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 "qemu-common.h" 28 #include "sysemu/tcg.h" 29 #include "sysemu/cpu-timers.h" 30 #include "tcg/tcg.h" 31 #include "qapi/error.h" 32 #include "qemu/error-report.h" 33 #include "hw/boards.h" 34 #include "qapi/qapi-builtin-visit.h" 35 #include "tcg-cpus.h" 36 37 struct TCGState { 38 AccelState parent_obj; 39 40 bool mttcg_enabled; 41 unsigned long tb_size; 42 }; 43 typedef struct TCGState TCGState; 44 45 #define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg") 46 47 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE, 48 TYPE_TCG_ACCEL) 49 50 /* 51 * We default to false if we know other options have been enabled 52 * which are currently incompatible with MTTCG. Otherwise when each 53 * guest (target) has been updated to support: 54 * - atomic instructions 55 * - memory ordering primitives (barriers) 56 * they can set the appropriate CONFIG flags in ${target}-softmmu.mak 57 * 58 * Once a guest architecture has been converted to the new primitives 59 * there are two remaining limitations to check. 60 * 61 * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host) 62 * - The host must have a stronger memory order than the guest 63 * 64 * It may be possible in future to support strong guests on weak hosts 65 * but that will require tagging all load/stores in a guest with their 66 * implicit memory order requirements which would likely slow things 67 * down a lot. 68 */ 69 70 static bool check_tcg_memory_orders_compatible(void) 71 { 72 #if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO) 73 return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0; 74 #else 75 return false; 76 #endif 77 } 78 79 static bool default_mttcg_enabled(void) 80 { 81 if (icount_enabled() || TCG_OVERSIZED_GUEST) { 82 return false; 83 } else { 84 #ifdef TARGET_SUPPORTS_MTTCG 85 return check_tcg_memory_orders_compatible(); 86 #else 87 return false; 88 #endif 89 } 90 } 91 92 static void tcg_accel_instance_init(Object *obj) 93 { 94 TCGState *s = TCG_STATE(obj); 95 96 s->mttcg_enabled = default_mttcg_enabled(); 97 } 98 99 bool mttcg_enabled; 100 101 static int tcg_init(MachineState *ms) 102 { 103 TCGState *s = TCG_STATE(current_accel()); 104 105 tcg_exec_init(s->tb_size * 1024 * 1024); 106 mttcg_enabled = s->mttcg_enabled; 107 cpus_register_accel(&tcg_cpus); 108 109 return 0; 110 } 111 112 static char *tcg_get_thread(Object *obj, Error **errp) 113 { 114 TCGState *s = TCG_STATE(obj); 115 116 return g_strdup(s->mttcg_enabled ? "multi" : "single"); 117 } 118 119 static void tcg_set_thread(Object *obj, const char *value, Error **errp) 120 { 121 TCGState *s = TCG_STATE(obj); 122 123 if (strcmp(value, "multi") == 0) { 124 if (TCG_OVERSIZED_GUEST) { 125 error_setg(errp, "No MTTCG when guest word size > hosts"); 126 } else if (icount_enabled()) { 127 error_setg(errp, "No MTTCG when icount is enabled"); 128 } else { 129 #ifndef TARGET_SUPPORTS_MTTCG 130 warn_report("Guest not yet converted to MTTCG - " 131 "you may get unexpected results"); 132 #endif 133 if (!check_tcg_memory_orders_compatible()) { 134 warn_report("Guest expects a stronger memory ordering " 135 "than the host provides"); 136 error_printf("This may cause strange/hard to debug errors\n"); 137 } 138 s->mttcg_enabled = true; 139 } 140 } else if (strcmp(value, "single") == 0) { 141 s->mttcg_enabled = false; 142 } else { 143 error_setg(errp, "Invalid 'thread' setting %s", value); 144 } 145 } 146 147 static void tcg_get_tb_size(Object *obj, Visitor *v, 148 const char *name, void *opaque, 149 Error **errp) 150 { 151 TCGState *s = TCG_STATE(obj); 152 uint32_t value = s->tb_size; 153 154 visit_type_uint32(v, name, &value, errp); 155 } 156 157 static void tcg_set_tb_size(Object *obj, Visitor *v, 158 const char *name, void *opaque, 159 Error **errp) 160 { 161 TCGState *s = TCG_STATE(obj); 162 uint32_t value; 163 164 if (!visit_type_uint32(v, name, &value, errp)) { 165 return; 166 } 167 168 s->tb_size = value; 169 } 170 171 static void tcg_accel_class_init(ObjectClass *oc, void *data) 172 { 173 AccelClass *ac = ACCEL_CLASS(oc); 174 ac->name = "tcg"; 175 ac->init_machine = tcg_init; 176 ac->allowed = &tcg_allowed; 177 178 object_class_property_add_str(oc, "thread", 179 tcg_get_thread, 180 tcg_set_thread); 181 182 object_class_property_add(oc, "tb-size", "int", 183 tcg_get_tb_size, tcg_set_tb_size, 184 NULL, NULL); 185 object_class_property_set_description(oc, "tb-size", 186 "TCG translation block cache size"); 187 188 } 189 190 static const TypeInfo tcg_accel_type = { 191 .name = TYPE_TCG_ACCEL, 192 .parent = TYPE_ACCEL, 193 .instance_init = tcg_accel_instance_init, 194 .class_init = tcg_accel_class_init, 195 .instance_size = sizeof(TCGState), 196 }; 197 198 static void register_accel_types(void) 199 { 200 type_register_static(&tcg_accel_type); 201 } 202 203 type_init(register_accel_types); 204