[PATCH i-g-t v4] lib/xe/xe_query: Do not require QUERY_OA_UNITS for all Xe tests

[Peter Senna Tschudin <peter.senna@linux.intel.com>]

The code currently requires the driver to support DRM_XE_DEVICE_QUERY_OA_UNITS
to run all tests while the only test that needs it is xe_oa. Removes the
requirement so that all other Xe tests can run when this single requirement is
not met.

I found it when trying to run IGT Xe tests on a recent kernel
6.9.9-200.fc40.x86_64 from Fedora 40.

V4:
 - Shorten the commit message
 - Adds back the the path prefix to the subject

V3:
 - Update comment syntax and shorten comments
 - Update comment content to describe from kernel version perspective only
 - Update test to make '!= 0' implicit

V2:
 - Cleanup headers from message body
 - Add 'lib/xe/xe_query:' to subject line

Signed-off-by: Peter Senna Tschudin <peter.senna@intel.com>
---
 lib/xe/xe_query.c   | 4 +++-
 tests/intel/xe_oa.c | 6 +++++-
 2 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/lib/xe/xe_query.c b/lib/xe/xe_query.c
index 84eaaac96..8694fa3f9 100644
--- a/lib/xe/xe_query.c
+++ b/lib/xe/xe_query.c
@@ -124,7 +124,9 @@ static struct drm_xe_query_oa_units *xe_query_oa_units_new(int fd)
 		.data = 0,
 	};
 
-	igt_assert_eq(igt_ioctl(fd, DRM_IOCTL_XE_DEVICE_QUERY, &query), 0);
+	/* Support older kernels where this uapi is not yet available */
+	if (igt_ioctl(fd, DRM_IOCTL_XE_DEVICE_QUERY, &query))
+		return NULL;
 
 	oa_units = malloc(query.size);
 	igt_assert(oa_units);
diff --git a/tests/intel/xe_oa.c b/tests/intel/xe_oa.c
index ff2218300..1f82dce06 100644
--- a/tests/intel/xe_oa.c
+++ b/tests/intel/xe_oa.c
@@ -4503,6 +4503,7 @@ static const char *xe_engine_class_name(uint32_t engine_class)
 igt_main
 {
 	struct drm_xe_engine_class_instance *hwe = NULL;
+	struct xe_device *xe_dev;
 
 	igt_fixture {
 		struct stat sb;
@@ -4527,7 +4528,10 @@ igt_main
 		igt_assert_eq(drm_fd, -1);
 
 		drm_fd = drm_open_driver(DRIVER_XE);
-		xe_device_get(drm_fd);
+		xe_dev = xe_device_get(drm_fd);
+
+		/* See xe_query_oa_units_new() */
+		igt_require(xe_dev->oa_units);
 
 		devid = intel_get_drm_devid(drm_fd);
 		sysfs = igt_sysfs_open(drm_fd);
-- 
2.34.1