On 5/12/2026 12:00 PM, Daniel P. Berrangé wrote: > 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. >
Where is the default value for this env var applied for both CI and users? yaml is for CI only. > > With regards, > Daniel
