1 /* 2 * Block dirty bitmap postcopy migration 3 * 4 * Copyright IBM, Corp. 2009 5 * Copyright (c) 2016-2017 Virtuozzo International GmbH. All rights reserved. 6 * 7 * Authors: 8 * Liran Schour <lirans@il.ibm.com> 9 * Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> 10 * 11 * This work is licensed under the terms of the GNU GPL, version 2. See 12 * the COPYING file in the top-level directory. 13 * This file is derived from migration/block.c, so it's author and IBM copyright 14 * are here, although content is quite different. 15 * 16 * Contributions after 2012-01-13 are licensed under the terms of the 17 * GNU GPL, version 2 or (at your option) any later version. 18 * 19 * *** 20 * 21 * Here postcopy migration of dirty bitmaps is realized. Only QMP-addressable 22 * bitmaps are migrated. 23 * 24 * Bitmap migration implies creating bitmap with the same name and granularity 25 * in destination QEMU. If the bitmap with the same name (for the same node) 26 * already exists on destination an error will be generated. 27 * 28 * format of migration: 29 * 30 * # Header (shared for different chunk types) 31 * 1, 2 or 4 bytes: flags (see qemu_{put,put}_flags) 32 * [ 1 byte: node name size ] \ flags & DEVICE_NAME 33 * [ n bytes: node name ] / 34 * [ 1 byte: bitmap name size ] \ flags & BITMAP_NAME 35 * [ n bytes: bitmap name ] / 36 * 37 * # Start of bitmap migration (flags & START) 38 * header 39 * be64: granularity 40 * 1 byte: bitmap flags (corresponds to BdrvDirtyBitmap) 41 * bit 0 - bitmap is enabled 42 * bit 1 - bitmap is persistent 43 * bit 2 - bitmap is autoloading 44 * bits 3-7 - reserved, must be zero 45 * 46 * # Complete of bitmap migration (flags & COMPLETE) 47 * header 48 * 49 * # Data chunk of bitmap migration 50 * header 51 * be64: start sector 52 * be32: number of sectors 53 * [ be64: buffer size ] \ ! (flags & ZEROES) 54 * [ n bytes: buffer ] / 55 * 56 * The last chunk in stream should contain flags & EOS. The chunk may skip 57 * device and/or bitmap names, assuming them to be the same with the previous 58 * chunk. 59 */ 60 61 #include "qemu/osdep.h" 62 #include "block/block.h" 63 #include "block/block_int.h" 64 #include "sysemu/block-backend.h" 65 #include "sysemu/runstate.h" 66 #include "qemu/main-loop.h" 67 #include "qemu/error-report.h" 68 #include "migration/misc.h" 69 #include "migration/migration.h" 70 #include "qemu-file.h" 71 #include "migration/vmstate.h" 72 #include "migration/register.h" 73 #include "qemu/hbitmap.h" 74 #include "qemu/cutils.h" 75 #include "qapi/error.h" 76 #include "trace.h" 77 78 #define CHUNK_SIZE (1 << 10) 79 80 /* Flags occupy one, two or four bytes (Big Endian). The size is determined as 81 * follows: 82 * in first (most significant) byte bit 8 is clear --> one byte 83 * in first byte bit 8 is set --> two or four bytes, depending on second 84 * byte: 85 * | in second byte bit 8 is clear --> two bytes 86 * | in second byte bit 8 is set --> four bytes 87 */ 88 #define DIRTY_BITMAP_MIG_FLAG_EOS 0x01 89 #define DIRTY_BITMAP_MIG_FLAG_ZEROES 0x02 90 #define DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME 0x04 91 #define DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME 0x08 92 #define DIRTY_BITMAP_MIG_FLAG_START 0x10 93 #define DIRTY_BITMAP_MIG_FLAG_COMPLETE 0x20 94 #define DIRTY_BITMAP_MIG_FLAG_BITS 0x40 95 96 #define DIRTY_BITMAP_MIG_EXTRA_FLAGS 0x80 97 98 #define DIRTY_BITMAP_MIG_START_FLAG_ENABLED 0x01 99 #define DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT 0x02 100 /* 0x04 was "AUTOLOAD" flags on elder versions, no it is ignored */ 101 #define DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK 0xf8 102 103 typedef struct DirtyBitmapMigBitmapState { 104 /* Written during setup phase. */ 105 BlockDriverState *bs; 106 const char *node_name; 107 BdrvDirtyBitmap *bitmap; 108 uint64_t total_sectors; 109 uint64_t sectors_per_chunk; 110 QSIMPLEQ_ENTRY(DirtyBitmapMigBitmapState) entry; 111 uint8_t flags; 112 113 /* For bulk phase. */ 114 bool bulk_completed; 115 uint64_t cur_sector; 116 } DirtyBitmapMigBitmapState; 117 118 typedef struct DirtyBitmapMigState { 119 QSIMPLEQ_HEAD(, DirtyBitmapMigBitmapState) dbms_list; 120 121 bool bulk_completed; 122 bool no_bitmaps; 123 124 /* for send_bitmap_bits() */ 125 BlockDriverState *prev_bs; 126 BdrvDirtyBitmap *prev_bitmap; 127 } DirtyBitmapMigState; 128 129 typedef struct DirtyBitmapLoadState { 130 uint32_t flags; 131 char node_name[256]; 132 char bitmap_name[256]; 133 BlockDriverState *bs; 134 BdrvDirtyBitmap *bitmap; 135 } DirtyBitmapLoadState; 136 137 static DirtyBitmapMigState dirty_bitmap_mig_state; 138 139 typedef struct DirtyBitmapLoadBitmapState { 140 BlockDriverState *bs; 141 BdrvDirtyBitmap *bitmap; 142 bool migrated; 143 } DirtyBitmapLoadBitmapState; 144 static GSList *enabled_bitmaps; 145 QemuMutex finish_lock; 146 147 void init_dirty_bitmap_incoming_migration(void) 148 { 149 qemu_mutex_init(&finish_lock); 150 } 151 152 static uint32_t qemu_get_bitmap_flags(QEMUFile *f) 153 { 154 uint8_t flags = qemu_get_byte(f); 155 if (flags & DIRTY_BITMAP_MIG_EXTRA_FLAGS) { 156 flags = flags << 8 | qemu_get_byte(f); 157 if (flags & DIRTY_BITMAP_MIG_EXTRA_FLAGS) { 158 flags = flags << 16 | qemu_get_be16(f); 159 } 160 } 161 162 return flags; 163 } 164 165 static void qemu_put_bitmap_flags(QEMUFile *f, uint32_t flags) 166 { 167 /* The code currently do not send flags more than one byte */ 168 assert(!(flags & (0xffffff00 | DIRTY_BITMAP_MIG_EXTRA_FLAGS))); 169 170 qemu_put_byte(f, flags); 171 } 172 173 static void send_bitmap_header(QEMUFile *f, DirtyBitmapMigBitmapState *dbms, 174 uint32_t additional_flags) 175 { 176 BlockDriverState *bs = dbms->bs; 177 BdrvDirtyBitmap *bitmap = dbms->bitmap; 178 uint32_t flags = additional_flags; 179 trace_send_bitmap_header_enter(); 180 181 if (bs != dirty_bitmap_mig_state.prev_bs) { 182 dirty_bitmap_mig_state.prev_bs = bs; 183 flags |= DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME; 184 } 185 186 if (bitmap != dirty_bitmap_mig_state.prev_bitmap) { 187 dirty_bitmap_mig_state.prev_bitmap = bitmap; 188 flags |= DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME; 189 } 190 191 qemu_put_bitmap_flags(f, flags); 192 193 if (flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { 194 qemu_put_counted_string(f, dbms->node_name); 195 } 196 197 if (flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { 198 qemu_put_counted_string(f, bdrv_dirty_bitmap_name(bitmap)); 199 } 200 } 201 202 static void send_bitmap_start(QEMUFile *f, DirtyBitmapMigBitmapState *dbms) 203 { 204 send_bitmap_header(f, dbms, DIRTY_BITMAP_MIG_FLAG_START); 205 qemu_put_be32(f, bdrv_dirty_bitmap_granularity(dbms->bitmap)); 206 qemu_put_byte(f, dbms->flags); 207 } 208 209 static void send_bitmap_complete(QEMUFile *f, DirtyBitmapMigBitmapState *dbms) 210 { 211 send_bitmap_header(f, dbms, DIRTY_BITMAP_MIG_FLAG_COMPLETE); 212 } 213 214 static void send_bitmap_bits(QEMUFile *f, DirtyBitmapMigBitmapState *dbms, 215 uint64_t start_sector, uint32_t nr_sectors) 216 { 217 /* align for buffer_is_zero() */ 218 uint64_t align = 4 * sizeof(long); 219 uint64_t unaligned_size = 220 bdrv_dirty_bitmap_serialization_size( 221 dbms->bitmap, start_sector << BDRV_SECTOR_BITS, 222 (uint64_t)nr_sectors << BDRV_SECTOR_BITS); 223 uint64_t buf_size = QEMU_ALIGN_UP(unaligned_size, align); 224 uint8_t *buf = g_malloc0(buf_size); 225 uint32_t flags = DIRTY_BITMAP_MIG_FLAG_BITS; 226 227 bdrv_dirty_bitmap_serialize_part( 228 dbms->bitmap, buf, start_sector << BDRV_SECTOR_BITS, 229 (uint64_t)nr_sectors << BDRV_SECTOR_BITS); 230 231 if (buffer_is_zero(buf, buf_size)) { 232 g_free(buf); 233 buf = NULL; 234 flags |= DIRTY_BITMAP_MIG_FLAG_ZEROES; 235 } 236 237 trace_send_bitmap_bits(flags, start_sector, nr_sectors, buf_size); 238 239 send_bitmap_header(f, dbms, flags); 240 241 qemu_put_be64(f, start_sector); 242 qemu_put_be32(f, nr_sectors); 243 244 /* if a block is zero we need to flush here since the network 245 * bandwidth is now a lot higher than the storage device bandwidth. 246 * thus if we queue zero blocks we slow down the migration. */ 247 if (flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) { 248 qemu_fflush(f); 249 } else { 250 qemu_put_be64(f, buf_size); 251 qemu_put_buffer(f, buf, buf_size); 252 } 253 254 g_free(buf); 255 } 256 257 /* Called with iothread lock taken. */ 258 static void dirty_bitmap_mig_cleanup(void) 259 { 260 DirtyBitmapMigBitmapState *dbms; 261 262 while ((dbms = QSIMPLEQ_FIRST(&dirty_bitmap_mig_state.dbms_list)) != NULL) { 263 QSIMPLEQ_REMOVE_HEAD(&dirty_bitmap_mig_state.dbms_list, entry); 264 bdrv_dirty_bitmap_set_busy(dbms->bitmap, false); 265 bdrv_unref(dbms->bs); 266 g_free(dbms); 267 } 268 } 269 270 /* Called with iothread lock taken. */ 271 static int init_dirty_bitmap_migration(void) 272 { 273 BlockDriverState *bs; 274 BdrvDirtyBitmap *bitmap; 275 DirtyBitmapMigBitmapState *dbms; 276 Error *local_err = NULL; 277 278 dirty_bitmap_mig_state.bulk_completed = false; 279 dirty_bitmap_mig_state.prev_bs = NULL; 280 dirty_bitmap_mig_state.prev_bitmap = NULL; 281 dirty_bitmap_mig_state.no_bitmaps = false; 282 283 for (bs = bdrv_next_all_states(NULL); bs; bs = bdrv_next_all_states(bs)) { 284 const char *name = bdrv_get_device_or_node_name(bs); 285 286 for (bitmap = bdrv_dirty_bitmap_next(bs, NULL); bitmap; 287 bitmap = bdrv_dirty_bitmap_next(bs, bitmap)) 288 { 289 if (!bdrv_dirty_bitmap_name(bitmap)) { 290 continue; 291 } 292 293 if (!name || strcmp(name, "") == 0) { 294 error_report("Found bitmap '%s' in unnamed node %p. It can't " 295 "be migrated", bdrv_dirty_bitmap_name(bitmap), bs); 296 goto fail; 297 } 298 299 if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, 300 &local_err)) { 301 error_report_err(local_err); 302 goto fail; 303 } 304 305 bdrv_ref(bs); 306 bdrv_dirty_bitmap_set_busy(bitmap, true); 307 308 dbms = g_new0(DirtyBitmapMigBitmapState, 1); 309 dbms->bs = bs; 310 dbms->node_name = name; 311 dbms->bitmap = bitmap; 312 dbms->total_sectors = bdrv_nb_sectors(bs); 313 dbms->sectors_per_chunk = CHUNK_SIZE * 8 * 314 bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS; 315 if (bdrv_dirty_bitmap_enabled(bitmap)) { 316 dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED; 317 } 318 if (bdrv_dirty_bitmap_get_persistence(bitmap)) { 319 dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT; 320 } 321 322 QSIMPLEQ_INSERT_TAIL(&dirty_bitmap_mig_state.dbms_list, 323 dbms, entry); 324 } 325 } 326 327 /* unset migration flags here, to not roll back it */ 328 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 329 bdrv_dirty_bitmap_set_migration(dbms->bitmap, true); 330 } 331 332 if (QSIMPLEQ_EMPTY(&dirty_bitmap_mig_state.dbms_list)) { 333 dirty_bitmap_mig_state.no_bitmaps = true; 334 } 335 336 return 0; 337 338 fail: 339 dirty_bitmap_mig_cleanup(); 340 341 return -1; 342 } 343 344 /* Called with no lock taken. */ 345 static void bulk_phase_send_chunk(QEMUFile *f, DirtyBitmapMigBitmapState *dbms) 346 { 347 uint32_t nr_sectors = MIN(dbms->total_sectors - dbms->cur_sector, 348 dbms->sectors_per_chunk); 349 350 send_bitmap_bits(f, dbms, dbms->cur_sector, nr_sectors); 351 352 dbms->cur_sector += nr_sectors; 353 if (dbms->cur_sector >= dbms->total_sectors) { 354 dbms->bulk_completed = true; 355 } 356 } 357 358 /* Called with no lock taken. */ 359 static void bulk_phase(QEMUFile *f, bool limit) 360 { 361 DirtyBitmapMigBitmapState *dbms; 362 363 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 364 while (!dbms->bulk_completed) { 365 bulk_phase_send_chunk(f, dbms); 366 if (limit && qemu_file_rate_limit(f)) { 367 return; 368 } 369 } 370 } 371 372 dirty_bitmap_mig_state.bulk_completed = true; 373 } 374 375 /* for SaveVMHandlers */ 376 static void dirty_bitmap_save_cleanup(void *opaque) 377 { 378 dirty_bitmap_mig_cleanup(); 379 } 380 381 static int dirty_bitmap_save_iterate(QEMUFile *f, void *opaque) 382 { 383 trace_dirty_bitmap_save_iterate(migration_in_postcopy()); 384 385 if (migration_in_postcopy() && !dirty_bitmap_mig_state.bulk_completed) { 386 bulk_phase(f, true); 387 } 388 389 qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); 390 391 return dirty_bitmap_mig_state.bulk_completed; 392 } 393 394 /* Called with iothread lock taken. */ 395 396 static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque) 397 { 398 DirtyBitmapMigBitmapState *dbms; 399 trace_dirty_bitmap_save_complete_enter(); 400 401 if (!dirty_bitmap_mig_state.bulk_completed) { 402 bulk_phase(f, false); 403 } 404 405 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 406 send_bitmap_complete(f, dbms); 407 } 408 409 qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); 410 411 trace_dirty_bitmap_save_complete_finish(); 412 413 dirty_bitmap_mig_cleanup(); 414 return 0; 415 } 416 417 static void dirty_bitmap_save_pending(QEMUFile *f, void *opaque, 418 uint64_t max_size, 419 uint64_t *res_precopy_only, 420 uint64_t *res_compatible, 421 uint64_t *res_postcopy_only) 422 { 423 DirtyBitmapMigBitmapState *dbms; 424 uint64_t pending = 0; 425 426 qemu_mutex_lock_iothread(); 427 428 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 429 uint64_t gran = bdrv_dirty_bitmap_granularity(dbms->bitmap); 430 uint64_t sectors = dbms->bulk_completed ? 0 : 431 dbms->total_sectors - dbms->cur_sector; 432 433 pending += DIV_ROUND_UP(sectors * BDRV_SECTOR_SIZE, gran); 434 } 435 436 qemu_mutex_unlock_iothread(); 437 438 trace_dirty_bitmap_save_pending(pending, max_size); 439 440 *res_postcopy_only += pending; 441 } 442 443 /* First occurrence of this bitmap. It should be created if doesn't exist */ 444 static int dirty_bitmap_load_start(QEMUFile *f, DirtyBitmapLoadState *s) 445 { 446 Error *local_err = NULL; 447 uint32_t granularity = qemu_get_be32(f); 448 uint8_t flags = qemu_get_byte(f); 449 450 if (s->bitmap) { 451 error_report("Bitmap with the same name ('%s') already exists on " 452 "destination", bdrv_dirty_bitmap_name(s->bitmap)); 453 return -EINVAL; 454 } else { 455 s->bitmap = bdrv_create_dirty_bitmap(s->bs, granularity, 456 s->bitmap_name, &local_err); 457 if (!s->bitmap) { 458 error_report_err(local_err); 459 return -EINVAL; 460 } 461 } 462 463 if (flags & DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK) { 464 error_report("Unknown flags in migrated dirty bitmap header: %x", 465 flags); 466 return -EINVAL; 467 } 468 469 if (flags & DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT) { 470 bdrv_dirty_bitmap_set_persistence(s->bitmap, true); 471 } 472 473 bdrv_disable_dirty_bitmap(s->bitmap); 474 if (flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED) { 475 DirtyBitmapLoadBitmapState *b; 476 477 bdrv_dirty_bitmap_create_successor(s->bs, s->bitmap, &local_err); 478 if (local_err) { 479 error_report_err(local_err); 480 return -EINVAL; 481 } 482 483 b = g_new(DirtyBitmapLoadBitmapState, 1); 484 b->bs = s->bs; 485 b->bitmap = s->bitmap; 486 b->migrated = false; 487 enabled_bitmaps = g_slist_prepend(enabled_bitmaps, b); 488 } 489 490 return 0; 491 } 492 493 void dirty_bitmap_mig_before_vm_start(void) 494 { 495 GSList *item; 496 497 qemu_mutex_lock(&finish_lock); 498 499 for (item = enabled_bitmaps; item; item = g_slist_next(item)) { 500 DirtyBitmapLoadBitmapState *b = item->data; 501 502 if (b->migrated) { 503 bdrv_enable_dirty_bitmap_locked(b->bitmap); 504 } else { 505 bdrv_dirty_bitmap_enable_successor(b->bitmap); 506 } 507 508 g_free(b); 509 } 510 511 g_slist_free(enabled_bitmaps); 512 enabled_bitmaps = NULL; 513 514 qemu_mutex_unlock(&finish_lock); 515 } 516 517 static void dirty_bitmap_load_complete(QEMUFile *f, DirtyBitmapLoadState *s) 518 { 519 GSList *item; 520 trace_dirty_bitmap_load_complete(); 521 bdrv_dirty_bitmap_deserialize_finish(s->bitmap); 522 523 qemu_mutex_lock(&finish_lock); 524 525 for (item = enabled_bitmaps; item; item = g_slist_next(item)) { 526 DirtyBitmapLoadBitmapState *b = item->data; 527 528 if (b->bitmap == s->bitmap) { 529 b->migrated = true; 530 break; 531 } 532 } 533 534 if (bdrv_dirty_bitmap_has_successor(s->bitmap)) { 535 bdrv_dirty_bitmap_lock(s->bitmap); 536 if (enabled_bitmaps == NULL) { 537 /* in postcopy */ 538 bdrv_reclaim_dirty_bitmap_locked(s->bs, s->bitmap, &error_abort); 539 bdrv_enable_dirty_bitmap_locked(s->bitmap); 540 } else { 541 /* target not started, successor must be empty */ 542 int64_t count = bdrv_get_dirty_count(s->bitmap); 543 BdrvDirtyBitmap *ret = bdrv_reclaim_dirty_bitmap_locked(s->bs, 544 s->bitmap, 545 NULL); 546 /* bdrv_reclaim_dirty_bitmap can fail only on no successor (it 547 * must be) or on merge fail, but merge can't fail when second 548 * bitmap is empty 549 */ 550 assert(ret == s->bitmap && 551 count == bdrv_get_dirty_count(s->bitmap)); 552 } 553 bdrv_dirty_bitmap_unlock(s->bitmap); 554 } 555 556 qemu_mutex_unlock(&finish_lock); 557 } 558 559 static int dirty_bitmap_load_bits(QEMUFile *f, DirtyBitmapLoadState *s) 560 { 561 uint64_t first_byte = qemu_get_be64(f) << BDRV_SECTOR_BITS; 562 uint64_t nr_bytes = (uint64_t)qemu_get_be32(f) << BDRV_SECTOR_BITS; 563 trace_dirty_bitmap_load_bits_enter(first_byte >> BDRV_SECTOR_BITS, 564 nr_bytes >> BDRV_SECTOR_BITS); 565 566 if (s->flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) { 567 trace_dirty_bitmap_load_bits_zeroes(); 568 bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte, nr_bytes, 569 false); 570 } else { 571 size_t ret; 572 uint8_t *buf; 573 uint64_t buf_size = qemu_get_be64(f); 574 uint64_t needed_size = 575 bdrv_dirty_bitmap_serialization_size(s->bitmap, 576 first_byte, nr_bytes); 577 578 if (needed_size > buf_size || 579 buf_size > QEMU_ALIGN_UP(needed_size, 4 * sizeof(long)) 580 /* Here used same alignment as in send_bitmap_bits */ 581 ) { 582 error_report("Migrated bitmap granularity doesn't " 583 "match the destination bitmap '%s' granularity", 584 bdrv_dirty_bitmap_name(s->bitmap)); 585 return -EINVAL; 586 } 587 588 buf = g_malloc(buf_size); 589 ret = qemu_get_buffer(f, buf, buf_size); 590 if (ret != buf_size) { 591 error_report("Failed to read bitmap bits"); 592 g_free(buf); 593 return -EIO; 594 } 595 596 bdrv_dirty_bitmap_deserialize_part(s->bitmap, buf, first_byte, nr_bytes, 597 false); 598 g_free(buf); 599 } 600 601 return 0; 602 } 603 604 static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s) 605 { 606 Error *local_err = NULL; 607 bool nothing; 608 s->flags = qemu_get_bitmap_flags(f); 609 trace_dirty_bitmap_load_header(s->flags); 610 611 nothing = s->flags == (s->flags & DIRTY_BITMAP_MIG_FLAG_EOS); 612 613 if (s->flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { 614 if (!qemu_get_counted_string(f, s->node_name)) { 615 error_report("Unable to read node name string"); 616 return -EINVAL; 617 } 618 s->bs = bdrv_lookup_bs(s->node_name, s->node_name, &local_err); 619 if (!s->bs) { 620 error_report_err(local_err); 621 return -EINVAL; 622 } 623 } else if (!s->bs && !nothing) { 624 error_report("Error: block device name is not set"); 625 return -EINVAL; 626 } 627 628 if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { 629 if (!qemu_get_counted_string(f, s->bitmap_name)) { 630 error_report("Unable to read bitmap name string"); 631 return -EINVAL; 632 } 633 s->bitmap = bdrv_find_dirty_bitmap(s->bs, s->bitmap_name); 634 635 /* bitmap may be NULL here, it wouldn't be an error if it is the 636 * first occurrence of the bitmap */ 637 if (!s->bitmap && !(s->flags & DIRTY_BITMAP_MIG_FLAG_START)) { 638 error_report("Error: unknown dirty bitmap " 639 "'%s' for block device '%s'", 640 s->bitmap_name, s->node_name); 641 return -EINVAL; 642 } 643 } else if (!s->bitmap && !nothing) { 644 error_report("Error: block device name is not set"); 645 return -EINVAL; 646 } 647 648 return 0; 649 } 650 651 static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) 652 { 653 static DirtyBitmapLoadState s; 654 int ret = 0; 655 656 trace_dirty_bitmap_load_enter(); 657 658 if (version_id != 1) { 659 return -EINVAL; 660 } 661 662 do { 663 ret = dirty_bitmap_load_header(f, &s); 664 if (ret < 0) { 665 return ret; 666 } 667 668 if (s.flags & DIRTY_BITMAP_MIG_FLAG_START) { 669 ret = dirty_bitmap_load_start(f, &s); 670 } else if (s.flags & DIRTY_BITMAP_MIG_FLAG_COMPLETE) { 671 dirty_bitmap_load_complete(f, &s); 672 } else if (s.flags & DIRTY_BITMAP_MIG_FLAG_BITS) { 673 ret = dirty_bitmap_load_bits(f, &s); 674 } 675 676 if (!ret) { 677 ret = qemu_file_get_error(f); 678 } 679 680 if (ret) { 681 return ret; 682 } 683 } while (!(s.flags & DIRTY_BITMAP_MIG_FLAG_EOS)); 684 685 trace_dirty_bitmap_load_success(); 686 return 0; 687 } 688 689 static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque) 690 { 691 DirtyBitmapMigBitmapState *dbms = NULL; 692 if (init_dirty_bitmap_migration() < 0) { 693 return -1; 694 } 695 696 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 697 send_bitmap_start(f, dbms); 698 } 699 qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); 700 701 return 0; 702 } 703 704 static bool dirty_bitmap_is_active(void *opaque) 705 { 706 return migrate_dirty_bitmaps() && !dirty_bitmap_mig_state.no_bitmaps; 707 } 708 709 static bool dirty_bitmap_is_active_iterate(void *opaque) 710 { 711 return dirty_bitmap_is_active(opaque) && !runstate_is_running(); 712 } 713 714 static bool dirty_bitmap_has_postcopy(void *opaque) 715 { 716 return true; 717 } 718 719 static SaveVMHandlers savevm_dirty_bitmap_handlers = { 720 .save_setup = dirty_bitmap_save_setup, 721 .save_live_complete_postcopy = dirty_bitmap_save_complete, 722 .save_live_complete_precopy = dirty_bitmap_save_complete, 723 .has_postcopy = dirty_bitmap_has_postcopy, 724 .save_live_pending = dirty_bitmap_save_pending, 725 .save_live_iterate = dirty_bitmap_save_iterate, 726 .is_active_iterate = dirty_bitmap_is_active_iterate, 727 .load_state = dirty_bitmap_load, 728 .save_cleanup = dirty_bitmap_save_cleanup, 729 .is_active = dirty_bitmap_is_active, 730 }; 731 732 void dirty_bitmap_mig_init(void) 733 { 734 QSIMPLEQ_INIT(&dirty_bitmap_mig_state.dbms_list); 735 736 register_savevm_live(NULL, "dirty-bitmap", 0, 1, 737 &savevm_dirty_bitmap_handlers, 738 &dirty_bitmap_mig_state); 739 } 740