Re: [PATCH v2 00/22] Fix error handling during bitmap postcopy

[Eric Blake <eblake@redhat.com>]

On 4/2/20 2:42 AM, Vladimir Sementsov-Ogievskiy wrote:
> Ping!
> 
> It's a fix, but not a degradation and I'm afraid too big for 5.0.
> 
> Still, I think I should ping it anyway. John, I'm afraid, that this all 
> is for your branch :)

Just noticing this thread, now that we've shuffled bitmaps maintainers. 
Is there anything here that we still need to include in 5.1?

> 
> 
> 17.02.2020 18:02, Vladimir Sementsov-Ogievskiy wrote:
>> Original idea of bitmaps postcopy migration is that bitmaps are non
>> critical data, and their loss is not serious problem. So, using postcopy
>> method on any failure we should just drop unfinished bitmaps and
>> continue guest execution.
>>
>> However, it doesn't work so. It crashes, fails, it goes to
>> postcopy-recovery feature. It does anything except for behavior we want.
>> These series fixes at least some problems with error handling during
>> bitmaps migration postcopy.
>>
>> v1 was "[PATCH 0/7] Fix crashes on early shutdown during bitmaps 
>> postcopy"
>>
>> v2:
>>
>> Most of patches are new or changed a lot.
>> Only patches 06,07 mostly unchanged, just rebased on refactorings.
>>
>> Vladimir Sementsov-Ogievskiy (22):
>>    migration/block-dirty-bitmap: fix dirty_bitmap_mig_before_vm_start
>>    migration/block-dirty-bitmap: rename state structure types
>>    migration/block-dirty-bitmap: rename dirty_bitmap_mig_cleanup
>>    migration/block-dirty-bitmap: move mutex init to dirty_bitmap_mig_init
>>    migration/block-dirty-bitmap: refactor state global variables
>>    migration/block-dirty-bitmap: rename finish_lock to just lock
>>    migration/block-dirty-bitmap: simplify dirty_bitmap_load_complete
>>    migration/block-dirty-bitmap: keep bitmap state for all bitmaps
>>    migration/block-dirty-bitmap: relax error handling in incoming part
>>    migration/block-dirty-bitmap: cancel migration on shutdown
>>    migration/savevm: don't worry if bitmap migration postcopy failed
>>    qemu-iotests/199: fix style
>>    qemu-iotests/199: drop extra constraints
>>    qemu-iotests/199: better catch postcopy time
>>    qemu-iotests/199: improve performance: set bitmap by discard
>>    qemu-iotests/199: change discard patterns
>>    qemu-iotests/199: increase postcopy period
>>    python/qemu/machine: add kill() method
>>    qemu-iotests/199: prepare for new test-cases addition
>>    qemu-iotests/199: check persistent bitmaps
>>    qemu-iotests/199: add early shutdown case to bitmaps postcopy
>>    qemu-iotests/199: add source-killed case to bitmaps postcopy
>>
>> Cc: John Snow <jsnow@redhat.com>
>> Cc: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> Cc: Stefan Hajnoczi <stefanha@redhat.com>
>> Cc: Fam Zheng <fam@euphon.net>
>> Cc: Juan Quintela <quintela@redhat.com>
>> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
>> Cc: Eduardo Habkost <ehabkost@redhat.com>
>> Cc: Cleber Rosa <crosa@redhat.com>
>> Cc: Kevin Wolf <kwolf@redhat.com>
>> Cc: Max Reitz <mreitz@redhat.com>
>> Cc: qemu-block@nongnu.org
>> Cc: qemu-devel@nongnu.org
>> Cc: qemu-stable@nongnu.org # for patch 01
>>
>>   migration/migration.h          |   3 +-
>>   migration/block-dirty-bitmap.c | 444 +++++++++++++++++++++------------
>>   migration/migration.c          |  15 +-
>>   migration/savevm.c             |  37 ++-
>>   python/qemu/machine.py         |  12 +-
>>   tests/qemu-iotests/199         | 244 ++++++++++++++----
>>   tests/qemu-iotests/199.out     |   4 +-
>>   7 files changed, 529 insertions(+), 230 deletions(-)
>>
> 
> 

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3226
Virtualization:  qemu.org | libvirt.org