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     int splitwx_enabled;
  42     unsigned long tb_size;
  43 };
  44 typedef struct TCGState TCGState;
  45
  46 #define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg")
  47
  48 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE,
  49                          TYPE_TCG_ACCEL)
  50
  51 /*
  52  * We default to false if we know other options have been enabled
  53  * which are currently incompatible with MTTCG. Otherwise when each
  54  * guest (target) has been updated to support:
  55  *   - atomic instructions
  56  *   - memory ordering primitives (barriers)
  57  * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
  58  *
  59  * Once a guest architecture has been converted to the new primitives
  60  * there are two remaining limitations to check.
  61  *
  62  * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
  63  * - The host must have a stronger memory order than the guest
  64  *
  65  * It may be possible in future to support strong guests on weak hosts
  66  * but that will require tagging all load/stores in a guest with their
  67  * implicit memory order requirements which would likely slow things
  68  * down a lot.
  69  */
  70
  71 static bool check_tcg_memory_orders_compatible(void)
  72 {
  73 #if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
  74     return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
  75 #else
  76     return false;
  77 #endif
  78 }
  79
  80 static bool default_mttcg_enabled(void)
  81 {
  82     if (icount_enabled() || TCG_OVERSIZED_GUEST) {
  83         return false;
  84     } else {
  85 #ifdef TARGET_SUPPORTS_MTTCG
  86         return check_tcg_memory_orders_compatible();
  87 #else
  88         return false;
  89 #endif
  90     }
  91 }
  92
  93 static void tcg_accel_instance_init(Object *obj)
  94 {
  95     TCGState *s = TCG_STATE(obj);
  96
  97     s->mttcg_enabled = default_mttcg_enabled();
  98
  99     /* If debugging enabled, default "auto on", otherwise off. */
 100 #ifdef CONFIG_DEBUG_TCG
 101     s->splitwx_enabled = -1;
 102 #else
 103     s->splitwx_enabled = 0;
 104 #endif
 105 }
 106
 107 bool mttcg_enabled;
 108
 109 static int tcg_init(MachineState *ms)
 110 {
 111     TCGState *s = TCG_STATE(current_accel());
 112
 113     tcg_exec_init(s->tb_size * 1024 * 1024, s->splitwx_enabled);
 114     mttcg_enabled = s->mttcg_enabled;
 115
 116     /*
 117      * Initialize TCG regions
 118      */
 119     tcg_region_init();
 120
 121     if (mttcg_enabled) {
 122         cpus_register_accel(&tcg_cpus_mttcg);
 123     } else if (icount_enabled()) {
 124         cpus_register_accel(&tcg_cpus_icount);
 125     } else {
 126         cpus_register_accel(&tcg_cpus_rr);
 127     }
 128     return 0;
 129 }
 130
 131 static char *tcg_get_thread(Object *obj, Error **errp)
 132 {
 133     TCGState *s = TCG_STATE(obj);
 134
 135     return g_strdup(s->mttcg_enabled ? "multi" : "single");
 136 }
 137
 138 static void tcg_set_thread(Object *obj, const char *value, Error **errp)
 139 {
 140     TCGState *s = TCG_STATE(obj);
 141
 142     if (strcmp(value, "multi") == 0) {
 143         if (TCG_OVERSIZED_GUEST) {
 144             error_setg(errp, "No MTTCG when guest word size > hosts");
 145         } else if (icount_enabled()) {
 146             error_setg(errp, "No MTTCG when icount is enabled");
 147         } else {
 148 #ifndef TARGET_SUPPORTS_MTTCG
 149             warn_report("Guest not yet converted to MTTCG - "
 150                         "you may get unexpected results");
 151 #endif
 152             if (!check_tcg_memory_orders_compatible()) {
 153                 warn_report("Guest expects a stronger memory ordering "
 154                             "than the host provides");
 155                 error_printf("This may cause strange/hard to debug errors\n");
 156             }
 157             s->mttcg_enabled = true;
 158         }
 159     } else if (strcmp(value, "single") == 0) {
 160         s->mttcg_enabled = false;
 161     } else {
 162         error_setg(errp, "Invalid 'thread' setting %s", value);
 163     }
 164 }
 165
 166 static void tcg_get_tb_size(Object *obj, Visitor *v,
 167                             const char *name, void *opaque,
 168                             Error **errp)
 169 {
 170     TCGState *s = TCG_STATE(obj);
 171     uint32_t value = s->tb_size;
 172
 173     visit_type_uint32(v, name, &value, errp);
 174 }
 175
 176 static void tcg_set_tb_size(Object *obj, Visitor *v,
 177                             const char *name, void *opaque,
 178                             Error **errp)
 179 {
 180     TCGState *s = TCG_STATE(obj);
 181     uint32_t value;
 182
 183     if (!visit_type_uint32(v, name, &value, errp)) {
 184         return;
 185     }
 186
 187     s->tb_size = value;
 188 }
 189
 190 static bool tcg_get_splitwx(Object *obj, Error **errp)
 191 {
 192     TCGState *s = TCG_STATE(obj);
 193     return s->splitwx_enabled;
 194 }
 195
 196 static void tcg_set_splitwx(Object *obj, bool value, Error **errp)
 197 {
 198     TCGState *s = TCG_STATE(obj);
 199     s->splitwx_enabled = value;
 200 }
 201
 202 static void tcg_accel_class_init(ObjectClass *oc, void *data)
 203 {
 204     AccelClass *ac = ACCEL_CLASS(oc);
 205     ac->name = "tcg";
 206     ac->init_machine = tcg_init;
 207     ac->allowed = &tcg_allowed;
 208
 209     object_class_property_add_str(oc, "thread",
 210                                   tcg_get_thread,
 211                                   tcg_set_thread);
 212
 213     object_class_property_add(oc, "tb-size", "int",
 214         tcg_get_tb_size, tcg_set_tb_size,
 215         NULL, NULL);
 216     object_class_property_set_description(oc, "tb-size",
 217         "TCG translation block cache size");
 218
 219     object_class_property_add_bool(oc, "split-wx",
 220         tcg_get_splitwx, tcg_set_splitwx);
 221     object_class_property_set_description(oc, "split-wx",
 222         "Map jit pages into separate RW and RX regions");
 223 }
 224
 225 static const TypeInfo tcg_accel_type = {
 226     .name = TYPE_TCG_ACCEL,
 227     .parent = TYPE_ACCEL,
 228     .instance_init = tcg_accel_instance_init,
 229     .class_init = tcg_accel_class_init,
 230     .instance_size = sizeof(TCGState),
 231 };
 232
 233 static void register_accel_types(void)
 234 {
 235     type_register_static(&tcg_accel_type);
 236 }
 237
 238 type_init(register_accel_types);