qemu/migration/block-dirty-bitmap.c

2  * Block dirty bitmap postcopy migration
13  * This file is derived from migration/block.c, so it's author and IBM copyright
21  * Here postcopy migration of dirty bitmaps is realized. Only QMP-addressable
24  * Bitmap migration implies creating bitmap with the same name and granularity
28  * format of migration:
37  * # Start of bitmap migration (flags & START)
46  * # Complete of bitmap migration (flags & COMPLETE)
49  * # Data chunk of bitmap migration
69 #include "migration/misc.h"
70 #include "migration/migration.h"
72 #include "migration/vmstate.h"
73 #include "migration/register.h"
78 #include "qapi/qapi-commands-migration.h"
79 #include "qapi/qapi-visit-migration.h"
126 /* State of the dirty bitmap migration (DBM) during save process */
145 /* State of the dirty bitmap migration (DBM) during load process */
159      * Incoming migration is cancelled for some reason. That means that we
160      * still should read our chunks from migration stream, to not affect other
161      * migration objects (like RAM), but just ignore them and do not touch any
198  * Therefore, we instead have to construct these maps when migration
201  * @bbm is the block_bitmap_mapping from the migration parameters.
205  * migration).
209  * migration).
334  * (This function is to be used by migration/migration.c to validate
335  * the user-specified block-bitmap-mapping migration parameter.)
456      * thus if we queue zero blocks we slow down the migration. */  in send_bitmap_bits()
609     /* Runs in the migration thread, but holds the BQL */  in init_dirty_bitmap_migration()
664     /* unset migration flags here, to not roll back it */  in init_dirty_bitmap_migration()
1004          * a bit larger (which means that bitmap migration will fail anyway and  in dirty_bitmap_load_bits()
1005          * the whole migration will most probably fail soon due to broken  in dirty_bitmap_load_bits()
1009             error_report("Bitmap migration stream buffer allocation request "  in dirty_bitmap_load_bits()
1155  * violations. On other errors just cancel bitmaps incoming migration and return
1158  * Note, than when incoming bitmap migration is canceled, we still must read all
1159  * our chunks (and just ignore them), to not affect other migration objects.