qemu

tcg-all.c (7821B)

---

 /*
  * QEMU System Emulator, accelerator interfaces
  *
  * Copyright (c) 2003-2008 Fabrice Bellard
  * Copyright (c) 2014 Red Hat Inc.
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */
 
 #include "qemu/osdep.h"
 #include "sysemu/tcg.h"
 #include "sysemu/replay.h"
 #include "sysemu/cpu-timers.h"
 #include "tcg/tcg.h"
 #include "qapi/error.h"
 #include "qemu/error-report.h"
 #include "qemu/accel.h"
 #include "qapi/qapi-builtin-visit.h"
 #include "qemu/units.h"
 #if !defined(CONFIG_USER_ONLY)
 #include "hw/boards.h"
 #endif
 #include "internal.h"
 
 struct TCGState {
     AccelState parent_obj;
 
     bool mttcg_enabled;
     int splitwx_enabled;
     unsigned long tb_size;
 };
 typedef struct TCGState TCGState;
 
 #define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg")
 
 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE,
                          TYPE_TCG_ACCEL)
 
 /*
  * We default to false if we know other options have been enabled
  * which are currently incompatible with MTTCG. Otherwise when each
  * guest (target) has been updated to support:
  *   - atomic instructions
  *   - memory ordering primitives (barriers)
  * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
  *
  * Once a guest architecture has been converted to the new primitives
  * there are two remaining limitations to check.
  *
  * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
  * - The host must have a stronger memory order than the guest
  *
  * It may be possible in future to support strong guests on weak hosts
  * but that will require tagging all load/stores in a guest with their
  * implicit memory order requirements which would likely slow things
  * down a lot.
  */
 
 static bool check_tcg_memory_orders_compatible(void)
 {
 #if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
     return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
 #else
     return false;
 #endif
 }
 
 static bool default_mttcg_enabled(void)
 {
     if (icount_enabled() || TCG_OVERSIZED_GUEST) {
         return false;
     } else {
 #ifdef TARGET_SUPPORTS_MTTCG
         return check_tcg_memory_orders_compatible();
 #else
         return false;
 #endif
     }
 }
 
 static void tcg_accel_instance_init(Object *obj)
 {
     TCGState *s = TCG_STATE(obj);
 
     s->mttcg_enabled = default_mttcg_enabled();
 
     /* If debugging enabled, default "auto on", otherwise off. */
 #if defined(CONFIG_DEBUG_TCG) && !defined(CONFIG_USER_ONLY)
     s->splitwx_enabled = -1;
 #else
     s->splitwx_enabled = 0;
 #endif
 }
 
 bool mttcg_enabled;
 
 static int tcg_init_machine(MachineState *ms)
 {
     TCGState *s = TCG_STATE(current_accel());
 #ifdef CONFIG_USER_ONLY
     unsigned max_cpus = 1;
 #else
     unsigned max_cpus = ms->smp.max_cpus;
 #endif
 
     tcg_allowed = true;
     mttcg_enabled = s->mttcg_enabled;
 
     page_init();
     tb_htable_init();
     tcg_init(s->tb_size * MiB, s->splitwx_enabled, max_cpus);
 
 #if defined(CONFIG_SOFTMMU)
     /*
      * There's no guest base to take into account, so go ahead and
      * initialize the prologue now.
      */
     tcg_prologue_init(tcg_ctx);
 #endif
 
     return 0;
 }
 
 static char *tcg_get_thread(Object *obj, Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
 
     return g_strdup(s->mttcg_enabled ? "multi" : "single");
 }
 
 static void tcg_set_thread(Object *obj, const char *value, Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
 
     if (strcmp(value, "multi") == 0) {
         if (TCG_OVERSIZED_GUEST) {
             error_setg(errp, "No MTTCG when guest word size > hosts");
         } else if (icount_enabled()) {
             error_setg(errp, "No MTTCG when icount is enabled");
         } else {
 #ifndef TARGET_SUPPORTS_MTTCG
             warn_report("Guest not yet converted to MTTCG - "
                         "you may get unexpected results");
 #endif
             if (!check_tcg_memory_orders_compatible()) {
                 warn_report("Guest expects a stronger memory ordering "
                             "than the host provides");
                 error_printf("This may cause strange/hard to debug errors\n");
             }
             s->mttcg_enabled = true;
         }
     } else if (strcmp(value, "single") == 0) {
         s->mttcg_enabled = false;
     } else {
         error_setg(errp, "Invalid 'thread' setting %s", value);
     }
 }
 
 static void tcg_get_tb_size(Object *obj, Visitor *v,
                             const char *name, void *opaque,
                             Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
     uint32_t value = s->tb_size;
 
     visit_type_uint32(v, name, &value, errp);
 }
 
 static void tcg_set_tb_size(Object *obj, Visitor *v,
                             const char *name, void *opaque,
                             Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
     uint32_t value;
 
     if (!visit_type_uint32(v, name, &value, errp)) {
         return;
     }
 
     s->tb_size = value;
 }
 
 static bool tcg_get_splitwx(Object *obj, Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
     return s->splitwx_enabled;
 }
 
 static void tcg_set_splitwx(Object *obj, bool value, Error **errp)
 {
     TCGState *s = TCG_STATE(obj);
     s->splitwx_enabled = value;
 }
 
 static int tcg_gdbstub_supported_sstep_flags(void)
 {
     /*
      * In replay mode all events will come from the log and can't be
      * suppressed otherwise we would break determinism. However as those
      * events are tied to the number of executed instructions we won't see
      * them occurring every time we single step.
      */
     if (replay_mode != REPLAY_MODE_NONE) {
         return SSTEP_ENABLE;
     } else {
         return SSTEP_ENABLE | SSTEP_NOIRQ | SSTEP_NOTIMER;
     }
 }
 
 static void tcg_accel_class_init(ObjectClass *oc, void *data)
 {
     AccelClass *ac = ACCEL_CLASS(oc);
     ac->name = "tcg";
     ac->init_machine = tcg_init_machine;
     ac->allowed = &tcg_allowed;
     ac->gdbstub_supported_sstep_flags = tcg_gdbstub_supported_sstep_flags;
 
     object_class_property_add_str(oc, "thread",
                                   tcg_get_thread,
                                   tcg_set_thread);
 
     object_class_property_add(oc, "tb-size", "int",
         tcg_get_tb_size, tcg_set_tb_size,
         NULL, NULL);
     object_class_property_set_description(oc, "tb-size",
         "TCG translation block cache size");
 
     object_class_property_add_bool(oc, "split-wx",
         tcg_get_splitwx, tcg_set_splitwx);
     object_class_property_set_description(oc, "split-wx",
         "Map jit pages into separate RW and RX regions");
 }
 
 static const TypeInfo tcg_accel_type = {
     .name = TYPE_TCG_ACCEL,
     .parent = TYPE_ACCEL,
     .instance_init = tcg_accel_instance_init,
     .class_init = tcg_accel_class_init,
     .instance_size = sizeof(TCGState),
 };
 module_obj(TYPE_TCG_ACCEL);
 
 static void register_accel_types(void)
 {
     type_register_static(&tcg_accel_type);
 }
 
 type_init(register_accel_types);