[Qemu-devel] [PATCH v3 0/9] QMP: Introduce incremental drive-backup with in-memory dirty bitmap

[Fam Zheng <famz@redhat.com>]

Introduction
------------

This implements incremental backup.

A convenient option "bitmap-use-mode" for drive-backup is introduced since v1.

Commands
--------

A new sync mode for drive-backup is introduced:

    drive-backup device=.. mode=.. sync=dirty-bitmap bitmap=bitmap0 bitmap-use-mode=reset

This mode will scan dirty bitmap "bitmap0" and only copy all dirty sectors to
target.

bitmap-use-mode controls what operation is done on the given bitmap:

 - reset: Clear all the bits (block job save a copy)
 - consume: Block job takes the bitmap and make it invisible to user, and
   release it after use.

A few low level commands related to dirty bitmap are also added:

    dirty-bitmap-add
    dirty-bitmap-remove
    dirty-bitmap-enable
    dirty-bitmap-disable

Example
-------

    (QMP) dirty-bitmap-add device=? name=bitmap0

    [guest writes to device]

    (QMP) drive-backup device=? target=backup1.qcow2 format=qcow2 \
          sync=dirty-bitmap bitmap=bitmap0 bitmap-use-mode=reset

    [guest writes more to device]

    (QMP) drive-backup device=? target=backup2.qcow2 format=qcow2 \
          sync=dirty-bitmap bitmap=bitmap0 bitmap-use-mode=reset

    ...

v3:
    Address Benoit's comments.

    [01/09] qapi: Add optional field "name" to block dirty bitmap
            Don't split line.

    [03/09] block: Handle error of bdrv_getlength in bdrv_create_dirty_bitmap
            Add reviewed-by.

    [04/09] block: Introduce bdrv_dirty_bitmap_granularity()
            Add reviewed-by.

    [05/09] hbitmap: Add hbitmap_copy
            Fix size calculation.

    [08/09] qmp: Add support of "dirty-bitmap" sync mode for drive-backup
            Fix typo in commit message.
            Add comment for sync_bitmap_gran.
            Add (Since 2.1).

Thanks,
Fam



Fam Zheng (9):
  qapi: Add optional field "name" to block dirty bitmap
  qmp: Add dirty-bitmap-add and dirty-bitmap-remove
  block: Handle error of bdrv_getlength in bdrv_create_dirty_bitmap
  block: Introduce bdrv_dirty_bitmap_granularity()
  hbitmap: Add hbitmap_copy
  block: Add bdrv_copy_dirty_bitmap and bdrv_reset_dirty_bitmap
  qmp: Add dirty-bitmap-enable and dirty-bitmap-disable
  qmp: Add support of "dirty-bitmap" sync mode for drive-backup
  qapi: Add transaction support to dirty-bitmap-{add,disable}

 block-migration.c         |   3 +-
 block.c                   |  89 ++++++++++++++++++++++-
 block/backup.c            |  53 +++++++++++++-
 block/mirror.c            |   6 +-
 blockdev.c                | 181 +++++++++++++++++++++++++++++++++++++++++++++-
 hmp.c                     |   4 +-
 include/block/block.h     |  16 +++-
 include/block/block_int.h |   3 +
 include/qemu/hbitmap.h    |   8 ++
 qapi-schema.json          | 116 +++++++++++++++++++++++++++--
 qmp-commands.hx           |  66 ++++++++++++++++-
 util/hbitmap.c            |  16 ++++
 12 files changed, 543 insertions(+), 18 deletions(-)

-- 
1.9.0