| /* |
| * Block dirty bitmap postcopy migration |
| * |
| * Copyright IBM, Corp. 2009 |
| * Copyright (c) 2016-2017 Virtuozzo International GmbH. All rights reserved. |
| * |
| * Authors: |
| * Liran Schour <lirans@il.ibm.com> |
| * Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> |
| * |
| * This work is licensed under the terms of the GNU GPL, version 2. See |
| * the COPYING file in the top-level directory. |
| * This file is derived from migration/block.c, so it's author and IBM copyright |
| * are here, although content is quite different. |
| * |
| * Contributions after 2012-01-13 are licensed under the terms of the |
| * GNU GPL, version 2 or (at your option) any later version. |
| * |
| * *** |
| * |
| * Here postcopy migration of dirty bitmaps is realized. Only QMP-addressable |
| * bitmaps are migrated. |
| * |
| * Bitmap migration implies creating bitmap with the same name and granularity |
| * in destination QEMU. If the bitmap with the same name (for the same node) |
| * already exists on destination an error will be generated. |
| * |
| * format of migration: |
| * |
| * # Header (shared for different chunk types) |
| * 1, 2 or 4 bytes: flags (see qemu_{put,put}_flags) |
| * [ 1 byte: node alias size ] \ flags & DEVICE_NAME |
| * [ n bytes: node alias ] / |
| * [ 1 byte: bitmap alias size ] \ flags & BITMAP_NAME |
| * [ n bytes: bitmap alias ] / |
| * |
| * # Start of bitmap migration (flags & START) |
| * header |
| * be64: granularity |
| * 1 byte: bitmap flags (corresponds to BdrvDirtyBitmap) |
| * bit 0 - bitmap is enabled |
| * bit 1 - bitmap is persistent |
| * bit 2 - bitmap is autoloading |
| * bits 3-7 - reserved, must be zero |
| * |
| * # Complete of bitmap migration (flags & COMPLETE) |
| * header |
| * |
| * # Data chunk of bitmap migration |
| * header |
| * be64: start sector |
| * be32: number of sectors |
| * [ be64: buffer size ] \ ! (flags & ZEROES) |
| * [ n bytes: buffer ] / |
| * |
| * The last chunk in stream should contain flags & EOS. The chunk may skip |
| * device and/or bitmap names, assuming them to be the same with the previous |
| * chunk. |
| */ |
| |
| #include "qemu/osdep.h" |
| #include "block/block.h" |
| #include "block/block_int.h" |
| #include "block/dirty-bitmap.h" |
| #include "sysemu/block-backend.h" |
| #include "sysemu/runstate.h" |
| #include "qemu/main-loop.h" |
| #include "qemu/error-report.h" |
| #include "migration/misc.h" |
| #include "migration/migration.h" |
| #include "qemu-file.h" |
| #include "migration/vmstate.h" |
| #include "migration/register.h" |
| #include "qemu/hbitmap.h" |
| #include "qemu/cutils.h" |
| #include "qemu/id.h" |
| #include "qapi/error.h" |
| #include "qapi/qapi-commands-migration.h" |
| #include "qapi/qapi-visit-migration.h" |
| #include "qapi/clone-visitor.h" |
| #include "trace.h" |
| #include "options.h" |
| |
| #define CHUNK_SIZE (1 << 10) |
| |
| /* Flags occupy one, two or four bytes (Big Endian). The size is determined as |
| * follows: |
| * in first (most significant) byte bit 8 is clear --> one byte |
| * in first byte bit 8 is set --> two or four bytes, depending on second |
| * byte: |
| * | in second byte bit 8 is clear --> two bytes |
| * | in second byte bit 8 is set --> four bytes |
| */ |
| #define DIRTY_BITMAP_MIG_FLAG_EOS 0x01 |
| #define DIRTY_BITMAP_MIG_FLAG_ZEROES 0x02 |
| #define DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME 0x04 |
| #define DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME 0x08 |
| #define DIRTY_BITMAP_MIG_FLAG_START 0x10 |
| #define DIRTY_BITMAP_MIG_FLAG_COMPLETE 0x20 |
| #define DIRTY_BITMAP_MIG_FLAG_BITS 0x40 |
| |
| #define DIRTY_BITMAP_MIG_EXTRA_FLAGS 0x80 |
| |
| #define DIRTY_BITMAP_MIG_START_FLAG_ENABLED 0x01 |
| #define DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT 0x02 |
| /* 0x04 was "AUTOLOAD" flags on older versions, now it is ignored */ |
| #define DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK 0xf8 |
| |
| /* State of one bitmap during save process */ |
| typedef struct SaveBitmapState { |
| /* Written during setup phase. */ |
| BlockDriverState *bs; |
| char *node_alias; |
| char *bitmap_alias; |
| BdrvDirtyBitmap *bitmap; |
| uint64_t total_sectors; |
| uint64_t sectors_per_chunk; |
| QSIMPLEQ_ENTRY(SaveBitmapState) entry; |
| uint8_t flags; |
| |
| /* For bulk phase. */ |
| bool bulk_completed; |
| uint64_t cur_sector; |
| } SaveBitmapState; |
| |
| /* State of the dirty bitmap migration (DBM) during save process */ |
| typedef struct DBMSaveState { |
| QSIMPLEQ_HEAD(, SaveBitmapState) dbms_list; |
| |
| bool bulk_completed; |
| bool no_bitmaps; |
| |
| /* for send_bitmap_bits() */ |
| BlockDriverState *prev_bs; |
| BdrvDirtyBitmap *prev_bitmap; |
| } DBMSaveState; |
| |
| typedef struct LoadBitmapState { |
| BlockDriverState *bs; |
| BdrvDirtyBitmap *bitmap; |
| bool migrated; |
| bool enabled; |
| } LoadBitmapState; |
| |
| /* State of the dirty bitmap migration (DBM) during load process */ |
| typedef struct DBMLoadState { |
| uint32_t flags; |
| char node_alias[256]; |
| char bitmap_alias[256]; |
| char bitmap_name[BDRV_BITMAP_MAX_NAME_SIZE + 1]; |
| BlockDriverState *bs; |
| BdrvDirtyBitmap *bitmap; |
| |
| bool before_vm_start_handled; /* set in dirty_bitmap_mig_before_vm_start */ |
| BitmapMigrationBitmapAlias *bmap_inner; |
| |
| /* |
| * cancelled |
| * Incoming migration is cancelled for some reason. That means that we |
| * still should read our chunks from migration stream, to not affect other |
| * migration objects (like RAM), but just ignore them and do not touch any |
| * bitmaps or nodes. |
| */ |
| bool cancelled; |
| |
| GSList *bitmaps; |
| QemuMutex lock; /* protect bitmaps */ |
| } DBMLoadState; |
| |
| typedef struct DBMState { |
| DBMSaveState save; |
| DBMLoadState load; |
| } DBMState; |
| |
| static DBMState dbm_state; |
| |
| /* For hash tables that map node/bitmap names to aliases */ |
| typedef struct AliasMapInnerNode { |
| char *string; |
| GHashTable *subtree; |
| } AliasMapInnerNode; |
| |
| static void free_alias_map_inner_node(void *amin_ptr) |
| { |
| AliasMapInnerNode *amin = amin_ptr; |
| |
| g_free(amin->string); |
| g_hash_table_unref(amin->subtree); |
| g_free(amin); |
| } |
| |
| /** |
| * Construct an alias map based on the given QMP structure. |
| * |
| * (Note that we cannot store such maps in the MigrationParameters |
| * object, because that struct is defined by the QAPI schema, which |
| * makes it basically impossible to have dicts with arbitrary keys. |
| * Therefore, we instead have to construct these maps when migration |
| * starts.) |
| * |
| * @bbm is the block_bitmap_mapping from the migration parameters. |
| * |
| * If @name_to_alias is true, the returned hash table will map node |
| * and bitmap names to their respective aliases (for outgoing |
| * migration). |
| * |
| * If @name_to_alias is false, the returned hash table will map node |
| * and bitmap aliases to their respective names (for incoming |
| * migration). |
| * |
| * The hash table maps node names/aliases to AliasMapInnerNode |
| * objects, whose .string is the respective node alias/name, and whose |
| * .subtree table maps bitmap names/aliases to the respective bitmap |
| * alias/name. |
| */ |
| static GHashTable *construct_alias_map(const BitmapMigrationNodeAliasList *bbm, |
| bool name_to_alias, |
| Error **errp) |
| { |
| GHashTable *alias_map; |
| size_t max_node_name_len = sizeof_field(BlockDriverState, node_name) - 1; |
| |
| alias_map = g_hash_table_new_full(g_str_hash, g_str_equal, |
| g_free, free_alias_map_inner_node); |
| |
| for (; bbm; bbm = bbm->next) { |
| const BitmapMigrationNodeAlias *bmna = bbm->value; |
| const BitmapMigrationBitmapAliasList *bmbal; |
| AliasMapInnerNode *amin; |
| GHashTable *bitmaps_map; |
| const char *node_map_from, *node_map_to; |
| GDestroyNotify gdn; |
| |
| if (!id_wellformed(bmna->alias)) { |
| error_setg(errp, "The node alias '%s' is not well-formed", |
| bmna->alias); |
| goto fail; |
| } |
| |
| if (strlen(bmna->alias) > UINT8_MAX) { |
| error_setg(errp, "The node alias '%s' is longer than %u bytes", |
| bmna->alias, UINT8_MAX); |
| goto fail; |
| } |
| |
| if (strlen(bmna->node_name) > max_node_name_len) { |
| error_setg(errp, "The node name '%s' is longer than %zu bytes", |
| bmna->node_name, max_node_name_len); |
| goto fail; |
| } |
| |
| if (name_to_alias) { |
| if (g_hash_table_contains(alias_map, bmna->node_name)) { |
| error_setg(errp, "The node name '%s' is mapped twice", |
| bmna->node_name); |
| goto fail; |
| } |
| |
| node_map_from = bmna->node_name; |
| node_map_to = bmna->alias; |
| } else { |
| if (g_hash_table_contains(alias_map, bmna->alias)) { |
| error_setg(errp, "The node alias '%s' is used twice", |
| bmna->alias); |
| goto fail; |
| } |
| |
| node_map_from = bmna->alias; |
| node_map_to = bmna->node_name; |
| } |
| |
| gdn = (GDestroyNotify) qapi_free_BitmapMigrationBitmapAlias; |
| bitmaps_map = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, |
| gdn); |
| |
| amin = g_new(AliasMapInnerNode, 1); |
| *amin = (AliasMapInnerNode){ |
| .string = g_strdup(node_map_to), |
| .subtree = bitmaps_map, |
| }; |
| |
| g_hash_table_insert(alias_map, g_strdup(node_map_from), amin); |
| |
| for (bmbal = bmna->bitmaps; bmbal; bmbal = bmbal->next) { |
| const BitmapMigrationBitmapAlias *bmba = bmbal->value; |
| const char *bmap_map_from; |
| |
| if (strlen(bmba->alias) > UINT8_MAX) { |
| error_setg(errp, |
| "The bitmap alias '%s' is longer than %u bytes", |
| bmba->alias, UINT8_MAX); |
| goto fail; |
| } |
| |
| if (strlen(bmba->name) > BDRV_BITMAP_MAX_NAME_SIZE) { |
| error_setg(errp, "The bitmap name '%s' is longer than %d bytes", |
| bmba->name, BDRV_BITMAP_MAX_NAME_SIZE); |
| goto fail; |
| } |
| |
| if (name_to_alias) { |
| bmap_map_from = bmba->name; |
| |
| if (g_hash_table_contains(bitmaps_map, bmba->name)) { |
| error_setg(errp, "The bitmap '%s'/'%s' is mapped twice", |
| bmna->node_name, bmba->name); |
| goto fail; |
| } |
| } else { |
| bmap_map_from = bmba->alias; |
| |
| if (g_hash_table_contains(bitmaps_map, bmba->alias)) { |
| error_setg(errp, "The bitmap alias '%s'/'%s' is used twice", |
| bmna->alias, bmba->alias); |
| goto fail; |
| } |
| } |
| |
| g_hash_table_insert(bitmaps_map, g_strdup(bmap_map_from), |
| QAPI_CLONE(BitmapMigrationBitmapAlias, bmba)); |
| } |
| } |
| |
| return alias_map; |
| |
| fail: |
| g_hash_table_destroy(alias_map); |
| return NULL; |
| } |
| |
| /** |
| * Run construct_alias_map() in both directions to check whether @bbm |
| * is valid. |
| * (This function is to be used by migration/migration.c to validate |
| * the user-specified block-bitmap-mapping migration parameter.) |
| * |
| * Returns true if and only if the mapping is valid. |
| */ |
| bool check_dirty_bitmap_mig_alias_map(const BitmapMigrationNodeAliasList *bbm, |
| Error **errp) |
| { |
| GHashTable *alias_map; |
| |
| alias_map = construct_alias_map(bbm, true, errp); |
| if (!alias_map) { |
| return false; |
| } |
| g_hash_table_destroy(alias_map); |
| |
| alias_map = construct_alias_map(bbm, false, errp); |
| if (!alias_map) { |
| return false; |
| } |
| g_hash_table_destroy(alias_map); |
| |
| return true; |
| } |
| |
| static uint32_t qemu_get_bitmap_flags(QEMUFile *f) |
| { |
| uint8_t flags = qemu_get_byte(f); |
| if (flags & DIRTY_BITMAP_MIG_EXTRA_FLAGS) { |
| flags = flags << 8 | qemu_get_byte(f); |
| if (flags & DIRTY_BITMAP_MIG_EXTRA_FLAGS) { |
| flags = flags << 16 | qemu_get_be16(f); |
| } |
| } |
| |
| return flags; |
| } |
| |
| static void qemu_put_bitmap_flags(QEMUFile *f, uint32_t flags) |
| { |
| /* The code currently does not send flags as more than one byte */ |
| assert(!(flags & (0xffffff00 | DIRTY_BITMAP_MIG_EXTRA_FLAGS))); |
| |
| qemu_put_byte(f, flags); |
| } |
| |
| static void send_bitmap_header(QEMUFile *f, DBMSaveState *s, |
| SaveBitmapState *dbms, uint32_t additional_flags) |
| { |
| BlockDriverState *bs = dbms->bs; |
| BdrvDirtyBitmap *bitmap = dbms->bitmap; |
| uint32_t flags = additional_flags; |
| trace_send_bitmap_header_enter(); |
| |
| if (bs != s->prev_bs) { |
| s->prev_bs = bs; |
| flags |= DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME; |
| } |
| |
| if (bitmap != s->prev_bitmap) { |
| s->prev_bitmap = bitmap; |
| flags |= DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME; |
| } |
| |
| qemu_put_bitmap_flags(f, flags); |
| |
| if (flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { |
| qemu_put_counted_string(f, dbms->node_alias); |
| } |
| |
| if (flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { |
| qemu_put_counted_string(f, dbms->bitmap_alias); |
| } |
| } |
| |
| static void send_bitmap_start(QEMUFile *f, DBMSaveState *s, |
| SaveBitmapState *dbms) |
| { |
| send_bitmap_header(f, s, dbms, DIRTY_BITMAP_MIG_FLAG_START); |
| qemu_put_be32(f, bdrv_dirty_bitmap_granularity(dbms->bitmap)); |
| qemu_put_byte(f, dbms->flags); |
| } |
| |
| static void send_bitmap_complete(QEMUFile *f, DBMSaveState *s, |
| SaveBitmapState *dbms) |
| { |
| send_bitmap_header(f, s, dbms, DIRTY_BITMAP_MIG_FLAG_COMPLETE); |
| } |
| |
| static void send_bitmap_bits(QEMUFile *f, DBMSaveState *s, |
| SaveBitmapState *dbms, |
| uint64_t start_sector, uint32_t nr_sectors) |
| { |
| /* align for buffer_is_zero() */ |
| uint64_t align = 4 * sizeof(long); |
| uint64_t unaligned_size = |
| bdrv_dirty_bitmap_serialization_size( |
| dbms->bitmap, start_sector << BDRV_SECTOR_BITS, |
| (uint64_t)nr_sectors << BDRV_SECTOR_BITS); |
| uint64_t buf_size = QEMU_ALIGN_UP(unaligned_size, align); |
| uint8_t *buf = g_malloc0(buf_size); |
| uint32_t flags = DIRTY_BITMAP_MIG_FLAG_BITS; |
| |
| bdrv_dirty_bitmap_serialize_part( |
| dbms->bitmap, buf, start_sector << BDRV_SECTOR_BITS, |
| (uint64_t)nr_sectors << BDRV_SECTOR_BITS); |
| |
| if (buffer_is_zero(buf, buf_size)) { |
| g_free(buf); |
| buf = NULL; |
| flags |= DIRTY_BITMAP_MIG_FLAG_ZEROES; |
| } |
| |
| trace_send_bitmap_bits(flags, start_sector, nr_sectors, buf_size); |
| |
| send_bitmap_header(f, s, dbms, flags); |
| |
| qemu_put_be64(f, start_sector); |
| qemu_put_be32(f, nr_sectors); |
| |
| /* if a block is zero we need to flush here since the network |
| * bandwidth is now a lot higher than the storage device bandwidth. |
| * thus if we queue zero blocks we slow down the migration. */ |
| if (flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) { |
| qemu_fflush(f); |
| } else { |
| qemu_put_be64(f, buf_size); |
| qemu_put_buffer(f, buf, buf_size); |
| } |
| |
| g_free(buf); |
| } |
| |
| /* Called with iothread lock taken. */ |
| static void dirty_bitmap_do_save_cleanup(DBMSaveState *s) |
| { |
| SaveBitmapState *dbms; |
| |
| while ((dbms = QSIMPLEQ_FIRST(&s->dbms_list)) != NULL) { |
| QSIMPLEQ_REMOVE_HEAD(&s->dbms_list, entry); |
| bdrv_dirty_bitmap_set_busy(dbms->bitmap, false); |
| bdrv_unref(dbms->bs); |
| g_free(dbms->node_alias); |
| g_free(dbms->bitmap_alias); |
| g_free(dbms); |
| } |
| } |
| |
| /* Called with iothread lock taken. */ |
| static int add_bitmaps_to_list(DBMSaveState *s, BlockDriverState *bs, |
| const char *bs_name, GHashTable *alias_map) |
| { |
| BdrvDirtyBitmap *bitmap; |
| SaveBitmapState *dbms; |
| GHashTable *bitmap_aliases; |
| const char *node_alias, *bitmap_name, *bitmap_alias; |
| Error *local_err = NULL; |
| |
| /* When an alias map is given, @bs_name must be @bs's node name */ |
| assert(!alias_map || !strcmp(bs_name, bdrv_get_node_name(bs))); |
| |
| FOR_EACH_DIRTY_BITMAP(bs, bitmap) { |
| if (bdrv_dirty_bitmap_name(bitmap)) { |
| break; |
| } |
| } |
| if (!bitmap) { |
| return 0; |
| } |
| |
| bitmap_name = bdrv_dirty_bitmap_name(bitmap); |
| |
| if (!bs_name || strcmp(bs_name, "") == 0) { |
| error_report("Bitmap '%s' in unnamed node can't be migrated", |
| bitmap_name); |
| return -1; |
| } |
| |
| if (alias_map) { |
| const AliasMapInnerNode *amin = g_hash_table_lookup(alias_map, bs_name); |
| |
| if (!amin) { |
| /* Skip bitmaps on nodes with no alias */ |
| return 0; |
| } |
| |
| node_alias = amin->string; |
| bitmap_aliases = amin->subtree; |
| } else { |
| node_alias = bs_name; |
| bitmap_aliases = NULL; |
| } |
| |
| if (node_alias[0] == '#') { |
| error_report("Bitmap '%s' in a node with auto-generated " |
| "name '%s' can't be migrated", |
| bitmap_name, node_alias); |
| return -1; |
| } |
| |
| FOR_EACH_DIRTY_BITMAP(bs, bitmap) { |
| BitmapMigrationBitmapAliasTransform *bitmap_transform = NULL; |
| bitmap_name = bdrv_dirty_bitmap_name(bitmap); |
| if (!bitmap_name) { |
| continue; |
| } |
| |
| if (bdrv_dirty_bitmap_check(bitmap, BDRV_BITMAP_DEFAULT, &local_err)) { |
| error_report_err(local_err); |
| return -1; |
| } |
| |
| if (bitmap_aliases) { |
| BitmapMigrationBitmapAlias *bmap_inner; |
| |
| bmap_inner = g_hash_table_lookup(bitmap_aliases, bitmap_name); |
| if (!bmap_inner) { |
| /* Skip bitmaps with no alias */ |
| continue; |
| } |
| |
| bitmap_alias = bmap_inner->alias; |
| if (bmap_inner->transform) { |
| bitmap_transform = bmap_inner->transform; |
| } |
| } else { |
| if (strlen(bitmap_name) > UINT8_MAX) { |
| error_report("Cannot migrate bitmap '%s' on node '%s': " |
| "Name is longer than %u bytes", |
| bitmap_name, bs_name, UINT8_MAX); |
| return -1; |
| } |
| bitmap_alias = bitmap_name; |
| } |
| |
| bdrv_ref(bs); |
| bdrv_dirty_bitmap_set_busy(bitmap, true); |
| |
| dbms = g_new0(SaveBitmapState, 1); |
| dbms->bs = bs; |
| dbms->node_alias = g_strdup(node_alias); |
| dbms->bitmap_alias = g_strdup(bitmap_alias); |
| dbms->bitmap = bitmap; |
| dbms->total_sectors = bdrv_nb_sectors(bs); |
| dbms->sectors_per_chunk = CHUNK_SIZE * 8LLU * |
| (bdrv_dirty_bitmap_granularity(bitmap) >> BDRV_SECTOR_BITS); |
| assert(dbms->sectors_per_chunk != 0); |
| if (bdrv_dirty_bitmap_enabled(bitmap)) { |
| dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_ENABLED; |
| } |
| if (bitmap_transform && |
| bitmap_transform->has_persistent) { |
| if (bitmap_transform->persistent) { |
| dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT; |
| } |
| } else { |
| if (bdrv_dirty_bitmap_get_persistence(bitmap)) { |
| dbms->flags |= DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT; |
| } |
| } |
| |
| QSIMPLEQ_INSERT_TAIL(&s->dbms_list, dbms, entry); |
| } |
| |
| return 0; |
| } |
| |
| /* Called with iothread lock taken. */ |
| static int init_dirty_bitmap_migration(DBMSaveState *s) |
| { |
| BlockDriverState *bs; |
| SaveBitmapState *dbms; |
| GHashTable *handled_by_blk = g_hash_table_new(NULL, NULL); |
| BlockBackend *blk; |
| GHashTable *alias_map = NULL; |
| |
| if (migrate_has_block_bitmap_mapping()) { |
| alias_map = construct_alias_map(migrate_block_bitmap_mapping(), true, |
| &error_abort); |
| } |
| |
| s->bulk_completed = false; |
| s->prev_bs = NULL; |
| s->prev_bitmap = NULL; |
| s->no_bitmaps = false; |
| |
| if (!alias_map) { |
| /* |
| * Use blockdevice name for direct (or filtered) children of named block |
| * backends. |
| */ |
| for (blk = blk_next(NULL); blk; blk = blk_next(blk)) { |
| const char *name = blk_name(blk); |
| |
| if (!name || strcmp(name, "") == 0) { |
| continue; |
| } |
| |
| bs = blk_bs(blk); |
| |
| /* Skip filters without bitmaps */ |
| while (bs && bs->drv && bs->drv->is_filter && |
| !bdrv_has_named_bitmaps(bs)) |
| { |
| bs = bdrv_filter_bs(bs); |
| } |
| |
| if (bs && bs->drv && !bs->drv->is_filter) { |
| if (add_bitmaps_to_list(s, bs, name, NULL)) { |
| goto fail; |
| } |
| g_hash_table_add(handled_by_blk, bs); |
| } |
| } |
| } |
| |
| for (bs = bdrv_next_all_states(NULL); bs; bs = bdrv_next_all_states(bs)) { |
| if (g_hash_table_contains(handled_by_blk, bs)) { |
| continue; |
| } |
| |
| if (add_bitmaps_to_list(s, bs, bdrv_get_node_name(bs), alias_map)) { |
| goto fail; |
| } |
| } |
| |
| /* unset migration flags here, to not roll back it */ |
| QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) { |
| bdrv_dirty_bitmap_skip_store(dbms->bitmap, true); |
| } |
| |
| if (QSIMPLEQ_EMPTY(&s->dbms_list)) { |
| s->no_bitmaps = true; |
| } |
| |
| g_hash_table_destroy(handled_by_blk); |
| if (alias_map) { |
| g_hash_table_destroy(alias_map); |
| } |
| |
| return 0; |
| |
| fail: |
| g_hash_table_destroy(handled_by_blk); |
| if (alias_map) { |
| g_hash_table_destroy(alias_map); |
| } |
| dirty_bitmap_do_save_cleanup(s); |
| |
| return -1; |
| } |
| |
| /* Called with no lock taken. */ |
| static void bulk_phase_send_chunk(QEMUFile *f, DBMSaveState *s, |
| SaveBitmapState *dbms) |
| { |
| uint32_t nr_sectors = MIN(dbms->total_sectors - dbms->cur_sector, |
| dbms->sectors_per_chunk); |
| |
| send_bitmap_bits(f, s, dbms, dbms->cur_sector, nr_sectors); |
| |
| dbms->cur_sector += nr_sectors; |
| if (dbms->cur_sector >= dbms->total_sectors) { |
| dbms->bulk_completed = true; |
| } |
| } |
| |
| /* Called with no lock taken. */ |
| static void bulk_phase(QEMUFile *f, DBMSaveState *s, bool limit) |
| { |
| SaveBitmapState *dbms; |
| |
| QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) { |
| while (!dbms->bulk_completed) { |
| bulk_phase_send_chunk(f, s, dbms); |
| if (limit && migration_rate_exceeded(f)) { |
| return; |
| } |
| } |
| } |
| |
| s->bulk_completed = true; |
| } |
| |
| /* for SaveVMHandlers */ |
| static void dirty_bitmap_save_cleanup(void *opaque) |
| { |
| DBMSaveState *s = &((DBMState *)opaque)->save; |
| |
| dirty_bitmap_do_save_cleanup(s); |
| } |
| |
| static int dirty_bitmap_save_iterate(QEMUFile *f, void *opaque) |
| { |
| DBMSaveState *s = &((DBMState *)opaque)->save; |
| |
| trace_dirty_bitmap_save_iterate(migration_in_postcopy()); |
| |
| if (migration_in_postcopy() && !s->bulk_completed) { |
| bulk_phase(f, s, true); |
| } |
| |
| qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); |
| |
| return s->bulk_completed; |
| } |
| |
| /* Called with iothread lock taken. */ |
| |
| static int dirty_bitmap_save_complete(QEMUFile *f, void *opaque) |
| { |
| DBMSaveState *s = &((DBMState *)opaque)->save; |
| SaveBitmapState *dbms; |
| trace_dirty_bitmap_save_complete_enter(); |
| |
| if (!s->bulk_completed) { |
| bulk_phase(f, s, false); |
| } |
| |
| QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) { |
| send_bitmap_complete(f, s, dbms); |
| } |
| |
| qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); |
| |
| trace_dirty_bitmap_save_complete_finish(); |
| |
| dirty_bitmap_save_cleanup(opaque); |
| return 0; |
| } |
| |
| static void dirty_bitmap_state_pending(void *opaque, |
| uint64_t *must_precopy, |
| uint64_t *can_postcopy) |
| { |
| DBMSaveState *s = &((DBMState *)opaque)->save; |
| SaveBitmapState *dbms; |
| uint64_t pending = 0; |
| |
| qemu_mutex_lock_iothread(); |
| |
| QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) { |
| uint64_t gran = bdrv_dirty_bitmap_granularity(dbms->bitmap); |
| uint64_t sectors = dbms->bulk_completed ? 0 : |
| dbms->total_sectors - dbms->cur_sector; |
| |
| pending += DIV_ROUND_UP(sectors * BDRV_SECTOR_SIZE, gran); |
| } |
| |
| qemu_mutex_unlock_iothread(); |
| |
| trace_dirty_bitmap_state_pending(pending); |
| |
| *can_postcopy += pending; |
| } |
| |
| /* First occurrence of this bitmap. It should be created if doesn't exist */ |
| static int dirty_bitmap_load_start(QEMUFile *f, DBMLoadState *s) |
| { |
| Error *local_err = NULL; |
| uint32_t granularity = qemu_get_be32(f); |
| uint8_t flags = qemu_get_byte(f); |
| LoadBitmapState *b; |
| bool persistent; |
| |
| if (s->cancelled) { |
| return 0; |
| } |
| |
| if (s->bitmap) { |
| error_report("Bitmap with the same name ('%s') already exists on " |
| "destination", bdrv_dirty_bitmap_name(s->bitmap)); |
| return -EINVAL; |
| } else { |
| s->bitmap = bdrv_create_dirty_bitmap(s->bs, granularity, |
| s->bitmap_name, &local_err); |
| if (!s->bitmap) { |
| error_report_err(local_err); |
| return -EINVAL; |
| } |
| } |
| |
| if (flags & DIRTY_BITMAP_MIG_START_FLAG_RESERVED_MASK) { |
| error_report("Unknown flags in migrated dirty bitmap header: %x", |
| flags); |
| return -EINVAL; |
| } |
| |
| if (s->bmap_inner && |
| s->bmap_inner->transform && |
| s->bmap_inner->transform->has_persistent) { |
| persistent = s->bmap_inner->transform->persistent; |
| } else { |
| persistent = flags & DIRTY_BITMAP_MIG_START_FLAG_PERSISTENT; |
| } |
| |
| if (persistent) { |
| bdrv_dirty_bitmap_set_persistence(s->bitmap, true); |
| } |
| |
| bdrv_disable_dirty_bitmap(s->bitmap); |
| if (flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED) { |
| bdrv_dirty_bitmap_create_successor(s->bitmap, &local_err); |
| if (local_err) { |
| error_report_err(local_err); |
| return -EINVAL; |
| } |
| } else { |
| bdrv_dirty_bitmap_set_busy(s->bitmap, true); |
| } |
| |
| b = g_new(LoadBitmapState, 1); |
| b->bs = s->bs; |
| b->bitmap = s->bitmap; |
| b->migrated = false; |
| b->enabled = flags & DIRTY_BITMAP_MIG_START_FLAG_ENABLED; |
| |
| s->bitmaps = g_slist_prepend(s->bitmaps, b); |
| |
| return 0; |
| } |
| |
| /* |
| * before_vm_start_handle_item |
| * |
| * g_slist_foreach helper |
| * |
| * item is LoadBitmapState* |
| * opaque is DBMLoadState* |
| */ |
| static void before_vm_start_handle_item(void *item, void *opaque) |
| { |
| DBMLoadState *s = opaque; |
| LoadBitmapState *b = item; |
| |
| if (b->enabled) { |
| if (b->migrated) { |
| bdrv_enable_dirty_bitmap(b->bitmap); |
| } else { |
| bdrv_dirty_bitmap_enable_successor(b->bitmap); |
| } |
| } |
| |
| if (b->migrated) { |
| s->bitmaps = g_slist_remove(s->bitmaps, b); |
| g_free(b); |
| } |
| } |
| |
| void dirty_bitmap_mig_before_vm_start(void) |
| { |
| DBMLoadState *s = &dbm_state.load; |
| qemu_mutex_lock(&s->lock); |
| |
| assert(!s->before_vm_start_handled); |
| g_slist_foreach(s->bitmaps, before_vm_start_handle_item, s); |
| s->before_vm_start_handled = true; |
| |
| qemu_mutex_unlock(&s->lock); |
| } |
| |
| static void cancel_incoming_locked(DBMLoadState *s) |
| { |
| GSList *item; |
| |
| if (s->cancelled) { |
| return; |
| } |
| |
| s->cancelled = true; |
| s->bs = NULL; |
| s->bitmap = NULL; |
| |
| /* Drop all unfinished bitmaps */ |
| for (item = s->bitmaps; item; item = g_slist_next(item)) { |
| LoadBitmapState *b = item->data; |
| |
| /* |
| * Bitmap must be unfinished, as finished bitmaps should already be |
| * removed from the list. |
| */ |
| assert(!s->before_vm_start_handled || !b->migrated); |
| if (bdrv_dirty_bitmap_has_successor(b->bitmap)) { |
| bdrv_reclaim_dirty_bitmap(b->bitmap, &error_abort); |
| } else { |
| bdrv_dirty_bitmap_set_busy(b->bitmap, false); |
| } |
| bdrv_release_dirty_bitmap(b->bitmap); |
| } |
| |
| g_slist_free_full(s->bitmaps, g_free); |
| s->bitmaps = NULL; |
| } |
| |
| void dirty_bitmap_mig_cancel_outgoing(void) |
| { |
| dirty_bitmap_do_save_cleanup(&dbm_state.save); |
| } |
| |
| void dirty_bitmap_mig_cancel_incoming(void) |
| { |
| DBMLoadState *s = &dbm_state.load; |
| |
| qemu_mutex_lock(&s->lock); |
| |
| cancel_incoming_locked(s); |
| |
| qemu_mutex_unlock(&s->lock); |
| } |
| |
| static void dirty_bitmap_load_complete(QEMUFile *f, DBMLoadState *s) |
| { |
| GSList *item; |
| trace_dirty_bitmap_load_complete(); |
| |
| if (s->cancelled) { |
| return; |
| } |
| |
| bdrv_dirty_bitmap_deserialize_finish(s->bitmap); |
| |
| if (bdrv_dirty_bitmap_has_successor(s->bitmap)) { |
| bdrv_reclaim_dirty_bitmap(s->bitmap, &error_abort); |
| } else { |
| bdrv_dirty_bitmap_set_busy(s->bitmap, false); |
| } |
| |
| for (item = s->bitmaps; item; item = g_slist_next(item)) { |
| LoadBitmapState *b = item->data; |
| |
| if (b->bitmap == s->bitmap) { |
| b->migrated = true; |
| if (s->before_vm_start_handled) { |
| s->bitmaps = g_slist_remove(s->bitmaps, b); |
| g_free(b); |
| } |
| break; |
| } |
| } |
| } |
| |
| static int dirty_bitmap_load_bits(QEMUFile *f, DBMLoadState *s) |
| { |
| uint64_t first_byte = qemu_get_be64(f) << BDRV_SECTOR_BITS; |
| uint64_t nr_bytes = (uint64_t)qemu_get_be32(f) << BDRV_SECTOR_BITS; |
| trace_dirty_bitmap_load_bits_enter(first_byte >> BDRV_SECTOR_BITS, |
| nr_bytes >> BDRV_SECTOR_BITS); |
| |
| if (s->flags & DIRTY_BITMAP_MIG_FLAG_ZEROES) { |
| trace_dirty_bitmap_load_bits_zeroes(); |
| if (!s->cancelled) { |
| bdrv_dirty_bitmap_deserialize_zeroes(s->bitmap, first_byte, |
| nr_bytes, false); |
| } |
| } else { |
| size_t ret; |
| g_autofree uint8_t *buf = NULL; |
| uint64_t buf_size = qemu_get_be64(f); |
| uint64_t needed_size; |
| |
| /* |
| * The actual check for buf_size is done a bit later. We can't do it in |
| * cancelled mode as we don't have the bitmap to check the constraints |
| * (so, we allocate a buffer and read prior to the check). On the other |
| * hand, we shouldn't blindly g_malloc the number from the stream. |
| * Actually one chunk should not be larger than CHUNK_SIZE. Let's allow |
| * a bit larger (which means that bitmap migration will fail anyway and |
| * the whole migration will most probably fail soon due to broken |
| * stream). |
| */ |
| if (buf_size > 10 * CHUNK_SIZE) { |
| error_report("Bitmap migration stream buffer allocation request " |
| "is too large"); |
| return -EIO; |
| } |
| |
| buf = g_malloc(buf_size); |
| ret = qemu_get_buffer(f, buf, buf_size); |
| if (ret != buf_size) { |
| error_report("Failed to read bitmap bits"); |
| return -EIO; |
| } |
| |
| if (s->cancelled) { |
| return 0; |
| } |
| |
| needed_size = bdrv_dirty_bitmap_serialization_size(s->bitmap, |
| first_byte, |
| nr_bytes); |
| |
| if (needed_size > buf_size || |
| buf_size > QEMU_ALIGN_UP(needed_size, 4 * sizeof(long)) |
| /* Here used same alignment as in send_bitmap_bits */ |
| ) { |
| error_report("Migrated bitmap granularity doesn't " |
| "match the destination bitmap '%s' granularity", |
| bdrv_dirty_bitmap_name(s->bitmap)); |
| cancel_incoming_locked(s); |
| return 0; |
| } |
| |
| bdrv_dirty_bitmap_deserialize_part(s->bitmap, buf, first_byte, nr_bytes, |
| false); |
| } |
| |
| return 0; |
| } |
| |
| static int dirty_bitmap_load_header(QEMUFile *f, DBMLoadState *s, |
| GHashTable *alias_map) |
| { |
| GHashTable *bitmap_alias_map = NULL; |
| Error *local_err = NULL; |
| bool nothing; |
| s->flags = qemu_get_bitmap_flags(f); |
| trace_dirty_bitmap_load_header(s->flags); |
| |
| nothing = s->flags == (s->flags & DIRTY_BITMAP_MIG_FLAG_EOS); |
| |
| if (s->flags & DIRTY_BITMAP_MIG_FLAG_DEVICE_NAME) { |
| if (!qemu_get_counted_string(f, s->node_alias)) { |
| error_report("Unable to read node alias string"); |
| return -EINVAL; |
| } |
| |
| if (!s->cancelled) { |
| if (alias_map) { |
| const AliasMapInnerNode *amin; |
| |
| amin = g_hash_table_lookup(alias_map, s->node_alias); |
| if (!amin) { |
| error_setg(&local_err, "Error: Unknown node alias '%s'", |
| s->node_alias); |
| s->bs = NULL; |
| } else { |
| bitmap_alias_map = amin->subtree; |
| s->bs = bdrv_lookup_bs(NULL, amin->string, &local_err); |
| } |
| } else { |
| s->bs = bdrv_lookup_bs(s->node_alias, s->node_alias, |
| &local_err); |
| } |
| if (!s->bs) { |
| error_report_err(local_err); |
| cancel_incoming_locked(s); |
| } |
| } |
| } else if (s->bs) { |
| if (alias_map) { |
| const AliasMapInnerNode *amin; |
| |
| /* Must be present in the map, or s->bs would not be set */ |
| amin = g_hash_table_lookup(alias_map, s->node_alias); |
| assert(amin != NULL); |
| |
| bitmap_alias_map = amin->subtree; |
| } |
| } else if (!nothing && !s->cancelled) { |
| error_report("Error: block device name is not set"); |
| cancel_incoming_locked(s); |
| } |
| |
| assert(nothing || s->cancelled || !!alias_map == !!bitmap_alias_map); |
| |
| if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITMAP_NAME) { |
| const char *bitmap_name; |
| |
| if (!qemu_get_counted_string(f, s->bitmap_alias)) { |
| error_report("Unable to read bitmap alias string"); |
| return -EINVAL; |
| } |
| |
| bitmap_name = s->bitmap_alias; |
| if (!s->cancelled && bitmap_alias_map) { |
| BitmapMigrationBitmapAlias *bmap_inner; |
| |
| bmap_inner = g_hash_table_lookup(bitmap_alias_map, s->bitmap_alias); |
| if (!bmap_inner) { |
| error_report("Error: Unknown bitmap alias '%s' on node " |
| "'%s' (alias '%s')", s->bitmap_alias, |
| s->bs->node_name, s->node_alias); |
| cancel_incoming_locked(s); |
| } else { |
| bitmap_name = bmap_inner->name; |
| } |
| |
| s->bmap_inner = bmap_inner; |
| } |
| |
| if (!s->cancelled) { |
| g_strlcpy(s->bitmap_name, bitmap_name, sizeof(s->bitmap_name)); |
| s->bitmap = bdrv_find_dirty_bitmap(s->bs, s->bitmap_name); |
| |
| /* |
| * bitmap may be NULL here, it wouldn't be an error if it is the |
| * first occurrence of the bitmap |
| */ |
| if (!s->bitmap && !(s->flags & DIRTY_BITMAP_MIG_FLAG_START)) { |
| error_report("Error: unknown dirty bitmap " |
| "'%s' for block device '%s'", |
| s->bitmap_name, s->bs->node_name); |
| cancel_incoming_locked(s); |
| } |
| } |
| } else if (!s->bitmap && !nothing && !s->cancelled) { |
| error_report("Error: block device name is not set"); |
| cancel_incoming_locked(s); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * dirty_bitmap_load |
| * |
| * Load sequence of dirty bitmap chunks. Return error only on fatal io stream |
| * violations. On other errors just cancel bitmaps incoming migration and return |
| * 0. |
| * |
| * Note, than when incoming bitmap migration is canceled, we still must read all |
| * our chunks (and just ignore them), to not affect other migration objects. |
| */ |
| static int dirty_bitmap_load(QEMUFile *f, void *opaque, int version_id) |
| { |
| GHashTable *alias_map = NULL; |
| DBMLoadState *s = &((DBMState *)opaque)->load; |
| int ret = 0; |
| |
| trace_dirty_bitmap_load_enter(); |
| |
| if (version_id != 1) { |
| QEMU_LOCK_GUARD(&s->lock); |
| cancel_incoming_locked(s); |
| return -EINVAL; |
| } |
| |
| if (migrate_has_block_bitmap_mapping()) { |
| alias_map = construct_alias_map(migrate_block_bitmap_mapping(), false, |
| &error_abort); |
| } |
| |
| do { |
| QEMU_LOCK_GUARD(&s->lock); |
| |
| ret = dirty_bitmap_load_header(f, s, alias_map); |
| if (ret < 0) { |
| cancel_incoming_locked(s); |
| goto fail; |
| } |
| |
| if (s->flags & DIRTY_BITMAP_MIG_FLAG_START) { |
| ret = dirty_bitmap_load_start(f, s); |
| } else if (s->flags & DIRTY_BITMAP_MIG_FLAG_COMPLETE) { |
| dirty_bitmap_load_complete(f, s); |
| } else if (s->flags & DIRTY_BITMAP_MIG_FLAG_BITS) { |
| ret = dirty_bitmap_load_bits(f, s); |
| } |
| |
| if (!ret) { |
| ret = qemu_file_get_error(f); |
| } |
| |
| if (ret) { |
| cancel_incoming_locked(s); |
| goto fail; |
| } |
| } while (!(s->flags & DIRTY_BITMAP_MIG_FLAG_EOS)); |
| |
| trace_dirty_bitmap_load_success(); |
| ret = 0; |
| fail: |
| if (alias_map) { |
| g_hash_table_destroy(alias_map); |
| } |
| return ret; |
| } |
| |
| static int dirty_bitmap_save_setup(QEMUFile *f, void *opaque) |
| { |
| DBMSaveState *s = &((DBMState *)opaque)->save; |
| SaveBitmapState *dbms = NULL; |
| |
| if (init_dirty_bitmap_migration(s) < 0) { |
| return -1; |
| } |
| |
| QSIMPLEQ_FOREACH(dbms, &s->dbms_list, entry) { |
| send_bitmap_start(f, s, dbms); |
| } |
| qemu_put_bitmap_flags(f, DIRTY_BITMAP_MIG_FLAG_EOS); |
| return 0; |
| } |
| |
| static bool dirty_bitmap_is_active(void *opaque) |
| { |
| DBMSaveState *s = &((DBMState *)opaque)->save; |
| |
| return migrate_dirty_bitmaps() && !s->no_bitmaps; |
| } |
| |
| static bool dirty_bitmap_is_active_iterate(void *opaque) |
| { |
| return dirty_bitmap_is_active(opaque) && !runstate_is_running(); |
| } |
| |
| static bool dirty_bitmap_has_postcopy(void *opaque) |
| { |
| return true; |
| } |
| |
| static SaveVMHandlers savevm_dirty_bitmap_handlers = { |
| .save_setup = dirty_bitmap_save_setup, |
| .save_live_complete_postcopy = dirty_bitmap_save_complete, |
| .save_live_complete_precopy = dirty_bitmap_save_complete, |
| .has_postcopy = dirty_bitmap_has_postcopy, |
| .state_pending_exact = dirty_bitmap_state_pending, |
| .state_pending_estimate = dirty_bitmap_state_pending, |
| .save_live_iterate = dirty_bitmap_save_iterate, |
| .is_active_iterate = dirty_bitmap_is_active_iterate, |
| .load_state = dirty_bitmap_load, |
| .save_cleanup = dirty_bitmap_save_cleanup, |
| .is_active = dirty_bitmap_is_active, |
| }; |
| |
| void dirty_bitmap_mig_init(void) |
| { |
| QSIMPLEQ_INIT(&dbm_state.save.dbms_list); |
| qemu_mutex_init(&dbm_state.load.lock); |
| |
| register_savevm_live("dirty-bitmap", 0, 1, |
| &savevm_dirty_bitmap_handlers, |
| &dbm_state); |
| } |
