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      2014-08-07 11:56:07.000000000 +0200
  27 +++ new/Makefile.objs   2014-08-07 11:56:38.000000000 +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    2014-08-02 15:03:20.000000000 +0200
  39 +++ new/block.c 2014-08-07 13:26:45.000000000 +0200
  40 @@ -2083,7 +2083,7 @@
  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    2014-08-07 11:56:20.000000000 +0200
  52 +++ new/hmp-commands.hx 2014-08-07 11:56:38.000000000 +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      2014-08-07 11:56:20.000000000 +0200
 101 +++ new/hmp.c   2014-08-07 11:56:38.000000000 +0200
 102 @@ -1805,3 +1805,60 @@
 103
 104      monitor_printf(mon, "\n");
 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      2014-08-07 11:56:19.000000000 +0200
 166 +++ new/hmp.h   2014-08-07 11:56:38.000000000 +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      2014-08-02 15:03:21.000000000 +0200
 189 +++ new/include/block/block.h   2014-08-07 11:56:38.000000000 +0200
 190 @@ -275,6 +275,7 @@
 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    2014-08-02 15:03:21.000000000 +0200
 201 +++ new/include/sysemu/sysemu.h 2014-08-07 11:56:38.000000000 +0200
 202 @@ -76,16 +76,17 @@
 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  2014-08-07 11:56:19.000000000 +0200
 225 +++ new/monitor.c       2014-08-07 11:56:38.000000000 +0200
 226 @@ -2876,6 +2876,13 @@
 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   2014-08-07 11:56:20.000000000 +0200
 243 +++ new/qapi-schema.json        2014-08-07 11:56:38.000000000 +0200
 244 @@ -547,6 +547,42 @@
 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 @@ -2644,8 +2680,18 @@
 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    2014-08-07 11:55:39.000000000 +0200
 309 +++ new/qemu-options.hx 2014-08-07 11:56:38.000000000 +0200
 310 @@ -2951,6 +2951,19 @@
 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    2014-08-07 11:56:19.000000000 +0200
 333 +++ new/qmp-commands.hx 2014-08-07 11:56:38.000000000 +0200
 334 @@ -3786,3 +3786,34 @@
 335  <- { "return": {} }
 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  2014-11-20 09:17:48.000000000 +0100
 373 @@ -0,0 +1,501 @@
 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 +    SAVE_STATE_CANCELLED
 403 +};
 404 +
 405 +
 406 +static struct SnapshotState {
 407 +    BlockDriverState *bs;
 408 +    size_t bs_pos;
 409 +    int state;
 410 +    Error *error;
 411 +    Error *blocker;
 412 +    int saved_vm_running;
 413 +    QEMUFile *file;
 414 +    int64_t total_time;
 415 +} snap_state;
 416 +
 417 +SaveVMInfo *qmp_query_savevm(Error **errp)
 418 +{
 419 +    SaveVMInfo *info = g_malloc0(sizeof(*info));
 420 +    struct SnapshotState *s = &snap_state;
 421 +
 422 +    if (s->state != SAVE_STATE_DONE) {
 423 +        info->has_bytes = true;
 424 +        info->bytes = s->bs_pos;
 425 +        switch (s->state) {
 426 +        case SAVE_STATE_ERROR:
 427 +            info->has_status = true;
 428 +            info->status = g_strdup("failed");
 429 +            info->has_total_time = true;
 430 +            info->total_time = s->total_time;
 431 +            if (s->error) {
 432 +                info->has_error = true;
 433 +                info->error = g_strdup(error_get_pretty(s->error));
 434 +            }
 435 +            break;
 436 +        case SAVE_STATE_ACTIVE:
 437 +            info->has_status = true;
 438 +            info->status = g_strdup("active");
 439 +            info->has_total_time = true;
 440 +            info->total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME)
 441 +                - s->total_time;
 442 +            break;
 443 +        case SAVE_STATE_COMPLETED:
 444 +            info->has_status = true;
 445 +            info->status = g_strdup("completed");
 446 +            info->has_total_time = true;
 447 +            info->total_time = s->total_time;
 448 +            break;
 449 +        }
 450 +    }
 451 +
 452 +    return info;
 453 +}
 454 +
 455 +static int save_snapshot_cleanup(void)
 456 +{
 457 +    int ret = 0;
 458 +
 459 +    DPRINTF("save_snapshot_cleanup\n");
 460 +
 461 +    snap_state.total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME) -
 462 +        snap_state.total_time;
 463 +
 464 +    if (snap_state.file) {
 465 +        ret = qemu_fclose(snap_state.file);
 466 +    }
 467 +
 468 +    if (snap_state.bs) {
 469 +        /* try to truncate, but ignore errors (will fail on block devices).
 470 +         * note: bdrv_read() need whole blocks, so we round up
 471 +         */
 472 +        size_t size = (snap_state.bs_pos + BDRV_SECTOR_SIZE) & BDRV_SECTOR_MASK;
 473 +        bdrv_truncate(snap_state.bs, size);
 474 +        bdrv_op_unblock_all(snap_state.bs, snap_state.blocker);
 475 +        error_free(snap_state.blocker);
 476 +        snap_state.blocker = NULL;
 477 +        bdrv_unref(snap_state.bs);
 478 +        snap_state.bs = NULL;
 479 +    }
 480 +
 481 +    return ret;
 482 +}
 483 +
 484 +static void save_snapshot_error(const char *fmt, ...)
 485 +{
 486 +    va_list ap;
 487 +    char *msg;
 488 +
 489 +    va_start(ap, fmt);
 490 +    msg = g_strdup_vprintf(fmt, ap);
 491 +    va_end(ap);
 492 +
 493 +    DPRINTF("save_snapshot_error: %s\n", msg);
 494 +
 495 +    if (!snap_state.error) {
 496 +        error_set(&snap_state.error, ERROR_CLASS_GENERIC_ERROR, "%s", msg);
 497 +    }
 498 +
 499 +    g_free (msg);
 500 +
 501 +    snap_state.state = SAVE_STATE_ERROR;
 502 +
 503 +    save_snapshot_cleanup();
 504 +}
 505 +
 506 +static void save_snapshot_completed(void)
 507 +{
 508 +    DPRINTF("save_snapshot_completed\n");
 509 +
 510 +    if (save_snapshot_cleanup() < 0) {
 511 +        snap_state.state = SAVE_STATE_ERROR;
 512 +    } else {
 513 +        snap_state.state = SAVE_STATE_COMPLETED;
 514 +    }
 515 +}
 516 +
 517 +static int block_state_close(void *opaque)
 518 +{
 519 +    snap_state.file = NULL;
 520 +    return bdrv_flush(snap_state.bs);
 521 +}
 522 +
 523 +static int block_state_put_buffer(void *opaque, const uint8_t *buf,
 524 +                                  int64_t pos, int size)
 525 +{
 526 +    int ret;
 527 +
 528 +    assert(pos == snap_state.bs_pos);
 529 +
 530 +    if ((ret = bdrv_pwrite(snap_state.bs, snap_state.bs_pos, buf, size)) > 0) {
 531 +        snap_state.bs_pos += ret;
 532 +    }
 533 +
 534 +    return ret;
 535 +}
 536 +
 537 +static void process_savevm_co(void *opaque)
 538 +{
 539 +    int ret;
 540 +    int64_t maxlen;
 541 +    MigrationParams params = {
 542 +        .blk = 0,
 543 +        .shared = 0
 544 +    };
 545 +
 546 +    snap_state.state = SAVE_STATE_ACTIVE;
 547 +
 548 +    qemu_mutex_unlock_iothread();
 549 +    ret = qemu_savevm_state_begin(snap_state.file, &params);
 550 +    qemu_mutex_lock_iothread();
 551 +
 552 +    if (ret < 0) {
 553 +        save_snapshot_error("qemu_savevm_state_begin failed");
 554 +        return;
 555 +    }
 556 +
 557 +    while (snap_state.state == SAVE_STATE_ACTIVE) {
 558 +        uint64_t pending_size;
 559 +
 560 +        pending_size = qemu_savevm_state_pending(snap_state.file, 0);
 561 +
 562 +        if (pending_size) {
 563 +                ret = qemu_savevm_state_iterate(snap_state.file);
 564 +                if (ret < 0) {
 565 +                    save_snapshot_error("qemu_savevm_state_iterate error %d", ret);
 566 +                    break;
 567 +                }
 568 +                DPRINTF("savevm inerate pending size %lu ret %d\n", pending_size, ret);
 569 +        } else {
 570 +            DPRINTF("done iterating\n");
 571 +            if (runstate_is_running()) {
 572 +                vm_stop(RUN_STATE_SAVE_VM);
 573 +            }
 574 +            DPRINTF("savevm inerate finished\n");
 575 +            qemu_savevm_state_complete(snap_state.file);
 576 +            DPRINTF("save complete\n");
 577 +            save_snapshot_completed();
 578 +            break;
 579 +        }
 580 +
 581 +        /* stop the VM if we get to the end of available space,
 582 +         * or if pending_size is just a few MB
 583 +         */
 584 +        maxlen = bdrv_getlength(snap_state.bs) - 30*1024*1024;
 585 +        if ((pending_size < 100000) ||
 586 +            ((snap_state.bs_pos + pending_size) >= maxlen)) {
 587 +            if (runstate_is_running()) {
 588 +                vm_stop(RUN_STATE_SAVE_VM);
 589 +            }
 590 +        }
 591 +    }
 592 +
 593 +    if(snap_state.state == SAVE_STATE_CANCELLED) {
 594 +        save_snapshot_completed();
 595 +        Error *errp = NULL;
 596 +        qmp_savevm_end(&errp);
 597 +    }
 598 +
 599 +}
 600 +
 601 +static const QEMUFileOps block_file_ops = {
 602 +    .put_buffer =     block_state_put_buffer,
 603 +    .close =          block_state_close,
 604 +};
 605 +
 606 +
 607 +void qmp_savevm_start(bool has_statefile, const char *statefile, Error **errp)
 608 +{
 609 +    BlockDriver *drv = NULL;
 610 +    Error *local_err = NULL;
 611 +
 612 +    int bdrv_oflags = BDRV_O_CACHE_WB | BDRV_O_RDWR;
 613 +    int ret;
 614 +
 615 +    if (snap_state.state != SAVE_STATE_DONE) {
 616 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 617 +                  "VM snapshot already started\n");
 618 +        return;
 619 +    }
 620 +
 621 +    /* initialize snapshot info */
 622 +    snap_state.saved_vm_running = runstate_is_running();
 623 +    snap_state.bs_pos = 0;
 624 +    snap_state.total_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
 625 +    snap_state.blocker = NULL;
 626 +
 627 +    if (snap_state.error) {
 628 +        error_free(snap_state.error);
 629 +        snap_state.error = NULL;
 630 +    }
 631 +
 632 +    if (!has_statefile) {
 633 +        vm_stop(RUN_STATE_SAVE_VM);
 634 +        snap_state.state = SAVE_STATE_COMPLETED;
 635 +        return;
 636 +    }
 637 +
 638 +    if (qemu_savevm_state_blocked(errp)) {
 639 +        return;
 640 +    }
 641 +
 642 +    /* Open the image */
 643 +    snap_state.bs = bdrv_new("vmstate", &local_err);
 644 +    if (local_err) {
 645 +        error_propagate(errp, local_err);
 646 +        goto restart;
 647 +    }
 648 +
 649 +    ret = bdrv_open(&snap_state.bs, statefile, NULL, NULL, bdrv_oflags, drv, &local_err);
 650 +    if (ret < 0) {
 651 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
 652 +        goto restart;
 653 +    }
 654 +
 655 +    snap_state.file = qemu_fopen_ops(&snap_state, &block_file_ops);
 656 +
 657 +    if (!snap_state.file) {
 658 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR, "failed to open '%s'", statefile);
 659 +        goto restart;
 660 +    }
 661 +
 662 +
 663 +    error_setg(&snap_state.blocker, "block device is in use by savevm");
 664 +    bdrv_op_block_all(snap_state.bs, snap_state.blocker);
 665 +
 666 +    Coroutine *co = qemu_coroutine_create(process_savevm_co);
 667 +    qemu_coroutine_enter(co, NULL);
 668 +
 669 +    return;
 670 +
 671 +restart:
 672 +
 673 +    save_snapshot_error("setup failed");
 674 +
 675 +    if (snap_state.saved_vm_running) {
 676 +        vm_start();
 677 +    }
 678 +}
 679 +
 680 +void qmp_savevm_end(Error **errp)
 681 +{
 682 +    if (snap_state.state == SAVE_STATE_DONE) {
 683 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 684 +                  "VM snapshot not started\n");
 685 +        return;
 686 +    }
 687 +
 688 +    if (snap_state.state == SAVE_STATE_ACTIVE) {
 689 +        snap_state.state = SAVE_STATE_CANCELLED;
 690 +        return;
 691 +    }
 692 +
 693 +    if (snap_state.saved_vm_running) {
 694 +        vm_start();
 695 +    }
 696 +
 697 +    snap_state.state = SAVE_STATE_DONE;
 698 +}
 699 +
 700 +void qmp_snapshot_drive(const char *device, const char *name, Error **errp)
 701 +{
 702 +    BlockDriverState *bs;
 703 +    QEMUSnapshotInfo sn1, *sn = &sn1;
 704 +    int ret;
 705 +#ifdef _WIN32
 706 +    struct _timeb tb;
 707 +#else
 708 +    struct timeval tv;
 709 +#endif
 710 +
 711 +    if (snap_state.state != SAVE_STATE_COMPLETED) {
 712 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 713 +                  "VM snapshot not ready/started\n");
 714 +        return;
 715 +    }
 716 +
 717 +    bs = bdrv_find(device);
 718 +    if (!bs) {
 719 +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 720 +        return;
 721 +    }
 722 +
 723 +    if (!bdrv_is_inserted(bs)) {
 724 +        error_set(errp, QERR_DEVICE_HAS_NO_MEDIUM, device);
 725 +        return;
 726 +    }
 727 +
 728 +    if (bdrv_is_read_only(bs)) {
 729 +        error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
 730 +        return;
 731 +    }
 732 +
 733 +    if (!bdrv_can_snapshot(bs)) {
 734 +        error_set(errp, QERR_UNSUPPORTED);
 735 +        return;
 736 +    }
 737 +
 738 +    if (bdrv_snapshot_find(bs, sn, name) >= 0) {
 739 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 740 +                  "snapshot '%s' already exists", name);
 741 +        return;
 742 +    }
 743 +
 744 +    sn = &sn1;
 745 +    memset(sn, 0, sizeof(*sn));
 746 +
 747 +#ifdef _WIN32
 748 +    _ftime(&tb);
 749 +    sn->date_sec = tb.time;
 750 +    sn->date_nsec = tb.millitm * 1000000;
 751 +#else
 752 +    gettimeofday(&tv, NULL);
 753 +    sn->date_sec = tv.tv_sec;
 754 +    sn->date_nsec = tv.tv_usec * 1000;
 755 +#endif
 756 +    sn->vm_clock_nsec = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
 757 +
 758 +    pstrcpy(sn->name, sizeof(sn->name), name);
 759 +
 760 +    sn->vm_state_size = 0; /* do not save state */
 761 +
 762 +    ret = bdrv_snapshot_create(bs, sn);
 763 +    if (ret < 0) {
 764 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 765 +                  "Error while creating snapshot on '%s'\n", device);
 766 +        return;
 767 +    }
 768 +}
 769 +
 770 +void qmp_delete_drive_snapshot(const char *device, const char *name,
 771 +                               Error **errp)
 772 +{
 773 +    BlockDriverState *bs;
 774 +    QEMUSnapshotInfo sn1, *sn = &sn1;
 775 +    Error *local_err = NULL;
 776 +
 777 +    int ret;
 778 +
 779 +    bs = bdrv_find(device);
 780 +    if (!bs) {
 781 +        error_set(errp, QERR_DEVICE_NOT_FOUND, device);
 782 +        return;
 783 +    }
 784 +    if (bdrv_is_read_only(bs)) {
 785 +        error_set(errp, QERR_DEVICE_IS_READ_ONLY, device);
 786 +        return;
 787 +    }
 788 +
 789 +    if (!bdrv_can_snapshot(bs)) {
 790 +        error_set(errp, QERR_UNSUPPORTED);
 791 +        return;
 792 +    }
 793 +
 794 +    if (bdrv_snapshot_find(bs, sn, name) < 0) {
 795 +        /* return success if snapshot does not exists */
 796 +        return;
 797 +    }
 798 +
 799 +    ret = bdrv_snapshot_delete(bs, NULL, name, &local_err);
 800 +    if (ret < 0) {
 801 +        error_set(errp, ERROR_CLASS_GENERIC_ERROR,
 802 +                  "Error while deleting snapshot on '%s'\n", device);
 803 +        return;
 804 +    }
 805 +}
 806 +
 807 +static int loadstate_get_buffer(void *opaque, uint8_t *buf, int64_t pos,
 808 +                                int size)
 809 +{
 810 +    BlockDriverState *bs = (BlockDriverState *)opaque;
 811 +    int64_t maxlen = bdrv_getlength(bs);
 812 +    if (pos > maxlen) {
 813 +        return -EIO;
 814 +    }
 815 +    if ((pos + size) > maxlen) {
 816 +        size = maxlen - pos - 1;
 817 +    }
 818 +    if (size == 0) {
 819 +        return 0;
 820 +    }
 821 +    return bdrv_pread(bs, pos, buf, size);
 822 +}
 823 +
 824 +static const QEMUFileOps loadstate_file_ops = {
 825 +    .get_buffer = loadstate_get_buffer,
 826 +};
 827 +
 828 +int load_state_from_blockdev(const char *filename)
 829 +{
 830 +    BlockDriverState *bs = NULL;
 831 +    BlockDriver *drv = NULL;
 832 +    Error *local_err = NULL;
 833 +    Error *blocker = NULL;
 834 +
 835 +    QEMUFile *f;
 836 +    int ret = -1;
 837 +
 838 +    bs = bdrv_new("vmstate", &error_abort);
 839 +    ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_CACHE_WB, drv, &local_err);
 840 +    error_setg(&blocker, "block device is in use by load state");
 841 +    bdrv_op_block_all(bs, blocker);
 842 +
 843 +    if (ret < 0) {
 844 +        error_report("Could not open VM state file");
 845 +        goto the_end;
 846 +    }
 847 +
 848 +    /* restore the VM state */
 849 +    f = qemu_fopen_ops(bs, &loadstate_file_ops);
 850 +    if (!f) {
 851 +        error_report("Could not open VM state file");
 852 +        ret = -EINVAL;
 853 +        goto the_end;
 854 +    }
 855 +
 856 +    qemu_system_reset(VMRESET_SILENT);
 857 +    ret = qemu_loadvm_state(f);
 858 +
 859 +    qemu_fclose(f);
 860 +    if (ret < 0) {
 861 +        error_report("Error %d while loading VM state", ret);
 862 +        goto the_end;
 863 +    }
 864 +
 865 +    ret = 0;
 866 +
 867 + the_end:
 868 +    if (bs) {
 869 +        bdrv_op_unblock_all(bs, blocker);
 870 +        error_free(blocker);
 871 +        bdrv_unref(bs);
 872 +    }
 873 +    return ret;
 874 +}
 875 Index: new/savevm.c
 876 ===================================================================
 877 --- new.orig/savevm.c   2014-08-02 15:03:21.000000000 +0200
 878 +++ new/savevm.c        2014-08-07 11:56:38.000000000 +0200
 879 @@ -596,11 +596,11 @@
 880      return false;
 881  }
 882
 883 -void qemu_savevm_state_begin(QEMUFile *f,
 884 +int qemu_savevm_state_begin(QEMUFile *f,
 885                               const MigrationParams *params)
 886  {
 887      SaveStateEntry *se;
 888 -    int ret;
 889 +    int ret = 0;
 890
 891      trace_savevm_state_begin();
 892      QTAILQ_FOREACH(se, &savevm_handlers, entry) {
 893 @@ -642,6 +642,7 @@
 894              break;
 895          }
 896      }
 897 +    return ret;
 898  }
 899
 900  /*
 901 @@ -690,7 +691,7 @@
 902      return ret;
 903  }
 904
 905 -void qemu_savevm_state_complete(QEMUFile *f)
 906 +int qemu_savevm_state_complete(QEMUFile *f)
 907  {
 908      SaveStateEntry *se;
 909      int ret;
 910 @@ -717,7 +718,7 @@
 911          trace_savevm_section_end(se->idstr, se->section_id);
 912          if (ret < 0) {
 913              qemu_file_set_error(f, ret);
 914 -            return;
 915 +            return ret;
 916          }
 917      }
 918
 919 @@ -746,6 +747,7 @@
 920
 921      qemu_put_byte(f, QEMU_VM_EOF);
 922      qemu_fflush(f);
 923 +    return qemu_file_get_error(f);
 924  }
 925
 926  uint64_t qemu_savevm_state_pending(QEMUFile *f, uint64_t max_size)
 927 Index: new/vl.c
 928 ===================================================================
 929 --- new.orig/vl.c       2014-08-07 11:55:57.000000000 +0200
 930 +++ new/vl.c    2014-08-07 11:56:38.000000000 +0200
 931 @@ -2930,6 +2930,7 @@
 932      int optind;
 933      const char *optarg;
 934      const char *loadvm = NULL;
 935 +    const char *loadstate = NULL;
 936      MachineClass *machine_class;
 937      const char *cpu_model;
 938      const char *vga_model = NULL;
 939 @@ -3625,6 +3626,9 @@
 940             case QEMU_OPTION_loadvm:
 941                 loadvm = optarg;
 942                 break;
 943 +            case QEMU_OPTION_loadstate:
 944 +                loadstate = optarg;
 945 +                break;
 946              case QEMU_OPTION_full_screen:
 947                  full_screen = 1;
 948                  break;
 949 @@ -4569,6 +4573,10 @@
 950          if (load_vmstate(loadvm) < 0) {
 951              autostart = 0;
 952          }
 953 +    } else if (loadstate) {
 954 +        if (load_state_from_blockdev(loadstate) < 0) {
 955 +            autostart = 0;
 956 +        }
 957      }
 958
 959      qdev_prop_check_global();