On Tue, May 12, 2026 at 10:53:05AM -0700, Pierrick Bouvier wrote: > On 5/12/2026 10:24 AM, Daniel P. Berrangé wrote: > > On Tue, May 12, 2026 at 10:09:53AM -0700, Pierrick Bouvier wrote: > >> On 5/12/2026 9:53 AM, Daniel P. Berrangé wrote: > >>> On Tue, May 12, 2026 at 09:47:12AM -0700, Pierrick Bouvier wrote: > >>>> On 5/12/2026 9:36 AM, Daniel P. Berrangé wrote: > >>>>> On Tue, May 12, 2026 at 09:19:45AM -0700, Pierrick Bouvier wrote: > >>>>>> On 5/12/2026 9:06 AM, Daniel P. Berrangé wrote: > >>>>>>> On Tue, May 12, 2026 at 08:56:54AM -0700, Pierrick Bouvier wrote: > >>>>>>>> On 4/24/2026 8:42 AM, Daniel P. Berrangé wrote: > >>>>>>>>> The nature of block I/O tests is such that there can be unexpected > >>>>>>>>> false > >>>>>>>>> positive failures in certain scenarios that have not been > >>>>>>>>> encountered > >>>>>>>>> before, and sometimes non-deterministic failures that are hard to > >>>>>>>>> reproduce. > >>>>>>>>> > >>>>>>>>> Before enabling the I/O tests as gating jobs in CI, there needs to > >>>>>>>>> be a > >>>>>>>>> mechanism to dynamically mark tests as skipped, without having to > >>>>>>>>> commit > >>>>>>>>> code changes. > >>>>>>>>> > >>>>>>>>> This introduces the QEMU_TEST_IO_SKIP environment variable that is > >>>>>>>>> set > >>>>>>>>> to a list of FORMAT-OR-PROTOCOL:NAME pairs. The intent is that this > >>>>>>>>> variable can be set as a GitLab CI pipeline variable to temporarily > >>>>>>>>> disable a test while problems are being debugged. > >>>>>>>>> > >>>>>>>>> Reviewed-by: Thomas Huth <[email protected]> > >>>>>>>>> Signed-off-by: Daniel P. Berrangé <[email protected]> > >>>>>>>>> --- > >>>>>>>>> docs/devel/testing/main.rst | 7 +++++++ > >>>>>>>>> tests/qemu-iotests/testrunner.py | 16 ++++++++++++++++ > >>>>>>>>> 2 files changed, 23 insertions(+) > >>>>>>>>> > >>>>>>>>> diff --git a/docs/devel/testing/main.rst > >>>>>>>>> b/docs/devel/testing/main.rst > >>>>>>>>> index 797111009a..f779a64415 100644 > >>>>>>>>> --- a/docs/devel/testing/main.rst > >>>>>>>>> +++ b/docs/devel/testing/main.rst > >>>>>>>>> @@ -284,6 +284,13 @@ that are specific to certain cache mode. > >>>>>>>>> More options are supported by the ``./check`` script, run > >>>>>>>>> ``./check -h`` for > >>>>>>>>> help. > >>>>>>>>> > >>>>>>>>> +If a test program is known to be broken, it can be disabled by > >>>>>>>>> setting > >>>>>>>>> +the ``QEMU_TEST_IO_SKIP`` environment variable with a list of > >>>>>>>>> tests to > >>>>>>>>> +be skipped. The values are of the form FORMAT-OR-PROTOCOL:NAME, the > >>>>>>>>> +leading component can be omitted to skip the test for all formats > >>>>>>>>> and > >>>>>>>>> +protocols. For example ``export QEMU_TEST_IO_SKIP="luks:149 185 > >>>>>>>>> iov-padding`` > >>>>>>>>> +will skip ``149`` for LUKS only, and ``185`` and ``iov-padding`` > >>>>>>>>> for all. > >>>>>>>>> + > >>>>>>>>> Writing a new test case > >>>>>>>>> ~~~~~~~~~~~~~~~~~~~~~~~ > >>>>>>>>> > >>>>>>>>> diff --git a/tests/qemu-iotests/testrunner.py > >>>>>>>>> b/tests/qemu-iotests/testrunner.py > >>>>>>>>> index dbe2dddc32..ecb5d4529f 100644 > >>>>>>>>> --- a/tests/qemu-iotests/testrunner.py > >>>>>>>>> +++ b/tests/qemu-iotests/testrunner.py > >>>>>>>>> @@ -145,6 +145,18 @@ def __init__(self, env: TestEnv, tap: bool = > >>>>>>>>> False, > >>>>>>>>> > >>>>>>>>> self._stack: contextlib.ExitStack > >>>>>>>>> > >>>>>>>>> + self.skip = {} > >>>>>>>>> + for rule in os.environ.get("QEMU_TEST_IO_SKIP", > >>>>>>>>> "").split(" "): > >>>>>>>>> + rule = rule.strip() > >>>>>>>>> + if rule == "": > >>>>>>>>> + continue > >>>>>>>>> + if ":" in rule: > >>>>>>>>> + fmt, name = rule.split(":") > >>>>>>>>> + if fmt in ("", env.imgfmt, env.imgproto): > >>>>>>>>> + self.skip[name] = True > >>>>>>>>> + else: > >>>>>>>>> + self.skip[rule] = True > >>>>>>>>> + > >>>>>>>>> def __enter__(self) -> 'TestRunner': > >>>>>>>>> self._stack = contextlib.ExitStack() > >>>>>>>>> self._stack.enter_context(self.env) > >>>>>>>>> @@ -251,6 +263,10 @@ def do_run_test(self, test: str) -> TestResult: > >>>>>>>>> description='No qualified output ' > >>>>>>>>> f'(expected > >>>>>>>>> {f_reference})') > >>>>>>>>> > >>>>>>>>> + if f_test.name in self.skip: > >>>>>>>>> + return TestResult(status='not run', > >>>>>>>>> + description='Listed in > >>>>>>>>> QEMU_TEST_IO_SKIP') > >>>>>>>>> + > >>>>>>>>> args = [str(f_test.resolve())] > >>>>>>>>> env = self.env.prepare_subprocess(args) > >>>>>>>>> > >>>>>>>> > >>>>>>>> Why not simply remove the broken tests, and create issues to add them > >>>>>>>> again in the future? > >>>>>>> > >>>>>>> In theory that's what our policy today is, but in practice it is > >>>>>>> too much of a burden on the release co-ordinator, to expect them > >>>>>>> to create such a patch themselves, or wait on a subsys maintainer > >>>>>>> todo it for them. > >>>>>>> > >>>>>>> They end up just ignoring brokenness in CI which is a bad practice, > >>>>>>> and will prevent us ever making CI truely gating or switching to > >>>>>>> using MRs for pull requests. This gives us a super-fast way to skip > >>>>>>> flaky tests, while the subsystem maintainers figure out the right > >>>>>>> permanent answer. > >>>>>>> > >>>>>> > >>>>>> I disagree on this one, merging a single patch doing a git rm, and a > >>>>>> git > >>>>>> revert later is not more expensive than merging a variable modifying a > >>>>>> variable in a yaml file. > >>>>> > >>>>> Any code changes like that need to be sent back to the subsystem > >>>>> maintainer to be acked. IMHO the release manager should not be > >>>>> unilaterally deleting tests without peer review. So that's > >>>>> got a non-negligible turn around time, during which CI is broken. > >>>>> > >>>> > >>>> I accept the argument, but it seems like a workaround for a human > >>>> process, more than a proper solution to the problem. > >>>> > >>>> It would be better to have a proper policy for build/test fixes, instead > >>>> of implementing local overrides to this. > >>>> > >>>>> Setting an env variable to skip a problematic test is something > >>>>> reasonable to do with zero oversight. > >>>>> > >>>>>> The issue with this approach is that people running tests locally will > >>>>>> not see which tests are skipped, and will see false positives. So you > >>>>>> just keep CI green, but not the test base itself. > >>>>> > >>>>> I would still expect the release manager to file a bug about any > >>>>> flaky test they disable via the env var, and the subsystem maintainer > >>>>> should still be fixing it or disabling it such that tests won't fail > >>>>> more broadly, or deciding to remove it if terminally broken. > >>>>> > >>>>> We're just decoupling the process so that there is an immediate > >>>>> workaround possible. It can also be used by people working in > >>>>> their forks - often I've been testing stuff in my fork, but > >>>>> see spurious failures because git master has a non-deterministic > >>>>> test failure merged. I would like to easily skip those in my fork > >>>>> too, without adding extra commits to me working branches, as that > >>>>> would require the same commit to be duped into several in-progress > >>>>> branches, vs setting the env var once. > >>>>> > >>>>>> The risk I see is that some tests will stay forever in this skip > >>>>>> variable, so it will be dead code for CI, but still alive and failing > >>>>>> for people running tests manually who hit the regression. > >>>>> > >>>>> Again, there should be a bug filed for any flaky test. Anyone can > >>>>> do this, if they see it locally or in their fork CI, or in staging > >>>>> CI. If no one can see an obvious fix, then anyone can also propose > >>>>> to disable the test. > >>>>> > >>>>>> If you still want an alternative to removing test, implementing a > >>>>>> skip_list in tests/qemu-iotests/meson.build is better than an env var > >>>>>> IMHO, and achieves the exact same effect, for CI and for users. > >>>>>> > >>>>>> What do you think? > >>>>> > >>>>> IMHO there needs to be a way to skip flaky tests which does not > >>>>> require code changes as the only available option. Code changes > >>>>> are the permanent fix, env var is the immediate workaround. > >>>>> > >>>> > >>>> I'm not sure all this answers to my question about How to ensure users > >>>> who run tests and the CI both see the same skip list. > >>>> > >>>> I don't mind having an env var, a black list in meson or any other > >>>> solution, but having different results on a dev machine and in CI is not > >>>> a good design. So whatever the solution is, the CI yaml file is not the > >>>> proper place to store this information. > >>> > >>> AFAICT the test 185 that is being skipped in the CI yaml file only > >>> fails when run under gitlab. I've never seen a failure running it > >>> locally. > >>> > >>> If it failed locally too, then I'd agree that it should not be > >>> skipped in the CI yaml, but universally skipped in all scenarios. > >>> > >> > >> If I get all this correctly, we add a generic mechanic to be able to > >> gate CI with block tests just because there is a single test failing > >> with a single driver. Is that the right approach? > > > > The env variable is the generic mechanism. > > > > The yaml file exclusion for 185 is the special case, but we get > > that basically for free with the former. > > > >> In the future, do we expect to merge code breaking tests? > > > > Yes. We will certainly merge more non-deterministic tests. We've seen > > this over & over again. Something passes CI initially but after a > > number of CI pipelines turns out to be flaky > > > > Then we can mark them as flaky in tests/qemu-iotests/meson.build.
That is a long term solution. It does not address the immediate time critical goal to have the ability to fix a broken CI pipeline immediately by skipping the test without waiting for code changes. > It seems like you ignore the point that there is a problem between > setting something in CI only vs making something that works for all > users. I'm not against an env var, I just don't see how it answers this > need. Again, I'm not saying that we fix this only for CI. The env var is to allow broken jobs to be immediately skipped, while waiting for code changes to permanently skipped/fix the tests. The latter addresses it for every scenario. With regards, Daniel -- |: https://berrange.com ~~ https://hachyderm.io/@berrange :| |: https://libvirt.org ~~ https://entangle-photo.org :| |: https://pixelfed.art/berrange ~~ https://fstop138.berrange.com :|
