Testing: add framework for the kernel unit tests.

This changes intends to reduce the bar to the kernel unit-testing by
 introducing a new kernel-testing framework ("ktest") based on Netlink,
 loadable test modules and python test suite integration.

This framework provides the following features:
* Integration to the FreeBSD test suite
* Automatic test discovery
* Automatic test module loading
* Minimal boiler-plate code in both kernel and userland
* Passing any metadata to the test
* Convenient environment pre-setup using python testing framework
* Streaming messages from the kernel to the userland
* Running tests in the dedicated taskqueues
* Skipping or parametrizing tests

Differential Revision: https://reviews.freebsd.org/D39385
MFC after:	2 weeks

17 files changed, 1078 insertions, 2 deletions

diff --git a/sys/modules/ktest/Makefile b/sys/modules/ktest/Makefile
new file mode 100644
index 000000000000..21c94caabc30
--- /dev/null
+++ b/sys/modules/ktest/Makefile
@@ -0,0 +1,7 @@
+SYSDIR?=${SRCTOP}/sys
+.include "${SYSDIR}/conf/kern.opts.mk"
+
+SUBDIR=	ktest \
+	ktest_example
+
+.include <bsd.subdir.mk>
diff --git a/sys/modules/ktest/ktest/Makefile b/sys/modules/ktest/ktest/Makefile
new file mode 100644
index 000000000000..86ed957ac2b7
--- /dev/null
+++ b/sys/modules/ktest/ktest/Makefile
@@ -0,0 +1,14 @@
+# $FreeBSD$
+
+PACKAGE=	tests
+
+SYSDIR?=${SRCTOP}/sys
+.include "${SYSDIR}/conf/kern.opts.mk"
+
+.PATH: ${SYSDIR}/tests
+
+KMOD=	ktest
+SRCS=	ktest.c
+SRCS+=	opt_netlink.h
+
+.include <bsd.kmod.mk>
diff --git a/sys/modules/ktest/ktest_example/Makefile b/sys/modules/ktest/ktest_example/Makefile
new file mode 100644
index 000000000000..b4a3e778e2ed
--- /dev/null
+++ b/sys/modules/ktest/ktest_example/Makefile
@@ -0,0 +1,13 @@
+# $FreeBSD$
+
+PACKAGE=	tests
+
+SYSDIR?=${SRCTOP}/sys
+.include "${SYSDIR}/conf/kern.opts.mk"
+
+.PATH: ${SYSDIR}/tests
+
+KMOD=	ktest_example
+SRCS=	ktest_example.c
+
+.include <bsd.kmod.mk>
diff --git a/sys/tests/ktest.c b/sys/tests/ktest.c
new file mode 100644
index 000000000000..fcb40130bcef
--- /dev/null
+++ b/sys/tests/ktest.c
@@ -0,0 +1,414 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Alexander V. Chernikov
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include "opt_netlink.h"
+
+#include <sys/param.h>
+#include <sys/refcount.h>
+#include <sys/types.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/malloc.h>
+#include <sys/module.h>
+#include <sys/socket.h>
+#include <sys/priv.h>
+
+#include <netlink/netlink.h>
+#include <netlink/netlink_ctl.h>
+#include <netlink/netlink_generic.h>
+#include <netlink/netlink_message_parser.h>
+
+#include <machine/stdarg.h>
+#include <tests/ktest.h>
+
+struct mtx ktest_mtx;
+#define	KTEST_LOCK()		mtx_lock(&ktest_mtx)
+#define	KTEST_UNLOCK()		mtx_unlock(&ktest_mtx)
+#define	KTEST_LOCK_ASSERT()	mtx_assert(&ktest_mtx, MA_OWNED)
+
+MTX_SYSINIT(ktest_mtx, &ktest_mtx, "ktest mutex", MTX_DEF);
+
+struct ktest_module {
+	struct ktest_module_info	*info;
+	volatile u_int			refcount;
+	TAILQ_ENTRY(ktest_module)	entries;
+};
+static TAILQ_HEAD(, ktest_module) module_list = TAILQ_HEAD_INITIALIZER(module_list);
+
+struct nl_ktest_parsed {
+	char		*mod_name;
+	char		*test_name;
+	struct nlattr	*test_meta;
+};
+
+#define	_IN(_field)	offsetof(struct genlmsghdr, _field)
+#define	_OUT(_field)	offsetof(struct nl_ktest_parsed, _field)
+
+static const struct nlattr_parser nla_p_get[] = {
+	{ .type = KTEST_ATTR_MOD_NAME, .off = _OUT(mod_name), .cb = nlattr_get_string },
+	{ .type = KTEST_ATTR_TEST_NAME, .off = _OUT(test_name), .cb = nlattr_get_string },
+	{ .type = KTEST_ATTR_TEST_META, .off = _OUT(test_meta), .cb = nlattr_get_nla },
+};
+static const struct nlfield_parser nlf_p_get[] = {
+};
+NL_DECLARE_PARSER(ktest_parser, struct genlmsghdr, nlf_p_get, nla_p_get);
+#undef _IN
+#undef _OUT
+
+static bool
+create_reply(struct nl_writer *nw, struct nlmsghdr *hdr, int cmd)
+{
+	if (!nlmsg_reply(nw, hdr, sizeof(struct genlmsghdr)))
+		return (false);
+
+	struct genlmsghdr *ghdr_new = nlmsg_reserve_object(nw, struct genlmsghdr);
+	ghdr_new->cmd = cmd;
+	ghdr_new->version = 0;
+	ghdr_new->reserved = 0;
+
+	return (true);
+}
+
+static int
+dump_mod_test(struct nlmsghdr *hdr, struct nl_pstate *npt,
+    struct ktest_module *mod, const struct ktest_test_info *test_info)
+{
+	struct nl_writer *nw = npt->nw;
+
+	if (!create_reply(nw, hdr, KTEST_CMD_NEWTEST))
+		goto enomem;
+
+	nlattr_add_string(nw, KTEST_ATTR_MOD_NAME, mod->info->name);
+	nlattr_add_string(nw, KTEST_ATTR_TEST_NAME, test_info->name);
+	nlattr_add_string(nw, KTEST_ATTR_TEST_DESCR, test_info->desc);
+
+	if (nlmsg_end(nw))
+		return (0);
+enomem:
+	nlmsg_abort(nw);
+	return (ENOMEM);
+}
+
+static int
+dump_mod_tests(struct nlmsghdr *hdr, struct nl_pstate *npt,
+    struct ktest_module *mod, struct nl_ktest_parsed *attrs)
+{
+	for (int i = 0; i < mod->info->num_tests; i++) {
+		const struct ktest_test_info *test_info = &mod->info->tests[i];
+		if (attrs->test_name != NULL && strcmp(attrs->test_name, test_info->name))
+			continue;
+		int error = dump_mod_test(hdr, npt, mod, test_info);
+		if (error != 0)
+			return (error);
+	}
+
+	return (0);
+}
+
+static int
+dump_tests(struct nlmsghdr *hdr, struct nl_pstate *npt)
+{
+	struct nl_ktest_parsed attrs = { };
+	struct ktest_module *mod;
+	int error;
+
+	error = nl_parse_nlmsg(hdr, &ktest_parser, npt, &attrs);
+	if (error != 0)
+		return (error);
+
+	hdr->nlmsg_flags |= NLM_F_MULTI;
+
+	KTEST_LOCK();
+	TAILQ_FOREACH(mod, &module_list, entries) {
+		if (attrs.mod_name && strcmp(attrs.mod_name, mod->info->name))
+			continue;
+		error = dump_mod_tests(hdr, npt, mod, &attrs);
+		if (error != 0)
+			break;
+	}
+	KTEST_UNLOCK();
+
+	if (!nlmsg_end_dump(npt->nw, error, hdr)) {
+		//NL_LOG(LOG_DEBUG, "Unable to finalize the dump");
+		return (ENOMEM);
+	}
+
+	return (error);
+}
+
+static int
+run_test(struct nlmsghdr *hdr, struct nl_pstate *npt)
+{
+	struct nl_ktest_parsed attrs = { };
+	struct ktest_module *mod;
+	int error;
+
+	error = nl_parse_nlmsg(hdr, &ktest_parser, npt, &attrs);
+	if (error != 0)
+		return (error);
+
+	if (attrs.mod_name == NULL) {
+		nlmsg_report_err_msg(npt, "KTEST_ATTR_MOD_NAME not set");
+		return (EINVAL);
+	}
+
+	if (attrs.test_name == NULL) {
+		nlmsg_report_err_msg(npt, "KTEST_ATTR_TEST_NAME not set");
+		return (EINVAL);
+	}
+
+	const struct ktest_test_info *test = NULL;
+
+	KTEST_LOCK();
+	TAILQ_FOREACH(mod, &module_list, entries) {
+		if (strcmp(attrs.mod_name, mod->info->name))
+			continue;
+
+		const struct ktest_module_info *info = mod->info;
+
+		for (int i = 0; i < info->num_tests; i++) {
+			const struct ktest_test_info *test_info = &info->tests[i];
+
+			if (!strcmp(attrs.test_name, test_info->name)) {
+				test = test_info;
+				break;
+			}
+		}
+		break;
+	}
+	if (test != NULL)
+		refcount_acquire(&mod->refcount);
+	KTEST_UNLOCK();
+
+	if (test == NULL)
+		return (ESRCH);
+
+	/* Run the test */
+	struct ktest_test_context ctx = {
+		.npt = npt,
+		.hdr = hdr,
+		.buf = npt_alloc(npt, KTEST_MAX_BUF),
+		.bufsize = KTEST_MAX_BUF,
+	};
+
+	if (ctx.buf == NULL) {
+		//NL_LOG(LOG_DEBUG, "unable to allocate temporary buffer");
+		return (ENOMEM);
+	}
+
+	if (test->parse != NULL && attrs.test_meta != NULL) {
+		error = test->parse(&ctx, attrs.test_meta);
+		if (error != 0)
+			return (error);
+	}
+
+	hdr->nlmsg_flags |= NLM_F_MULTI;
+
+	KTEST_LOG_LEVEL(&ctx, LOG_INFO, "start running %s", test->name);
+	error = test->func(&ctx);
+	KTEST_LOG_LEVEL(&ctx, LOG_INFO, "end running %s", test->name);
+
+	refcount_release(&mod->refcount);
+
+	if (!nlmsg_end_dump(npt->nw, error, hdr)) {
+		//NL_LOG(LOG_DEBUG, "Unable to finalize the dump");
+		return (ENOMEM);
+	}
+
+	return (error);
+}
+
+
+/* USER API */
+static void
+register_test_module(struct ktest_module_info *info)
+{
+	struct ktest_module *mod = malloc(sizeof(*mod), M_TEMP, M_WAITOK | M_ZERO);
+
+	mod->info = info;
+	info->module_ptr = mod;
+	KTEST_LOCK();
+	TAILQ_INSERT_TAIL(&module_list, mod, entries);
+	KTEST_UNLOCK();
+}
+
+static void
+unregister_test_module(struct ktest_module_info *info)
+{
+	struct ktest_module *mod = info->module_ptr;
+
+	info->module_ptr = NULL;
+
+	KTEST_LOCK();
+	TAILQ_REMOVE(&module_list, mod, entries);
+	KTEST_UNLOCK();
+
+	free(mod, M_TEMP);
+}
+
+static bool
+can_unregister(struct ktest_module_info *info)
+{
+	struct ktest_module *mod = info->module_ptr;
+
+	return (refcount_load(&mod->refcount) == 0);
+}
+
+int
+ktest_default_modevent(module_t mod, int type, void *arg)
+{
+	struct ktest_module_info *info = (struct ktest_module_info *)arg;
+	int error = 0;
+
+	switch (type) {
+	case MOD_LOAD:
+		register_test_module(info);
+		break;
+	case MOD_UNLOAD:
+		if (!can_unregister(info))
+			return (EBUSY);
+		unregister_test_module(info);
+		break;
+	default:
+		error = EOPNOTSUPP;
+		break;
+	}
+	return (error);
+}
+
+bool
+ktest_start_msg(struct ktest_test_context *ctx)
+{
+	return (create_reply(ctx->npt->nw, ctx->hdr, KTEST_CMD_NEWMESSAGE));
+}
+
+void
+ktest_add_msg_meta(struct ktest_test_context *ctx, const char *func,
+    const char *fname, int line)
+{
+	struct nl_writer *nw = ctx->npt->nw;
+	struct timespec ts;
+
+	nanouptime(&ts);
+	nlattr_add(nw, KTEST_MSG_ATTR_TS, sizeof(ts), &ts);
+
+	nlattr_add_string(nw, KTEST_MSG_ATTR_FUNC, func);
+	nlattr_add_string(nw, KTEST_MSG_ATTR_FILE, fname);
+	nlattr_add_u32(nw, KTEST_MSG_ATTR_LINE, line);
+}
+
+void
+ktest_add_msg_text(struct ktest_test_context *ctx, int msg_level,
+    const char *fmt, ...)
+{
+	va_list ap;
+
+	va_start(ap, fmt);
+	vsnprintf(ctx->buf, ctx->bufsize, fmt, ap);
+	va_end(ap);
+
+	nlattr_add_u8(ctx->npt->nw, KTEST_MSG_ATTR_LEVEL, msg_level);
+	nlattr_add_string(ctx->npt->nw, KTEST_MSG_ATTR_TEXT, ctx->buf);
+}
+
+void
+ktest_end_msg(struct ktest_test_context *ctx)
+{
+	nlmsg_end(ctx->npt->nw);
+}
+
+/* Module glue */
+
+static const struct nlhdr_parser *all_parsers[] = { &ktest_parser };
+
+static const struct genl_cmd ktest_cmds[] = {
+	{
+		.cmd_num = KTEST_CMD_LIST,
+		.cmd_name = "KTEST_CMD_LIST",
+		.cmd_cb = dump_tests,
+		.cmd_flags = GENL_CMD_CAP_DO | GENL_CMD_CAP_DUMP | GENL_CMD_CAP_HASPOL,
+	},
+	{
+		.cmd_num = KTEST_CMD_RUN,
+		.cmd_name = "KTEST_CMD_RUN",
+		.cmd_cb = run_test,
+		.cmd_flags = GENL_CMD_CAP_DO | GENL_CMD_CAP_HASPOL,
+		.cmd_priv = PRIV_KLD_LOAD,
+	},
+};
+
+static void
+ktest_nl_register(void)
+{
+	bool ret __diagused;
+	int family_id __diagused;
+
+	NL_VERIFY_PARSERS(all_parsers);
+	family_id = genl_register_family(KTEST_FAMILY_NAME, 0, 1, KTEST_CMD_MAX);
+	MPASS(family_id != 0);
+
+	ret = genl_register_cmds(KTEST_FAMILY_NAME, ktest_cmds, NL_ARRAY_LEN(ktest_cmds));
+	MPASS(ret);
+}
+
+static void
+ktest_nl_unregister(void)
+{
+	MPASS(TAILQ_EMPTY(&module_list));
+
+	genl_unregister_family(KTEST_FAMILY_NAME);
+}
+
+static int
+ktest_modevent(module_t mod, int type, void *unused)
+{
+	int error = 0;
+
+	switch (type) {
+	case MOD_LOAD:
+		ktest_nl_register();
+		break;
+	case MOD_UNLOAD:
+		ktest_nl_unregister();
+		break;
+	default:
+		error = EOPNOTSUPP;
+		break;
+	}
+	return (error);
+}
+
+static moduledata_t ktestmod = {
+        "ktest",
+        ktest_modevent,
+        0
+};
+
+DECLARE_MODULE(ktestmod, ktestmod, SI_SUB_PSEUDO, SI_ORDER_ANY);
+MODULE_VERSION(ktestmod, 1);
+MODULE_DEPEND(ktestmod, netlink, 1, 1, 1);
+
diff --git a/sys/tests/ktest.h b/sys/tests/ktest.h
new file mode 100644
index 000000000000..feadb800551b
--- /dev/null
+++ b/sys/tests/ktest.h
@@ -0,0 +1,141 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Alexander V. Chernikov
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef	SYS_TESTS_KTEST_H_
+#define SYS_TESTS_KTEST_H_
+
+#ifdef _KERNEL
+
+#include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/module.h>
+#include <sys/syslog.h>
+
+struct nlattr;
+struct nl_pstate;
+struct nlmsghdr;
+
+struct ktest_test_context {
+	void			*arg;
+	struct nl_pstate	*npt;
+	struct nlmsghdr		*hdr;
+	char			*buf;
+	size_t			bufsize;
+};
+
+typedef int (*ktest_run_t)(struct ktest_test_context *ctx);
+typedef int (*ktest_parse_t)(struct ktest_test_context *ctx, struct nlattr *container);
+
+struct ktest_test_info {
+	const char	*name;
+	const char	*desc;
+	ktest_run_t	func;
+	ktest_parse_t	parse;
+};
+
+struct ktest_module_info {
+	const char			*name;
+	const struct ktest_test_info	*tests;
+	int				num_tests;
+	void				*module_ptr;
+};
+
+int ktest_default_modevent(module_t mod, int type, void *arg);
+
+bool ktest_start_msg(struct ktest_test_context *ctx);
+void ktest_add_msg_meta(struct ktest_test_context *ctx, const char *func,
+    const char *fname, int line);
+void ktest_add_msg_text(struct ktest_test_context *ctx, int msg_level,
+    const char *fmt, ...);
+void ktest_end_msg(struct ktest_test_context *ctx);
+
+#define	KTEST_LOG_LEVEL(_ctx, _l, _fmt, ...) {				\
+	if (ktest_start_msg(_ctx)) {					\
+		ktest_add_msg_meta(_ctx, __func__, __FILE__, __LINE__);	\
+		ktest_add_msg_text(_ctx, _l, _fmt, ## __VA_ARGS__);	\
+		ktest_end_msg(_ctx);					\
+	}								\
+}
+
+#define	KTEST_LOG(_ctx, _fmt, ...)					\
+	KTEST_LOG_LEVEL(_ctx, LOG_DEBUG, _fmt, ## __VA_ARGS__)
+
+#define KTEST_MAX_BUF	512
+
+#define	KTEST_MODULE_DECLARE(_n, _t) 					\
+static struct ktest_module_info _module_info = {			\
+	.name = #_n,							\
+	.tests = _t,							\
+	.num_tests = nitems(_t),					\
+};									\
+									\
+static moduledata_t _module_data = {					\
+        "__"  #_n  "_module",						\
+        ktest_default_modevent,						\
+        &_module_info,							\
+};									\
+									\
+DECLARE_MODULE(ktest_##_n, _module_data, SI_SUB_PSEUDO, SI_ORDER_ANY);	\
+MODULE_VERSION(ktest_##_n, 1);						\
+MODULE_DEPEND(ktest_##_n, ktestmod, 1, 1, 1);				\
+
+#endif /* _KERNEL */
+
+/* genetlink definitions */
+#define KTEST_FAMILY_NAME	"ktest"
+
+/* commands */
+enum {
+	KTEST_CMD_UNSPEC	= 0,
+	KTEST_CMD_LIST		= 1,
+	KTEST_CMD_RUN		= 2,
+	KTEST_CMD_NEWTEST	= 3,
+	KTEST_CMD_NEWMESSAGE	= 4,
+	__KTEST_CMD_MAX,
+};
+#define	KTEST_CMD_MAX	(__KTEST_CMD_MAX - 1)
+
+enum ktest_attr_type_t {
+	KTEST_ATTR_UNSPEC,
+	KTEST_ATTR_MOD_NAME	= 1,	/* string: test module name */
+	KTEST_ATTR_TEST_NAME	= 2,	/* string: test name */
+	KTEST_ATTR_TEST_DESCR	= 3,	/* string: test description */
+	KTEST_ATTR_TEST_META	= 4,	/* nested: container with test-specific metadata */
+};
+
+enum ktest_msg_attr_type_t {
+	KTEST_MSG_ATTR_UNSPEC,
+	KTEST_MSG_ATTR_TS	= 1,	/* struct timespec */
+	KTEST_MSG_ATTR_FUNC	= 2,	/* string: function name */
+	KTEST_MSG_ATTR_FILE	= 3,	/* string: file name */
+	KTEST_MSG_ATTR_LINE	= 4,	/* u32: line in the file */
+	KTEST_MSG_ATTR_TEXT	= 5,	/* string: actual message data */
+	KTEST_MSG_ATTR_LEVEL	= 6,	/* u8: syslog loglevel */
+	KTEST_MSG_ATTR_META	= 7,	/* nested: message metadata */
+};
+
+#endif
diff --git a/sys/tests/ktest_example.c b/sys/tests/ktest_example.c
new file mode 100644
index 000000000000..7cccaad7a855
--- /dev/null
+++ b/sys/tests/ktest_example.c
@@ -0,0 +1,134 @@
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause
+ *
+ * Copyright (c) 2023 Alexander V. Chernikov
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <tests/ktest.h>
+#include <sys/cdefs.h>
+#include <sys/systm.h>
+
+
+static int
+test_something(struct ktest_test_context *ctx)
+{
+	KTEST_LOG(ctx, "I'm here, [%s]", __func__);
+
+	pause("sleeping...", hz / 10);
+
+	KTEST_LOG(ctx, "done");
+
+	return (0);
+}
+
+static int
+test_something_else(struct ktest_test_context *ctx)
+{
+	return (0);
+}
+
+static int
+test_failed(struct ktest_test_context *ctx)
+{
+	return (EBUSY);
+}
+
+static int
+test_failed2(struct ktest_test_context *ctx)
+{
+	KTEST_LOG(ctx, "failed because it always fails");
+	return (EBUSY);
+}
+
+#include <sys/malloc.h>
+#include <netlink/netlink.h>
+#include <netlink/netlink_ctl.h>
+
+struct test1_attrs {
+	uint32_t	arg1;
+	uint32_t	arg2;
+	char		*text;
+};
+
+#define	_OUT(_field)	offsetof(struct test1_attrs, _field)
+static const struct nlattr_parser nla_p_test1[] = {
+	{ .type = 1, .off = _OUT(arg1), .cb = nlattr_get_uint32 },
+	{ .type = 2, .off = _OUT(arg2), .cb = nlattr_get_uint32 },
+	{ .type = 3, .off = _OUT(text), .cb = nlattr_get_string },
+};
+#undef _OUT
+NL_DECLARE_ATTR_PARSER(test1_parser, nla_p_test1);
+
+static int
+test_with_params_parser(struct ktest_test_context *ctx, struct nlattr *nla)
+{
+	struct test1_attrs *attrs = npt_alloc(ctx->npt, sizeof(*attrs));
+
+	ctx->arg = attrs;
+	if (attrs != NULL)
+		return (nl_parse_nested(nla, &test1_parser, ctx->npt, attrs));
+	return (ENOMEM);
+}
+
+static int
+test_with_params(struct ktest_test_context *ctx)
+{
+	struct test1_attrs *attrs = ctx->arg;
+
+	if (attrs->text != NULL)
+		KTEST_LOG(ctx, "Get '%s'", attrs->text);
+	KTEST_LOG(ctx, "%u + %u = %u", attrs->arg1, attrs->arg2,
+	    attrs->arg1 + attrs->arg2);
+	return (0);
+}
+
+static const struct ktest_test_info tests[] = {
+	{
+		.name = "test_something",
+		.desc = "example description",
+		.func = &test_something,
+	},
+	{
+		.name = "test_something_else",
+		.desc = "example description 2",
+		.func = &test_something_else,
+	},
+	{
+		.name = "test_failed",
+		.desc = "always failing test",
+		.func = &test_failed,
+	},
+	{
+		.name = "test_failed2",
+		.desc = "always failing test",
+		.func = &test_failed2,
+	},
+	{
+		.name = "test_with_params",
+		.desc = "test summing integers",
+		.func = &test_with_params,
+		.parse = &test_with_params_parser,
+	},
+};
+KTEST_MODULE_DECLARE(ktest_example, tests);
diff --git a/tests/atf_python/Makefile b/tests/atf_python/Makefile
index 1a2fec387eda..889cdcdf9592 100644
--- a/tests/atf_python/Makefile
+++ b/tests/atf_python/Makefile
@@ -2,7 +2,7 @@
 
 .PATH:	${.CURDIR}
 
-FILES=	__init__.py atf_pytest.py utils.py
+FILES=	__init__.py atf_pytest.py ktest.py utils.py
 SUBDIR=	sys
 
 .include <bsd.own.mk>
diff --git a/tests/atf_python/atf_pytest.py b/tests/atf_python/atf_pytest.py
index 0dd3a225b73d..19b5f88fa200 100644
--- a/tests/atf_python/atf_pytest.py
+++ b/tests/atf_python/atf_pytest.py
@@ -6,6 +6,7 @@ from typing import NamedTuple
 from typing import Optional
 from typing import Tuple
 
+from atf_python.ktest import generate_ktests
 from atf_python.utils import nodeid_to_method_name
 
 import pytest
@@ -42,6 +43,8 @@ class ATFTestObj(object):
 
     def _get_test_description(self, obj):
         """Returns first non-empty line from func docstring or func name"""
+        if getattr(obj, "descr", None) is not None:
+            return getattr(obj, "descr")
         docstr = obj.function.__doc__
         if docstr:
             for line in docstr.split("\n"):
@@ -163,6 +166,9 @@ class ATFHandler(object):
         items.clear()
         items.extend(new_items)
 
+    def expand_tests(self, collector, name, obj):
+        return generate_ktests(collector, name, obj)
+
     def modify_tests(self, items, config):
         if config.option.atf_cleanup:
             self._generate_test_cleanups(items)
diff --git a/tests/atf_python/ktest.py b/tests/atf_python/ktest.py
new file mode 100644
index 000000000000..4cd9970aaec1
--- /dev/null
+++ b/tests/atf_python/ktest.py
@@ -0,0 +1,173 @@
+import logging
+import time
+from typing import NamedTuple
+
+import pytest
+from atf_python.sys.netlink.attrs import NlAttrNested
+from atf_python.sys.netlink.attrs import NlAttrStr
+from atf_python.sys.netlink.netlink import NetlinkMultipartIterator
+from atf_python.sys.netlink.netlink import NlHelper
+from atf_python.sys.netlink.netlink import Nlsock
+from atf_python.sys.netlink.netlink_generic import KtestAttrType
+from atf_python.sys.netlink.netlink_generic import KtestInfoMessage
+from atf_python.sys.netlink.netlink_generic import KtestLogMsgType
+from atf_python.sys.netlink.netlink_generic import KtestMsgAttrType
+from atf_python.sys.netlink.netlink_generic import KtestMsgType
+from atf_python.sys.netlink.netlink_generic import timespec
+from atf_python.sys.netlink.utils import NlConst
+from atf_python.utils import BaseTest
+from atf_python.utils import libc
+from atf_python.utils import nodeid_to_method_name
+
+
+datefmt = "%H:%M:%S"
+fmt = "%(asctime)s.%(msecs)03d %(filename)s:%(funcName)s:%(lineno)d %(message)s"
+logging.basicConfig(level=logging.DEBUG, format=fmt, datefmt=datefmt)
+logger = logging.getLogger("ktest")
+
+
+NETLINK_FAMILY = "ktest"
+
+
+class KtestItem(pytest.Item):
+    def __init__(self, *, descr, kcls, **kwargs):
+        super().__init__(**kwargs)
+        self.descr = descr
+        self._kcls = kcls
+
+    def runtest(self):
+        self._kcls().runtest()
+
+
+class KtestCollector(pytest.Class):
+    def collect(self):
+        obj = self.obj
+        exclude_names = set([n for n in dir(obj) if not n.startswith("_")])
+
+        autoload = obj.KTEST_MODULE_AUTOLOAD
+        module_name = obj.KTEST_MODULE_NAME
+        loader = KtestLoader(module_name, autoload)
+        ktests = loader.load_ktests()
+        if not ktests:
+            return
+
+        orig = pytest.Class.from_parent(self.parent, name=self.name, obj=obj)
+        for py_test in orig.collect():
+            yield py_test
+
+        for ktest in ktests:
+            name = ktest["name"]
+            descr = ktest["desc"]
+            if name in exclude_names:
+                continue
+            yield KtestItem.from_parent(self, name=name, descr=descr, kcls=obj)
+
+
+class KtestLoader(object):
+    def __init__(self, module_name: str, autoload: bool):
+        self.module_name = module_name
+        self.autoload = autoload
+        self.helper = NlHelper()
+        self.nlsock = Nlsock(NlConst.NETLINK_GENERIC, self.helper)
+        self.family_id = self._get_family_id()
+
+    def _get_family_id(self):
+        try:
+            family_id = self.nlsock.get_genl_family_id(NETLINK_FAMILY)
+        except ValueError:
+            if self.autoload:
+                libc.kldload(self.module_name)
+                family_id = self.nlsock.get_genl_family_id(NETLINK_FAMILY)
+            else:
+                raise
+        return family_id
+
+    def _load_ktests(self):
+        msg = KtestInfoMessage(self.helper, self.family_id, KtestMsgType.KTEST_CMD_LIST)
+        msg.set_request()
+        msg.add_nla(NlAttrStr(KtestAttrType.KTEST_ATTR_MOD_NAME, self.module_name))
+        self.nlsock.write_message(msg, verbose=False)
+        nlmsg_seq = msg.nl_hdr.nlmsg_seq
+
+        ret = []
+        for rx_msg in NetlinkMultipartIterator(self.nlsock, nlmsg_seq, self.family_id):
+            # test_msg.print_message()
+            tst = {
+                "mod_name": rx_msg.get_nla(KtestAttrType.KTEST_ATTR_MOD_NAME).text,
+                "name": rx_msg.get_nla(KtestAttrType.KTEST_ATTR_TEST_NAME).text,
+                "desc": rx_msg.get_nla(KtestAttrType.KTEST_ATTR_TEST_DESCR).text,
+            }
+            ret.append(tst)
+        return ret
+
+    def load_ktests(self):
+        ret = self._load_ktests()
+        if not ret and self.autoload:
+            libc.kldload(self.module_name)
+            ret = self._load_ktests()
+        return ret
+
+
+def generate_ktests(collector, name, obj):
+    if getattr(obj, "KTEST_MODULE_NAME", None) is not None:
+        return KtestCollector.from_parent(collector, name=name, obj=obj)
+    return None
+
+
+class BaseKernelTest(BaseTest):
+    KTEST_MODULE_AUTOLOAD = True
+    KTEST_MODULE_NAME = None
+
+    def _get_record_time(self, msg) -> float:
+        timespec = msg.get_nla(KtestMsgAttrType.KTEST_MSG_ATTR_TS).ts
+        epoch_ktime = timespec.tv_sec * 1.0 + timespec.tv_nsec * 1.0 / 1000000000
+        if not hasattr(self, "_start_epoch"):
+            self._start_ktime = epoch_ktime
+            self._start_time = time.time()
+            epoch_time = self._start_time
+        else:
+            epoch_time = time.time() - self._start_time + epoch_ktime
+        return epoch_time
+
+    def _log_message(self, msg):
+        # Convert syslog-type l
+        syslog_level = msg.get_nla(KtestMsgAttrType.KTEST_MSG_ATTR_LEVEL).u8
+        if syslog_level <= 6:
+            loglevel = logging.INFO
+        else:
+            loglevel = logging.DEBUG
+        rec = logging.LogRecord(
+            self.KTEST_MODULE_NAME,
+            loglevel,
+            msg.get_nla(KtestMsgAttrType.KTEST_MSG_ATTR_FILE).text,
+            msg.get_nla(KtestMsgAttrType.KTEST_MSG_ATTR_LINE).u32,
+            "%s",
+            (msg.get_nla(KtestMsgAttrType.KTEST_MSG_ATTR_TEXT).text),
+            None,
+            msg.get_nla(KtestMsgAttrType.KTEST_MSG_ATTR_FUNC).text,
+            None,
+        )
+        rec.created = self._get_record_time(msg)
+        logger.handle(rec)
+
+    def _runtest_name(self, test_name: str, test_data):
+        module_name = self.KTEST_MODULE_NAME
+        # print("Running kernel test {} for module {}".format(test_name, module_name))
+        helper = NlHelper()
+        nlsock = Nlsock(NlConst.NETLINK_GENERIC, helper)
+        family_id = nlsock.get_genl_family_id(NETLINK_FAMILY)
+        msg = KtestInfoMessage(helper, family_id, KtestMsgType.KTEST_CMD_RUN)
+        msg.set_request()
+        msg.add_nla(NlAttrStr(KtestAttrType.KTEST_ATTR_MOD_NAME, module_name))
+        msg.add_nla(NlAttrStr(KtestAttrType.KTEST_ATTR_TEST_NAME, test_name))
+        if test_data is not None:
+            msg.add_nla(NlAttrNested(KtestAttrType.KTEST_ATTR_TEST_META, test_data))
+        nlsock.write_message(msg, verbose=False)
+
+        for log_msg in NetlinkMultipartIterator(
+            nlsock, msg.nl_hdr.nlmsg_seq, family_id
+        ):
+            self._log_message(log_msg)
+
+    def runtest(self, test_data=None):
+        self._runtest_name(nodeid_to_method_name(self.test_id), test_data)
diff --git a/tests/atf_python/sys/netlink/attrs.py b/tests/atf_python/sys/netlink/attrs.py
index f6fe9ee43c98..58fbab7fc8db 100644
--- a/tests/atf_python/sys/netlink/attrs.py
+++ b/tests/atf_python/sys/netlink/attrs.py
@@ -7,6 +7,8 @@ from atf_python.sys.netlink.utils import enum_or_int
 
 
 class NlAttr(object):
+    HDR_LEN = 4  # sizeof(struct nlattr)
+
     def __init__(self, nla_type, data):
         if isinstance(nla_type, Enum):
             self._nla_type = nla_type.value
diff --git a/tests/atf_python/sys/netlink/base_headers.py b/tests/atf_python/sys/netlink/base_headers.py
index 759d8827fb3c..71771a249b3d 100644
--- a/tests/atf_python/sys/netlink/base_headers.py
+++ b/tests/atf_python/sys/netlink/base_headers.py
@@ -15,6 +15,13 @@ class Nlmsghdr(Structure):
     ]
 
 
+class Nlattr(Structure):
+    _fields_ = [
+        ("nla_len", c_ushort),
+        ("nla_type", c_ushort),
+    ]
+
+
 class NlMsgType(Enum):
     NLMSG_NOOP = 1
     NLMSG_ERROR = 2
diff --git a/tests/atf_python/sys/netlink/netlink.py b/tests/atf_python/sys/netlink/netlink.py
index f813727d55b4..4bdefc2d5014 100644
--- a/tests/atf_python/sys/netlink/netlink.py
+++ b/tests/atf_python/sys/netlink/netlink.py
@@ -22,8 +22,8 @@ from atf_python.sys.netlink.message import BaseNetlinkMessage
 from atf_python.sys.netlink.message import NlMsgCategory
 from atf_python.sys.netlink.message import NlMsgProps
 from atf_python.sys.netlink.message import StdNetlinkMessage
-from atf_python.sys.netlink.netlink_generic import GenlCtrlMsgType
 from atf_python.sys.netlink.netlink_generic import GenlCtrlAttrType
+from atf_python.sys.netlink.netlink_generic import GenlCtrlMsgType
 from atf_python.sys.netlink.netlink_generic import handler_classes as genl_classes
 from atf_python.sys.netlink.netlink_route import handler_classes as rt_classes
 from atf_python.sys.netlink.utils import align4
diff --git a/tests/atf_python/sys/netlink/netlink_generic.py b/tests/atf_python/sys/netlink/netlink_generic.py
index ee75d5bf37f3..06dc8704fe07 100644
--- a/tests/atf_python/sys/netlink/netlink_generic.py
+++ b/tests/atf_python/sys/netlink/netlink_generic.py
@@ -1,10 +1,16 @@
 #!/usr/local/bin/python3
+from ctypes import c_int64
+from ctypes import c_long
 from ctypes import sizeof
+from ctypes import Structure
 from enum import Enum
+import struct
 
+from atf_python.sys.netlink.attrs import NlAttr
 from atf_python.sys.netlink.attrs import NlAttrStr
 from atf_python.sys.netlink.attrs import NlAttrU16
 from atf_python.sys.netlink.attrs import NlAttrU32
+from atf_python.sys.netlink.attrs import NlAttrU8
 from atf_python.sys.netlink.base_headers import GenlMsgHdr
 from atf_python.sys.netlink.message import NlMsgCategory
 from atf_python.sys.netlink.message import NlMsgProps
@@ -105,6 +111,118 @@ class NetlinkGenlCtrlMessage(NetlinkGenlMessage):
     family_name = GenlCtrlFamilyName
 
 
+KtestFamilyName = "ktest"
+
+
+class KtestMsgType(Enum):
+    KTEST_CMD_UNSPEC = 0
+    KTEST_CMD_LIST = 1
+    KTEST_CMD_RUN = 2
+    KTEST_CMD_NEWTEST = 3
+    KTEST_CMD_NEWMESSAGE = 4
+
+
+class KtestAttrType(Enum):
+    KTEST_ATTR_MOD_NAME = 1
+    KTEST_ATTR_TEST_NAME = 2
+    KTEST_ATTR_TEST_DESCR = 3
+    KTEST_ATTR_TEST_META = 4
+
+
+class KtestLogMsgType(Enum):
+    KTEST_MSG_START = 1
+    KTEST_MSG_END = 2
+    KTEST_MSG_LOG = 3
+    KTEST_MSG_FAIL = 4
+
+
+class KtestMsgAttrType(Enum):
+    KTEST_MSG_ATTR_TS = 1
+    KTEST_MSG_ATTR_FUNC = 2
+    KTEST_MSG_ATTR_FILE = 3
+    KTEST_MSG_ATTR_LINE = 4
+    KTEST_MSG_ATTR_TEXT = 5
+    KTEST_MSG_ATTR_LEVEL = 6
+    KTEST_MSG_ATTR_META = 7
+
+
+class timespec(Structure):
+    _fields_ = [
+        ("tv_sec", c_int64),
+        ("tv_nsec", c_long),
+    ]
+
+
+class NlAttrTS(NlAttr):
+    DATA_LEN = sizeof(timespec)
+
+    def __init__(self, nla_type, val):
+        self.ts = val
+        super().__init__(nla_type, b"")
+
+    @property
+    def nla_len(self):
+        return NlAttr.HDR_LEN + self.DATA_LEN
+
+    def _print_attr_value(self):
+        return " tv_sec={} tv_nsec={}".format(self.ts.tv_sec, self.ts.tv_nsec)
+
+    @staticmethod
+    def _validate(data):
+        assert len(data) == NlAttr.HDR_LEN + NlAttrTS.DATA_LEN
+        nla_len, nla_type = struct.unpack("@HH", data[:NlAttr.HDR_LEN])
+        assert nla_len == NlAttr.HDR_LEN + NlAttrTS.DATA_LEN
+
+    @classmethod
+    def _parse(cls, data):
+        nla_len, nla_type = struct.unpack("@HH", data[:NlAttr.HDR_LEN])
+        val = timespec.from_buffer_copy(data[NlAttr.HDR_LEN:])
+        return cls(nla_type, val)
+
+    def __bytes__(self):
+        return self._to_bytes(bytes(self.ts))
+
+
+ktest_info_attrs = prepare_attrs_map(
+    [
+        AttrDescr(KtestAttrType.KTEST_ATTR_MOD_NAME, NlAttrStr),
+        AttrDescr(KtestAttrType.KTEST_ATTR_TEST_NAME, NlAttrStr),
+        AttrDescr(KtestAttrType.KTEST_ATTR_TEST_DESCR, NlAttrStr),
+    ]
+)
+
+
+ktest_msg_attrs = prepare_attrs_map(
+    [
+        AttrDescr(KtestMsgAttrType.KTEST_MSG_ATTR_FUNC, NlAttrStr),
+        AttrDescr(KtestMsgAttrType.KTEST_MSG_ATTR_FILE, NlAttrStr),
+        AttrDescr(KtestMsgAttrType.KTEST_MSG_ATTR_LINE, NlAttrU32),
+        AttrDescr(KtestMsgAttrType.KTEST_MSG_ATTR_TEXT, NlAttrStr),
+        AttrDescr(KtestMsgAttrType.KTEST_MSG_ATTR_LEVEL, NlAttrU8),
+        AttrDescr(KtestMsgAttrType.KTEST_MSG_ATTR_TS, NlAttrTS),
+    ]
+)
+
+
+class KtestInfoMessage(NetlinkGenlMessage):
+    messages = [
+        NlMsgProps(KtestMsgType.KTEST_CMD_LIST, NlMsgCategory.GET),
+        NlMsgProps(KtestMsgType.KTEST_CMD_RUN, NlMsgCategory.NEW),
+        NlMsgProps(KtestMsgType.KTEST_CMD_NEWTEST, NlMsgCategory.NEW),
+    ]
+    nl_attrs_map = ktest_info_attrs
+    family_name = KtestFamilyName
+
+
+class KtestMsgMessage(NetlinkGenlMessage):
+    messages = [
+        NlMsgProps(KtestMsgType.KTEST_CMD_NEWMESSAGE, NlMsgCategory.NEW),
+    ]
+    nl_attrs_map = ktest_msg_attrs
+    family_name = KtestFamilyName
+
+
 handler_classes = {
     GenlCtrlFamilyName: [NetlinkGenlCtrlMessage],
+    KtestFamilyName: [KtestInfoMessage, KtestMsgMessage],
 }
diff --git a/tests/atf_python/utils.py b/tests/atf_python/utils.py
index 591a532ca476..1c0a68dad383 100644
--- a/tests/atf_python/utils.py
+++ b/tests/atf_python/utils.py
@@ -28,6 +28,11 @@ class LibCWrapper(object):
             return get_errno()
         return 0
 
+    def kldload(self, kld_name: str) -> int:
+        if self._libc.kldload(bytes(kld_name, encoding="ascii")) == -1:
+            return get_errno()
+        return 0
+
     def jail_attach(self, jid: int) -> int:
         if self._libc.jail_attach(jid) != 0:
             return get_errno()
diff --git a/tests/conftest.py b/tests/conftest.py
index 5d319863af73..8e3c004b74d6 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -99,6 +99,12 @@ def pytest_configure(config):
         handler.setup_configure()
 
 
+def pytest_pycollect_makeitem(collector, name, obj):
+    if PLUGIN_ENABLED:
+        handler = get_handler()
+        return handler.expand_tests(collector, name, obj)
+
+
 def pytest_collection_modifyitems(session, config, items):
     """If cleanup is requested, replace collected tests with their cleanups (if any)"""
     if PLUGIN_ENABLED:
diff --git a/tests/examples/Makefile b/tests/examples/Makefile
index 7a5d84a98dfe..6bb87b300ee7 100644
--- a/tests/examples/Makefile
+++ b/tests/examples/Makefile
@@ -5,6 +5,7 @@ PACKAGE=	tests
 TESTSDIR=       ${TESTSBASE}/examples
 
 ATF_TESTS_PYTEST +=	test_examples.py
+ATF_TESTS_PYTEST +=	test_ktest_example.py
 
 .include <bsd.test.mk>
 
diff --git a/tests/examples/test_ktest_example.py b/tests/examples/test_ktest_example.py
new file mode 100644
index 000000000000..c11f178cb054
--- /dev/null
+++ b/tests/examples/test_ktest_example.py
@@ -0,0 +1,35 @@
+import pytest
+
+from atf_python.ktest import BaseKernelTest
+
+from atf_python.sys.netlink.attrs import NlAttrStr
+from atf_python.sys.netlink.attrs import NlAttrU32
+
+
+class TestExample(BaseKernelTest):
+    KTEST_MODULE_NAME = "ktest_example"
+
+    @pytest.mark.parametrize(
+        "numbers",
+        [
+            pytest.param([1, 2], id="1_2_Sum"),
+            pytest.param([3, 4], id="3_4_Sum"),
+        ],
+    )
+    def test_with_params(self, numbers):
+        """override to parametrize"""
+
+        test_meta = [
+            NlAttrU32(1, numbers[0]),
+            NlAttrU32(2, numbers[1]),
+            NlAttrStr(3, "test string"),
+        ]
+        self.runtest(test_meta)
+
+    @pytest.mark.skip(reason="comment me ( or delete the func) to run the test")
+    def test_failed(self):
+        pass
+
+    @pytest.mark.skip(reason="comment me ( or delete the func) to run the test")
+    def test_failed2(self):
+        pass