accel/tcg/tcg-all.c

   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);