On Tue, Aug 23, 2022 at 9:31 PM David Gow <davidgow@xxxxxxxxxx> wrote:
>
> On Tue, Aug 23, 2022 at 10:25 PM 'Joe Fradley' via KUnit Development
> <kunit-dev@xxxxxxxxxxxxxxxx> wrote:
> >
> > This patch adds the kunit.enable module parameter that will need to be
> > set to true in addition to KUNIT being enabled for KUnit tests to run.
> > The default value is true giving backwards compatibility. However, for
> > the production+testing use case the new config option
> > KUNIT_DEFAULT_ENABLED can be set to N requiring the tester to opt-in
> > by passing kunit.enable=1 to the kernel.
> >
> > Signed-off-by: Joe Fradley <joefradley@xxxxxxxxxx>
> > ---
>
> Thanks very much. This looks good to me, and works on my machine.
>
> I've put a few comments/ideas below, but none of them feel necessary to me.
Thank you for the review. I need to do one follow up revision to base this
off of the appropriate `linux-kselftest/kunit` branch.
>
> Regardless, this is
> Reviewed-by: David Gow <davidgow@xxxxxxxxxx>
>
> Cheers,
> -- David
>
> > Changes since v1:
> > - Created a function to get kunit enable state
> > - Check kunit enable state in kunit_run_all_tests() in executor.c
> > - Load test module even if KUnit is disabled but still don't execute
> > tests
> > - Simplified kunit disable message and kunit.enable parameter
> > description
> > - Flipped around logic of new config to be KUNIT_DEFAULT_ENABLED
> > - kunit_tool.py now passes kunit.enable=1 to kernel
> >
> > .../admin-guide/kernel-parameters.txt | 6 +++++
> > include/kunit/test.h | 2 ++
> > lib/kunit/Kconfig | 11 +++++++++
> > lib/kunit/executor.c | 4 ++++
> > lib/kunit/test.c | 24 +++++++++++++++++++
> > tools/testing/kunit/kunit_kernel.py | 1 +
> > 6 files changed, 48 insertions(+)
> >
> > diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> > index adfda56b2691..7aa3abd7f1c5 100644
> > --- a/Documentation/admin-guide/kernel-parameters.txt
> > +++ b/Documentation/admin-guide/kernel-parameters.txt
> > @@ -2432,6 +2432,12 @@
> > 0: force disabled
> > 1: force enabled
> >
> > + kunit.enable= [KUNIT] Enable executing KUnit tests. Requires
> > + CONFIG_KUNIT to be set to be fully enabled. The
> > + default value can be overridden via
> > + KUNIT_DEFAULT_ENABLED.
> > + Default is 1 (enabled)
> > +
> > kvm.ignore_msrs=[KVM] Ignore guest accesses to unhandled MSRs.
> > Default is 0 (don't ignore, but inject #GP)
> >
> > diff --git a/include/kunit/test.h b/include/kunit/test.h
> > index c958855681cc..ee6bf4ecbd89 100644
> > --- a/include/kunit/test.h
> > +++ b/include/kunit/test.h
> > @@ -228,6 +228,8 @@ static inline void kunit_set_failure(struct kunit *test)
> > WRITE_ONCE(test->status, KUNIT_FAILURE);
> > }
> >
> > +bool kunit_enabled(void);
> > +
>
> This probably isn't strictly necessary at this stage, given that it
> just checks one variable. That being said, I don't think it hurts (and
> personally, I quite like it), and find it more future-proof than
> exposing the variable more widely anyway.
It also addressed it being a static variable.
>
> > void kunit_init_test(struct kunit *test, const char *name, char *log);
> >
> > int kunit_run_tests(struct kunit_suite *suite);
> > diff --git a/lib/kunit/Kconfig b/lib/kunit/Kconfig
> > index 0b5dfb001bac..626719b95bad 100644
> > --- a/lib/kunit/Kconfig
> > +++ b/lib/kunit/Kconfig
> > @@ -59,4 +59,15 @@ config KUNIT_ALL_TESTS
> >
> > If unsure, say N.
> >
> > +config KUNIT_DEFAULT_ENABLED
> > + bool "Default value of kunit.enable"
> > + default y
> > + help
> > + Sets the default value of kunit.enable. If set to N then KUnit
> > + tests will not execute unless kunit.enable=1 is passed to the
> > + kernel command line.
> > +
> > + In most cases this should be left as Y. Only if additional opt-in
> > + behavior is needed should this be set to N.
> > +
> > endif # KUNIT
> > diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
> > index 5e223327196a..9bbc422c284b 100644
> > --- a/lib/kunit/executor.c
> > +++ b/lib/kunit/executor.c
> > @@ -190,6 +190,10 @@ int kunit_run_all_tests(void)
> > {
> > struct suite_set suite_set = {__kunit_suites_start, __kunit_suites_end};
> > int err = 0;
> > + if (!kunit_enabled()) {
> > + pr_info("kunit: disabled\n");
> > + goto out;
> > + }
> >
> > if (filter_glob_param) {
> > suite_set = kunit_filter_suites(&suite_set, filter_glob_param, &err);
> > diff --git a/lib/kunit/test.c b/lib/kunit/test.c
> > index b73d5bb5c473..1e54373309a4 100644
> > --- a/lib/kunit/test.c
> > +++ b/lib/kunit/test.c
> > @@ -54,6 +54,17 @@ void __kunit_fail_current_test(const char *file, int line, const char *fmt, ...)
> > EXPORT_SYMBOL_GPL(__kunit_fail_current_test);
> > #endif
> >
> > +/*
> > + * Enable KUnit tests to run.
> > + */
> > +#ifdef CONFIG_KUNIT_DEFAULT_ENABLED
> > +static bool enable_param = true;
> > +#else
> > +static bool enable_param;
> > +#endif
> > +module_param_named(enable, enable_param, bool, 0);
> > +MODULE_PARM_DESC(enable, "Enable KUnit tests");
> > +
> > /*
> > * KUnit statistic mode:
> > * 0 - disabled
> > @@ -586,10 +597,20 @@ static void kunit_init_suite(struct kunit_suite *suite)
> > suite->suite_init_err = 0;
> > }
> >
> > +bool kunit_enabled(void)
> > +{
> > + return enable_param;
> > +}
> > +
> > int __kunit_test_suites_init(struct kunit_suite * const * const suites, int num_suites)
> > {
> > unsigned int i;
> >
> > + if (!kunit_enabled() && num_suites > 0) {
> > + pr_info("kunit: disabled\n");
>
> _Maybe_ this could be pr_info_once(), if you were worried about spam
> (if a whole bunch of test modules were loaded at once). That being
> said, I prefer it as-is, as I don't think there are a lot of cases
> where large number of kunit test modules are loaded on a system with
> KUnit disable. And I'm liable to forget that KUnit is disabled if a
> system has been running for a while (and maybe one test module was
> loaded a boot), and end up wondering why my test isn't running.
That's the same conclusion I came to after considering the one time
message used for the test taint message.
>
> So, I'm all for leaving this as-is, personally.
>
> > + return 0;
> > + }
> > +
> > for (i = 0; i < num_suites; i++) {
> > kunit_init_suite(suites[i]);
> > kunit_run_tests(suites[i]);
> > @@ -607,6 +628,9 @@ void __kunit_test_suites_exit(struct kunit_suite **suites, int num_suites)
> > {
> > unsigned int i;
> >
> > + if (!kunit_enabled())
> > + return;
> > +
> > for (i = 0; i < num_suites; i++)
> > kunit_exit_suite(suites[i]);
> >
> > diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
> > index f5c26ea89714..ef794da420d7 100644
> > --- a/tools/testing/kunit/kunit_kernel.py
> > +++ b/tools/testing/kunit/kunit_kernel.py
> > @@ -359,6 +359,7 @@ class LinuxSourceTree:
> > args = []
> > if filter_glob:
> > args.append('kunit.filter_glob='+filter_glob)
> > + args.append('kunit.enable=1')
> >
> > process = self._ops.start(args, build_dir)
> > assert process.stdout is not None # tell mypy it's set
> > --
> > 2.37.1.595.g718a3a8f04-goog
> >
> > --
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