Re: [PATCH 1/2] kunit: Add ability to skip entire test suites

Le 05/06/2026 à 12:28 AM, Vaibhav Jain a écrit :
> Currently, KUnit provides mechanisms to skip individual test cases, but
> there is no way to skip an entire test suite based on runtime conditions
> checked during suite initialization. This limitation forces test suites
> to either fail or skip tests individually when certain prerequisites are
> not available.
> 
> To address this limitation, the patch adds a 'status' field to struct
> kunit_suite that allows suite_init callbacks to mark the entire suite as
> KUNIT_SKIPPED. When a suite is marked as skipped, all test cases within
> that suite are bypassed without execution.
> 
> The patch proposes changes to kunit_suite_has_succeeded() to check suite
> status before evaluating individual test case results. Also
> kunit_run_tests() is updated to skip suite execution if 'kunit_suite.status'
> is set to KUNIT_SKIPPED, thats either set before suite_init or by the
> suite_init callback itself.
> 
> This enables test suites to perform runtime capability checks in their
> 'suite_init' callback and gracefully skip all tests when prerequisites are
> not met, rather than reporting failures or requiring each test case to
> perform redundant checks.
> 
> Signed-off-by: Vaibhav Jain <[email protected]>
> ---

Thanks — this is great! There are a few cases it's not handling
properly, though, particularly with respect to the debugfs support.

I think we need to:
- Reset suite->status to KUNIT_SUCCESS in kunit_init_suite(), so that a
suite which is re-run via debugfs isn't automatically skipped again.
- Fix the result handling in debugfs to handle skipped suites.
- (Optional) Maybe we could get rid of kunit_suite::suite_init_err now
that there's a specific status value. That'd have to be done carefully
to preserve all of the semantics, though.

Here's a quick (and slightly hacky) patch to fix the first couple of issues:
---
diff --git a/lib/kunit/debugfs.c b/lib/kunit/debugfs.c
index 9c326f1837bd..23d34bfdba95 100644
--- a/lib/kunit/debugfs.c
+++ b/lib/kunit/debugfs.c
@@ -58,6 +58,22 @@ static void debugfs_print_result(struct seq_file
*seq, struct string_stream *log
 	spin_unlock(&log->lock);
 }

+/* Print the result line for a suite. */
+static void debugfs_print_ok_not_ok(struct seq_file *seq,
+				    enum kunit_status status,
+				    size_t test_number,
+				    const char *description,
+				    const char *directive)
+{
+	const char *directive_header = (status == KUNIT_SKIPPED) ? " # SKIP "
: "";
+	const char *directive_body = (status == KUNIT_SKIPPED) ? directive : "";
+
+	seq_printf(seq, "%s %zd %s%s%s\n",
+		   kunit_status_to_ok_not_ok(status),
+		   test_number, description, directive_header,
+		   directive_body);
+}
+
 /*
  * /sys/kernel/debug/kunit/<testsuite>/results shows all results for
testsuite.
  */
@@ -77,17 +93,17 @@ static int debugfs_print_results(struct seq_file
*seq, void *v)
 	seq_puts(seq, "1..1\n");

 	/* Print suite header because it is not stored in the test logs. */
-	seq_puts(seq, KUNIT_SUBTEST_INDENT "KTAP version 1\n");
-	seq_printf(seq, KUNIT_SUBTEST_INDENT "# Subtest: %s\n", suite->name);
-	seq_printf(seq, KUNIT_SUBTEST_INDENT "1..%zd\n",
kunit_suite_num_test_cases(suite));
-
-	kunit_suite_for_each_test_case(suite, test_case)
-		debugfs_print_result(seq, test_case->log);
+	if (suite->status != KUNIT_SKIPPED) {
+		seq_puts(seq, KUNIT_SUBTEST_INDENT "KTAP version 1\n");
+		seq_printf(seq, KUNIT_SUBTEST_INDENT "# Subtest: %s\n", suite->name);
+		seq_printf(seq, KUNIT_SUBTEST_INDENT "1..%zd\n",
kunit_suite_num_test_cases(suite));

+		kunit_suite_for_each_test_case(suite, test_case)
+			debugfs_print_result(seq, test_case->log);
+	}
 	debugfs_print_result(seq, suite->log);

-	seq_printf(seq, "%s %d %s\n",
-		   kunit_status_to_ok_not_ok(success), 1, suite->name);
+	debugfs_print_ok_not_ok(seq, success, 1, suite->name,
suite->status_comment);
 	return 0;
 }

diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index c0ae45a22b2c..2ff145796450 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -798,9 +798,6 @@ int kunit_run_tests(struct kunit_suite *suite)
 	/* Taint the kernel so we know we've run tests. */
 	add_taint(TAINT_TEST, LOCKDEP_STILL_OK);

-	if (suite->status == KUNIT_SKIPPED)
-		goto suite_end;
-
 	if (suite->suite_init) {
 		suite->suite_init_err = suite->suite_init(suite);
 		if (suite->suite_init_err) {
@@ -836,6 +833,7 @@ static void kunit_init_suite(struct kunit_suite *suite)
 	kunit_debugfs_create_suite(suite);
 	suite->status_comment[0] = '\0';
 	suite->suite_init_err = 0;
+	suite->status = KUNIT_SUCCESS;

 	if (suite->log)
 		string_stream_clear(suite->log);
---


>  include/kunit/test.h |  1 +
>  lib/kunit/test.c     | 11 +++++++++++
>  2 files changed, 12 insertions(+)
> 
> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index ce0573e196ce..395221d623f7 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -285,6 +285,7 @@ struct kunit_suite {
>  	struct string_stream *log;
>  	int suite_init_err;
>  	bool is_init;
> +	enum kunit_status status;
>  };
>  
>  /* Stores an array of suites, end points one past the end */
> diff --git a/lib/kunit/test.c b/lib/kunit/test.c
> index 99773e000e1b..989acc770265 100644
> --- a/lib/kunit/test.c
> +++ b/lib/kunit/test.c
> @@ -214,6 +214,9 @@ enum kunit_status kunit_suite_has_succeeded(struct kunit_suite *suite)
>  	const struct kunit_case *test_case;
>  	enum kunit_status status = KUNIT_SKIPPED;
>  
> +	if (suite->status == KUNIT_SKIPPED)
> +		return KUNIT_SKIPPED;
> +
>  	if (suite->suite_init_err)
>  		return KUNIT_FAILURE;
>  
> @@ -795,12 +798,20 @@ int kunit_run_tests(struct kunit_suite *suite)
>  	/* Taint the kernel so we know we've run tests. */
>  	add_taint(TAINT_TEST, LOCKDEP_STILL_OK);
>  
> +	if (suite->status == KUNIT_SKIPPED)
> +		goto suite_end;
> +

Do we want this? If a test is run more than once, we probably want to
re-run suite_init so that we can tell if we should still skip it.

While I don't think it's likely that a test which was previously skipped
will suddenly become available, it's not impossible with, e.g., CPU hotplug.

>  	if (suite->suite_init) {
>  		suite->suite_init_err = suite->suite_init(suite);
>  		if (suite->suite_init_err) {
> +			suite->status = KUNIT_FAILURE;
>  			kunit_err(suite, KUNIT_SUBTEST_INDENT
>  				  "# failed to initialize (%d)", suite->suite_init_err);
>  			goto suite_end;
> +
> +		} else if (suite->status == KUNIT_SKIPPED) {
> +			/* Skip this kunit suite */
> +			goto suite_end;
>  		}
>  	}
>  

Cheers,
-- David