Re: [PATCH v2 3/5] tests/qtest/migration: check the destination run state in postcopy tests

[Eric Blake <eblake@redhat.com>]

On Tue, Nov 10, 2026 at 07:32:55PM +0100, Denis V. Lunev wrote:
> From: Denis V. Lunev <den@openvz.org>
> 
> The destination must not report postcopy-active or completed while it
> is still in RUN_STATE_INMIGRATE. The destination autostarts in these
> tests, so the run state change emits RESUME and the order is visible in
> the event stream: record a MIGRATION postcopy-active or completed event
> seen before RESUME and fail the postcopy tests on it once the
> destination has completed.
> 
> migrate_postcopy_start() waited for the destination's RESUME with
> qtest_qmp_eventwait(), which reads events past the event callback and
> drops the ones it does not want. Poll query-status instead, so every
> destination event reaches the callback.
> 
> Signed-off-by: Denis V. Lunev <den@openvz.org>
> Cc: Peter Xu <peterx@redhat.com>
> Cc: Fabiano Rosas <farosas@suse.de>
> Cc: Juraj Marcin <jmarcin@redhat.com>
> ---
>  tests/qtest/migration/framework.c      |  6 ++++--
>  tests/qtest/migration/migration-qmp.c  | 10 ++++++++--
>  tests/qtest/migration/migration-qmp.h  |  3 ++-
>  tests/qtest/migration/migration-util.c |  8 ++++++++
>  tests/qtest/migration/migration-util.h |  2 ++
>  5 files changed, 24 insertions(+), 5 deletions(-)

Took me a while to figure out that I needed a temporary:

$ sudo sysctl -w vm.unprivileged_userfaultfd=1

to get the test to pass/fail rather than skip, but with that done, I
can confirm that the test was sufficient to show failure without 2/5,
and pass when the series is applied in order. I'd be remiss if I did
not mention how handy it was to have AI help me dig up the specific
configuration and tests I needed to run for double-checking your patch
(thankfully, much different than the ethical worries about using AI to
write a patch in the first place).

Tested-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.
Virtualization:  qemu.org | libguestfs.org