kunit: tool: add --kernel_args to allow setting module params

kunit.py currently does not make it possible for users to specify module
parameters (/kernel arguments more generally) unless one directly tweaks
the kunit.py code itself.

This hasn't mattered much so far, but this would make it easier to port
existing tests that expose module parameters over to KUnit and/or let
current KUnit tests take advantage of them.

Tested using an kunit internal parameter:
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit \
    --kernel_args=kunit.filter_glob=kunit_status
...
Testing complete. 2 tests run. 0 failed. 0 crashed. 0 skipped.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Author: dlatypov

Documentation/dev-tools/kunit/running_tips.rst

@@ -80,6 +80,16 @@ file ``.kunitconfig``, you can just pass in the dir, e.g.
 	automagically, but tests could theoretically depend on incompatible
 	options, so handling that would be tricky.
 
+Setting kernel commandline parameters
+-------------------------------------
+
+You can use ``--kernel_args`` to pass arbitrary kernel arguments, e.g.
+
+.. code-block:: bash
+
+	$ ./tools/testing/kunit/kunit.py run --kernel_args=param=42 --kernel_args=param2=false
+
+
 Generating code coverage reports under UML
 ------------------------------------------
 

tools/testing/kunit/kunit.py

@@ -30,12 +30,13 @@
 			       ['jobs', 'build_dir', 'alltests',
 				'make_options'])
 KunitExecRequest = namedtuple('KunitExecRequest',
-			      ['timeout', 'build_dir', 'alltests', 'filter_glob'])
+                              ['timeout', 'build_dir', 'alltests',
+                               'filter_glob', 'kernel_args'])
 KunitParseRequest = namedtuple('KunitParseRequest',
 			       ['raw_output', 'input_data', 'build_dir', 'json'])
 KunitRequest = namedtuple('KunitRequest', ['raw_output','timeout', 'jobs',
 					   'build_dir', 'alltests', 'filter_glob',
-					   'json', 'make_options'])
+					   'kernel_args', 'json', 'make_options'])
 
 KernelDirectoryPath = sys.argv[0].split('tools/testing/kunit/')[0]
 
@@ -94,6 +95,7 @@ def exec_tests(linux: kunit_kernel.LinuxSourceTree,
 	kunit_parser.print_with_timestamp('Starting KUnit Kernel ...')
 	test_start = time.time()
 	result = linux.run_kernel(
+		args=request.kernel_args,
 		timeout=None if request.alltests else request.timeout,
                 filter_glob=request.filter_glob,
 		build_dir=request.build_dir)
@@ -152,7 +154,8 @@ def run_tests(linux: kunit_kernel.LinuxSourceTree,
 		return build_result
 
 	exec_request = KunitExecRequest(request.timeout, request.build_dir,
-					request.alltests, request.filter_glob)
+				 request.alltests, request.filter_glob,
+				 request.kernel_args)
 	exec_result = exec_tests(linux, exec_request)
 	if exec_result.status != KunitStatus.SUCCESS:
 		return exec_result
@@ -238,6 +241,9 @@ def add_exec_opts(parser) -> None:
 			    nargs='?',
 			    default='',
 			    metavar='filter_glob')
+	parser.add_argument('--kernel_args',
+			    help='Kernel command-line parameters. Maybe be repeated',
+			     action='append')
 
 def add_parse_opts(parser) -> None:
 	parser.add_argument('--raw_output', help='don\'t format output from kernel',
@@ -309,6 +315,7 @@ def main(argv, linux=None):
 				       cli_args.build_dir,
 				       cli_args.alltests,
 				       cli_args.filter_glob,
+				       cli_args.kernel_args,
 				       cli_args.json,
 				       cli_args.make_options)
 		result = run_tests(linux, request)
@@ -363,7 +370,8 @@ def main(argv, linux=None):
 		exec_request = KunitExecRequest(cli_args.timeout,
 						cli_args.build_dir,
 						cli_args.alltests,
-						cli_args.filter_glob)
+						cli_args.filter_glob,
+						cli_args.kernel_args)
 		exec_result = exec_tests(linux, exec_request)
 		parse_request = KunitParseRequest(cli_args.raw_output,
 						  exec_result.result,

tools/testing/kunit/kunit_tool_test.py

@@ -356,15 +356,15 @@ def test_exec_passes_args_pass(self):
 		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 0)
 		self.assertEqual(self.linux_source_mock.run_kernel.call_count, 1)
 		self.linux_source_mock.run_kernel.assert_called_once_with(
-			build_dir='.kunit', filter_glob='', timeout=300)
+			args=None, build_dir='.kunit', filter_glob='', timeout=300)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	def test_run_passes_args_pass(self):
 		kunit.main(['run'], self.linux_source_mock)
 		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 1)
 		self.assertEqual(self.linux_source_mock.run_kernel.call_count, 1)
 		self.linux_source_mock.run_kernel.assert_called_once_with(
-			build_dir='.kunit', filter_glob='', timeout=300)
+			args=None, build_dir='.kunit', filter_glob='', timeout=300)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	def test_exec_passes_args_fail(self):
@@ -403,23 +403,23 @@ def test_exec_timeout(self):
 		timeout = 3453
 		kunit.main(['exec', '--timeout', str(timeout)], self.linux_source_mock)
 		self.linux_source_mock.run_kernel.assert_called_once_with(
-			build_dir='.kunit', filter_glob='', timeout=timeout)
+			args=None, build_dir='.kunit', filter_glob='', timeout=timeout)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	def test_run_timeout(self):
 		timeout = 3453
 		kunit.main(['run', '--timeout', str(timeout)], self.linux_source_mock)
 		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 1)
 		self.linux_source_mock.run_kernel.assert_called_once_with(
-			build_dir='.kunit', filter_glob='', timeout=timeout)
+			args=None, build_dir='.kunit', filter_glob='', timeout=timeout)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	def test_run_builddir(self):
 		build_dir = '.kunit'
 		kunit.main(['run', '--build_dir=.kunit'], self.linux_source_mock)
 		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 1)
 		self.linux_source_mock.run_kernel.assert_called_once_with(
-			build_dir=build_dir, filter_glob='', timeout=300)
+			args=None, build_dir=build_dir, filter_glob='', timeout=300)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	def test_config_builddir(self):
@@ -436,7 +436,7 @@ def test_exec_builddir(self):
 		build_dir = '.kunit'
 		kunit.main(['exec', '--build_dir', build_dir], self.linux_source_mock)
 		self.linux_source_mock.run_kernel.assert_called_once_with(
-			build_dir=build_dir, filter_glob='', timeout=300)
+			args=None, build_dir=build_dir, filter_glob='', timeout=300)
 		self.print_mock.assert_any_call(StrContains('Testing complete.'))
 
 	@mock.patch.object(kunit_kernel, 'LinuxSourceTree')
@@ -461,5 +461,13 @@ def test_config_kunitconfig(self, mock_linux_init):
 							cross_compile=None,
 							qemu_config_path=None)
 
+	def test_run_kernel_args(self):
+		kunit.main(['run', '--kernel_args=a=1', '--kernel_args=b=2'], self.linux_source_mock)
+		self.assertEqual(self.linux_source_mock.build_reconfig.call_count, 1)
+		self.linux_source_mock.run_kernel.assert_called_once_with(
+		      args=['a=1','b=2'], build_dir='.kunit', filter_glob='', timeout=300)
+		self.print_mock.assert_any_call(StrContains('Testing complete.'))
+
+
 if __name__ == '__main__':
 	unittest.main()