DEVICE state was introduced back in 2017:
https://lore.kernel.org/qemu-devel/20171020090556.18631-1-dgilbert@redhat.com/
Quote from Dave's cover letter, when the pre-switchover phase was enabled,
the state transition looks like this:
The precopy flow is:
active->pre-switchover->device->completed
The postcopy flow is:
active->pre-switchover->postcopy-active->completed
To supplement above, when the cap is not enabled:
The precopy flow is:
active->completed
The postcopy flow is:
active->postcopy-active->completed
It works for us, though we have some code just to special case these state
transitions, so the DEVICE state currently is special only to precopy, and
only conditionally.
I had a quick discussion with Libvirt developers, it turns out that this
may not be necessary. IOW, it seems okay we can have DEVICE state to be
generic, so that we don't have over-complicated state machines. It not
only helps align all the migration state machine, help cleanup the code
path especially on pre-switchover handling (see the patch itself), another
side benefit is we can unconditionally have a specific state to mark the
switchover phase, which might be helpful for debugging too.
This patch makes the DEVICE state to be present always, marking that source
QEMU is switching over. Then the state machine will be always as simple
as:
active-> [pre-switchover->] -> device -> [postcopy-active->] -> complete
After the change, no matter whether pre-switchover or postcopy is enabled
or not, we always have DEVICE state showing the switchover phase. When
pre-switchover enabled, we'll have an extra stage before that. When
postcopy is enabled, we'll have an extra stage after that.
A few qtests need touch up in QEMU tree for this change:
- A few iotest outputs (194, 203, 234, 262, 280)
- Teach libqos's migrate() on "device" state
Cc: Jiri Denemark <jdenemar@redhat.com>
Cc: Daniel P. Berrangé <berrange@redhat.com>
Cc: Dr. David Alan Gilbert <dave@treblig.org>
Signed-off-by: Peter Xu <peterx@redhat.com>
Tested-by: Jiri Denemark <jdenemar@redhat.com>
Reviewed-by: Juraj Marcin <jmarcin@redhat.com>
Link: https://lore.kernel.org/r/20250114230746.3268797-15-peterx@redhat.com
Signed-off-by: Fabiano Rosas <farosas@suse.de>
The event is racy: it will not appear in the output if bitmap is
migrated during downtime period of migration and postcopy phase is not
started.
Fixes: ae00aa239847 "iotests: 194: test also migration of dirty bitmap"
Reported-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20230607143606.1557395-1-vsementsov@yandex-team.ru>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The same information is available via the 'recording' and 'busy' fields.
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
It is possible, that shutdown on target occurs earlier than migration
finish. In this case we crash in bdrv_release_dirty_bitmap_locked()
on assertion "assert(!bdrv_dirty_bitmap_busy(bitmap));" as we do have
busy bitmap, as bitmap migration is ongoing.
We'll fix bitmap migration to gracefully cancel on early shutdown soon.
Now let's fix iotest 194 to wait migration completion before shutdown.
Note that in this test dest_vm.shutdown() is called implicitly, as vms
used as context-providers, see __exit__() method of QEMUMachine class.
Actually, not waiting migration finish is a wrong thing, but the test
started to crash after commit ae00aa239847682
"iotests: 194: test also migration of dirty bitmap", which added dirty
bitmaps here. So, Fixes: tag won't hurt.
Fixes: ae00aa2398476824f0eca80461da215e7cdc1c3b
Reported-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Tested-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[eblake: grammar tweak]
Message-Id: <20200604083341.26978-1-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Test that dirty bitmap migration works when we deal with mirror.
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20200521220648.3255-5-vsementsov@virtuozzo.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
When dumping an object into the log, there are differences between
Python 2 and 3. First, unicode strings are prefixed by 'u' in Python 2
(they are no longer in 3, because unicode strings are the default
there). Second, the order of keys in dicts may differ. Third,
especially long numbers are longs in Python 2 and thus get an 'L'
suffix, which does not happen in Python 3.
We can get around all of these differences by dumping objects (lists and
dicts) in a language-independent format, namely JSON. The JSON
generator even allows emitting dicts with their keys sorted
alphabetically.
This changes the output of all tests that use these logging functions
(dict keys are ordered now, strings in dicts are now enclosed in double
quotes instead of single quotes, the 'L' suffix of large integers is
dropped, and "true" and "false" are now in lower case).
The quote change necessitates a small change to a filter used in test
207.
Suggested-by: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20181022135307.14398-10-mreitz@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This is the follow-up patch that was discussed[*] as part of feedback to
qemu-iotest 194.
Changes in this patch:
- Supply 'job-id' parameter to `drive-mirror` invocation.
- Once migration completes, issue QMP `block-job-cancel` command on
the source QEMU to gracefully complete `drive-mirror` operation.
- Once the BLOCK_JOB_COMPLETED event is emitted, stop the NBD server
on the destination QEMU.
- Check for both the events: MIGRATION and BLOCK_JOB_COMPLETED.
With the above, the test will also be (almost) in sync with the
procedure outlined in the document 'live-block-operations.rst'[+]
(section: "QMP invocation for live storage migration with
``drive-mirror`` + NBD").
[*] https://lists.nongnu.org/archive/html/qemu-devel/2017-08/msg04820.html
-- qemu-iotests: add 194 non-shared storage migration test
[+] https://git.qemu.org/gitweb.cgi?p=qemu.git;a=blob;f=docs/interop/live-block-operations.rst
Signed-off-by: Kashyap Chamarthy <kchamart@redhat.com>
Message-Id: <20170829165058.8229-1-kchamart@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
Non-shared storage migration with NBD and drive-mirror is currently not
tested by qemu-iotests. This test case covers the basic migration
scenario.
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Based-on: <20170823134242.12080-1-famz@redhat.com>
Message-Id: <20170823140506.28723-1-stefanha@redhat.com>
Tested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Eric Blake <eblake@redhat.com>
