_size, 223 NULL, NULL); 224 object_class_property_set_description(oc, "tb-size", 225 "TCG translation block cache size"); 226 227 object_class_property_add_bool(oc, "split-wx", 228 tcg_get_splitwx, tcg_set_splitwx); 229 object_class_property_set_description(oc, "split-wx", 230 "Map jit pages into separate RW and RX regions"); 231 } 232 233 static const TypeInfo tcg_accel_type = { 234 .name = TYPE_TCG_ACCEL, 235 .parent = TYPE_ACCEL, 236 .instance_init = tcg_accel_instance_init, 237 .class_init = tcg_accel_class_init, 238 .instance_size = sizeof(TCGState), 239 }; 240 module_obj(TYPE_TCG_ACCEL); 241 242 static void register_accel_types(void) 243 { 244 type_register_static(&tcg_accel_type); 245 } 246 247 type_init(register_accel_types); 248