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_EACH_DIRTY_BITMAP(bs, bitmap) { 287 if (!bdrv_dirty_bitmap_name(bitmap)) { 288 continue; 289 } 290 291 if (!name || strcmp(name, "") == 0) { 292 error_report("Found bitmap '%s' in unnamed node %p. It can't " 293 "be migrated", bdrv_dirty_bitmap_name(bitmap), bs); 294 goto fail; 295 } 296 297 if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, 298 &local_err)) { 299 error_report_err(local_err); 300 goto fail; 301 } 302 303 bdrv_ref(bs); 304 bdrv_dirty_bitmap_set_busy(bitmap, true); 305 306 dbms = g_new0(DirtyBitmapMigBitmapState, 1); 307 dbms->bs = bs; 308 dbms->node_name = name; 309 dbms->bitmap = bitmap; 310 dbms->total_sectors = bdrv_nb_sectors(bs); 311 dbms->sectors_per_chunk = CHUNK_SIZE * 8 * 312 bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS; 313 if (bdrv_dirty_bitmap_enabled(bitmap)) { 314 dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED; 315 } 316 if (bdrv_dirty_bitmap_get_persistence(bitmap)) { 317 dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT; 318 } 319 320 QSIMPLEQ_INSERT_TAIL(&dirty_bitmap_mig_state.dbms_list, 321 dbms, entry); 322 } 323 } 324 325 /* unset migration flags here, to not roll back it */ 326 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 327 bdrv_dirty_bitmap_skip_store(dbms->bitmap, true); 328 } 329 330 if (QSIMPLEQ_EMPTY(&dirty_bitmap_mig_state.dbms_list)) { 331 dirty_bitmap_mig_state.no_bitmaps = true; 332 } 333 334 return 0; 335 336 fail: 337 dirty_bitmap_mig_cleanup(); 338 339 return -1; 340 } 341 342 /* Called with no lock taken. */ 343 static void bulk_phase_send_chunk(QEMUFile *f, DirtyBitmapMigBitmapState *dbms) 344 { 345 uint32_t nr_sectors = MIN(dbms->total_sectors - dbms->cur_sector, 346 dbms->sectors_per_chunk); 347 348 send_bitmap_bits(f, dbms, dbms->cur_sector, nr_sectors); 349 350 dbms->cur_sector += nr_sectors; 351 if (dbms->cur_sector >= dbms->total_sectors) { 352 dbms->bulk_completed = true; 353 } 354 } 355 356 /* Called with no lock taken. */ 357 static void bulk_phase(QEMUFile *f, bool limit) 358 { 359 DirtyBitmapMigBitmapState *dbms; 360 361 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 362 while (!dbms->bulk_completed) { 363 bulk_phase_send_chunk(f, dbms); 364 if (limit && qemu_file_rate_limit(f)) { 365 return; 366 } 367 } 368 } 369 370 dirty_bitmap_mig_state.bulk_completed = true; 371 } 372 373 /* for SaveVMHandlers */ 374 static void dirty_bitmap_save_cleanup(void *opaque) 375 { 376 dirty_bitmap_mig_cleanup(); 377 } 378 379 static int dirty_bitmap_save_iterate(QEMUFile *f, void *opaque) 380 { 381 trace_dirty_bitmap_save_iterate(migration_in_postcopy()); 382 383 if (migration_in_postcopy() && !dirty_bitmap_mig_state.bulk_completed) { 384 bulk_phase(f, true); 385 } 386 387 qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); 388 389 return dirty_bitmap_mig_state.bulk_completed; 390 } 391 392 /* Called with iothread lock taken. */ 393 394 static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque) 395 { 396 DirtyBitmapMigBitmapState *dbms; 397 trace_dirty_bitmap_save_complete_enter(); 398 399 if (!dirty_bitmap_mig_state.bulk_completed) { 400 bulk_phase(f, false); 401 } 402 403 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 404 send_bitmap_complete(f, dbms); 405 } 406 407 qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); 408 409 trace_dirty_bitmap_save_complete_finish(); 410 411 dirty_bitmap_mig_cleanup(); 412 return 0; 413 } 414 415 static void dirty_bitmap_save_pending(QEMUFile *f, void *opaque, 416 uint64_t max_size, 417 uint64_t *res_precopy_only, 418 uint64_t *res_compatible, 419 uint64_t *res_postcopy_only) 420 { 421 DirtyBitmapMigBitmapState *dbms; 422 uint64_t pending = 0; 423 424 qemu_mutex_lock_iothread(); 425 426 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 427 uint64_t gran = bdrv_dirty_bitmap_granularity(dbms->bitmap); 428 uint64_t sectors = dbms->bulk_completed ? 0 : 429 dbms->total_sectors - dbms->cur_sector; 430 431 pending += DIV_ROUND_UP(sectors * BDRV_SECTOR_SIZE, gran); 432 } 433 434 qemu_mutex_unlock_iothread(); 435 436 trace_dirty_bitmap_save_pending(pending, max_size); 437 438 *res_postcopy_only += pending; 439 } 440 441 /* First occurrence of this bitmap. It should be created if doesn't exist */ 442 static int dirty_bitmap_load_start(QEMUFile *f, DirtyBitmapLoadState *s) 443 { 444 Error *local_err = NULL; 445 uint32_t granularity = qemu_get_be32(f); 446 uint8_t flags = qemu_get_byte(f); 447 448 if (s->bitmap) { 449 error_report("Bitmap with the same name ('%s') already exists on " 450 "destination", bdrv_dirty_bitmap_name(s->bitmap)); 451 return -EINVAL; 452 } else { 453 s->bitmap = bdrv_create_dirty_bitmap(s->bs, granularity, 454 s->bitmap_name, &local_err); 455 if (!s->bitmap) { 456 error_report_err(local_err); 457 return -EINVAL; 458 } 459 } 460 461 if (flags & DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK) { 462 error_report("Unknown flags in migrated dirty bitmap header: %x", 463 flags); 464 return -EINVAL; 465 } 466 467 if (flags & DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT) { 468 bdrv_dirty_bitmap_set_persistence(s->bitmap, true); 469 } 470 471 bdrv_disable_dirty_bitmap(s->bitmap); 472 if (flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED) { 473 DirtyBitmapLoadBitmapState *b; 474 475 bdrv_dirty_bitmap_create_successor(s->bitmap, &local_err); 476 if (local_err) { 477 error_report_err(local_err); 478 return -EINVAL; 479 } 480 481 b = g_new(DirtyBitmapLoadBitmapState, 1); 482 b->bs = s->bs; 483 b->bitmap = s->bitmap; 484 b->migrated = false; 485 enabled_bitmaps = g_slist_prepend(enabled_bitmaps, b); 486 } 487 488 return 0; 489 } 490 491 void dirty_bitmap_mig_before_vm_start(void) 492 { 493 GSList *item; 494 495 qemu_mutex_lock(&finish_lock); 496 497 for (item = enabled_bitmaps; item; item = g_slist_next(item)) { 498 DirtyBitmapLoadBitmapState *b = item->data; 499 500 if (b->migrated) { 501 bdrv_enable_dirty_bitmap_locked(b->bitmap); 502 } else { 503 bdrv_dirty_bitmap_enable_successor(b->bitmap); 504 } 505 506 g_free(b); 507 } 508 509 g_slist_free(enabled_bitmaps); 510 enabled_bitmaps = NULL; 511 512 qemu_mutex_unlock(&finish_lock); 513 } 514 515 static void dirty_bitmap_load_complete(QEMUFile *f, DirtyBitmapLoadState *s) 516 { 517 GSList *item; 518 trace_dirty_bitmap_load_complete(); 519 bdrv_dirty_bitmap_deserialize_finish(s->bitmap); 520 521 qemu_mutex_lock(&finish_lock); 522 523 for (item = enabled_bitmaps; item; item = g_slist_next(item)) { 524 DirtyBitmapLoadBitmapState *b = item->data; 525 526 if (b->bitmap == s->bitmap) { 527 b->migrated = true; 528 break; 529 } 530 } 531 532 if (bdrv_dirty_bitmap_has_successor(s->bitmap)) { 533 bdrv_dirty_bitmap_lock(s->bitmap); 534 if (enabled_bitmaps == NULL) { 535 /* in postcopy */ 536 bdrv_reclaim_dirty_bitmap_locked(s->bitmap, &error_abort); 537 bdrv_enable_dirty_bitmap_locked(s->bitmap); 538 } else { 539 /* target not started, successor must be empty */ 540 int64_t count = bdrv_get_dirty_count(s->bitmap); 541 BdrvDirtyBitmap *ret = bdrv_reclaim_dirty_bitmap_locked(s->bitmap, 542 NULL); 543 /* bdrv_reclaim_dirty_bitmap can fail only on no successor (it 544 * must be) or on merge fail, but merge can't fail when second 545 * bitmap is empty 546 */ 547 assert(ret == s->bitmap && 548 count == bdrv_get_dirty_count(s->bitmap)); 549 } 550 bdrv_dirty_bitmap_unlock(s->bitmap); 551 } 552 553 qemu_mutex_unlock(&finish_lock); 554 } 555 556 static int dirty_bitmap_load_bits(QEMUFile *f, DirtyBitmapLoadState *s) 557 { 558 uint64_t first_byte = qemu_get_be64(f) << BDRV_SECTOR_BITS; 559 uint64_t nr_bytes = (uint64_t)qemu_get_be32(f) << BDRV_SECTOR_BITS; 560 trace_dirty_bitmap_load_bits_enter(first_byte >> BDRV_SECTOR_BITS, 561 nr_bytes >> BDRV_SECTOR_BITS); 562 563 if (s->flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) { 564 trace_dirty_bitmap_load_bits_zeroes(); 565 bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte, nr_bytes, 566 false); 567 } else { 568 size_t ret; 569 uint8_t *buf; 570 uint64_t buf_size = qemu_get_be64(f); 571 uint64_t needed_size = 572 bdrv_dirty_bitmap_serialization_size(s->bitmap, 573 first_byte, nr_bytes); 574 575 if (needed_size > buf_size || 576 buf_size > QEMU_ALIGN_UP(needed_size, 4 * sizeof(long)) 577 /* Here used same alignment as in send_bitmap_bits */ 578 ) { 579 error_report("Migrated bitmap granularity doesn't " 580 "match the destination bitmap '%s' granularity", 581 bdrv_dirty_bitmap_name(s->bitmap)); 582 return -EINVAL; 583 } 584 585 buf = g_malloc(buf_size); 586 ret = qemu_get_buffer(f, buf, buf_size); 587 if (ret != buf_size) { 588 error_report("Failed to read bitmap bits"); 589 g_free(buf); 590 return -EIO; 591 } 592 593 bdrv_dirty_bitmap_deserialize_part(s->bitmap, buf, first_byte, nr_bytes, 594 false); 595 g_free(buf); 596 } 597 598 return 0; 599 } 600 601 static int dirty_bitmap_load_header(QEMUFile *f, DirtyBitmapLoadState *s) 602 { 603 Error *local_err = NULL; 604 bool nothing; 605 s->flags = qemu_get_bitmap_flags(f); 606 trace_dirty_bitmap_load_header(s->flags); 607 608 nothing = s->flags == (s->flags & DIRTY_BITMAP_MIG_FLAG_EOS); 609 610 if (s->flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { 611 if (!qemu_get_counted_string(f, s->node_name)) { 612 error_report("Unable to read node name string"); 613 return -EINVAL; 614 } 615 s->bs = bdrv_lookup_bs(s->node_name, s->node_name, &local_err); 616 if (!s->bs) { 617 error_report_err(local_err); 618 return -EINVAL; 619 } 620 } else if (!s->bs && !nothing) { 621 error_report("Error: block device name is not set"); 622 return -EINVAL; 623 } 624 625 if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { 626 if (!qemu_get_counted_string(f, s->bitmap_name)) { 627 error_report("Unable to read bitmap name string"); 628 return -EINVAL; 629 } 630 s->bitmap = bdrv_find_dirty_bitmap(s->bs, s->bitmap_name); 631 632 /* bitmap may be NULL here, it wouldn't be an error if it is the 633 * first occurrence of the bitmap */ 634 if (!s->bitmap && !(s->flags & DIRTY_BITMAP_MIG_FLAG_START)) { 635 error_report("Error: unknown dirty bitmap " 636 "'%s' for block device '%s'", 637 s->bitmap_name, s->node_name); 638 return -EINVAL; 639 } 640 } else if (!s->bitmap && !nothing) { 641 error_report("Error: block device name is not set"); 642 return -EINVAL; 643 } 644 645 return 0; 646 } 647 648 static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) 649 { 650 static DirtyBitmapLoadState s; 651 int ret = 0; 652 653 trace_dirty_bitmap_load_enter(); 654 655 if (version_id != 1) { 656 return -EINVAL; 657 } 658 659 do { 660 ret = dirty_bitmap_load_header(f, &s); 661 if (ret < 0) { 662 return ret; 663 } 664 665 if (s.flags & DIRTY_BITMAP_MIG_FLAG_START) { 666 ret = dirty_bitmap_load_start(f, &s); 667 } else if (s.flags & DIRTY_BITMAP_MIG_FLAG_COMPLETE) { 668 dirty_bitmap_load_complete(f, &s); 669 } else if (s.flags & DIRTY_BITMAP_MIG_FLAG_BITS) { 670 ret = dirty_bitmap_load_bits(f, &s); 671 } 672 673 if (!ret) { 674 ret = qemu_file_get_error(f); 675 } 676 677 if (ret) { 678 return ret; 679 } 680 } while (!(s.flags & DIRTY_BITMAP_MIG_FLAG_EOS)); 681 682 trace_dirty_bitmap_load_success(); 683 return 0; 684 } 685 686 static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque) 687 { 688 DirtyBitmapMigBitmapState *dbms = NULL; 689 if (init_dirty_bitmap_migration() < 0) { 690 return -1; 691 } 692 693 QSIMPLEQ_FOREACH(dbms, &dirty_bitmap_mig_state.dbms_list, entry) { 694 send_bitmap_start(f, dbms); 695 } 696 qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); 697 698 return 0; 699 } 700 701 static bool dirty_bitmap_is_active(void *opaque) 702 { 703 return migrate_dirty_bitmaps() && !dirty_bitmap_mig_state.no_bitmaps; 704 } 705 706 static bool dirty_bitmap_is_active_iterate(void *opaque) 707 { 708 return dirty_bitmap_is_active(opaque) && !runstate_is_running(); 709 } 710 711 static bool dirty_bitmap_has_postcopy(void *opaque) 712 { 713 return true; 714 } 715 716 static SaveVMHandlers savevm_dirty_bitmap_handlers = { 717 .save_setup = dirty_bitmap_save_setup, 718 .save_live_complete_postcopy = dirty_bitmap_save_complete, 719 .save_live_complete_precopy = dirty_bitmap_save_complete, 720 .has_postcopy = dirty_bitmap_has_postcopy, 721 .save_live_pending = dirty_bitmap_save_pending, 722 .save_live_iterate = dirty_bitmap_save_iterate, 723 .is_active_iterate = dirty_bitmap_is_active_iterate, 724 .load_state = dirty_bitmap_load, 725 .save_cleanup = dirty_bitmap_save_cleanup, 726 .is_active = dirty_bitmap_is_active, 727 }; 728 729 void dirty_bitmap_mig_init(void) 730 { 731 QSIMPLEQ_INIT(&dirty_bitmap_mig_state.dbms_list); 732 733 register_savevm_live("dirty-bitmap", 0, 1, 734 &savevm_dirty_bitmap_handlers, 735 &dirty_bitmap_mig_state); 736 } 737