Re: [PATCH v4 3/7] kunit: Pass parameterized test context to generate_params()

[Lucas De Marchi]

On Tue, Aug 26, 2025 at 05:13:33PM +0800, David Gow wrote:

From: Marie Zhussupova <marie...@google.com>

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.

Reviewed-by: David Gow <david...@google.com>
Reviewed-by: Rae Moar <rm...@google.com>
Acked-by: Marco Elver <el...@google.com>
Acked-by: Rodrigo Vivi <rodrigo.v...@intel.com>
Signed-off-by: Marie Zhussupova <marie...@google.com>
[Catch some additional gen_params signatures in drm/xe/tests --David]
Signed-off-by: David Gow <david...@google.com>
---

Changes in v4:
v3: 
https://lore.kernel.org/linux-kselftest/20250815103604.3857930-4-marie...@google.com/
- Fixup some additional generate_params signature changes in xe_pci.
- These are also available as a separate patch here:
 
https://lore.kernel.org/linux-kselftest/20250821135447.1618942-1-david...@google.com/

Changes in v3:
v2: https://lore.kernel.org/all/20250811221739.2694336-4-marie...@google.com/
- Commit message formatting.

Changes in v2:
v1: https://lore.kernel.org/all/20250729193647.3410634-4-marie...@google.com/
   https://lore.kernel.org/all/20250729193647.3410634-5-marie...@google.com/
   https://lore.kernel.org/all/20250729193647.3410634-6-marie...@google.com/
- 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      | 14 +++++++-------
drivers/gpu/drm/xe/tests/xe_pci_test.h |  9 +++++----

Acked-by: Lucas De Marchi <lucas.demar...@intel.com>

thanks
Lucas De Marchi

include/kunit/test.h                   |  9 ++++++---
kernel/kcsan/kcsan_test.c              |  2 +-
lib/kunit/test.c                       |  5 +++--
5 files changed, 22 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/xe/tests/xe_pci.c 
b/drivers/gpu/drm/xe/tests/xe_pci.c
index 9c715e59f030..f707e0a54295 100644
--- a/drivers/gpu/drm/xe/tests/xe_pci.c
+++ b/drivers/gpu/drm/xe/tests/xe_pci.c
@@ -44,9 +44,9 @@ KUNIT_ARRAY_PARAM(pci_id, pciidlist, xe_pci_id_kunit_desc);
 *
 * Return: pointer to the next parameter or NULL if no more parameters
 */
-const void *xe_pci_graphics_ip_gen_param(const void *prev, char *desc)
+const void *xe_pci_graphics_ip_gen_param(struct kunit *test, const void *prev, 
char *desc)
{
-       return graphics_ip_gen_params(prev, desc);
+       return graphics_ip_gen_params(test, prev, desc);
}
EXPORT_SYMBOL_IF_KUNIT(xe_pci_graphics_ip_gen_param);

@@ -61,9 +61,9 @@ EXPORT_SYMBOL_IF_KUNIT(xe_pci_graphics_ip_gen_param);
 *
 * Return: pointer to the next parameter or NULL if no more parameters
 */
-const void *xe_pci_media_ip_gen_param(const void *prev, char *desc)
+const void *xe_pci_media_ip_gen_param(struct kunit *test, const void *prev, 
char *desc)
{
-       return media_ip_gen_params(prev, desc);
+       return media_ip_gen_params(test, prev, desc);
}
EXPORT_SYMBOL_IF_KUNIT(xe_pci_media_ip_gen_param);

@@ -78,9 +78,9 @@ EXPORT_SYMBOL_IF_KUNIT(xe_pci_media_ip_gen_param);
 *
 * Return: pointer to the next parameter or NULL if no more parameters
 */
-const void *xe_pci_id_gen_param(const void *prev, char *desc)
+const void *xe_pci_id_gen_param(struct kunit *test, const void *prev, char 
*desc)
{
-       const struct pci_device_id *pci = pci_id_gen_params(prev, desc);
+       const struct pci_device_id *pci = pci_id_gen_params(test, prev, desc);

        return pci->driver_data ? pci : NULL;
}
@@ -159,7 +159,7 @@ 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;
diff --git a/drivers/gpu/drm/xe/tests/xe_pci_test.h 
b/drivers/gpu/drm/xe/tests/xe_pci_test.h
index ce4d2b86b778..6d8bc56f7bde 100644
--- a/drivers/gpu/drm/xe/tests/xe_pci_test.h
+++ b/drivers/gpu/drm/xe/tests/xe_pci_test.h
@@ -7,6 +7,7 @@
#define _XE_PCI_TEST_H_

#include <linux/types.h>
+#include <kunit/test.h>

#include "xe_platform_types.h"
#include "xe_sriov_types.h"
@@ -25,9 +26,9 @@ struct xe_pci_fake_data {

int xe_pci_fake_device_init(struct xe_device *xe);

-const void *xe_pci_graphics_ip_gen_param(const void *prev, char *desc);
-const void *xe_pci_media_ip_gen_param(const void *prev, char *desc);
-const void *xe_pci_id_gen_param(const void *prev, char *desc);
-const void *xe_pci_live_device_gen_param(const void *prev, char *desc);
+const void *xe_pci_graphics_ip_gen_param(struct kunit *test, const void *prev, 
char *desc);
+const void *xe_pci_media_ip_gen_param(struct kunit *test, const void *prev, 
char *desc);
+const void *xe_pci_id_gen_param(struct kunit *test, const void *prev, char 
*desc);
+const void *xe_pci_live_device_gen_param(struct kunit *test, const void *prev, 
char *desc);

#endif
diff --git a/include/kunit/test.h b/include/kunit/test.h
index fc8fd55b2dfb..8eba1b03c3e3 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);
@@ -1703,7 +1704,8 @@ 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))) {                   
                     \
@@ -1724,7 +1726,8 @@ 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 49ab81faaed9..a13a090bb2a7 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 0fe61dec5a96..50705248abad 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -700,7 +700,7 @@ 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");
@@ -731,7 +731,8 @@ 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
--
2.51.0.261.g7ce5a0a67e-goog