debian/patches/internal-snapshot-async.patch

   1 From 46fd4bb673a91d40352c95e9d3f62f63b5021053 Mon Sep 17 00:00:00 2001
   2 From: Stefan Priebe <s.priebe@profihost.ag>
   3 Date: Fri, 29 Nov 2013 22:17:03 +0100
   4 Subject: [PATCH] internal-snapshot-async-qemu1.7.patch
   5
   6 ---
   7  Makefile.objs           |    1 +
   8  block.c                 |    2 +-
   9  hmp-commands.hx         |   34 ++++
  10  hmp.c                   |   57 ++++++
  11  hmp.h                   |    5 +
  12  include/block/block.h   |    1 +
  13  include/sysemu/sysemu.h |    5 +-
  14  monitor.c               |    7 +
  15  qapi-schema.json        |   46 +++++
  16  qemu-options.hx         |   13 ++
  17  qmp-commands.hx         |   31 +++
  18  savevm-async.c          |  478 +++++++++++++++++++++++++++++++++++++++++++++++
  19  savevm.c                |   10 +-
  20  vl.c                    |    9 +
  21  14 files changed, 692 insertions(+), 7 deletions(-)
  22  create mode 100644 savevm-async.c
  23
  24 Index: new/Makefile.objs
  25 ===================================================================
  26 --- new.orig/Makefile.objs      2014-06-12 11:17:40.000000000 +0200
  27 +++ new/Makefile.objs   2014-06-12 12:08:10.000000000 +0200
  28 @@ -57,6 +57,7 @@
  29  common-obj-y += qemu-char.o #aio.o
  30  common-obj-y += block-migration.o
  31  common-obj-y += page_cache.o xbzrle.o
  32 +common-obj-y += savevm-async.o
  33
  34  common-obj-$(CONFIG_POSIX) += migration-exec.o migration-unix.o migration-fd.o
  35
  36 Index: new/block.c
  37 ===================================================================
  38 --- new.orig/block.c    2014-06-12 10:19:18.000000000 +0200
  39 +++ new/block.c 2014-06-12 12:08:10.000000000 +0200
  40 @@ -2077,7 +2077,7 @@
  41      bdrv_set_backing_hd(bs_top, bs_new);
  42  }
  43
  44 -static void bdrv_delete(BlockDriverState *bs)
  45 +void bdrv_delete(BlockDriverState *bs)
  46  {
  47      assert(!bs->dev);
  48      assert(!bs->job);
  49 Index: new/hmp-commands.hx
  50 ===================================================================
  51 --- new.orig/hmp-commands.hx    2014-06-12 11:51:17.000000000 +0200
  52 +++ new/hmp-commands.hx 2014-06-12 12:08:10.000000000 +0200
  53 @@ -1803,6 +1803,8 @@
  54  show current migration capabilities
  55  @item info migrate_cache_size
  56  show current migration XBZRLE cache size
  57 +@item info savevm
  58 +show savevm status
  59  @item info balloon
  60  show balloon information
  61  @item info qtree
  62 @@ -1824,3 +1826,35 @@
  63  STEXI
  64  @end table
  65  ETEXI
  66 +
  67 +    {
  68 +        .name       = "savevm-start",
  69 +        .args_type  = "statefile:s?",
  70 +        .params     = "[statefile]",
  71 +        .help       = "Prepare for snapshot and halt VM. Save VM state to statefile.",
  72 +        .mhandler.cmd = hmp_savevm_start,
  73 +    },
  74 +
  75 +    {
  76 +        .name       = "snapshot-drive",
  77 +        .args_type  = "device:s,name:s",
  78 +        .params     = "device name",
  79 +        .help       = "Create internal snapshot.",
  80 +        .mhandler.cmd = hmp_snapshot_drive,
  81 +    },
  82 +
  83 +    {
  84 +        .name       = "delete-drive-snapshot",
  85 +        .args_type  = "device:s,name:s",
  86 +        .params     = "device name",
  87 +        .help       = "Delete internal snapshot.",
  88 +        .mhandler.cmd = hmp_delete_drive_snapshot,
  89 +    },
  90 +
  91 +    {
  92 +        .name       = "savevm-end",
  93 +        .args_type  = "",
  94 +        .params     = "",
  95 +        .help       = "Resume VM after snaphot.",
  96 +        .mhandler.cmd = hmp_savevm_end,
  97 +    },
  98 Index: new/hmp.c
  99 ===================================================================
 100 --- new.orig/hmp.c      2014-06-12 11:51:17.000000000 +0200
 101 +++ new/hmp.c   2014-06-12 12:08:10.000000000 +0200
 102 @@ -1767,3 +1767,60 @@
 103      qmp_object_del(id, &err);
 104      hmp_handle_error(mon, &err);
 105  }
 106 +
 107 +void hmp_savevm_start(Monitor *mon, const QDict *qdict)
 108 +{
 109 +    Error *errp = NULL;
 110 +    const char *statefile = qdict_get_try_str(qdict, "statefile");
 111 +
 112 +    qmp_savevm_start(statefile != NULL, statefile, &errp);
 113 +    hmp_handle_error(mon, &errp);
 114 +}
 115 +
 116 +void hmp_snapshot_drive(Monitor *mon, const QDict *qdict)
 117 +{
 118 +    Error *errp = NULL;
 119 +    const char *name = qdict_get_str(qdict, "name");
 120 +    const char *device = qdict_get_str(qdict, "device");
 121 +
 122 +    qmp_snapshot_drive(device, name, &errp);
 123 +    hmp_handle_error(mon, &errp);
 124 +}
 125 +
 126 +void hmp_delete_drive_snapshot(Monitor *mon, const QDict *qdict)
 127 +{
 128 +    Error *errp = NULL;
 129 +    const char *name = qdict_get_str(qdict, "name");
 130 +    const char *device = qdict_get_str(qdict, "device");
 131 +
 132 +    qmp_delete_drive_snapshot(device, name, &errp);
 133 +    hmp_handle_error(mon, &errp);
 134 +}
 135 +
 136 +void hmp_savevm_end(Monitor *mon, const QDict *qdict)
 137 +{
 138 +    Error *errp = NULL;
 139 +
 140 +    qmp_savevm_end(&errp);
 141 +    hmp_handle_error(mon, &errp);
 142 +}
 143 +
 144 +void hmp_info_savevm(Monitor *mon, const QDict *qdict)
 145 +{
 146 +    SaveVMInfo *info;
 147 +    info = qmp_query_savevm(NULL);
 148 +
 149 +    if (info->has_status) {
 150 +        monitor_printf(mon, "savevm status: %s\n", info->status);
 151 +        monitor_printf(mon, "total time: %" PRIu64 " milliseconds\n",
 152 +                       info->total_time);
 153 +    } else {
 154 +        monitor_printf(mon, "savevm status: not running\n");
 155 +    }
 156 +    if (info->has_bytes) {
 157 +        monitor_printf(mon, "Bytes saved: %"PRIu64"\n", info->bytes);
 158 +    }
 159 +    if (info->has_error) {
 160 +        monitor_printf(mon, "Error: %s\n", info->error);
 161 +    }
 162 +}
 163 Index: new/hmp.h
 164 ===================================================================
 165 --- new.orig/hmp.h      2014-06-12 11:39:32.000000000 +0200
 166 +++ new/hmp.h   2014-06-12 12:08:10.000000000 +0200
 167 @@ -26,6 +26,7 @@
 168  void hmp_info_uuid(Monitor *mon, const QDict *qdict);
 169  void hmp_info_chardev(Monitor *mon, const QDict *qdict);
 170  void hmp_info_mice(Monitor *mon, const QDict *qdict);
 171 +void hmp_info_savevm(Monitor *mon, const QDict *qdict);
 172  void hmp_info_migrate(Monitor *mon, const QDict *qdict);
 173  void hmp_info_migrate_capabilities(Monitor *mon, const QDict *qdict);
 174  void hmp_info_migrate_cache_size(Monitor *mon, const QDict *qdict);
 175 @@ -85,6 +86,10 @@
 176  void hmp_netdev_del(Monitor *mon, const QDict *qdict);
 177  void hmp_getfd(Monitor *mon, const QDict *qdict);
 178  void hmp_closefd(Monitor *mon, const QDict *qdict);
 179 +void hmp_savevm_start(Monitor *mon, const QDict *qdict);
 180 +void hmp_snapshot_drive(Monitor *mon, const QDict *qdict);
 181 +void hmp_delete_drive_snapshot(Monitor *mon, const QDict *qdict);
 182 +void hmp_savevm_end(Monitor *mon, const QDict *qdict);
 183  void hmp_send_key(Monitor *mon, const QDict *qdict);
 184  void hmp_screen_dump(Monitor *mon, const QDict *qdict);
 185  void hmp_nbd_server_start(Monitor *mon, const QDict *qdict);
 186 Index: new/include/block/block.h
 187 ===================================================================
 188 --- new.orig/include/block/block.h      2014-06-12 10:19:18.000000000 +0200
 189 +++ new/include/block/block.h   2014-06-12 12:08:10.000000000 +0200
 190 @@ -279,6 +279,7 @@
 191      const char *backing_file);
 192  int bdrv_get_backing_file_depth(BlockDriverState *bs);
 193  int bdrv_truncate(BlockDriverState *bs, int64_t offset);
 194 +void bdrv_delete(BlockDriverState *bs);
 195  int64_t bdrv_getlength(BlockDriverState *bs);
 196  int64_t bdrv_get_allocated_file_size(BlockDriverState *bs);
 197  void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
 198 Index: new/include/sysemu/sysemu.h
 199 ===================================================================
 200 --- new.orig/include/sysemu/sysemu.h    2014-06-12 10:19:18.000000000 +0200
 201 +++ new/include/sysemu/sysemu.h 2014-06-12 12:08:10.000000000 +0200
 202 @@ -73,16 +73,17 @@
 203
 204  void do_savevm(Monitor *mon, const QDict *qdict);
 205  int load_vmstate(const char *name);
 206 +int load_state_from_blockdev(const char *filename);
 207  void do_delvm(Monitor *mon, const QDict *qdict);
 208  void do_info_snapshots(Monitor *mon, const QDict *qdict);
 209
 210  void qemu_announce_self(void);
 211
 212  bool qemu_savevm_state_blocked(Error **errp);
 213 -void qemu_savevm_state_begin(QEMUFile *f,
 214 +int qemu_savevm_state_begin(QEMUFile *f,
 215                               const MigrationParams *params);
 216  int qemu_savevm_state_iterate(QEMUFile *f);
 217 -void qemu_savevm_state_complete(QEMUFile *f);
 218 +int qemu_savevm_state_complete(QEMUFile *f);
 219  void qemu_savevm_state_cancel(void);
 220  uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size);
 221  int qemu_loadvm_state(QEMUFile *f);
 222 Index: new/monitor.c
 223 ===================================================================
 224 --- new.orig/monitor.c  2014-06-12 11:39:32.000000000 +0200
 225 +++ new/monitor.c       2014-06-12 12:08:10.000000000 +0200
 226 @@ -2925,6 +2925,13 @@
 227          .mhandler.cmd = hmp_info_migrate_cache_size,
 228      },
 229      {
 230 +        .name       = "savevm",
 231 +        .args_type  = "",
 232 +        .params     = "",
 233 +        .help       = "show savevm status",
 234 +        .mhandler.cmd = hmp_info_savevm,
 235 +    },
 236 +    {
 237          .name       = "balloon",
 238          .args_type  = "",
 239          .params     = "",
 240 Index: new/qapi-schema.json
 241 ===================================================================
 242 --- new.orig/qapi-schema.json   2014-06-12 11:51:17.000000000 +0200
 243 +++ new/qapi-schema.json        2014-06-12 12:08:10.000000000 +0200
 244 @@ -538,6 +538,42 @@
 245             '*downtime': 'int',
 246             '*setup-time': 'int'} }
 247
 248 +
 249 +# @SaveVMInfo
 250 +#
 251 +# Information about current migration process.
 252 +#
 253 +# @status: #optional string describing the current savevm status.
 254 +#          This can be 'active', 'completed', 'failed'.
 255 +#          If this field is not returned, no savevm process
 256 +#          has been initiated
 257 +#
 258 +# @error: #optional string containing error message is status is failed.
 259 +#
 260 +# @total-time: #optional total amount of milliseconds since savevm started.
 261 +#        If savevm has ended, it returns the total save time
 262 +#
 263 +# @bytes: #optional total amount of data transfered
 264 +#
 265 +# Since: 1.3
 266 +##
 267 +{ 'type': 'SaveVMInfo',
 268 +  'data': {'*status': 'str', '*error': 'str',
 269 +           '*total-time': 'int', '*bytes': 'int'} }
 270 +
 271 +##
 272 +# @query-savevm
 273 +#
 274 +# Returns information about current savevm process.
 275 +#
 276 +# Returns: @SaveVMInfo
 277 +#
 278 +# Since: 1.3
 279 +##
 280 +{ 'command': 'query-savevm', 'returns': 'SaveVMInfo' }
 281 +
 282 +##
 283 +
 284  ##
 285  # @query-migrate
 286  #
 287 @@ -2497,8 +2533,18 @@
 288  #
 289  # Since: 1.2.0
 290  ##
 291 +
 292  { 'command': 'query-target', 'returns': 'TargetInfo' }
 293
 294 +{ 'command': 'savevm-start', 'data': { '*statefile': 'str' } }
 295 +
 296 +{ 'command': 'snapshot-drive', 'data': { 'device': 'str', 'name': 'str' } }
 297 +
 298 +{ 'command': 'delete-drive-snapshot', 'data': { 'device': 'str', 'name': 'str' } }
 299 +
 300 +{ 'command': 'savevm-end' }
 301 +
 302 +
 303  ##
 304  # @QKeyCode:
 305  #
 306 Index: new/qemu-options.hx
 307 ===================================================================
 308 --- new.orig/qemu-options.hx    2014-06-12 10:39:20.000000000 +0200
 309 +++ new/qemu-options.hx 2014-06-12 12:08:10.000000000 +0200
 310 @@ -2838,6 +2838,19 @@
 311  Start right away with a saved state (@code{loadvm} in monitor)
 312  ETEXI
 313
 314 +DEF("loadstate", HAS_ARG, QEMU_OPTION_loadstate, \
 315 +    "-loadstate file\n" \
 316 +    "                start right away with a saved state\n",
 317 +    QEMU_ARCH_ALL)
 318 +STEXI
 319 +@item -loadstate @var{file}
 320 +@findex -loadstate
 321 +Start right away with a saved state. This option does not rollback
 322 +disk state like @code{loadvm}, so user must make sure that disk
 323 +have correct state. @var{file} can be any valid device URL. See the section
 324 +for "Device URL Syntax" for more information.
 325 +ETEXI
 326 +
 327  #ifndef _WIN32
 328  DEF("daemonize", 0, QEMU_OPTION_daemonize, \
 329      "-daemonize      daemonize QEMU after initializing\n", QEMU_ARCH_ALL)
 330 Index: new/qmp-commands.hx
 331 ===================================================================
 332 --- new.orig/qmp-commands.hx    2014-06-12 11:39:32.000000000 +0200
 333 +++ new/qmp-commands.hx 2014-06-12 12:08:10.000000000 +0200
 334 @@ -3603,3 +3603,34 @@
 335                     } } ] }
 336
 337  EQMP
 338 +
 339 +
 340 +    {
 341 +        .name       = "savevm-start",
 342 +        .args_type  = "statefile:s?",
 343 +        .mhandler.cmd_new = qmp_marshal_input_savevm_start,
 344 +    },
 345 +
 346 +    {
 347 +        .name       = "snapshot-drive",
 348 +        .args_type  = "device:s,name:s",
 349 +        .mhandler.cmd_new = qmp_marshal_input_snapshot_drive,
 350 +    },
 351 +
 352 +    {
 353 +        .name       = "delete-drive-snapshot",
 354 +        .args_type  = "device:s,name:s",
 355 +        .mhandler.cmd_new = qmp_marshal_input_delete_drive_snapshot,
 356 +    },
 357 +
 358 +    {
 359 +        .name       = "savevm-end",
 360 +        .args_type  = "",
 361 +        .mhandler.cmd_new = qmp_marshal_input_savevm_end,
 362 +    },
 363 +
 364 +    {
 365 +        .name       = "query-savevm",
 366 +        .args_type  = "",
 367 +        .mhandler.cmd_new = qmp_marshal_input_query_savevm,
 368 +    },
 369 Index: new/savevm-async.c
 370 ===================================================================
 371 --- /dev/null   1970-01-01 00:00:00.000000000 +0000
 372 +++ new/savevm-async.c  2014-06-12 12:38:38.000000000 +0200
 373 @@ -0,0 +1,486 @@
 374 +#include "qemu-common.h"
 375 +#include "qapi/qmp/qerror.h"
 376 +#include "sysemu/sysemu.h"
 377 +#include "qmp-commands.h"
 378 +#include "qemu-options.h"
 379 +#include "migration/qemu-file.h"
 380 +#include "qom/qom-qobject.h"
 381 +#include "migration/migration.h"
 382 +#include "block/snapshot.h"
 383 +#include "block/qapi.h"
 384 +#include "block/block.h"
 385 +#include "qemu/timer.h"
 386 +
 387 +/* #define DEBUG_SAVEVM_STATE */
 388 +
 389 +#ifdef DEBUG_SAVEVM_STATE
 390 +#define DPRINTF(fmt, ...) \
 391 +    do { printf("savevm-async: " fmt, ## __VA_ARGS__); } while (0)
 392 +#else
 393 +#define DPRINTF(fmt, ...) \
 394 +    do { } while (0)
 395 +#endif
 396 +
 397 +enum {
 398 +    SAVE_STATE_DONE,
 399 +    SAVE_STATE_ERROR,
 400 +    SAVE_STATE_ACTIVE,
 401 +    SAVE_STATE_COMPLETED,
 402 +};
 403 +
 404 +
 405 +static struct SnapshotState {
 406 +    BlockDriverState *bs;
 407 +    size_t bs_pos;
 408 +    int state;
 409 +    Error *error;
 410 +    Error *blocker;
 411 +    int saved_vm_running;
 412 +    QEMUFile *file;
 413 +    int64_t total_time;
 414 +} snap_state;
 415 +
 416 +SaveVMInfo *qmp_query_savevm(Error **errp)
 417 +{
 418 +    SaveVMInfo *info = g_malloc0(sizeof(*info));
 419 +    struct SnapshotState *s = &snap_state;
 420 +
 421 +    if (s->state != SAVE_STATE_DONE) {
 422 +        info->has_bytes = true;
 423 +        info->bytes = s->bs_pos;
 424 +        switch (s->state) {
 425 +        case SAVE_STATE_ERROR:
 426 +            info->has_status = true;
 427 +            info->status = g_strdup("failed");
 428 +            info->has_total_time = true;
 429 +            info->total_time = s->total_time;
 430 +            if (s->error) {
 431 +                info->has_error = true;
 432 +                info->error = g_strdup(error_get_pretty(s->error));
 433 +            }
 434 +            break;
 435 +        case SAVE_STATE_ACTIVE:
 436 +            info->has_status = true;
 437 +            info->status = g_strdup("active");
 438 +            info->has_total_time = true;
 439 +            info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
 440 +                - s->total_time;
 441 +            break;
 442 +        case SAVE_STATE_COMPLETED:
 443 +            info->has_status = true;
 444 +            info->status = g_strdup("completed");
 445 +            info->has_total_time = true;
 446 +            info->total_time = s->total_time;
 447 +            break;
 448 +        }
 449 +    }
 450 +
 451 +    return info;
 452 +}
 453 +
 454 +static int save_snapshot_cleanup(void)
 455 +{
 456 +    int ret = 0;
 457 +
 458 +    DPRINTF("save_snapshot_cleanup\n");
 459 +
 460 +    snap_state.total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) -
 461 +        snap_state.total_time;
 462 +
 463 +    if (snap_state.file) {
 464 +        ret = qemu_fclose(snap_state.file);
 465 +    }
 466 +
 467 +    if (snap_state.bs) {
 468 +        /* try to truncate, but ignore errors (will fail on block devices).
 469 +         * note: bdrv_read() need whole blocks, so we round up
 470 +         */
 471 +        size_t size = (snap_state.bs_pos + BDRV_SECTOR_SIZE) & BDRV_SECTOR_MASK;
 472 +        bdrv_truncate(snap_state.bs, size);
 473 +        bdrv_op_unblock_all(snap_state.bs, snap_state.blocker);
 474 +        error_free(snap_state.blocker);
 475 +        snap_state.blocker = NULL;
 476 +        bdrv_unref(snap_state.bs);
 477 +        snap_state.bs = NULL;
 478 +    }
 479 +
 480 +    return ret;
 481 +}
 482 +
 483 +static void save_snapshot_error(const char *fmt, ...)
 484 +{
 485 +    va_list ap;
 486 +    char *msg;
 487 +
 488 +    va_start(ap, fmt);
 489 +    msg = g_strdup_vprintf(fmt, ap);
 490 +    va_end(ap);
 491 +
 492 +    DPRINTF("save_snapshot_error: %s\n", msg);
 493 +
 494 +    if (!snap_state.error) {
 495 +        error_set(&snap_state.error, ERROR_CLASS_GENERIC_ERROR, "%s", msg);
 496 +    }
 497 +
 498 +    g_free (msg);
 499 +
 500 +    snap_state.state = SAVE_STATE_ERROR;
 501 +
 502 +    save_snapshot_cleanup();
 503 +}
 504 +
 505 +static void save_snapshot_completed(void)
 506 +{
 507 +    DPRINTF("save_snapshot_completed\n");
 508 +
 509 +    if (save_snapshot_cleanup() < 0) {
 510 +        snap_state.state = SAVE_STATE_ERROR;
 511 +    } else {
 512 +        snap_state.state = SAVE_STATE_COMPLETED;
 513 +    }
 514 +}
 515 +
 516 +static int block_state_close(void *opaque)
 517 +{
 518 +    snap_state.file = NULL;
 519 +    return bdrv_flush(snap_state.bs);
 520 +}
 521 +
 522 +static int block_state_put_buffer(void *opaque, const uint8_t *buf,
 523 +                                  int64_t pos, int size)
 524 +{
 525 +    int ret;
 526 +
 527 +    assert(pos == snap_state.bs_pos);
 528 +
 529 +    if ((ret = bdrv_pwrite(snap_state.bs, snap_state.bs_pos, buf, size)) > 0) {
 530 +        snap_state.bs_pos += ret;
 531 +    }
 532 +
 533 +    return ret;
 534 +}
 535 +
 536 +static void process_savevm_co(void *opaque)
 537 +{
 538 +    int ret;
 539 +    int64_t maxlen;
 540 +    MigrationParams params = {
 541 +        .blk = 0,
 542 +        .shared = 0
 543 +    };
 544 +
 545 +    snap_state.state = SAVE_STATE_ACTIVE;
 546 +
 547 +    qemu_mutex_unlock_iothread();
 548 +    ret = qemu_savevm_state_begin(snap_state.file, &params);
 549 +    qemu_mutex_lock_iothread();
 550 +
 551 +    if (ret < 0) {
 552 +        save_snapshot_error("qemu_savevm_state_begin failed");
 553 +        return;
 554 +    }
 555 +
 556 +    while (snap_state.state == SAVE_STATE_ACTIVE) {
 557 +        uint64_t pending_size;
 558 +
 559 +        pending_size = qemu_savevm_state_pending(snap_state.file, 0);
 560 +
 561 +        if (pending_size) {
 562 +                ret = qemu_savevm_state_iterate(snap_state.file);
 563 +                if (ret < 0) {
 564 +                    save_snapshot_error("qemu_savevm_state_iterate error %d", ret);
 565 +                    break;
 566 +                }
 567 +                DPRINTF("savevm inerate pending size %lu ret %d\n", pending_size, ret);
 568 +        } else {
 569 +            DPRINTF("done iterating\n");
 570 +            if (runstate_is_running()) {
 571 +                vm_stop(RUN_STATE_SAVE_VM);
 572 +            }
 573 +            DPRINTF("savevm inerate finished\n");
 574 +            qemu_savevm_state_complete(snap_state.file);
 575 +            DPRINTF("save complete\n");
 576 +            save_snapshot_completed();
 577 +            break;
 578 +        }
 579 +
 580 +        /* stop the VM if we get to the end of available space,
 581 +         * or if pending_size is just a few MB
 582 +         */
 583 +        maxlen = bdrv_getlength(snap_state.bs) - 30*1024*1024;
 584 +        if ((pending_size < 100000) ||
 585 +            ((snap_state.bs_pos + pending_size) >= maxlen)) {
 586 +            if (runstate_is_running()) {
 587 +                vm_stop(RUN_STATE_SAVE_VM);
 588 +            }
 589 +        }
 590 +    }
 591 +}
 592 +
 593 +static const QEMUFileOps block_file_ops = {
 594 +    .put_buffer =     block_state_put_buffer,
 595 +    .close =          block_state_close,
 596 +};
 597 +
 598 +
 599 +void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
 600 +{
 601 +    BlockDriver *drv = NULL;
 602 +    Error *local_err = NULL;
 603 +
 604 +    int bdrv_oflags = BDRV_O_CACHE_WB | BDRV_O_RDWR;
 605 +    int ret;
 606 +
 607 +    if (snap_state.state != SAVE_STATE_DONE) {
 608 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 609 +                  "VM snapshot already started\n");
 610 +        return;
 611 +    }
 612 +
 613 +    /* initialize snapshot info */
 614 +    snap_state.saved_vm_running = runstate_is_running();
 615 +    snap_state.bs_pos = 0;
 616 +    snap_state.total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 617 +    snap_state.blocker = NULL;
 618 +
 619 +    if (snap_state.error) {
 620 +        error_free(snap_state.error);
 621 +        snap_state.error = NULL;
 622 +    }
 623 +
 624 +    if (!has_statefile) {
 625 +        vm_stop(RUN_STATE_SAVE_VM);
 626 +        snap_state.state = SAVE_STATE_COMPLETED;
 627 +        return;
 628 +    }
 629 +
 630 +    if (qemu_savevm_state_blocked(errp)) {
 631 +        return;
 632 +    }
 633 +
 634 +    /* Open the image */
 635 +    snap_state.bs = bdrv_new("vmstate", &error_abort);
 636 +    ret = bdrv_open(&snap_state.bs, statefile, NULL, NULL, bdrv_oflags, drv, &local_err);
 637 +
 638 +    if (ret < 0) {
 639 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
 640 +        goto restart;
 641 +    }
 642 +
 643 +    snap_state.file = qemu_fopen_ops(&snap_state, &block_file_ops);
 644 +
 645 +    if (!snap_state.file) {
 646 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
 647 +        goto restart;
 648 +    }
 649 +
 650 +
 651 +    error_setg(&snap_state.blocker, "block device is in use by savevm");
 652 +    bdrv_op_block_all(snap_state.bs, snap_state.blocker);
 653 +    bdrv_ref(snap_state.bs);
 654 +
 655 +    Coroutine *co = qemu_coroutine_create(process_savevm_co);
 656 +    qemu_coroutine_enter(co, NULL);
 657 +
 658 +    return;
 659 +
 660 +restart:
 661 +
 662 +    save_snapshot_error("setup failed");
 663 +
 664 +    if (snap_state.saved_vm_running) {
 665 +        vm_start();
 666 +    }
 667 +}
 668 +
 669 +void qmp_savevm_end(Error **errp)
 670 +{
 671 +    if (snap_state.state == SAVE_STATE_DONE) {
 672 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 673 +                  "VM snapshot not started\n");
 674 +        return;
 675 +    }
 676 +
 677 +    if (snap_state.saved_vm_running) {
 678 +        vm_start();
 679 +    }
 680 +
 681 +    snap_state.state = SAVE_STATE_DONE;
 682 +}
 683 +
 684 +void qmp_snapshot_drive(const char *device, const char *name, Error **errp)
 685 +{
 686 +    BlockDriverState *bs;
 687 +    QEMUSnapshotInfo sn1, *sn = &sn1;
 688 +    int ret;
 689 +#ifdef _WIN32
 690 +    struct _timeb tb;
 691 +#else
 692 +    struct timeval tv;
 693 +#endif
 694 +
 695 +    if (snap_state.state != SAVE_STATE_COMPLETED) {
 696 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 697 +                  "VM snapshot not ready/started\n");
 698 +        return;
 699 +    }
 700 +
 701 +    bs = bdrv_find(device);
 702 +    if (!bs) {
 703 +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 704 +        return;
 705 +    }
 706 +
 707 +    if (!bdrv_is_inserted(bs)) {
 708 +        error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
 709 +        return;
 710 +    }
 711 +
 712 +    if (bdrv_is_read_only(bs)) {
 713 +        error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
 714 +        return;
 715 +    }
 716 +
 717 +    if (!bdrv_can_snapshot(bs)) {
 718 +        error_set(errp, QERR_UNSUPPORTED);
 719 +        return;
 720 +    }
 721 +
 722 +    if (bdrv_snapshot_find(bs, sn, name) >= 0) {
 723 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 724 +                  "snapshot '%s' already exists", name);
 725 +        return;
 726 +    }
 727 +
 728 +    sn = &sn1;
 729 +    memset(sn, 0, sizeof(*sn));
 730 +
 731 +#ifdef _WIN32
 732 +    _ftime(&tb);
 733 +    sn->date_sec = tb.time;
 734 +    sn->date_nsec = tb.millitm * 1000000;
 735 +#else
 736 +    gettimeofday(&tv, NULL);
 737 +    sn->date_sec = tv.tv_sec;
 738 +    sn->date_nsec = tv.tv_usec * 1000;
 739 +#endif
 740 +    sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 741 +
 742 +    pstrcpy(sn->name, sizeof(sn->name), name);
 743 +
 744 +    sn->vm_state_size = 0; /* do not save state */
 745 +
 746 +    ret = bdrv_snapshot_create(bs, sn);
 747 +    if (ret < 0) {
 748 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 749 +                  "Error while creating snapshot on '%s'\n", device);
 750 +        return;
 751 +    }
 752 +}
 753 +
 754 +void qmp_delete_drive_snapshot(const char *device, const char *name,
 755 +                               Error **errp)
 756 +{
 757 +    BlockDriverState *bs;
 758 +    QEMUSnapshotInfo sn1, *sn = &sn1;
 759 +    Error *local_err = NULL;
 760 +
 761 +    int ret;
 762 +
 763 +    bs = bdrv_find(device);
 764 +    if (!bs) {
 765 +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 766 +        return;
 767 +    }
 768 +    if (bdrv_is_read_only(bs)) {
 769 +        error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
 770 +        return;
 771 +    }
 772 +
 773 +    if (!bdrv_can_snapshot(bs)) {
 774 +        error_set(errp, QERR_UNSUPPORTED);
 775 +        return;
 776 +    }
 777 +
 778 +    if (bdrv_snapshot_find(bs, sn, name) < 0) {
 779 +        /* return success if snapshot does not exists */
 780 +        return;
 781 +    }
 782 +
 783 +    ret = bdrv_snapshot_delete(bs, NULL, name, &local_err);
 784 +    if (ret < 0) {
 785 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 786 +                  "Error while deleting snapshot on '%s'\n", device);
 787 +        return;
 788 +    }
 789 +}
 790 +
 791 +static int loadstate_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
 792 +                                int size)
 793 +{
 794 +    BlockDriverState *bs = (BlockDriverState *)opaque;
 795 +    int64_t maxlen = bdrv_getlength(bs);
 796 +    if (pos > maxlen) {
 797 +        return -EIO;
 798 +    }
 799 +    if ((pos + size) > maxlen) {
 800 +        size = maxlen - pos - 1;
 801 +    }
 802 +    if (size == 0) {
 803 +        return 0;
 804 +    }
 805 +    return bdrv_pread(bs, pos, buf, size);
 806 +}
 807 +
 808 +static const QEMUFileOps loadstate_file_ops = {
 809 +    .get_buffer = loadstate_get_buffer,
 810 +};
 811 +
 812 +int load_state_from_blockdev(const char *filename)
 813 +{
 814 +    BlockDriverState *bs = NULL;
 815 +    BlockDriver *drv = NULL;
 816 +    Error *local_err = NULL;
 817 +    Error *blocker = NULL;
 818 +
 819 +    QEMUFile *f;
 820 +    int ret = -1;
 821 +
 822 +    bs = bdrv_new("vmstate", &error_abort);
 823 +    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_CACHE_WB, drv, &local_err);
 824 +    error_setg(&blocker, "block device is in use by load state");
 825 +    bdrv_op_block_all(bs, blocker);
 826 +    bdrv_ref(bs);
 827 +
 828 +    if (ret < 0) {
 829 +        error_report("Could not open VM state file");
 830 +        goto the_end;
 831 +    }
 832 +
 833 +    /* restore the VM state */
 834 +    f = qemu_fopen_ops(bs, &loadstate_file_ops);
 835 +    if (!f) {
 836 +        error_report("Could not open VM state file");
 837 +        ret = -EINVAL;
 838 +        goto the_end;
 839 +    }
 840 +
 841 +    qemu_system_reset(VMRESET_SILENT);
 842 +    ret = qemu_loadvm_state(f);
 843 +
 844 +    qemu_fclose(f);
 845 +    if (ret < 0) {
 846 +        error_report("Error %d while loading VM state", ret);
 847 +        goto the_end;
 848 +    }
 849 +
 850 +    ret = 0;
 851 +
 852 + the_end:
 853 +    if (bs) {
 854 +        bdrv_op_unblock_all(bs, blocker);
 855 +        error_free(blocker);
 856 +        bdrv_unref(bs);
 857 +    }
 858 +    return ret;
 859 +}
 860 Index: new/savevm.c
 861 ===================================================================
 862 --- new.orig/savevm.c   2014-06-12 10:19:18.000000000 +0200
 863 +++ new/savevm.c        2014-06-12 12:08:10.000000000 +0200
 864 @@ -461,11 +461,11 @@
 865      return false;
 866  }
 867
 868 -void qemu_savevm_state_begin(QEMUFile *f,
 869 +int qemu_savevm_state_begin(QEMUFile *f,
 870                               const MigrationParams *params)
 871  {
 872      SaveStateEntry *se;
 873 -    int ret;
 874 +    int ret = 0;
 875
 876      trace_savevm_state_begin();
 877      QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 878 @@ -507,6 +507,7 @@
 879              break;
 880          }
 881      }
 882 +    return ret;
 883  }
 884
 885  /*
 886 @@ -555,7 +556,7 @@
 887      return ret;
 888  }
 889
 890 -void qemu_savevm_state_complete(QEMUFile *f)
 891 +int qemu_savevm_state_complete(QEMUFile *f)
 892  {
 893      SaveStateEntry *se;
 894      int ret;
 895 @@ -582,7 +583,7 @@
 896          trace_savevm_section_end(se->idstr, se->section_id);
 897          if (ret < 0) {
 898              qemu_file_set_error(f, ret);
 899 -            return;
 900 +            return ret;
 901          }
 902      }
 903
 904 @@ -611,6 +612,7 @@
 905
 906      qemu_put_byte(f, QEMU_VM_EOF);
 907      qemu_fflush(f);
 908 +    return qemu_file_get_error(f);
 909  }
 910
 911  uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
 912 Index: new/vl.c
 913 ===================================================================
 914 --- new.orig/vl.c       2014-06-12 11:09:49.000000000 +0200
 915 +++ new/vl.c    2014-06-12 12:08:10.000000000 +0200
 916 @@ -2979,6 +2979,7 @@
 917      int optind;
 918      const char *optarg;
 919      const char *loadvm = NULL;
 920 +    const char *loadstate = NULL;
 921      MachineClass *machine_class;
 922      const char *cpu_model;
 923      const char *vga_model = NULL;
 924 @@ -3628,6 +3629,9 @@
 925             case QEMU_OPTION_loadvm:
 926                 loadvm = optarg;
 927                 break;
 928 +            case QEMU_OPTION_loadstate:
 929 +                loadstate = optarg;
 930 +                break;
 931              case QEMU_OPTION_full_screen:
 932                  full_screen = 1;
 933                  break;
 934 @@ -4599,6 +4603,10 @@
 935          if (load_vmstate(loadvm) < 0) {
 936              autostart = 0;
 937          }
 938 +    } else if (loadstate) {
 939 +        if (load_state_from_blockdev(loadstate) < 0) {
 940 +            autostart = 0;
 941 +        }
 942      }
 943
 944      qdev_prop_check_global();