On 13.01.2015 20:02, Vladimir Sementsov-Ogievskiy wrote:
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
hbitmap: store / restore
qcow2: add dirty-bitmaps feature
block: store persistent dirty bitmaps
block: add bdrv_load_dirty_bitmap
qemu: command line option for dirty bitmaps
qmp: print dirty bitmap
iotests: test internal persistent dirty bitmap
block.c | 113 ++++++++++
block/Makefile.objs | 2 +-
block/qcow2-dirty-bitmap.c | 514 +++++++++++++++++++++++++++++++++++++++++++++
block/qcow2.c | 26 +++
block/qcow2.h | 48 +++++
blockdev.c | 51 +++++
docs/specs/qcow2.txt | 59 ++++++
hmp-commands.hx | 15 ++
hmp.c | 8 +
hmp.h | 1 +
include/block/block.h | 9 +
include/block/block_int.h | 10 +
include/qemu/hbitmap.h | 49 +++++
include/sysemu/blockdev.h | 1 +
include/sysemu/sysemu.h | 1 +
qapi-schema.json | 3 +-
qapi/block-core.json | 3 +
qemu-options.hx | 37 ++++
qmp-commands.hx | 5 +
tests/qemu-iotests/115 | 96 +++++++++
tests/qemu-iotests/115.out | 64 ++++++
tests/qemu-iotests/group | 1 +
util/hbitmap.c | 87 ++++++++
vl.c | 100 +++++++++
24 files changed, 1301 insertions(+), 2 deletions(-)
create mode 100644 block/qcow2-dirty-bitmap.c
create mode 100755 tests/qemu-iotests/115
create mode 100644 tests/qemu-iotests/115.out
Ping. I've already done (locally):
1) using qcow2 header extension instead of changing the header
2) normal qmp query request instead of "print dirty bitmap"
- thanks to Eric and Markus
Now I'm waiting for some comments on the concept and it's realization to
roll v3.
--
Best regards,
Vladimir
