Re: [PATCH v2 3/7] kunit: Pass parameterized test context to generate_params()

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Mon, Aug 11, 2025 at 10:17:35PM +0000, Marie Zhussupova wrote:
> To enable more complex parameterized testing scenarios,
> the generate_params() function needs additional context
> beyond just the previously generated parameter. This patch
> modifies the generate_params() function signature to
> include an extra `struct kunit *test` argument, giving
> test users access to the parameterized test context when
> generating parameters.
> 
> The `struct kunit *test` argument was added as the first parameter
> to the function signature as it aligns with the convention
> of other KUnit functions that accept `struct kunit *test` first.
> This also mirrors the "this" or "self" reference found
> in object-oriented programming languages.
> 
> This patch also modifies xe_pci_live_device_gen_param()
> in xe_pci.c and nthreads_gen_params() in kcsan_test.c
> to reflect this signature change.
> 
> Signed-off-by: Marie Zhussupova <marievic@google.com>
> ---
> 
> Changes in v2:
> 
> - generate_params signature changes in
>   xe_pci.c and kcsan_test.c were squashed
>   into a single patch to avoid in-between
>   breakages in the series.
> - The comments and the commit message were changed to
>   reflect the parameterized testing terminology. See
>   the patch series cover letter change log for the
>   definitions.
> 
> ---
>  drivers/gpu/drm/xe/tests/xe_pci.c | 2 +-
>  include/kunit/test.h              | 9 ++++++---
>  kernel/kcsan/kcsan_test.c         | 2 +-
>  lib/kunit/test.c                  | 5 +++--
>  4 files changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xe/tests/xe_pci.c b/drivers/gpu/drm/xe/tests/xe_pci.c
> index 1d3e2e50c355..62c016e84227 100644
> --- a/drivers/gpu/drm/xe/tests/xe_pci.c
> +++ b/drivers/gpu/drm/xe/tests/xe_pci.c
> @@ -129,7 +129,7 @@ EXPORT_SYMBOL_IF_KUNIT(xe_pci_fake_device_init);
>   * Return: pointer to the next &struct xe_device ready to be used as a parameter
>   *         or NULL if there are no more Xe devices on the system.
>   */
> -const void *xe_pci_live_device_gen_param(const void *prev, char *desc)
> +const void *xe_pci_live_device_gen_param(struct kunit *test, const void *prev, char *desc)
>  {
>  	const struct xe_device *xe = prev;
>  	struct device *dev = xe ? xe->drm.dev : NULL;

Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> diff --git a/include/kunit/test.h b/include/kunit/test.h
> index d2e1b986b161..b527189d2d1c 100644
> --- a/include/kunit/test.h
> +++ b/include/kunit/test.h
> @@ -128,7 +128,8 @@ struct kunit_attributes {
>  struct kunit_case {
>  	void (*run_case)(struct kunit *test);
>  	const char *name;
> -	const void* (*generate_params)(const void *prev, char *desc);
> +	const void* (*generate_params)(struct kunit *test,
> +				       const void *prev, char *desc);
>  	struct kunit_attributes attr;
>  	int (*param_init)(struct kunit *test);
>  	void (*param_exit)(struct kunit *test);
> @@ -1691,7 +1692,8 @@ do {									       \
>   * Define function @name_gen_params which uses @array to generate parameters.
>   */
>  #define KUNIT_ARRAY_PARAM(name, array, get_desc)						\
> -	static const void *name##_gen_params(const void *prev, char *desc)			\
> +	static const void *name##_gen_params(struct kunit *test,				\
> +					     const void *prev, char *desc)			\
>  	{											\
>  		typeof((array)[0]) *__next = prev ? ((typeof(__next)) prev) + 1 : (array);	\
>  		if (__next - (array) < ARRAY_SIZE((array))) {					\
> @@ -1712,7 +1714,8 @@ do {									       \
>   * Define function @name_gen_params which uses @array to generate parameters.
>   */
>  #define KUNIT_ARRAY_PARAM_DESC(name, array, desc_member)					\
> -	static const void *name##_gen_params(const void *prev, char *desc)			\
> +	static const void *name##_gen_params(struct kunit *test,				\
> +					     const void *prev, char *desc)			\
>  	{											\
>  		typeof((array)[0]) *__next = prev ? ((typeof(__next)) prev) + 1 : (array);	\
>  		if (__next - (array) < ARRAY_SIZE((array))) {					\
> diff --git a/kernel/kcsan/kcsan_test.c b/kernel/kcsan/kcsan_test.c
> index c2871180edcc..fc76648525ac 100644
> --- a/kernel/kcsan/kcsan_test.c
> +++ b/kernel/kcsan/kcsan_test.c
> @@ -1383,7 +1383,7 @@ static void test_atomic_builtins_missing_barrier(struct kunit *test)
>   * The thread counts are chosen to cover potentially interesting boundaries and
>   * corner cases (2 to 5), and then stress the system with larger counts.
>   */
> -static const void *nthreads_gen_params(const void *prev, char *desc)
> +static const void *nthreads_gen_params(struct kunit *test, const void *prev, char *desc)
>  {
>  	long nthreads = (long)prev;
>  
> diff --git a/lib/kunit/test.c b/lib/kunit/test.c
> index 49a5e6c30c86..01b20702a5a2 100644
> --- a/lib/kunit/test.c
> +++ b/lib/kunit/test.c
> @@ -695,7 +695,7 @@ int kunit_run_tests(struct kunit_suite *suite)
>  			/* Get initial param. */
>  			param_desc[0] = '\0';
>  			/* TODO: Make generate_params try-catch */
> -			curr_param = test_case->generate_params(NULL, param_desc);
> +			curr_param = test_case->generate_params(&test, NULL, param_desc);
>  			test_case->status = KUNIT_SKIPPED;
>  			kunit_log(KERN_INFO, &test, KUNIT_SUBTEST_INDENT KUNIT_SUBTEST_INDENT
>  				  "KTAP version 1\n");
> @@ -726,7 +726,8 @@ int kunit_run_tests(struct kunit_suite *suite)
>  
>  				/* Get next param. */
>  				param_desc[0] = '\0';
> -				curr_param = test_case->generate_params(curr_param, param_desc);
> +				curr_param = test_case->generate_params(&test, curr_param,
> +									param_desc);
>  			}
>  			/*
>  			 * TODO: Put into a try catch. Since we don't need suite->exit
> -- 
> 2.51.0.rc0.205.g4a044479a3-goog
>