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/accel.h"
  28 #include "sysemu/tcg.h"
  29 #include "qom/object.h"
  30 #include "cpu.h"
  31 #include "sysemu/cpus.h"
  32 #include "qemu/main-loop.h"
  33 #include "tcg/tcg.h"
  34 #include "qapi/error.h"
  35 #include "qemu/error-report.h"
  36 #include "hw/boards.h"
  37 #include "qapi/qapi-builtin-visit.h"
  38
  39 struct TCGState {
  40     AccelState parent_obj;
  41
  42     bool mttcg_enabled;
  43     unsigned long tb_size;
  44 };
  45 typedef struct TCGState TCGState;
  46
  47 #define TYPE_TCG_ACCEL ACCEL_CLASS_NAME("tcg")
  48
  49 DECLARE_INSTANCE_CHECKER(TCGState, TCG_STATE,
  50                          TYPE_TCG_ACCEL)
  51
  52 /* mask must never be zero, except for A20 change call */
  53 static void tcg_handle_interrupt(CPUState *cpu, int mask)
  54 {
  55     int old_mask;
  56     g_assert(qemu_mutex_iothread_locked());
  57
  58     old_mask = cpu->interrupt_request;
  59     cpu->interrupt_request |= mask;
  60
  61     /*
  62      * If called from iothread context, wake the target cpu in
  63      * case its halted.
  64      */
  65     if (!qemu_cpu_is_self(cpu)) {
  66         qemu_cpu_kick(cpu);
  67     } else {
  68         qatomic_set(&cpu_neg(cpu)->icount_decr.u16.high, -1);
  69         if (use_icount &&
  70             !cpu->can_do_io
  71             && (mask & ~old_mask) != 0) {
  72             cpu_abort(cpu, "Raised interrupt while not in I/O function");
  73         }
  74     }
  75 }
  76
  77 /*
  78  * We default to false if we know other options have been enabled
  79  * which are currently incompatible with MTTCG. Otherwise when each
  80  * guest (target) has been updated to support:
  81  *   - atomic instructions
  82  *   - memory ordering primitives (barriers)
  83  * they can set the appropriate CONFIG flags in ${target}-softmmu.mak
  84  *
  85  * Once a guest architecture has been converted to the new primitives
  86  * there are two remaining limitations to check.
  87  *
  88  * - The guest can't be oversized (e.g. 64 bit guest on 32 bit host)
  89  * - The host must have a stronger memory order than the guest
  90  *
  91  * It may be possible in future to support strong guests on weak hosts
  92  * but that will require tagging all load/stores in a guest with their
  93  * implicit memory order requirements which would likely slow things
  94  * down a lot.
  95  */
  96
  97 static bool check_tcg_memory_orders_compatible(void)
  98 {
  99 #if defined(TCG_GUEST_DEFAULT_MO) && defined(TCG_TARGET_DEFAULT_MO)
 100     return (TCG_GUEST_DEFAULT_MO & ~TCG_TARGET_DEFAULT_MO) == 0;
 101 #else
 102     return false;
 103 #endif
 104 }
 105
 106 static bool default_mttcg_enabled(void)
 107 {
 108     if (use_icount || TCG_OVERSIZED_GUEST) {
 109         return false;
 110     } else {
 111 #ifdef TARGET_SUPPORTS_MTTCG
 112         return check_tcg_memory_orders_compatible();
 113 #else
 114         return false;
 115 #endif
 116     }
 117 }
 118
 119 static void tcg_accel_instance_init(Object *obj)
 120 {
 121     TCGState *s = TCG_STATE(obj);
 122
 123     s->mttcg_enabled = default_mttcg_enabled();
 124 }
 125
 126 static int tcg_init(MachineState *ms)
 127 {
 128     TCGState *s = TCG_STATE(current_accel());
 129
 130     tcg_exec_init(s->tb_size * 1024 * 1024);
 131     cpu_interrupt_handler = tcg_handle_interrupt;
 132     mttcg_enabled = s->mttcg_enabled;
 133     return 0;
 134 }
 135
 136 static char *tcg_get_thread(Object *obj, Error **errp)
 137 {
 138     TCGState *s = TCG_STATE(obj);
 139
 140     return g_strdup(s->mttcg_enabled ? "multi" : "single");
 141 }
 142
 143 static void tcg_set_thread(Object *obj, const char *value, Error **errp)
 144 {
 145     TCGState *s = TCG_STATE(obj);
 146
 147     if (strcmp(value, "multi") == 0) {
 148         if (TCG_OVERSIZED_GUEST) {
 149             error_setg(errp, "No MTTCG when guest word size > hosts");
 150         } else if (use_icount) {
 151             error_setg(errp, "No MTTCG when icount is enabled");
 152         } else {
 153 #ifndef TARGET_SUPPORTS_MTTCG
 154             warn_report("Guest not yet converted to MTTCG - "
 155                         "you may get unexpected results");
 156 #endif
 157             if (!check_tcg_memory_orders_compatible()) {
 158                 warn_report("Guest expects a stronger memory ordering "
 159                             "than the host provides");
 160                 error_printf("This may cause strange/hard to debug errors\n");
 161             }
 162             s->mttcg_enabled = true;
 163         }
 164     } else if (strcmp(value, "single") == 0) {
 165         s->mttcg_enabled = false;
 166     } else {
 167         error_setg(errp, "Invalid 'thread' setting %s", value);
 168     }
 169 }
 170
 171 static void tcg_get_tb_size(Object *obj, Visitor *v,
 172                             const char *name, void *opaque,
 173                             Error **errp)
 174 {
 175     TCGState *s = TCG_STATE(obj);
 176     uint32_t value = s->tb_size;
 177
 178     visit_type_uint32(v, name, &value, errp);
 179 }
 180
 181 static void tcg_set_tb_size(Object *obj, Visitor *v,
 182                             const char *name, void *opaque,
 183                             Error **errp)
 184 {
 185     TCGState *s = TCG_STATE(obj);
 186     uint32_t value;
 187
 188     if (!visit_type_uint32(v, name, &value, errp)) {
 189         return;
 190     }
 191
 192     s->tb_size = value;
 193 }
 194
 195 static void tcg_accel_class_init(ObjectClass *oc, void *data)
 196 {
 197     AccelClass *ac = ACCEL_CLASS(oc);
 198     ac->name = "tcg";
 199     ac->init_machine = tcg_init;
 200     ac->allowed = &tcg_allowed;
 201
 202     object_class_property_add_str(oc, "thread",
 203                                   tcg_get_thread,
 204                                   tcg_set_thread);
 205
 206     object_class_property_add(oc, "tb-size", "int",
 207         tcg_get_tb_size, tcg_set_tb_size,
 208         NULL, NULL);
 209     object_class_property_set_description(oc, "tb-size",
 210         "TCG translation block cache size");
 211
 212 }
 213
 214 static const TypeInfo tcg_accel_type = {
 215     .name = TYPE_TCG_ACCEL,
 216     .parent = TYPE_ACCEL,
 217     .instance_init = tcg_accel_instance_init,
 218     .class_init = tcg_accel_class_init,
 219     .instance_size = sizeof(TCGState),
 220 };
 221
 222 static void register_accel_types(void)
 223 {
 224     type_register_static(&tcg_accel_type);
 225 }
 226
 227 type_init(register_accel_types);