block-migration.c

   1 /*
   2  * QEMU live block migration
   3  *
   4  * Copyright IBM, Corp. 2009
   5  *
   6  * Authors:
   7  *  Liran Schour   <lirans@il.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 "block_int.h"
  16 #include "hw/hw.h"
  17 #include "qemu-queue.h"
  18 #include "qemu-timer.h"
  19 #include "monitor.h"
  20 #include "block-migration.h"
  21 #include "migration.h"
  22 #include <assert.h>
  23
  24 #define BLOCK_SIZE (BDRV_SECTORS_PER_DIRTY_CHUNK << BDRV_SECTOR_BITS)
  25
  26 #define BLK_MIG_FLAG_DEVICE_BLOCK       0x01
  27 #define BLK_MIG_FLAG_EOS                0x02
  28 #define BLK_MIG_FLAG_PROGRESS           0x04
  29
  30 #define MAX_IS_ALLOCATED_SEARCH 65536
  31
  32 //#define DEBUG_BLK_MIGRATION
  33
  34 #ifdef DEBUG_BLK_MIGRATION
  35 #define DPRINTF(fmt, ...) \
  36     do { printf("blk_migration: " fmt, ## __VA_ARGS__); } while (0)
  37 #else
  38 #define DPRINTF(fmt, ...) \
  39     do { } while (0)
  40 #endif
  41
  42 typedef struct BlkMigDevState {
  43     BlockDriverState *bs;
  44     int bulk_completed;
  45     int shared_base;
  46     int64_t cur_sector;
  47     int64_t cur_dirty;
  48     int64_t completed_sectors;
  49     int64_t total_sectors;
  50     int64_t dirty;
  51     QSIMPLEQ_ENTRY(BlkMigDevState) entry;
  52     unsigned long *aio_bitmap;
  53 } BlkMigDevState;
  54
  55 typedef struct BlkMigBlock {
  56     uint8_t *buf;
  57     BlkMigDevState *bmds;
  58     int64_t sector;
  59     int nr_sectors;
  60     struct iovec iov;
  61     QEMUIOVector qiov;
  62     BlockDriverAIOCB *aiocb;
  63     int ret;
  64     int64_t time;
  65     QSIMPLEQ_ENTRY(BlkMigBlock) entry;
  66 } BlkMigBlock;
  67
  68 typedef struct BlkMigState {
  69     int blk_enable;
  70     int shared_base;
  71     QSIMPLEQ_HEAD(bmds_list, BlkMigDevState) bmds_list;
  72     QSIMPLEQ_HEAD(blk_list, BlkMigBlock) blk_list;
  73     int submitted;
  74     int read_done;
  75     int transferred;
  76     int64_t total_sector_sum;
  77     int prev_progress;
  78     int bulk_completed;
  79     long double total_time;
  80     int reads;
  81 } BlkMigState;
  82
  83 static BlkMigState block_mig_state;
  84
  85 static void blk_send(QEMUFile *f, BlkMigBlock * blk)
  86 {
  87     int len;
  88
  89     /* sector number and flags */
  90     qemu_put_be64(f, (blk->sector << BDRV_SECTOR_BITS)
  91                      | BLK_MIG_FLAG_DEVICE_BLOCK);
  92
  93     /* device name */
  94     len = strlen(blk->bmds->bs->device_name);
  95     qemu_put_byte(f, len);
  96     qemu_put_buffer(f, (uint8_t *)blk->bmds->bs->device_name, len);
  97
  98     qemu_put_buffer(f, blk->buf, BLOCK_SIZE);
  99 }
 100
 101 int blk_mig_active(void)
 102 {
 103     return !QSIMPLEQ_EMPTY(&block_mig_state.bmds_list);
 104 }
 105
 106 uint64_t blk_mig_bytes_transferred(void)
 107 {
 108     BlkMigDevState *bmds;
 109     uint64_t sum = 0;
 110
 111     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 112         sum += bmds->completed_sectors;
 113     }
 114     return sum << BDRV_SECTOR_BITS;
 115 }
 116
 117 uint64_t blk_mig_bytes_remaining(void)
 118 {
 119     return blk_mig_bytes_total() - blk_mig_bytes_transferred();
 120 }
 121
 122 uint64_t blk_mig_bytes_total(void)
 123 {
 124     BlkMigDevState *bmds;
 125     uint64_t sum = 0;
 126
 127     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 128         sum += bmds->total_sectors;
 129     }
 130     return sum << BDRV_SECTOR_BITS;
 131 }
 132
 133 static inline void add_avg_read_time(int64_t time)
 134 {
 135     block_mig_state.reads++;
 136     block_mig_state.total_time += time;
 137 }
 138
 139 static inline long double compute_read_bwidth(void)
 140 {
 141     assert(block_mig_state.total_time != 0);
 142     return  (block_mig_state.reads * BLOCK_SIZE)/ block_mig_state.total_time;
 143 }
 144
 145 static int bmds_aio_inflight(BlkMigDevState *bmds, int64_t sector)
 146 {
 147     int64_t chunk = sector / (int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK;
 148
 149     if (bmds->aio_bitmap &&
 150         (sector << BDRV_SECTOR_BITS) < bdrv_getlength(bmds->bs)) {
 151         return !!(bmds->aio_bitmap[chunk / (sizeof(unsigned long) * 8)] &
 152             (1UL << (chunk % (sizeof(unsigned long) * 8))));
 153     } else {
 154         return 0;
 155     }
 156 }
 157
 158 static void bmds_set_aio_inflight(BlkMigDevState *bmds, int64_t sector_num,
 159                              int nb_sectors, int set)
 160 {
 161     int64_t start, end;
 162     unsigned long val, idx, bit;
 163
 164     start = sector_num / BDRV_SECTORS_PER_DIRTY_CHUNK;
 165     end = (sector_num + nb_sectors - 1) / BDRV_SECTORS_PER_DIRTY_CHUNK;
 166
 167     for (; start <= end; start++) {
 168         idx = start / (sizeof(unsigned long) * 8);
 169         bit = start % (sizeof(unsigned long) * 8);
 170         val = bmds->aio_bitmap[idx];
 171         if (set) {
 172             if (!(val & (1UL << bit))) {
 173                 val |= 1UL << bit;
 174             }
 175         } else {
 176             if (val & (1UL << bit)) {
 177                 val &= ~(1UL << bit);
 178             }
 179         }
 180         bmds->aio_bitmap[idx] = val;
 181     }
 182 }
 183
 184 static void alloc_aio_bitmap(BlkMigDevState *bmds)
 185 {
 186     BlockDriverState *bs = bmds->bs;
 187     int64_t bitmap_size;
 188
 189     bitmap_size = (bdrv_getlength(bs) >> BDRV_SECTOR_BITS) +
 190             BDRV_SECTORS_PER_DIRTY_CHUNK * 8 - 1;
 191     bitmap_size /= BDRV_SECTORS_PER_DIRTY_CHUNK * 8;
 192
 193     bmds->aio_bitmap = qemu_mallocz(bitmap_size);
 194 }
 195
 196 static void blk_mig_read_cb(void *opaque, int ret)
 197 {
 198     BlkMigBlock *blk = opaque;
 199
 200     blk->ret = ret;
 201
 202     blk->time = qemu_get_clock_ns(rt_clock) - blk->time;
 203
 204     add_avg_read_time(blk->time);
 205
 206     QSIMPLEQ_INSERT_TAIL(&block_mig_state.blk_list, blk, entry);
 207     bmds_set_aio_inflight(blk->bmds, blk->sector, blk->nr_sectors, 0);
 208
 209     block_mig_state.submitted--;
 210     block_mig_state.read_done++;
 211     assert(block_mig_state.submitted >= 0);
 212 }
 213
 214 static int mig_save_device_bulk(Monitor *mon, QEMUFile *f,
 215                                 BlkMigDevState *bmds)
 216 {
 217     int64_t total_sectors = bmds->total_sectors;
 218     int64_t cur_sector = bmds->cur_sector;
 219     BlockDriverState *bs = bmds->bs;
 220     BlkMigBlock *blk;
 221     int nr_sectors;
 222
 223     if (bmds->shared_base) {
 224         while (cur_sector < total_sectors &&
 225                !bdrv_is_allocated(bs, cur_sector, MAX_IS_ALLOCATED_SEARCH,
 226                                   &nr_sectors)) {
 227             cur_sector += nr_sectors;
 228         }
 229     }
 230
 231     if (cur_sector >= total_sectors) {
 232         bmds->cur_sector = bmds->completed_sectors = total_sectors;
 233         return 1;
 234     }
 235
 236     bmds->completed_sectors = cur_sector;
 237
 238     cur_sector &= ~((int64_t)BDRV_SECTORS_PER_DIRTY_CHUNK - 1);
 239
 240     /* we are going to transfer a full block even if it is not allocated */
 241     nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
 242
 243     if (total_sectors - cur_sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
 244         nr_sectors = total_sectors - cur_sector;
 245     }
 246
 247     blk = qemu_malloc(sizeof(BlkMigBlock));
 248     blk->buf = qemu_malloc(BLOCK_SIZE);
 249     blk->bmds = bmds;
 250     blk->sector = cur_sector;
 251     blk->nr_sectors = nr_sectors;
 252
 253     blk->iov.iov_base = blk->buf;
 254     blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
 255     qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
 256
 257     blk->time = qemu_get_clock_ns(rt_clock);
 258
 259     blk->aiocb = bdrv_aio_readv(bs, cur_sector, &blk->qiov,
 260                                 nr_sectors, blk_mig_read_cb, blk);
 261     if (!blk->aiocb) {
 262         goto error;
 263     }
 264     block_mig_state.submitted++;
 265
 266     bdrv_reset_dirty(bs, cur_sector, nr_sectors);
 267     bmds->cur_sector = cur_sector + nr_sectors;
 268
 269     return (bmds->cur_sector >= total_sectors);
 270
 271 error:
 272     monitor_printf(mon, "Error reading sector %" PRId64 "\n", cur_sector);
 273     qemu_file_set_error(f);
 274     qemu_free(blk->buf);
 275     qemu_free(blk);
 276     return 0;
 277 }
 278
 279 static void set_dirty_tracking(int enable)
 280 {
 281     BlkMigDevState *bmds;
 282
 283     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 284         bdrv_set_dirty_tracking(bmds->bs, enable);
 285     }
 286 }
 287
 288 static void init_blk_migration_it(void *opaque, BlockDriverState *bs)
 289 {
 290     Monitor *mon = opaque;
 291     BlkMigDevState *bmds;
 292     int64_t sectors;
 293
 294     if (!bdrv_is_read_only(bs)) {
 295         sectors = bdrv_getlength(bs) >> BDRV_SECTOR_BITS;
 296         if (sectors <= 0) {
 297             return;
 298         }
 299
 300         bmds = qemu_mallocz(sizeof(BlkMigDevState));
 301         bmds->bs = bs;
 302         bmds->bulk_completed = 0;
 303         bmds->total_sectors = sectors;
 304         bmds->completed_sectors = 0;
 305         bmds->shared_base = block_mig_state.shared_base;
 306         alloc_aio_bitmap(bmds);
 307
 308         block_mig_state.total_sector_sum += sectors;
 309
 310         if (bmds->shared_base) {
 311             monitor_printf(mon, "Start migration for %s with shared base "
 312                                 "image\n",
 313                            bs->device_name);
 314         } else {
 315             monitor_printf(mon, "Start full migration for %s\n",
 316                            bs->device_name);
 317         }
 318
 319         QSIMPLEQ_INSERT_TAIL(&block_mig_state.bmds_list, bmds, entry);
 320     }
 321 }
 322
 323 static void init_blk_migration(Monitor *mon, QEMUFile *f)
 324 {
 325     block_mig_state.submitted = 0;
 326     block_mig_state.read_done = 0;
 327     block_mig_state.transferred = 0;
 328     block_mig_state.total_sector_sum = 0;
 329     block_mig_state.prev_progress = -1;
 330     block_mig_state.bulk_completed = 0;
 331     block_mig_state.total_time = 0;
 332     block_mig_state.reads = 0;
 333
 334     bdrv_iterate(init_blk_migration_it, mon);
 335 }
 336
 337 static int blk_mig_save_bulked_block(Monitor *mon, QEMUFile *f)
 338 {
 339     int64_t completed_sector_sum = 0;
 340     BlkMigDevState *bmds;
 341     int progress;
 342     int ret = 0;
 343
 344     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 345         if (bmds->bulk_completed == 0) {
 346             if (mig_save_device_bulk(mon, f, bmds) == 1) {
 347                 /* completed bulk section for this device */
 348                 bmds->bulk_completed = 1;
 349             }
 350             completed_sector_sum += bmds->completed_sectors;
 351             ret = 1;
 352             break;
 353         } else {
 354             completed_sector_sum += bmds->completed_sectors;
 355         }
 356     }
 357
 358     progress = completed_sector_sum * 100 / block_mig_state.total_sector_sum;
 359     if (progress != block_mig_state.prev_progress) {
 360         block_mig_state.prev_progress = progress;
 361         qemu_put_be64(f, (progress << BDRV_SECTOR_BITS)
 362                          | BLK_MIG_FLAG_PROGRESS);
 363         monitor_printf(mon, "Completed %d %%\r", progress);
 364         monitor_flush(mon);
 365     }
 366
 367     return ret;
 368 }
 369
 370 static void blk_mig_reset_dirty_cursor(void)
 371 {
 372     BlkMigDevState *bmds;
 373
 374     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 375         bmds->cur_dirty = 0;
 376     }
 377 }
 378
 379 static int mig_save_device_dirty(Monitor *mon, QEMUFile *f,
 380                                  BlkMigDevState *bmds, int is_async)
 381 {
 382     BlkMigBlock *blk;
 383     int64_t total_sectors = bmds->total_sectors;
 384     int64_t sector;
 385     int nr_sectors;
 386
 387     for (sector = bmds->cur_dirty; sector < bmds->total_sectors;) {
 388         if (bmds_aio_inflight(bmds, sector))
 389             qemu_aio_flush();
 390         if (bdrv_get_dirty(bmds->bs, sector)) {
 391
 392             if (total_sectors - sector < BDRV_SECTORS_PER_DIRTY_CHUNK) {
 393                 nr_sectors = total_sectors - sector;
 394             } else {
 395                 nr_sectors = BDRV_SECTORS_PER_DIRTY_CHUNK;
 396             }
 397             blk = qemu_malloc(sizeof(BlkMigBlock));
 398             blk->buf = qemu_malloc(BLOCK_SIZE);
 399             blk->bmds = bmds;
 400             blk->sector = sector;
 401             blk->nr_sectors = nr_sectors;
 402
 403             if (is_async) {
 404                 blk->iov.iov_base = blk->buf;
 405                 blk->iov.iov_len = nr_sectors * BDRV_SECTOR_SIZE;
 406                 qemu_iovec_init_external(&blk->qiov, &blk->iov, 1);
 407
 408                 blk->time = qemu_get_clock_ns(rt_clock);
 409
 410                 blk->aiocb = bdrv_aio_readv(bmds->bs, sector, &blk->qiov,
 411                                             nr_sectors, blk_mig_read_cb, blk);
 412                 if (!blk->aiocb) {
 413                     goto error;
 414                 }
 415                 block_mig_state.submitted++;
 416                 bmds_set_aio_inflight(bmds, sector, nr_sectors, 1);
 417             } else {
 418                 if (bdrv_read(bmds->bs, sector, blk->buf,
 419                               nr_sectors) < 0) {
 420                     goto error;
 421                 }
 422                 blk_send(f, blk);
 423
 424                 qemu_free(blk->buf);
 425                 qemu_free(blk);
 426             }
 427
 428             bdrv_reset_dirty(bmds->bs, sector, nr_sectors);
 429             break;
 430         }
 431         sector += BDRV_SECTORS_PER_DIRTY_CHUNK;
 432         bmds->cur_dirty = sector;
 433     }
 434
 435     return (bmds->cur_dirty >= bmds->total_sectors);
 436
 437 error:
 438     monitor_printf(mon, "Error reading sector %" PRId64 "\n", sector);
 439     qemu_file_set_error(f);
 440     qemu_free(blk->buf);
 441     qemu_free(blk);
 442     return 0;
 443 }
 444
 445 static int blk_mig_save_dirty_block(Monitor *mon, QEMUFile *f, int is_async)
 446 {
 447     BlkMigDevState *bmds;
 448     int ret = 0;
 449
 450     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 451         if (mig_save_device_dirty(mon, f, bmds, is_async) == 0) {
 452             ret = 1;
 453             break;
 454         }
 455     }
 456
 457     return ret;
 458 }
 459
 460 static void flush_blks(QEMUFile* f)
 461 {
 462     BlkMigBlock *blk;
 463
 464     DPRINTF("%s Enter submitted %d read_done %d transferred %d\n",
 465             __FUNCTION__, block_mig_state.submitted, block_mig_state.read_done,
 466             block_mig_state.transferred);
 467
 468     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
 469         if (qemu_file_rate_limit(f)) {
 470             break;
 471         }
 472         if (blk->ret < 0) {
 473             qemu_file_set_error(f);
 474             break;
 475         }
 476         blk_send(f, blk);
 477
 478         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
 479         qemu_free(blk->buf);
 480         qemu_free(blk);
 481
 482         block_mig_state.read_done--;
 483         block_mig_state.transferred++;
 484         assert(block_mig_state.read_done >= 0);
 485     }
 486
 487     DPRINTF("%s Exit submitted %d read_done %d transferred %d\n", __FUNCTION__,
 488             block_mig_state.submitted, block_mig_state.read_done,
 489             block_mig_state.transferred);
 490 }
 491
 492 static int64_t get_remaining_dirty(void)
 493 {
 494     BlkMigDevState *bmds;
 495     int64_t dirty = 0;
 496
 497     QSIMPLEQ_FOREACH(bmds, &block_mig_state.bmds_list, entry) {
 498         dirty += bdrv_get_dirty_count(bmds->bs);
 499     }
 500
 501     return dirty * BLOCK_SIZE;
 502 }
 503
 504 static int is_stage2_completed(void)
 505 {
 506     int64_t remaining_dirty;
 507     long double bwidth;
 508
 509     if (block_mig_state.bulk_completed == 1) {
 510
 511         remaining_dirty = get_remaining_dirty();
 512         if (remaining_dirty == 0) {
 513             return 1;
 514         }
 515
 516         bwidth = compute_read_bwidth();
 517
 518         if ((remaining_dirty / bwidth) <=
 519             migrate_max_downtime()) {
 520             /* finish stage2 because we think that we can finish remaing work
 521                below max_downtime */
 522
 523             return 1;
 524         }
 525     }
 526
 527     return 0;
 528 }
 529
 530 static void blk_mig_cleanup(Monitor *mon)
 531 {
 532     BlkMigDevState *bmds;
 533     BlkMigBlock *blk;
 534
 535     while ((bmds = QSIMPLEQ_FIRST(&block_mig_state.bmds_list)) != NULL) {
 536         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.bmds_list, entry);
 537         qemu_free(bmds->aio_bitmap);
 538         qemu_free(bmds);
 539     }
 540
 541     while ((blk = QSIMPLEQ_FIRST(&block_mig_state.blk_list)) != NULL) {
 542         QSIMPLEQ_REMOVE_HEAD(&block_mig_state.blk_list, entry);
 543         qemu_free(blk->buf);
 544         qemu_free(blk);
 545     }
 546
 547     set_dirty_tracking(0);
 548
 549     monitor_printf(mon, "\n");
 550 }
 551
 552 static int block_save_live(Monitor *mon, QEMUFile *f, int stage, void *opaque)
 553 {
 554     DPRINTF("Enter save live stage %d submitted %d transferred %d\n",
 555             stage, block_mig_state.submitted, block_mig_state.transferred);
 556
 557     if (stage < 0) {
 558         blk_mig_cleanup(mon);
 559         return 0;
 560     }
 561
 562     if (block_mig_state.blk_enable != 1) {
 563         /* no need to migrate storage */
 564         qemu_put_be64(f, BLK_MIG_FLAG_EOS);
 565         return 1;
 566     }
 567
 568     if (stage == 1) {
 569         init_blk_migration(mon, f);
 570
 571         /* start track dirty blocks */
 572         set_dirty_tracking(1);
 573     }
 574
 575     flush_blks(f);
 576
 577     if (qemu_file_has_error(f)) {
 578         blk_mig_cleanup(mon);
 579         return 0;
 580     }
 581
 582     blk_mig_reset_dirty_cursor();
 583
 584     if (stage == 2) {
 585         /* control the rate of transfer */
 586         while ((block_mig_state.submitted +
 587                 block_mig_state.read_done) * BLOCK_SIZE <
 588                qemu_file_get_rate_limit(f)) {
 589             if (block_mig_state.bulk_completed == 0) {
 590                 /* first finish the bulk phase */
 591                 if (blk_mig_save_bulked_block(mon, f) == 0) {
 592                     /* finished saving bulk on all devices */
 593                     block_mig_state.bulk_completed = 1;
 594                 }
 595             } else {
 596                 if (blk_mig_save_dirty_block(mon, f, 1) == 0) {
 597                     /* no more dirty blocks */
 598                     break;
 599                 }
 600             }
 601         }
 602
 603         flush_blks(f);
 604
 605         if (qemu_file_has_error(f)) {
 606             blk_mig_cleanup(mon);
 607             return 0;
 608         }
 609     }
 610
 611     if (stage == 3) {
 612         /* we know for sure that save bulk is completed and
 613            all async read completed */
 614         assert(block_mig_state.submitted == 0);
 615
 616         while (blk_mig_save_dirty_block(mon, f, 0) != 0);
 617         blk_mig_cleanup(mon);
 618
 619         /* report completion */
 620         qemu_put_be64(f, (100 << BDRV_SECTOR_BITS) | BLK_MIG_FLAG_PROGRESS);
 621
 622         if (qemu_file_has_error(f)) {
 623             return 0;
 624         }
 625
 626         monitor_printf(mon, "Block migration completed\n");
 627     }
 628
 629     qemu_put_be64(f, BLK_MIG_FLAG_EOS);
 630
 631     return ((stage == 2) && is_stage2_completed());
 632 }
 633
 634 static int block_load(QEMUFile *f, void *opaque, int version_id)
 635 {
 636     static int banner_printed;
 637     int len, flags;
 638     char device_name[256];
 639     int64_t addr;
 640     BlockDriverState *bs;
 641     uint8_t *buf;
 642
 643     do {
 644         addr = qemu_get_be64(f);
 645
 646         flags = addr & ~BDRV_SECTOR_MASK;
 647         addr >>= BDRV_SECTOR_BITS;
 648
 649         if (flags & BLK_MIG_FLAG_DEVICE_BLOCK) {
 650             int ret;
 651             /* get device name */
 652             len = qemu_get_byte(f);
 653             qemu_get_buffer(f, (uint8_t *)device_name, len);
 654             device_name[len] = '\0';
 655
 656             bs = bdrv_find(device_name);
 657             if (!bs) {
 658                 fprintf(stderr, "Error unknown block device %s\n",
 659                         device_name);
 660                 return -EINVAL;
 661             }
 662
 663             buf = qemu_malloc(BLOCK_SIZE);
 664
 665             qemu_get_buffer(f, buf, BLOCK_SIZE);
 666             ret = bdrv_write(bs, addr, buf, BDRV_SECTORS_PER_DIRTY_CHUNK);
 667
 668             qemu_free(buf);
 669             if (ret < 0) {
 670                 return ret;
 671             }
 672         } else if (flags & BLK_MIG_FLAG_PROGRESS) {
 673             if (!banner_printed) {
 674                 printf("Receiving block device images\n");
 675                 banner_printed = 1;
 676             }
 677             printf("Completed %d %%%c", (int)addr,
 678                    (addr == 100) ? '\n' : '\r');
 679             fflush(stdout);
 680         } else if (!(flags & BLK_MIG_FLAG_EOS)) {
 681             fprintf(stderr, "Unknown flags\n");
 682             return -EINVAL;
 683         }
 684         if (qemu_file_has_error(f)) {
 685             return -EIO;
 686         }
 687     } while (!(flags & BLK_MIG_FLAG_EOS));
 688
 689     return 0;
 690 }
 691
 692 static void block_set_params(int blk_enable, int shared_base, void *opaque)
 693 {
 694     block_mig_state.blk_enable = blk_enable;
 695     block_mig_state.shared_base = shared_base;
 696
 697     /* shared base means that blk_enable = 1 */
 698     block_mig_state.blk_enable |= shared_base;
 699 }
 700
 701 void blk_mig_init(void)
 702 {
 703     QSIMPLEQ_INIT(&block_mig_state.bmds_list);
 704     QSIMPLEQ_INIT(&block_mig_state.blk_list);
 705
 706     register_savevm_live(NULL, "block", 0, 1, block_set_params,
 707                          block_save_live, NULL, block_load, &block_mig_state);
 708 }