migration.c

   1 /*
   2  * QEMU live migration
   3  *
   4  * Copyright IBM, Corp. 2008
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #include "qemu-common.h"
  15 #include "migration.h"
  16 #include "monitor.h"
  17 #include "buffered_file.h"
  18 #include "sysemu.h"
  19 #include "block.h"
  20 #include "qemu_socket.h"
  21
  22 //#define DEBUG_MIGRATION
  23
  24 #ifdef DEBUG_MIGRATION
  25 #define dprintf(fmt, ...) \
  26     do { printf("migration: " fmt, ## __VA_ARGS__); } while (0)
  27 #else
  28 #define dprintf(fmt, ...) \
  29     do { } while (0)
  30 #endif
  31
  32 /* Migration speed throttling */
  33 static uint32_t max_throttle = (32 << 20);
  34
  35 static MigrationState *current_migration;
  36
  37 void qemu_start_incoming_migration(const char *uri)
  38 {
  39     const char *p;
  40
  41     if (strstart(uri, "tcp:", &p))
  42         tcp_start_incoming_migration(p);
  43 #if !defined(WIN32)
  44     else if (strstart(uri, "exec:", &p))
  45         exec_start_incoming_migration(p);
  46 #endif
  47     else
  48         fprintf(stderr, "unknown migration protocol: %s\n", uri);
  49 }
  50
  51 void do_migrate(Monitor *mon, int detach, const char *uri)
  52 {
  53     MigrationState *s = NULL;
  54     const char *p;
  55
  56     if (strstart(uri, "tcp:", &p))
  57         s = tcp_start_outgoing_migration(p, max_throttle, detach);
  58 #if !defined(WIN32)
  59     else if (strstart(uri, "exec:", &p))
  60         s = exec_start_outgoing_migration(p, max_throttle, detach);
  61 #endif
  62     else
  63         monitor_printf(mon, "unknown migration protocol: %s\n", uri);
  64
  65     if (s == NULL)
  66         monitor_printf(mon, "migration failed\n");
  67     else {
  68         if (current_migration)
  69             current_migration->release(current_migration);
  70
  71         current_migration = s;
  72     }
  73 }
  74
  75 void do_migrate_cancel(Monitor *mon)
  76 {
  77     MigrationState *s = current_migration;
  78
  79     if (s)
  80         s->cancel(s);
  81 }
  82
  83 void do_migrate_set_speed(Monitor *mon, const char *value)
  84 {
  85     double d;
  86     char *ptr;
  87     FdMigrationState *s;
  88
  89     d = strtod(value, &ptr);
  90     switch (*ptr) {
  91     case 'G': case 'g':
  92         d *= 1024;
  93     case 'M': case 'm':
  94         d *= 1024;
  95     case 'K': case 'k':
  96         d *= 1024;
  97     default:
  98         break;
  99     }
 100
 101     max_throttle = (uint32_t)d;
 102     s = migrate_to_fms(current_migration);
 103
 104     if (s) {
 105         qemu_file_set_rate_limit(s->file, max_throttle);
 106     }
 107
 108 }
 109
 110 void do_info_migrate(Monitor *mon)
 111 {
 112     MigrationState *s = current_migration;
 113
 114     if (s) {
 115         monitor_printf(mon, "Migration status: ");
 116         switch (s->get_status(s)) {
 117         case MIG_STATE_ACTIVE:
 118             monitor_printf(mon, "active\n");
 119             monitor_printf(mon, "transferred ram: %" PRIu64 " kbytes\n", ram_bytes_transferred() >> 10);
 120             monitor_printf(mon, "remaining ram: %" PRIu64 " kbytes\n", ram_bytes_remaining() >> 10);
 121             monitor_printf(mon, "total ram: %" PRIu64 " kbytes\n", ram_bytes_total() >> 10);
 122             break;
 123         case MIG_STATE_COMPLETED:
 124             monitor_printf(mon, "completed\n");
 125             break;
 126         case MIG_STATE_ERROR:
 127             monitor_printf(mon, "failed\n");
 128             break;
 129         case MIG_STATE_CANCELLED:
 130             monitor_printf(mon, "cancelled\n");
 131             break;
 132         }
 133     }
 134 }
 135
 136 /* shared migration helpers */
 137
 138 void migrate_fd_monitor_suspend(FdMigrationState *s)
 139 {
 140     s->mon_resume = cur_mon;
 141     if (monitor_suspend(cur_mon) == 0)
 142         dprintf("suspending monitor\n");
 143     else
 144         monitor_printf(cur_mon, "terminal does not allow synchronous "
 145                        "migration, continuing detached\n");
 146 }
 147
 148 void migrate_fd_error(FdMigrationState *s)
 149 {
 150     dprintf("setting error state\n");
 151     s->state = MIG_STATE_ERROR;
 152     migrate_fd_cleanup(s);
 153 }
 154
 155 void migrate_fd_cleanup(FdMigrationState *s)
 156 {
 157     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 158
 159     if (s->file) {
 160         dprintf("closing file\n");
 161         qemu_fclose(s->file);
 162     }
 163
 164     if (s->fd != -1)
 165         close(s->fd);
 166
 167     /* Don't resume monitor until we've flushed all of the buffers */
 168     if (s->mon_resume)
 169         monitor_resume(s->mon_resume);
 170
 171     s->fd = -1;
 172 }
 173
 174 void migrate_fd_put_notify(void *opaque)
 175 {
 176     FdMigrationState *s = opaque;
 177
 178     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 179     qemu_file_put_notify(s->file);
 180 }
 181
 182 ssize_t migrate_fd_put_buffer(void *opaque, const void *data, size_t size)
 183 {
 184     FdMigrationState *s = opaque;
 185     ssize_t ret;
 186
 187     do {
 188         ret = s->write(s, data, size);
 189     } while (ret == -1 && ((s->get_error(s)) == EINTR));
 190
 191     if (ret == -1)
 192         ret = -(s->get_error(s));
 193
 194     if (ret == -EAGAIN)
 195         qemu_set_fd_handler2(s->fd, NULL, NULL, migrate_fd_put_notify, s);
 196
 197     return ret;
 198 }
 199
 200 void migrate_fd_connect(FdMigrationState *s)
 201 {
 202     int ret;
 203
 204     s->file = qemu_fopen_ops_buffered(s,
 205                                       s->bandwidth_limit,
 206                                       migrate_fd_put_buffer,
 207                                       migrate_fd_put_ready,
 208                                       migrate_fd_wait_for_unfreeze,
 209                                       migrate_fd_close);
 210
 211     dprintf("beginning savevm\n");
 212     ret = qemu_savevm_state_begin(s->file);
 213     if (ret < 0) {
 214         dprintf("failed, %d\n", ret);
 215         migrate_fd_error(s);
 216         return;
 217     }
 218
 219     migrate_fd_put_ready(s);
 220 }
 221
 222 void migrate_fd_put_ready(void *opaque)
 223 {
 224     FdMigrationState *s = opaque;
 225
 226     if (s->state != MIG_STATE_ACTIVE) {
 227         dprintf("put_ready returning because of non-active state\n");
 228         return;
 229     }
 230
 231     dprintf("iterate\n");
 232     if (qemu_savevm_state_iterate(s->file) == 1) {
 233         int state;
 234         dprintf("done iterating\n");
 235         vm_stop(0);
 236
 237         bdrv_flush_all();
 238         if ((qemu_savevm_state_complete(s->file)) < 0) {
 239             vm_start();
 240             state = MIG_STATE_ERROR;
 241         } else {
 242             state = MIG_STATE_COMPLETED;
 243         }
 244         migrate_fd_cleanup(s);
 245         s->state = state;
 246     }
 247 }
 248
 249 int migrate_fd_get_status(MigrationState *mig_state)
 250 {
 251     FdMigrationState *s = migrate_to_fms(mig_state);
 252     return s->state;
 253 }
 254
 255 void migrate_fd_cancel(MigrationState *mig_state)
 256 {
 257     FdMigrationState *s = migrate_to_fms(mig_state);
 258
 259     if (s->state != MIG_STATE_ACTIVE)
 260         return;
 261
 262     dprintf("cancelling migration\n");
 263
 264     s->state = MIG_STATE_CANCELLED;
 265
 266     migrate_fd_cleanup(s);
 267 }
 268
 269 void migrate_fd_release(MigrationState *mig_state)
 270 {
 271     FdMigrationState *s = migrate_to_fms(mig_state);
 272
 273     dprintf("releasing state\n");
 274
 275     if (s->state == MIG_STATE_ACTIVE) {
 276         s->state = MIG_STATE_CANCELLED;
 277         migrate_fd_cleanup(s);
 278     }
 279     free(s);
 280 }
 281
 282 void migrate_fd_wait_for_unfreeze(void *opaque)
 283 {
 284     FdMigrationState *s = opaque;
 285     int ret;
 286
 287     dprintf("wait for unfreeze\n");
 288     if (s->state != MIG_STATE_ACTIVE)
 289         return;
 290
 291     do {
 292         fd_set wfds;
 293
 294         FD_ZERO(&wfds);
 295         FD_SET(s->fd, &wfds);
 296
 297         ret = select(s->fd + 1, NULL, &wfds, NULL, NULL);
 298     } while (ret == -1 && (s->get_error(s)) == EINTR);
 299 }
 300
 301 int migrate_fd_close(void *opaque)
 302 {
 303     FdMigrationState *s = opaque;
 304
 305     qemu_set_fd_handler2(s->fd, NULL, NULL, NULL, NULL);
 306     return s->close(s);
 307 }