[Qemu-devel] [PATCH v2 RFC 0/8] block: persistent dirty bitmaps

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

v2:
 - rebase on my 'Dirty bitmaps migration' series
 - remove 'print dirty bitmap', 'query-dirty-bitmap' and use md5 for
   testing like with dirty bitmaps migration
 - autoclean features

v1:

The bitmaps are saved into qcow2 file format. It provides both
'internal' and 'external' dirty bitmaps feature:
 - for qcow2 drives we can store bitmaps in the same file
 - for other formats we can store bitmaps in the separate qcow2 file

QCow2 header is extended by fields 'nb_dirty_bitmaps' and
'dirty_bitmaps_offset' like with snapshots.

Proposed command line syntax is the following:

-dirty-bitmap [option1=val1][,option2=val2]...
    Available options are:
    name         The name for the bitmap (necessary).

    file         The file to load the bitmap from.

    file_id      When specified with 'file' option, then this file will
                 be available through this id for other -dirty-bitmap
                 options when specified without 'file' option, then it
                 is a reference to 'file', specified with another
                 -dirty-bitmap option, and it will be used to load the
                 bitmap from.

    drive        The drive to bind the bitmap to. It should be specified
                 as 'id' suboption of one of -drive options. If nor
                 'file' neither 'file_id' are specified, then the bitmap
                 will be loaded from that drive (internal dirty bitmap).

    granularity  The granularity for the bitmap. Not necessary, the
                 default value may be used.

    enabled      on|off. Default is 'on'. Disabled bitmaps are not
                 changing regardless of writes to corresponding drive.

Examples:

qemu -drive file=a.qcow2,id=disk -dirty-bitmap name=b,drive=disk
qemu -drive file=a.raw,id=disk \
     -dirty-bitmap name=b,drive=disk,file=b.qcow2,enabled=off

Vladimir Sementsov-Ogievskiy (8):
  spec: add qcow2-dirty-bitmaps specification
  qcow2: add dirty-bitmaps feature
  block: store persistent dirty bitmaps
  block: add bdrv_load_dirty_bitmap
  qcow2: add qcow2_dirty_bitmap_delete_all
  qcow2: add autoclear bit for dirty bitmaps
  qemu: command line option for dirty bitmaps
  iotests: test internal persistent dirty bitmap

 block.c                       |  82 +++++++
 block/Makefile.objs           |   2 +-
 block/qcow2-dirty-bitmap.c    | 537 ++++++++++++++++++++++++++++++++++++++++++
 block/qcow2.c                 |  69 +++++-
 block/qcow2.h                 |  61 +++++
 blockdev.c                    |  38 +++
 docs/specs/qcow2.txt          |  66 ++++++
 include/block/block.h         |   9 +
 include/block/block_int.h     |  10 +
 include/sysemu/blockdev.h     |   1 +
 include/sysemu/sysemu.h       |   1 +
 qemu-options.hx               |  37 +++
 tests/qemu-iotests/118        |  83 +++++++
 tests/qemu-iotests/118.out    |   5 +
 tests/qemu-iotests/group      |   1 +
 tests/qemu-iotests/iotests.py |   6 +
 vl.c                          | 100 ++++++++
 17 files changed, 1105 insertions(+), 3 deletions(-)
 create mode 100644 block/qcow2-dirty-bitmap.c
 create mode 100755 tests/qemu-iotests/118
 create mode 100644 tests/qemu-iotests/118.out

-- 
1.9.1