Re: [Qemu-devel] [PATCH v5 00/12] Dirty bitmaps migration

[John Snow <jsnow@redhat.com>]

Ping for maintainer reviews -- I've given it a first pass and it should
hopefully be close.

Thanks,
--js

On 05/13/2015 11:29 AM, Vladimir Sementsov-Ogievskiy wrote:
> These patches provide dirty bitmap migration feature. Only named dirty
> bitmaps are to be migrated. Migration may be enabled using migration
> capabilities.
> 
> v5:
>     - rebase on master
>     - drop [PATCH RFC v4 10/13] iotests: add event_wait to VM class
>     - remove rfc, as incremental backup series by John Snow are in
>       upstream
>     
> 
> v4 significant changes:
>  0001: tiny bugfix: out[i] -> out[i-start], same for 'in'
>  0007: set chunk size to 1kb, disable live iteration for
>        migrating data < 1mb size.
> 
>  tests: only one with md5 sum is here. used function event_wait
>         by John Snow. (I hope, you don't mind me just adding this
>         function with your 'Signed-off-by')
> 
>  rfc: This patch set is based on v13 of
>       "block: incremental backup series" by John Snow, which are
>       not pushed yet.
> 
> v3:
>  based on v13 of "block: incremental backup series" by John Snow.
> 
>  changes from v2:
>  removed patch for adding dirty parameter (migration capablities used
>  instead).
>  
>  0001: printf's dropped, qapi used
>  0002: part0 -> zeroes
>  0003: part0 -> zeroes
>  0005: dirty_dirty -> meta
>        add comments about meta bitmap
>        
>  0006: the format is changed, nodes used instead of devices.
> 
>  other patches are new.
> 
>  rfc: there are two tests. They are the same but using different
>  interfaces: md5 checksum of the bitmap last layer in query-block or
>  separate query-block-dirty-bitmap with dirty bitmap regions.
>  The second form is more appropriate for debugging, the first is more
>  appropriate for simple regression control. Which should go to
>  upstream?
> 
> v2:
>  1. bug-fixes, that are already in upstream, and renaming of function
>  bdrv_reset_dirty_bitmap (which is already in Snow's series) are
>  dropped
>  2. bitmap store/restore: the concept renamed to serialization, added
>  function hbitmap_deserialize_part0, to not transfer zero blocks
>  3. migration dirty parameter: added description comment
>  4. Other patches are new.
> 
> v2.rfc:
> Actually, in this version of the series I'm trying not use
> migration/block.c at all. Instead a separate migration unit is added
> in the new file migration/dirty-bitmap.c. Now bitmaps are migrated
> like blocks in block migration, they have their "dirty-dirty" bitmaps,
> for tracking set/unset changes during migration.
> 
> The advantages are:
>   - no complications of migration/block.c
>   - separate dirty-dirty bitmaps provide handling of "unset's"
>   - more effective meta-data/data ratio - no tiny bitmap-blocks.
> 
> 
> 
> v1:
> These patches provide dirty bitmap migration feature. Only named dirty
> bitmaps are to be migrated. Migration is made as a part of block
> migration in block-migration.c.
> 
> Dirty bitmap migration may be enabled by "dirty" parameter for qmp migrate
> command. If "blk" and "inc" parameters are false when "dirty" is true
> block migration is actually skipped: no allocatoions, no bdrv_read's,
> no bdrv_write's, only bitmaps are migrated.
> 
> The patch set includes two my previous bug fixes, which are necessary
> for it. The patch set is based on Incremental backup series by John
> Snow.
> Vladimir Sementsov-Ogievskiy (12):
>   hbitmap: serialization
>   block: BdrvDirtyBitmap serialization interface
>   block: tiny refactoring: minimize hbitmap_(set/reset) usage
>   block: add meta bitmaps
>   block: add bdrv_next_dirty_bitmap()
>   qapi: add dirty-bitmaps migration capability
>   migration: add migration/block-dirty-bitmap.c
>   iotests: maintain several vms in test
>   iotests: add add_incoming_migration to VM class
>   qapi: add md5 checksum of last dirty bitmap level to query-block
>   iotests: add dirty bitmap migration test
>   migration/qemu-file: make functions qemu_(get/put)_string public
> 
>  block.c                        |  98 +++++-
>  include/block/block.h          |  22 ++
>  include/migration/block.h      |   1 +
>  include/migration/migration.h  |   1 +
>  include/migration/qemu-file.h  |  17 +
>  include/qemu/hbitmap.h         |  67 ++++
>  migration/Makefile.objs        |   2 +-
>  migration/block-dirty-bitmap.c | 693 +++++++++++++++++++++++++++++++++++++++++
>  migration/migration.c          |   9 +
>  migration/qemu-file.c          |  18 ++
>  qapi-schema.json               |   4 +-
>  qapi/block-core.json           |   4 +-
>  tests/qemu-iotests/117         |  84 +++++
>  tests/qemu-iotests/117.out     |   5 +
>  tests/qemu-iotests/group       |   1 +
>  tests/qemu-iotests/iotests.py  |  14 +-
>  util/hbitmap.c                 | 106 +++++++
>  vl.c                           |   1 +
>  18 files changed, 1137 insertions(+), 10 deletions(-)
>  create mode 100644 migration/block-dirty-bitmap.c
>  create mode 100755 tests/qemu-iotests/117
>  create mode 100644 tests/qemu-iotests/117.out
>