[PATCH i-g-t 1/3] lib/kunit: Support writable filter* parameters of kunit module

Kamil Konieczny kamil.konieczny at linux.intel.com
Fri Jan 26 09:37:28 UTC 2024


Hi Janusz,
On 2024-01-25 at 17:52:10 +0100, Janusz Krzysztofik wrote:
> Instead of wasting resources on reloading the base Kunit module each time
> a different set of filter parameters is needed, try to write the required
> values to sysfs representation of those parameters.  If that fails (e.g.
> on older LTS kernels with read-only filter parameters), fall back to
> reloading the module.
> 
> This change also provides a workaround for the issue of impossibility to
> unload the base Kunit module on Xe platforms, available as soon as the
> module supports writable filter parameters.
> 
> Since the base Kunit module is now unloaded from kunit_set_params() when
> needed, drop other attempts to unload it.
> 
> To reuse an existing open_parameters() helper, moved it up in the source
> file to avoid a forward declaration.

Could you split your patch into smaller parts? You described four
actions you did, maybe four patches?

Regards,
Kamil

> 
> Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
> ---
>  lib/igt_kmod.c | 147 +++++++++++++++++++++++++++++++++++--------------
>  1 file changed, 107 insertions(+), 40 deletions(-)
> 
> diff --git a/lib/igt_kmod.c b/lib/igt_kmod.c
> index 250ab2107b..4f96dafe01 100644
> --- a/lib/igt_kmod.c
> +++ b/lib/igt_kmod.c
> @@ -803,6 +803,78 @@ void igt_kselftest_get_tests(struct kmod_module *kmod,
>  	kmod_module_info_free_list(pre);
>  }
>  
> +static int open_parameters(const char *module_name)
> +{
> +	char path[256];
> +
> +	snprintf(path, sizeof(path), "/sys/module/%s/parameters", module_name);
> +	return open(path, O_RDONLY);
> +}
> +
> +static bool kunit_set_params(const char **name, const char **value, int count)
> +{
> +	static bool writable = true;
> +	int i, ret, params;
> +	char *opts = NULL;
> +
> +	if (!writable) {
> +		if (count)
> +			if (igt_debug_on(asprintf(&opts, "%s=%s",
> +						  name[0], value[0]) < 0)) {
> +				free(opts);
> +				return false;
> +			}
> +
> +		for (i = 1; i < count; i++) {
> +			char *head = opts;
> +
> +			opts = NULL;
> +			ret = asprintf(&opts, "%s %s=%s", head, name[i], value[i]);
> +			free(head);
> +			if (igt_debug_on(ret < 0)) {
> +				free(opts);
> +				return false;
> +			}
> +		}
> +
> +		igt_ignore_warn(igt_kmod_unload("kunit", KMOD_REMOVE_FORCE));
> +	}
> +
> +	ret = igt_debug_on(igt_kmod_load("kunit", opts));
> +	free(opts);
> +
> +	if (ret && !writable)
> +		return false;
> +
> +	params = open_parameters("kunit");
> +	ret = igt_debug_on(params < 0);
> +
> +	for (i = 0; !ret && i < count; i++) {
> +		char *param = igt_sysfs_get(params, name[i]);
> +
> +		if (igt_debug_on_f(!param, "param: %s\n", name[i])) {
> +			ret = -1;
> +			continue;
> +		}
> +
> +		ret = strcmp(param, value[i]);
> +		free(param);
> +		if (ret)
> +			ret = !igt_sysfs_set(params, name[i], value[i]);
> +	}
> +
> +	if (params >= 0)
> +		close(params);
> +
> +	if (!ret)
> +		return true;
> +	if (!writable)
> +		return false;
> +
> +	writable = false;
> +	return kunit_set_params(name, value, count);
> +}
> +
>  struct modprobe_data {
>  	struct kmod_module *kmod;
>  	const char *opts;
> @@ -814,11 +886,17 @@ struct modprobe_data {
>  
>  static void *modprobe_task(void *arg)
>  {
> +	const char *param[3] = { "filter_glob", "filter", "filter_action", };
> +	const char *value[3] = { "*", "", "", };
>  	struct modprobe_data *data = arg;
> +	bool ret;
> +
> +	ret = kunit_set_params(param, value, ARRAY_SIZE(param));
>  
> -	data->err = modprobe(data->kmod, data->opts);
> +	if (ret)
> +		data->err = modprobe(data->kmod, data->opts);
>  
> -	if (igt_debug_on(data->err)) {
> +	if (igt_debug_on(!ret || data->err)) {
>  		bool once = false;
>  		int err;
>  
> @@ -1092,9 +1170,20 @@ static void kunit_get_tests(struct igt_list_head *tests,
>  			    const char *filter,
>  			    const char *opts)
>  {
> +	/*
> +	 * To get a list of test cases provided by a kunit test module, ask the
> +	 * generic kunit module to respond with SKIP result for each test found.
> +	 * We could also try to use action=list kunit parameter to get the
> +	 * listing, however, parsing a KTAP report -- something that we already
> +	 * can do perfectly -- seems to be more safe than extracting a test case
> +	 * list of unknown length from /dev/kmsg.
> +	 */
> +	const char *param[3] = { "filter_glob", "filter", "filter_action", };
> +	const char *value[3] = { "*", "module=none", "skip", };
>  	char *suite_name = NULL, *case_name = NULL;
>  	struct igt_ktap_result *r, *rn;
>  	struct igt_ktap_results *ktap;
> +	unsigned long taints;
>  	int flags, err;
>  
>  	igt_skip_on_f(tst->kmsg < 0, "Could not open /dev/kmsg\n");
> @@ -1105,26 +1194,23 @@ static void kunit_get_tests(struct igt_list_head *tests,
>  
>  	igt_skip_on(lseek(tst->kmsg, 0, SEEK_END) < 0);
>  
> -	/*
> -	 * To get a list of test cases provided by a kunit test module, ask the
> -	 * generic kunit module to respond with SKIP result for each test found.
> -	 * We could also use action=list kunit parameter to get the listing,
> -	 * however, parsing a KTAP report -- something that we already can do
> -	 * perfectly -- seems to be more safe than extracting a test case list
> -	 * of unknown length from /dev/kmsg.
> -	 *
> -	 * TODO: drop the following workaround, which is required by LTS kernel
> -	 *       v6.1 not capable of listing test cases when built as a module.
> -	 * If loading the kunit module with required parameters fails then
> -	 * assume that we are running on a kernel with missing test case listing
> -	 * capabilities.  Dont's skip but just return with empty list of test
> -	 * cases, that should tell the caller to use a legacy method of
> -	 * iterating over KTAP results collected from blind execution of all
> -	 * Kunit test cases provided by a Kunit test module.
> -	 */
> -	if (igt_debug_on(igt_kmod_load("kunit",
> -				       "filter=module=none filter_action=skip")))
> +	if (igt_debug_on(!kunit_set_params(param, value, ARRAY_SIZE(param)))) {
> +		/*
> +		 * TODO: drop the following workaround, required by LTS kernel
> +		 *       v6.1 not capable of listing test cases when built as as
> +		 *       module, when no longer needed.
> +		 * If updating writable filter parameters of the kunit base
> +		 * module with required values or reloading that module with
> +		 * those parameters specified fails then assume that we are
> +		 * running on a kernel with missing test case listing
> +		 * capabilities.  Dont skip but just return with empty list of
> +		 * test cases, which should tell the caller to use a legacy
> +		 * method of iterating over KTAP results collected from blind
> +		 * execution of all Kunit test cases provided by a Kunit test
> +		 * module.
> +		 */
>  		return;
> +	}
>  
>  	igt_skip_on(modprobe(tst->kmod, opts));
>  
> @@ -1159,7 +1245,6 @@ static void kunit_get_tests(struct igt_list_head *tests,
>  	}
>  
>  	igt_skip_on(kmod_module_remove_module(tst->kmod, KMOD_REMOVE_FORCE));
> -	igt_skip_on(igt_kmod_unload("kunit", KMOD_REMOVE_FORCE));
>  
>  	igt_skip_on_f(err,
>  		      "KTAP parser failed while getting a list of test cases\n");
> @@ -1355,15 +1440,6 @@ void igt_kunit(const char *module_name, const char *name, const char *opts)
>  		igt_skip_on(igt_ktest_init(&tst, module_name));
>  		igt_skip_on(igt_ktest_begin(&tst));
>  
> -		/*
> -		 * Since we need to load kunit base module with specific
> -		 * options in order to get a list of test cases, make
> -		 * sure that the module is not loaded.  However, since
> -		 * unload may fail if kunit base module is not loaded,
> -		 * ignore any failures, we'll fail later if still loaded.
> -		 */
> -		igt_ignore_warn(igt_kmod_unload("kunit", KMOD_REMOVE_FORCE));
> -
>  		igt_assert(igt_list_empty(&tests));
>  	}
>  
> @@ -1395,20 +1471,11 @@ void igt_kunit(const char *module_name, const char *name, const char *opts)
>  		kunit_results_free(&tests, &suite_name, &case_name);
>  
>  		igt_ktest_end(&tst);
> -		igt_debug_on(igt_kmod_unload("kunit", KMOD_REMOVE_FORCE));
>  	}
>  
>  	igt_ktest_fini(&tst);
>  }
>  
> -static int open_parameters(const char *module_name)
> -{
> -	char path[256];
> -
> -	snprintf(path, sizeof(path), "/sys/module/%s/parameters", module_name);
> -	return open(path, O_RDONLY);
> -}
> -
>  int igt_ktest_init(struct igt_ktest *tst,
>  		   const char *module_name)
>  {
> -- 
> 2.43.0
> 


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