Re: [PATCH v7 5/5] drm/xe/ggtt: Add KUnit tests for usable and shareable pools

["Piotr Piórkowski" <piotr.piorkowski@intel.com>]

Piotr Piórkowski <piotr.piorkowski@intel.com> wrote on czw [2026-paź-29 13:12:33 +0100]:
> Jani Nikula <jani.nikula@linux.intel.com> wrote on wto [2026-paź-27 18:31:53 +0200]:
> > On Wed, 21 Oct 2026, Piórkowski, Piotr <piotr.piorkowski@intel.com> wrote:
> > > diff --git a/drivers/gpu/drm/xe/xe_ggtt.c b/drivers/gpu/drm/xe/xe_ggtt.c
> > > index b7e3d626e8cb8..3dd029bc76dfc 100644
> > > --- a/drivers/gpu/drm/xe/xe_ggtt.c
> > > +++ b/drivers/gpu/drm/xe/xe_ggtt.c
> > > @@ -1395,3 +1395,7 @@ u64 xe_ggtt_node_size(const struct xe_ggtt_node *node)
> > >  {
> > >  	return node->base.size;
> > >  }
> > > +
> > > +#if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
> > > +#include "tests/xe_ggtt_kunit.c"
> > > +#endif
> > 
> > Why IS_BUILTIN()?
> > 
> > It smells like a mistake.
> > 
> > 
> > BR,
> > Jani.
> Hello Jani,
> 
> I simply used a pattern that had already been used earlier in the other files — to be honest,
> I didn't give it any further thought.
> 
> List of files with #if IS_BUILTIN(CONFIG_DRM_XE_KUNIT_TEST)
> xe_lmtt.c
> xe_guc_db_mgr.c
> xe_guc_relay.c
> xe_guc_id_mgr.c
> xe_sriov_pf_service.c
> xe_guc_buf.c
> xe_gt_sriov_pf_config.c
> xe_guc_klv_helpers.c
> xe_sriov_packet.c
> xe_log.c
> 
> If we have to use IS_ENABLED In that case, I guess we'll have to fix that
> in the other places as well.
> 
> Thanks,
> Piotr

Hi Jani,

Sorry, my previous answer was too short. I looked into it more closely,
and I believe IS_BUILTIN() is the right choice for this kind of test.

xe_ggtt_kunit.c calls kunit_test_suites() directly. Because the file is
#included into xe_ggtt.c, that puts the suite array into the
.kunit_test_suites section of xe.ko itself. The module loader picks up
that section for every module, and the KUnit module notifier runs those
suites on MODULE_STATE_LIVE. In other words, they run on module load,
as documented in include/kunit/test.h.

So with CONFIG_DRM_XE=m and CONFIG_DRM_XE_KUNIT_TEST=m:

IS_ENABLED(): every "modprobe xe", even on real hardware, would also
run the xe_ggtt/xe_ggtt_iov suites and taint the kernel with
TAINT_TEST.

IS_BUILTIN(): these tests are only built with =y, which is the
configuration used by kunit.py with drivers/gpu/drm/xe/.kunitconfig.

With =y, both variants behave the same.

The xe files that use IS_ENABLED() (xe_bo.c, xe_mocs.c, xe_migrate.c,
...) follow a different pattern. Their included test file does not call
kunit_test_suites(). It only exports the suite with
EXPORT_SYMBOL_IF_KUNIT(), and the separate xe_live_test.ko module
registers it. Nothing runs on xe.ko load, so =m is safe there.

So IIUC the rule is:

kunit_test_suites() in a file #included into xe.ko -> IS_BUILTIN()
suite exported and registered from a separate test module -> IS_ENABLED()
The other files I listed (xe_lmtt.c, xe_guc_id_mgr.c, xe_guc_relay.c,
...) follow the first rule.

Thanks,
Piotr




> > 
> > 
> > -- 
> > Jani Nikula, Intel
> 
> -- 

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