kunit: Add 'kunit_shutdown' option

Add a new kernel command-line option, 'kunit_shutdown', which allows the
user to specify that the kernel poweroff, halt, or reboot after
completing all KUnit tests; this is very handy for running KUnit tests
on UML or a VM so that the UML/VM process exits cleanly immediately
after running all tests without needing a special initramfs.
Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-By: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

lib/kunit/executor.c

 // SPDX-License-Identifier: GPL-2.0
 
+#include <linux/reboot.h>
 #include <kunit/test.h>
 #include <linux/glob.h>
 #include <linux/moduleparam.h>
@@ -18,6 +19,9 @@ module_param(filter_glob, charp, 0);
 MODULE_PARM_DESC(filter_glob,
 		"Filter which KUnit test suites run at boot-time, e.g. list*");
 
+static char *kunit_shutdown;
+core_param(kunit_shutdown, kunit_shutdown, charp, 0644);
+
 static struct kunit_suite * const *
 kunit_filter_subsuite(struct kunit_suite * const * const subsuite)
 {
@@ -82,6 +86,20 @@ static struct suite_set kunit_filter_suites(void)
 	return filtered;
 }
 
+static void kunit_handle_shutdown(void)
+{
+	if (!kunit_shutdown)
+		return;
+
+	if (!strcmp(kunit_shutdown, "poweroff"))
+		kernel_power_off();
+	else if (!strcmp(kunit_shutdown, "halt"))
+		kernel_halt();
+	else if (!strcmp(kunit_shutdown, "reboot"))
+		kernel_restart(NULL);
+
+}
+
 static void kunit_print_tap_header(struct suite_set *suite_set)
 {
 	struct kunit_suite * const * const *suites, * const *subsuite;
@@ -112,6 +130,8 @@ int kunit_run_all_tests(void)
 		kfree(suite_set.start);
 	}
 
+	kunit_handle_shutdown();
+
 	return 0;
 }
 

tools/testing/kunit/kunit_kernel.py

@@ -208,7 +208,7 @@ class LinuxSourceTree(object):
 	def run_kernel(self, args=None, build_dir='', filter_glob='', timeout=None) -> Iterator[str]:
 		if not args:
 			args = []
-		args.extend(['mem=1G', 'console=tty'])
+		args.extend(['mem=1G', 'console=tty', 'kunit_shutdown=halt'])
 		if filter_glob:
 			args.append('kunit.filter_glob='+filter_glob)
 		self._ops.linux_bin(args, timeout, build_dir)

tools/testing/kunit/kunit_parser.py

@@ -49,7 +49,7 @@ class TestStatus(Enum):
 
 kunit_start_re = re.compile(r'TAP version [0-9]+$')
 kunit_end_re = re.compile('(List of all partitions:|'
-			  'Kernel panic - not syncing: VFS:)')
+			  'Kernel panic - not syncing: VFS:|reboot: System halted)')
 
 def isolate_kunit_output(kernel_output) -> Iterator[str]:
 	started = False