On Tue, May 12, 2026 at 11:52:45AM -0700, Pierrick Bouvier wrote: > On 5/12/2026 11:46 AM, Daniel P. Berrangé wrote: > > 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. > > > > I might have missed where we have a default value for this env var, out > of yaml file, that makes it apply the exact same set of skip tests for > CI, and for users running tests manually. > > Where is this default applied for both CI and users? > > I understand it's not needed for test 185 which fails only in GitLab, > but as you mentioned, we'll probably have non deterministic tests in the > future, so we need to consider this.
I was considering any change in meson.build to permanently skip a test would be independent of the env var handling, and outside the scope of this series since there's no need for it here. 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 :|
