14 files changed, 1413 insertions, 518 deletions

diff --git a/Documentation/dev-tools/kunit/running_tips.rst b/Documentation/dev-tools/kunit/running_tips.rst
index 30d2147eb5b5..7b6d26a25959 100644
--- a/Documentation/dev-tools/kunit/running_tips.rst
+++ b/Documentation/dev-tools/kunit/running_tips.rst
@@ -25,8 +25,8 @@ It can be handy to create a bash function like:
 Running a subset of tests
 -------------------------
 
-``kunit.py run`` accepts an optional glob argument to filter tests. Currently
-this only matches against suite names, but this may change in the future.
+``kunit.py run`` accepts an optional glob argument to filter tests. The format
+is ``"<suite_glob>[.test_glob]"``.
 
 Say that we wanted to run the sysctl tests, we could do so via:
 
@@ -35,6 +35,13 @@ Say that we wanted to run the sysctl tests, we could do so via:
 	$ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
 	$ ./tools/testing/kunit/kunit.py run 'sysctl*'
 
+We can filter down to just the "write" tests via:
+
+.. code-block:: bash
+
+	$ echo -e 'CONFIG_KUNIT=y\nCONFIG_KUNIT_ALL_TESTS=y' > .kunit/.kunitconfig
+	$ ./tools/testing/kunit/kunit.py run 'sysctl*.*write*'
+
 We're paying the cost of building more tests than we need this way, but it's
 easier than fiddling with ``.kunitconfig`` files or commenting out
 ``kunit_suite``'s.
diff --git a/lib/kunit/executor.c b/lib/kunit/executor.c
index acd1de436f59..22640c9ee819 100644
--- a/lib/kunit/executor.c
+++ b/lib/kunit/executor.c
@@ -15,23 +15,89 @@ extern struct kunit_suite * const * const __kunit_suites_end[];
 #if IS_BUILTIN(CONFIG_KUNIT)
 
 static char *filter_glob_param;
+static char *action_param;
+
 module_param_named(filter_glob, filter_glob_param, charp, 0);
 MODULE_PARM_DESC(filter_glob,
-		"Filter which KUnit test suites run at boot-time, e.g. list*");
+		"Filter which KUnit test suites/tests run at boot-time, e.g. list* or list*.*del_test");
+module_param_named(action, action_param, charp, 0);
+MODULE_PARM_DESC(action,
+		 "Changes KUnit executor behavior, valid values are:\n"
+		 "<none>: run the tests like normal\n"
+		 "'list' to list test names instead of running them.\n");
+
+/* glob_match() needs NULL terminated strings, so we need a copy of filter_glob_param. */
+struct kunit_test_filter {
+	char *suite_glob;
+	char *test_glob;
+};
+
+/* Split "suite_glob.test_glob" into two. Assumes filter_glob is not empty. */
+static void kunit_parse_filter_glob(struct kunit_test_filter *parsed,
+				    const char *filter_glob)
+{
+	const int len = strlen(filter_glob);
+	const char *period = strchr(filter_glob, '.');
+
+	if (!period) {
+		parsed->suite_glob = kzalloc(len + 1, GFP_KERNEL);
+		parsed->test_glob = NULL;
+		strcpy(parsed->suite_glob, filter_glob);
+		return;
+	}
+
+	parsed->suite_glob = kzalloc(period - filter_glob + 1, GFP_KERNEL);
+	parsed->test_glob = kzalloc(len - (period - filter_glob) + 1, GFP_KERNEL);
+
+	strncpy(parsed->suite_glob, filter_glob, period - filter_glob);
+	strncpy(parsed->test_glob, period + 1, len - (period - filter_glob));
+}
+
+/* Create a copy of suite with only tests that match test_glob. */
+static struct kunit_suite *
+kunit_filter_tests(struct kunit_suite *const suite, const char *test_glob)
+{
+	int n = 0;
+	struct kunit_case *filtered, *test_case;
+	struct kunit_suite *copy;
+
+	kunit_suite_for_each_test_case(suite, test_case) {
+		if (!test_glob || glob_match(test_glob, test_case->name))
+			++n;
+	}
+
+	if (n == 0)
+		return NULL;
+
+	/* Use memcpy to workaround copy->name being const. */
+	copy = kmalloc(sizeof(*copy), GFP_KERNEL);
+	memcpy(copy, suite, sizeof(*copy));
+
+	filtered = kcalloc(n + 1, sizeof(*filtered), GFP_KERNEL);
+
+	n = 0;
+	kunit_suite_for_each_test_case(suite, test_case) {
+		if (!test_glob || glob_match(test_glob, test_case->name))
+			filtered[n++] = *test_case;
+	}
+
+	copy->test_cases = filtered;
+	return copy;
+}
 
 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,
-			const char *filter_glob)
+		      struct kunit_test_filter *filter)
 {
 	int i, n = 0;
-	struct kunit_suite **filtered;
+	struct kunit_suite **filtered, *filtered_suite;
 
 	n = 0;
-	for (i = 0; subsuite[i] != NULL; ++i) {
-		if (glob_match(filter_glob, subsuite[i]->name))
+	for (i = 0; subsuite[i]; ++i) {
+		if (glob_match(filter->suite_glob, subsuite[i]->name))
 			++n;
 	}
 
@@ -44,8 +110,11 @@ kunit_filter_subsuite(struct kunit_suite * const * const subsuite,
 
 	n = 0;
 	for (i = 0; subsuite[i] != NULL; ++i) {
-		if (glob_match(filter_glob, subsuite[i]->name))
-			filtered[n++] = subsuite[i];
+		if (!glob_match(filter->suite_glob, subsuite[i]->name))
+			continue;
+		filtered_suite = kunit_filter_tests(subsuite[i], filter->test_glob);
+		if (filtered_suite)
+			filtered[n++] = filtered_suite;
 	}
 	filtered[n] = NULL;
 
@@ -57,12 +126,32 @@ struct suite_set {
 	struct kunit_suite * const * const *end;
 };
 
+static void kunit_free_subsuite(struct kunit_suite * const *subsuite)
+{
+	unsigned int i;
+
+	for (i = 0; subsuite[i]; i++)
+		kfree(subsuite[i]);
+
+	kfree(subsuite);
+}
+
+static void kunit_free_suite_set(struct suite_set suite_set)
+{
+	struct kunit_suite * const * const *suites;
+
+	for (suites = suite_set.start; suites < suite_set.end; suites++)
+		kunit_free_subsuite(*suites);
+	kfree(suite_set.start);
+}
+
 static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 					    const char *filter_glob)
 {
 	int i;
 	struct kunit_suite * const **copy, * const *filtered_subsuite;
 	struct suite_set filtered;
+	struct kunit_test_filter filter;
 
 	const size_t max = suite_set->end - suite_set->start;
 
@@ -73,12 +162,17 @@ static struct suite_set kunit_filter_suites(const struct suite_set *suite_set,
 		return filtered;
 	}
 
+	kunit_parse_filter_glob(&filter, filter_glob);
+
 	for (i = 0; i < max; ++i) {
-		filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], filter_glob);
+		filtered_subsuite = kunit_filter_subsuite(suite_set->start[i], &filter);
 		if (filtered_subsuite)
 			*copy++ = filtered_subsuite;
 	}
 	filtered.end = copy;
+
+	kfree(filter.suite_glob);
+	kfree(filter.test_glob);
 	return filtered;
 }
 
@@ -109,9 +203,35 @@ static void kunit_print_tap_header(struct suite_set *suite_set)
 	pr_info("1..%d\n", num_of_suites);
 }
 
-int kunit_run_all_tests(void)
+static void kunit_exec_run_tests(struct suite_set *suite_set)
+{
+	struct kunit_suite * const * const *suites;
+
+	kunit_print_tap_header(suite_set);
+
+	for (suites = suite_set->start; suites < suite_set->end; suites++)
+		__kunit_test_suites_init(*suites);
+}
+
+static void kunit_exec_list_tests(struct suite_set *suite_set)
 {
+	unsigned int i;
 	struct kunit_suite * const * const *suites;
+	struct kunit_case *test_case;
+
+	/* Hack: print a tap header so kunit.py can find the start of KUnit output. */
+	pr_info("TAP version 14\n");
+
+	for (suites = suite_set->start; suites < suite_set->end; suites++)
+		for (i = 0; (*suites)[i] != NULL; i++) {
+			kunit_suite_for_each_test_case((*suites)[i], test_case) {
+				pr_info("%s.%s\n", (*suites)[i]->name, test_case->name);
+			}
+		}
+}
+
+int kunit_run_all_tests(void)
+{
 	struct suite_set suite_set = {
 		.start = __kunit_suites_start,
 		.end = __kunit_suites_end,
@@ -120,15 +240,15 @@ int kunit_run_all_tests(void)
 	if (filter_glob_param)
 		suite_set = kunit_filter_suites(&suite_set, filter_glob_param);
 
-	kunit_print_tap_header(&suite_set);
-
-	for (suites = suite_set.start; suites < suite_set.end; suites++)
-		__kunit_test_suites_init(*suites);
+	if (!action_param)
+		kunit_exec_run_tests(&suite_set);
+	else if (strcmp(action_param, "list") == 0)
+		kunit_exec_list_tests(&suite_set);
+	else
+		pr_err("kunit executor: unknown action '%s'\n", action_param);
 
 	if (filter_glob_param) { /* a copy was made of each array */
-		for (suites = suite_set.start; suites < suite_set.end; suites++)
-			kfree(*suites);
-		kfree(suite_set.start);
+		kunit_free_suite_set(suite_set);
 	}
 
 	kunit_handle_shutdown();
diff --git a/lib/kunit/executor_test.c b/lib/kunit/executor_test.c
index e14a18af573d..4ed57fd94e42 100644
--- a/lib/kunit/executor_test.c
+++ b/lib/kunit/executor_test.c
@@ -9,38 +9,103 @@
 #include <kunit/test.h>
 
 static void kfree_at_end(struct kunit *test, const void *to_free);
+static void free_subsuite_at_end(struct kunit *test,
+				 struct kunit_suite *const *to_free);
 static struct kunit_suite *alloc_fake_suite(struct kunit *test,
-					    const char *suite_name);
+					    const char *suite_name,
+					    struct kunit_case *test_cases);
+
+static void dummy_test(struct kunit *test) {}
+
+static struct kunit_case dummy_test_cases[] = {
+	/* .run_case is not important, just needs to be non-NULL */
+	{ .name = "test1", .run_case = dummy_test },
+	{ .name = "test2", .run_case = dummy_test },
+	{},
+};
+
+static void parse_filter_test(struct kunit *test)
+{
+	struct kunit_test_filter filter = {NULL, NULL};
+
+	kunit_parse_filter_glob(&filter, "suite");
+	KUNIT_EXPECT_STREQ(test, filter.suite_glob, "suite");
+	KUNIT_EXPECT_FALSE(test, filter.test_glob);
+	kfree(filter.suite_glob);
+	kfree(filter.test_glob);
+
+	kunit_parse_filter_glob(&filter, "suite.test");
+	KUNIT_EXPECT_STREQ(test, filter.suite_glob, "suite");
+	KUNIT_EXPECT_STREQ(test, filter.test_glob, "test");
+	kfree(filter.suite_glob);
+	kfree(filter.test_glob);
+}
 
 static void filter_subsuite_test(struct kunit *test)
 {
 	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
 	struct kunit_suite * const *filtered;
+	struct kunit_test_filter filter = {
+		.suite_glob = "suite2",
+		.test_glob = NULL,
+	};
 
-	subsuite[0] = alloc_fake_suite(test, "suite1");
-	subsuite[1] = alloc_fake_suite(test, "suite2");
+	subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+	subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
 
 	/* Want: suite1, suite2, NULL -> suite2, NULL */
-	filtered = kunit_filter_subsuite(subsuite, "suite2*");
+	filtered = kunit_filter_subsuite(subsuite, &filter);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
-	kfree_at_end(test, filtered);
+	free_subsuite_at_end(test, filtered);
 
+	/* Validate we just have suite2 */
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]);
 	KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->name, "suite2");
+	KUNIT_EXPECT_FALSE(test, filtered[1]);
+}
+
+static void filter_subsuite_test_glob_test(struct kunit *test)
+{
+	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
+	struct kunit_suite * const *filtered;
+	struct kunit_test_filter filter = {
+		.suite_glob = "suite2",
+		.test_glob = "test2",
+	};
+
+	subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+	subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
 
+	/* Want: suite1, suite2, NULL -> suite2 (just test1), NULL */
+	filtered = kunit_filter_subsuite(subsuite, &filter);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered);
+	free_subsuite_at_end(test, filtered);
+
+	/* Validate we just have suite2 */
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]);
+	KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->name, "suite2");
 	KUNIT_EXPECT_FALSE(test, filtered[1]);
+
+	/* Now validate we just have test2 */
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered[0]->test_cases);
+	KUNIT_EXPECT_STREQ(test, (const char *)filtered[0]->test_cases[0].name, "test2");
+	KUNIT_EXPECT_FALSE(test, filtered[0]->test_cases[1].name);
 }
 
 static void filter_subsuite_to_empty_test(struct kunit *test)
 {
 	struct kunit_suite *subsuite[3] = {NULL, NULL, NULL};
 	struct kunit_suite * const *filtered;
+	struct kunit_test_filter filter = {
+		.suite_glob = "not_found",
+		.test_glob = NULL,
+	};
 
-	subsuite[0] = alloc_fake_suite(test, "suite1");
-	subsuite[1] = alloc_fake_suite(test, "suite2");
+	subsuite[0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
+	subsuite[1] = alloc_fake_suite(test, "suite2", dummy_test_cases);
 
-	filtered = kunit_filter_subsuite(subsuite, "not_found");
-	kfree_at_end(test, filtered); /* just in case */
+	filtered = kunit_filter_subsuite(subsuite, &filter);
+	free_subsuite_at_end(test, filtered); /* just in case */
 
 	KUNIT_EXPECT_FALSE_MSG(test, filtered,
 			       "should be NULL to indicate no match");
@@ -52,7 +117,7 @@ static void kfree_subsuites_at_end(struct kunit *test, struct suite_set *suite_s
 
 	kfree_at_end(test, suite_set->start);
 	for (suites = suite_set->start; suites < suite_set->end; suites++)
-		kfree_at_end(test, *suites);
+		free_subsuite_at_end(test, *suites);
 }
 
 static void filter_suites_test(struct kunit *test)
@@ -74,8 +139,8 @@ static void filter_suites_test(struct kunit *test)
 	struct suite_set filtered = {.start = NULL, .end = NULL};
 
 	/* Emulate two files, each having one suite */
-	subsuites[0][0] = alloc_fake_suite(test, "suite0");
-	subsuites[1][0] = alloc_fake_suite(test, "suite1");
+	subsuites[0][0] = alloc_fake_suite(test, "suite0", dummy_test_cases);
+	subsuites[1][0] = alloc_fake_suite(test, "suite1", dummy_test_cases);
 
 	/* Filter out suite1 */
 	filtered = kunit_filter_suites(&suite_set, "suite0");
@@ -84,11 +149,14 @@ static void filter_suites_test(struct kunit *test)
 
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start);
 	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0]);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, filtered.start[0][0]);
 	KUNIT_EXPECT_STREQ(test, (const char *)filtered.start[0][0]->name, "suite0");
 }
 
 static struct kunit_case executor_test_cases[] = {
+	KUNIT_CASE(parse_filter_test),
 	KUNIT_CASE(filter_subsuite_test),
+	KUNIT_CASE(filter_subsuite_test_glob_test),
 	KUNIT_CASE(filter_subsuite_to_empty_test),
 	KUNIT_CASE(filter_suites_test),
 	{}
@@ -120,14 +188,30 @@ static void kfree_at_end(struct kunit *test, const void *to_free)
 			     (void *)to_free);
 }
 
+static void free_subsuite_res_free(struct kunit_resource *res)
+{
+	kunit_free_subsuite(res->data);
+}
+
+static void free_subsuite_at_end(struct kunit *test,
+				 struct kunit_suite *const *to_free)
+{
+	if (IS_ERR_OR_NULL(to_free))
+		return;
+	kunit_alloc_resource(test, NULL, free_subsuite_res_free,
+			     GFP_KERNEL, (void *)to_free);
+}
+
 static struct kunit_suite *alloc_fake_suite(struct kunit *test,
-					    const char *suite_name)
+					    const char *suite_name,
+					    struct kunit_case *test_cases)
 {
 	struct kunit_suite *suite;
 
 	/* We normally never expect to allocate suites, hence the non-const cast. */
 	suite = kunit_kzalloc(test, sizeof(*suite), GFP_KERNEL);
 	strncpy((char *)suite->name, suite_name, sizeof(suite->name) - 1);
+	suite->test_cases = test_cases;
 
 	return suite;
 }
diff --git a/lib/kunit/kunit-test.c b/lib/kunit/kunit-test.c
index d69efcbed624..555601d17f79 100644
--- a/lib/kunit/kunit-test.c
+++ b/lib/kunit/kunit-test.c
@@ -415,12 +415,15 @@ static struct kunit_suite kunit_log_test_suite = {
 
 static void kunit_log_test(struct kunit *test)
 {
-	struct kunit_suite *suite = &kunit_log_test_suite;
+	struct kunit_suite suite;
+
+	suite.log = kunit_kzalloc(test, KUNIT_LOG_SIZE, GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, suite.log);
 
 	kunit_log(KERN_INFO, test, "put this in log.");
 	kunit_log(KERN_INFO, test, "this too.");
-	kunit_log(KERN_INFO, suite, "add to suite log.");
-	kunit_log(KERN_INFO, suite, "along with this.");
+	kunit_log(KERN_INFO, &suite, "add to suite log.");
+	kunit_log(KERN_INFO, &suite, "along with this.");
 
 #ifdef CONFIG_KUNIT_DEBUGFS
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
@@ -428,12 +431,11 @@ static void kunit_log_test(struct kunit *test)
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
 				     strstr(test->log, "this too."));
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
-				     strstr(suite->log, "add to suite log."));
+				     strstr(suite.log, "add to suite log."));
 	KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
-				     strstr(suite->log, "along with this."));
+				     strstr(suite.log, "along with this."));
 #else
 	KUNIT_EXPECT_PTR_EQ(test, test->log, (char *)NULL);
-	KUNIT_EXPECT_PTR_EQ(test, suite->log, (char *)NULL);
 #endif
 }
 
diff --git a/lib/kunit/test.c b/lib/kunit/test.c
index f246b847024e..3bd741e50a2d 100644
--- a/lib/kunit/test.c
+++ b/lib/kunit/test.c
@@ -190,10 +190,10 @@ enum kunit_status kunit_suite_has_succeeded(struct kunit_suite *suite)
 }
 EXPORT_SYMBOL_GPL(kunit_suite_has_succeeded);
 
+static size_t kunit_suite_counter = 1;
+
 static void kunit_print_subtest_end(struct kunit_suite *suite)
 {
-	static size_t kunit_suite_counter = 1;
-
 	kunit_print_ok_not_ok((void *)suite, false,
 			      kunit_suite_has_succeeded(suite),
 			      kunit_suite_counter++,
@@ -583,6 +583,8 @@ void __kunit_test_suites_exit(struct kunit_suite **suites)
 
 	for (i = 0; suites[i] != NULL; i++)
 		kunit_exit_suite(suites[i]);
+
+	kunit_suite_counter = 1;
 }
 EXPORT_SYMBOL_GPL(__kunit_test_suites_exit);
 
diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
index ac35c61f65f5..68e6f461c758 100755
--- a/tools/testing/kunit/kunit.py
+++ b/tools/testing/kunit/kunit.py
@@ -8,17 +8,17 @@
 # Author: Brendan Higgins <brendanhiggins@google.com>
 
 import argparse
-import sys
 import os
+import re
+import sys
 import time
 
 assert sys.version_info >= (3, 7), "Python version is too old"
 
 from collections import namedtuple
 from enum import Enum, auto
-from typing import Iterable, Sequence
+from typing import Iterable, Sequence, List
 
-import kunit_config
 import kunit_json
 import kunit_kernel
 import kunit_parser
@@ -31,13 +31,13 @@ KunitBuildRequest = namedtuple('KunitBuildRequest',
 			       ['jobs', 'build_dir', 'alltests',
 				'make_options'])
 KunitExecRequest = namedtuple('KunitExecRequest',
-                              ['timeout', 'build_dir', 'alltests',
-                               'filter_glob', 'kernel_args'])
+			      ['timeout', 'build_dir', 'alltests',
+			       'filter_glob', 'kernel_args', 'run_isolated'])
 KunitParseRequest = namedtuple('KunitParseRequest',
-			       ['raw_output', 'input_data', 'build_dir', 'json'])
+			       ['raw_output', 'build_dir', 'json'])
 KunitRequest = namedtuple('KunitRequest', ['raw_output','timeout', 'jobs',
 					   'build_dir', 'alltests', 'filter_glob',
-					   'kernel_args', 'json', 'make_options'])
+					   'kernel_args', 'run_isolated', 'json', 'make_options'])
 
 KernelDirectoryPath = sys.argv[0].split('tools/testing/kunit/')[0]
 
@@ -91,31 +91,93 @@ def build_tests(linux: kunit_kernel.LinuxSourceTree,
 			   'built kernel successfully',
 			   build_end - build_start)
 
-def exec_tests(linux: kunit_kernel.LinuxSourceTree,
-	       request: KunitExecRequest) -> KunitResult:
-	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)
-
-	test_end = time.time()
-
-	return KunitResult(KunitStatus.SUCCESS,
-			   result,
-			   test_end - test_start)
+def _list_tests(linux: kunit_kernel.LinuxSourceTree, request: KunitExecRequest) -> List[str]:
+	args = ['kunit.action=list']
+	if request.kernel_args:
+		args.extend(request.kernel_args)
+
+	output = linux.run_kernel(args=args,
+			   timeout=None if request.alltests else request.timeout,
+			   filter_glob=request.filter_glob,
+			   build_dir=request.build_dir)
+	lines = kunit_parser.extract_tap_lines(output)
+	# Hack! Drop the dummy TAP version header that the executor prints out.
+	lines.pop()
+
+	# Filter out any extraneous non-test output that might have gotten mixed in.
+	return [l for l in lines if re.match('^[^\s.]+\.[^\s.]+$', l)]
+
+def _suites_from_test_list(tests: List[str]) -> List[str]:
+	"""Extracts all the suites from an ordered list of tests."""
+	suites = []  # type: List[str]
+	for t in tests:
+		parts = t.split('.', maxsplit=2)
+		if len(parts) != 2:
+			raise ValueError(f'internal KUnit error, test name should be of the form "<suite>.<test>", got "{t}"')
+		suite, case = parts
+		if not suites or suites[-1] != suite:
+			suites.append(suite)
+	return suites
+
+
+
+def exec_tests(linux: kunit_kernel.LinuxSourceTree, request: KunitExecRequest,
+	       parse_request: KunitParseRequest) -> KunitResult:
+	filter_globs = [request.filter_glob]
+	if request.run_isolated:
+		tests = _list_tests(linux, request)
+		if request.run_isolated == 'test':
+			filter_globs = tests
+		if request.run_isolated == 'suite':
+			filter_globs = _suites_from_test_list(tests)
+			# Apply the test-part of the user's glob, if present.
+			if '.' in request.filter_glob:
+				test_glob = request.filter_glob.split('.', maxsplit=2)[1]
+				filter_globs = [g + '.'+ test_glob for g in filter_globs]
+
+	test_counts = kunit_parser.TestCounts()
+	exec_time = 0.0
+	for i, filter_glob in enumerate(filter_globs):
+		kunit_parser.print_with_timestamp('Starting KUnit Kernel ({}/{})...'.format(i+1, len(filter_globs)))
+
+		test_start = time.time()
+		run_result = linux.run_kernel(
+			args=request.kernel_args,
+			timeout=None if request.alltests else request.timeout,
+			filter_glob=filter_glob,
+			build_dir=request.build_dir)
+
+		result = parse_tests(parse_request, run_result)
+		# run_kernel() doesn't block on the kernel exiting.
+		# That only happens after we get the last line of output from `run_result`.
+		# So exec_time here actually contains parsing + execution time, which is fine.
+		test_end = time.time()
+		exec_time += test_end - test_start
+
+		test_counts.add_subtest_counts(result.result.test.counts)
+
+	kunit_status = _map_to_overall_status(test_counts.get_status())
+	return KunitResult(status=kunit_status, result=result.result, elapsed_time=exec_time)
+
+def _map_to_overall_status(test_status: kunit_parser.TestStatus) -> KunitStatus:
+	if test_status in (kunit_parser.TestStatus.SUCCESS, kunit_parser.TestStatus.SKIPPED):
+		return KunitStatus.SUCCESS
+	else:
+		return KunitStatus.TEST_FAILURE
 
-def parse_tests(request: KunitParseRequest) -> KunitResult:
+def parse_tests(request: KunitParseRequest, input_data: Iterable[str]) -> KunitResult:
 	parse_start = time.time()
 
 	test_result = kunit_parser.TestResult(kunit_parser.TestStatus.SUCCESS,
-					      [],
+					      kunit_parser.Test(),
 					      'Tests not Parsed.')
 
 	if request.raw_output:
-		output: Iterable[str] = request.input_data
+		# Treat unparsed results as one passing test.
+		test_result.test.status = kunit_parser.TestStatus.SUCCESS
+		test_result.test.counts.passed = 1
+
+		output: Iterable[str] = input_data
 		if request.raw_output == 'all':
 			pass
 		elif request.raw_output == 'kunit':
@@ -126,7 +188,7 @@ def parse_tests(request: KunitParseRequest) -> KunitResult:
 			print(line.rstrip())
 
 	else:
-		test_result = kunit_parser.parse_run_tests(request.input_data)
+		test_result = kunit_parser.parse_run_tests(input_data)
 	parse_end = time.time()
 
 	if request.json:
@@ -164,16 +226,12 @@ def run_tests(linux: kunit_kernel.LinuxSourceTree,
 
 	exec_request = KunitExecRequest(request.timeout, request.build_dir,
 				 request.alltests, request.filter_glob,
-				 request.kernel_args)
-	exec_result = exec_tests(linux, exec_request)
-	if exec_result.status != KunitStatus.SUCCESS:
-		return exec_result
-
+				 request.kernel_args, request.run_isolated)
 	parse_request = KunitParseRequest(request.raw_output,
-					  exec_result.result,
 					  request.build_dir,
 					  request.json)
-	parse_result = parse_tests(parse_request)
+
+	exec_result = exec_tests(linux, exec_request, parse_request)
 
 	run_end = time.time()
 
@@ -184,7 +242,7 @@ def run_tests(linux: kunit_kernel.LinuxSourceTree,
 				config_result.elapsed_time,
 				build_result.elapsed_time,
 				exec_result.elapsed_time))
-	return parse_result
+	return exec_result
 
 # Problem:
 # $ kunit.py run --json
@@ -263,9 +321,8 @@ def add_exec_opts(parser) -> None:
 			    default=300,
 			    metavar='timeout')
 	parser.add_argument('filter_glob',
-			    help='maximum number of seconds to allow for all tests '
-			    'to run. This does not include time taken to build the '
-			    'tests.',
+			    help='Filter which KUnit test suites/tests run at '
+			    'boot-time, e.g. list* or list*.*del_test',
 			    type=str,
 			    nargs='?',
 			    default='',
@@ -273,6 +330,12 @@ def add_exec_opts(parser) -> None:
 	parser.add_argument('--kernel_args',
 			    help='Kernel command-line parameters. Maybe be repeated',
 			     action='append')
+	parser.add_argument('--run_isolated', help='If set, boot the kernel for each '
+			    'individual suite/test. This is can be useful for debugging '
+			    'a non-hermetic test, one that might pass/fail based on '
+			    'what ran before it.',
+			    type=str,
+			    choices=['suite', 'test']),
 
 def add_parse_opts(parser) -> None:
 	parser.add_argument('--raw_output', help='If set don\'t format output from kernel. '
@@ -346,6 +409,7 @@ def main(argv, linux=None):
 				       cli_args.alltests,
 				       cli_args.filter_glob,
 				       cli_args.kernel_args,
+				       cli_args.run_isolated,
 				       cli_args.json,
 				       cli_args.make_options)
 		result = run_tests(linux, request)
@@ -401,29 +465,27 @@ def main(argv, linux=None):
 						cli_args.build_dir,
 						cli_args.alltests,
 						cli_args.filter_glob,
-						cli_args.kernel_args)
-		exec_result = exec_tests(linux, exec_request)
+						cli_args.kernel_args,
+						cli_args.run_isolated)
 		parse_request = KunitParseRequest(cli_args.raw_output,
-						  exec_result.result,
 						  cli_args.build_dir,
 						  cli_args.json)
-		result = parse_tests(parse_request)
+		result = exec_tests(linux, exec_request, parse_request)
 		kunit_parser.print_with_timestamp((
-			'Elapsed time: %.3fs\n') % (
-				exec_result.elapsed_time))
+			'Elapsed time: %.3fs\n') % (result.elapsed_time))
 		if result.status != KunitStatus.SUCCESS:
 			sys.exit(1)
 	elif cli_args.subcommand == 'parse':
 		if cli_args.file == None:
+			sys.stdin.reconfigure(errors='backslashreplace')  # pytype: disable=attribute-error
 			kunit_output = sys.stdin
 		else:
-			with open(cli_args.file, 'r') as f:
+			with open(cli_args.file, 'r', errors='backslashreplace') as f:
 				kunit_output = f.read().splitlines()
 		request = KunitParseRequest(cli_args.raw_output,
-					    kunit_output,
 					    None,
 					    cli_args.json)
-		result = parse_tests(request)
+		result = parse_tests(request, kunit_output)
 		if result.status != KunitStatus.SUCCESS:
 			sys.exit(1)
 	else:
diff --git a/tools/testing/kunit/kunit_json.py b/tools/testing/kunit/kunit_json.py
index f5cca5c38cac..746bec72b9ac 100644
--- a/tools/testing/kunit/kunit_json.py
+++ b/tools/testing/kunit/kunit_json.py
@@ -11,47 +11,47 @@ import os
 
 import kunit_parser
 
-from kunit_parser import TestStatus
-
-def get_json_result(test_result, def_config, build_dir, json_path) -> str:
-	sub_groups = []
-
-	# Each test suite is mapped to a KernelCI sub_group
-	for test_suite in test_result.suites:
-		sub_group = {
-			"name": test_suite.name,
-			"arch": "UM",
-			"defconfig": def_config,
-			"build_environment": build_dir,
-			"test_cases": [],
-			"lab_name": None,
-			"kernel": None,
-			"job": None,
-			"git_branch": "kselftest",
-		}
-		test_cases = []
-		# TODO: Add attachments attribute in test_case with detailed
-		#  failure message, see https://api.kernelci.org/schema-test-case.html#get
-		for case in test_suite.cases:
-			test_case = {"name": case.name, "status": "FAIL"}
-			if case.status == TestStatus.SUCCESS:
+from kunit_parser import Test, TestResult, TestStatus
+from typing import Any, Dict, Optional
+
+JsonObj = Dict[str, Any]
+
+def _get_group_json(test: Test, def_config: str,
+		build_dir: Optional[str]) -> JsonObj:
+	sub_groups = []  # List[JsonObj]
+	test_cases = []  # List[JsonObj]
+
+	for subtest in test.subtests:
+		if len(subtest.subtests):
+			sub_group = _get_group_json(subtest, def_config,
+				build_dir)
+			sub_groups.append(sub_group)
+		else:
+			test_case = {"name": subtest.name, "status": "FAIL"}
+			if subtest.status == TestStatus.SUCCESS:
 				test_case["status"] = "PASS"
-			elif case.status == TestStatus.TEST_CRASHED:
+			elif subtest.status == TestStatus.TEST_CRASHED:
 				test_case["status"] = "ERROR"
 			test_cases.append(test_case)
-		sub_group["test_cases"] = test_cases
-		sub_groups.append(sub_group)
+
 	test_group = {
-		"name": "KUnit Test Group",
+		"name": test.name,
 		"arch": "UM",
 		"defconfig": def_config,
 		"build_environment": build_dir,
 		"sub_groups": sub_groups,
+		"test_cases": test_cases,
 		"lab_name": None,
 		"kernel": None,
 		"job": None,
 		"git_branch": "kselftest",
 	}
+	return test_group
+
+def get_json_result(test_result: TestResult, def_config: str,
+		build_dir: Optional[str], json_path: str) -> str:
+	test_group = _get_group_json(test_result.test, def_config, build_dir)
+	test_group["name"] = "KUnit Test Group"
 	json_obj = json.dumps(test_group, indent=4)
 	if json_path != 'stdout':
 		with open(json_path, 'w') as result_path:
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index 2c6f916ccbaf..66095568bf32 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -12,11 +12,8 @@ import subprocess
 import os
 import shutil
 import signal
-from typing import Iterator, Optional, Tuple
-
-from contextlib import ExitStack
-
-from collections import namedtuple
+import threading
+from typing import Iterator, List, Optional, Tuple
 
 import kunit_config
 import kunit_parser
@@ -103,8 +100,8 @@ class LinuxSourceTreeOperations(object):
 		if stderr:  # likely only due to build warnings
 			print(stderr.decode())
 
-	def run(self, params, timeout, build_dir, outfile) -> None:
-		pass
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
+		raise RuntimeError('not implemented!')
 
 
 class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
@@ -123,7 +120,7 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
 		kconfig.parse_from_string(self._kconfig)
 		base_kunitconfig.merge_in_entries(kconfig)
 
-	def run(self, params, timeout, build_dir, outfile):
+	def start(self, params: List[str], build_dir: str) -> subprocess.Popen:
 		kernel_path = os.path.join(build_dir, self._kernel_path)
 		qemu_command = ['qemu-system-' + self._qemu_arch,
 				'-nodefaults',
@@ -134,18 +131,11 @@ class LinuxSourceTreeOperationsQemu(LinuxSourceTreeOperations):
 				'-nographic',
 				'-serial stdio'] + self._extra_qemu_params
 		print('Running tests with:\n$', ' '.join(qemu_command))
-		with open(outfile, 'w') as output:
-			process = subprocess.Popen(' '.join(qemu_command),
-						   stdin=subprocess.PIPE,
-						   stdout=output,
-						   stderr=subprocess.STDOUT,
-						   text=True, shell=True)
-		try:
-			process.wait(timeout=timeout)
-		except Exception as e:
-			print(e)
-			process.terminate()
-		return process
+		return subprocess.Popen(' '.join(qemu_command),
+					   stdin=subprocess.PIPE,
+					   stdout=subprocess.PIPE,
+					   stderr=subprocess.STDOUT,
+					   text=True, shell=True, errors='backslashreplace')
 
 class LinuxSourceTreeOperationsUml(LinuxSourceTreeOperations):
 	"""An abstraction over command line operations performed on a source tree."""
@@ -168,24 +158,21 @@ class LinuxSourceTreeOperationsUml(LinuxSourceTreeOperations):
 		process.wait()
 		kunit_parser.print_with_timestamp(
 			'Disabling broken configs to run KUnit tests...')
-		with ExitStack() as es:
-			config = open(get_kconfig_path(build_dir), 'a')
-			disable = open(BROKEN_ALLCONFIG_PATH, 'r').read()
-			config.write(disable)
+
+		with open(get_kconfig_path(build_dir), 'a') as config:
+			with open(BROKEN_ALLCONFIG_PATH, 'r') as disable:
+				config.write(disable.read())
 		kunit_parser.print_with_timestamp(
 			'Starting Kernel with all configs takes a few minutes...')
 
-	def run(self, params, timeout, build_dir, outfile):
+	def start(self,