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Re: [Qemu-devel] ping Re: [PATCH 00/18] Dirty bitmaps postcopy migration
From: |
Stefan Hajnoczi |
Subject: |
Re: [Qemu-devel] ping Re: [PATCH 00/18] Dirty bitmaps postcopy migration |
Date: |
Wed, 2 Nov 2016 11:13:32 +0000 |
User-agent: |
Mutt/1.7.1 (2016-10-04) |
On Tue, Oct 25, 2016 at 04:04:35PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> ping
>
> For now there are some notes mostly about accessory patches. What about
> migration itself? Is it ok? Has it a chance of being merged one day?
This series mostly touches migration/ code. Juan or DaveG?
> 16.08.2016 13:25, Vladimir Sementsov-Ogievskiy wrote:
> > v2:
> > some bugs fixed, iotests a bit changed and merged into one test.
> > based on block-next (https://github.com/XanClic/qemu/commits/block-next)
> > clone: tag postcopy-v2 from https://src.openvz.org/scm/~vsementsov/qemu.git
> > online:
> > https://src.openvz.org/users/vsementsov/repos/qemu/browse?at=refs%2Ftags%2Fpostcopy-v2
> >
> > v1:
> >
> > These series are derived from my 'Dirty bitmaps migration' series. The
> > core idea is switch to postcopy migration and drop usage of meta
> > bitmaps.
> >
> > These patches provide dirty bitmap postcopy migration feature. Only
> > named dirty bitmaps are to be migrated. Migration may be enabled using
> > migration capabilities.
> >
> > The overall method (thanks to John Snow):
> >
> > 1. migrate bitmaps meta data in .save_live_setup
> > - create/find related bitmaps on target
> > - disable them
> > - create successors (anonimous children) only for enabled migrated
> > bitmaps
> > 2. do nothing in precopy stage
> > 3. just before target vm start: enable successors, created in (1)
> > 4. migrate bitmap data
> > 5. reclaime bitmaps (merge successors to their parents)
> > 6. enable bitmaps (only bitmaps, which was enabled in source)
> >
> >
> > Some patches are unchnaged from (v7) of 'Dirty bitmaps migration'
> > (DBMv7). I've left Reviewed-by's for them, if you don't like it, say me
> > and I'll drop them in the following version.
> >
> > So, relatively to last DBMv7:
> >
> > 01-04: new patches, splitting common postcopy migration out of ram
> > postcopy migration
> > 05: equal to DBMv7.05
> > 06: new
> > 07: equal to DBMv7.06
> > 08: new
> > 09: equal to DBMv7.07
> > 10: new
> > 11: derived from DBMv7.08, see below
> > 12-15: equal to DBMv7.09-12
> > 16: derived from DBMv7.13
> > - switch from fifo to socket, as postcopy don't work with fifo
> > for now
> > - change parameters: size, granularity, regions
> > - add time.sleep, to wait for postcopy migration phase (bad
> > temporary solution.
> > - drop Reviewed-by
> > 17: new
> >
> > 11: the core patch of the series, it is derived from
> > [DBMv7.08: migration: add migration_block-dirty-bitmap.c]
> > There are a lot of changes related to switching from precopy to
> > postcopy, but functions related to migration stream itself
> > (structs, send/load sequences) are mostly unchnaged.
> >
> > So, changes, to switch from precopy to postcopy:
> > - removed all staff related to meta bitmaps and dirty phase!!!
> > - add dirty_bitmap_mig_enable_successors, and call it before
> > target vm start in loadvm_postcopy_handle_run
> > - add enabled_bitmaps list of bitmaps for
> > dirty_bitmap_mig_enable_successors
> >
> > - enabled flag is send with start bitmap chunk instead of
> > completion chunk
> > - sectors_per_chunk is calculated directly from CHUNK_SIZE, not
> > using meta bitmap granularity
> >
> > - dirty_bitmap_save_iterate: remove dirty_phase, move bulk_phase
> > to postcopy stage
> > - dirty_bitmap_save_pending: remove dirty phase related pending,
> > switch pending to non-postcopyable
> > - dirty_bitmap_load_start: get enabled flag and prepare
> > successors for enabled bitmaps, also add them to
> > enabled_bitmaps list
> > - dirty_bitmap_load_complete: for enabled bitmaps: merge them
> > with successors and enable
> >
> > - savevm handlers:
> > * remove separate savevm_dirty_bitmap_live_iterate_handlers state
> > (it was bad idea, any way), and move its save_live_iterate to
> > savevm_dirty_bitmap_handlers
> > * add is_active_iterate savevm handler, which allows iterations
> > only in postcopy stage (after stopping source vm)
> > * add has_postcopy savevm handler. (ofcourse, just returning true)
> > * use save_live_complete_postcopy instead of
> > save_live_complete_precopy
> >
> > Other changes:
> > - some debug output changed
> > - remove MIN_LIVE_SIZE, is_live_iterative and related staff (it
> > was needed to omit iterations if bitmap data is small, possibly
> > this should be reimplemented)
> >
> > Vladimir Sementsov-Ogievskiy (18):
> > migration: add has_postcopy savevm handler
> > migration: fix ram_save_pending
> > migration: split common postcopy out of ram postcopy
> > migration: introduce postcopy-only pending
> > block: add bdrv_next_dirty_bitmap()
> > block: add bdrv_dirty_bitmap_enable_successor()
> > qapi: add dirty-bitmaps migration capability
> > block/dirty-bitmap: add bdrv_dirty_bitmap_release_successor
> > migration: include migrate_dirty_bitmaps in migrate_postcopy
> > migration/qemu-file: add qemu_put_counted_string()
> > migration: add is_active_iterate handler
> > migration: add postcopy migration of dirty bitmaps
> > 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 default node-name
> > iotests: add dirty bitmap migration test 117
> > iotests: add dirty bitmap postcopy test
> >
> > block/dirty-bitmap.c | 26 ++
> > include/block/dirty-bitmap.h | 6 +
> > include/migration/block.h | 1 +
> > include/migration/migration.h | 6 +
> > include/migration/qemu-file.h | 2 +
> > include/migration/vmstate.h | 7 +-
> > include/qemu/hbitmap.h | 8 +
> > include/sysemu/sysemu.h | 5 +-
> > migration/Makefile.objs | 2 +-
> > migration/block-dirty-bitmap.c | 699
> > +++++++++++++++++++++++++++++++++++++++++
> > migration/block.c | 7 +-
> > migration/migration.c | 66 ++--
> > migration/postcopy-ram.c | 4 +-
> > migration/qemu-file.c | 13 +
> > migration/ram.c | 19 +-
> > migration/savevm.c | 56 +++-
> > migration/trace-events | 2 +-
> > qapi-schema.json | 4 +-
> > qapi/block-core.json | 5 +-
> > tests/qemu-iotests/169 | 134 ++++++++
> > tests/qemu-iotests/169.out | 5 +
> > tests/qemu-iotests/group | 2 +
> > tests/qemu-iotests/iotests.py | 21 +-
> > util/hbitmap.c | 8 +
> > vl.c | 1 +
> > 25 files changed, 1055 insertions(+), 54 deletions(-)
> > create mode 100644 migration/block-dirty-bitmap.c
> > create mode 100755 tests/qemu-iotests/169
> > create mode 100644 tests/qemu-iotests/169.out
> >
>
>
> --
> Best regards,
> Vladimir
>
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- Re: [Qemu-devel] ping Re: [PATCH 00/18] Dirty bitmaps postcopy migration,
Stefan Hajnoczi <=