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 "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);