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. 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. > With regards, > Daniel
