[PATCH 3/3] kunit: tool: properly report the used arch for --json, or '' if not known

[Daniel Latypov]

Before, kunit.py always printed "arch": "UM" in its json output, but...
1. With `kunit.py parse`, we could be parsing output from anywhere, so
    we can't say that.
2. Capitalizing it is probably wrong, as it's `ARCH=um`
3. Commit 87c9c1631788 ("kunit: tool: add support for QEMU") made it so
   kunit.py could knowingly run a different arch, yet we'd still always
   claim "UM".

This patch addresses all of those. E.g.

1.
$ ./tools/testing/kunit/kunit.py parse .kunit/test.log --json | grep -o '"arch.*' | sort -u
"arch": "",

2.
$ ./tools/testing/kunit/kunit.py run --json | ...
"arch": "um",

3.
$ ./tools/testing/kunit/kunit.py run --json --arch=x86_64 | ...
"arch": "x86_64",

Signed-off-by: Daniel Latypov <dlatypov@xxxxxxxxxx>
---
 tools/testing/kunit/kunit.py        | 4 ++--
 tools/testing/kunit/kunit_kernel.py | 2 ++
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/tools/testing/kunit/kunit.py b/tools/testing/kunit/kunit.py
index 7dd6ed42141f..5ccdafd4d5aa 100755
--- a/tools/testing/kunit/kunit.py
+++ b/tools/testing/kunit/kunit.py
@@ -153,7 +153,7 @@ def exec_tests(linux: kunit_kernel.LinuxSourceTree, request: KunitExecRequest) -
 				test_glob = request.filter_glob.split('.', maxsplit=2)[1]
 				filter_globs = [g + '.'+ test_glob for g in filter_globs]
 
-	metadata = kunit_json.Metadata(build_dir=request.build_dir)
+	metadata = kunit_json.Metadata(arch=linux.arch(), build_dir=request.build_dir)
 
 	test_counts = kunit_parser.TestCounts()
 	exec_time = 0.0
@@ -506,7 +506,7 @@ def main(argv, linux=None):
 			with open(cli_args.file, 'r', errors='backslashreplace') as f:
 				kunit_output = f.read().splitlines()
 		# We know nothing about how the result was created!
-		metadata = kunit_json.Metadata()
+		metadata = kunit_json.Metadata(arch='', build_dir='', def_config='')
 		request = KunitParseRequest(raw_output=cli_args.raw_output,
 					    json=cli_args.json)
 		result, _ = parse_tests(request, metadata, kunit_output)
diff --git a/tools/testing/kunit/kunit_kernel.py b/tools/testing/kunit/kunit_kernel.py
index fe159e7ff697..bbbe2ffe30b7 100644
--- a/tools/testing/kunit/kunit_kernel.py
+++ b/tools/testing/kunit/kunit_kernel.py
@@ -248,6 +248,8 @@ class LinuxSourceTree(object):
 			kconfig = kunit_config.parse_from_string('\n'.join(kconfig_add))
 			self._kconfig.merge_in_entries(kconfig)
 
+	def arch(self) -> str:
+		return self._arch
 
 	def clean(self) -> bool:
 		try:
-- 
2.35.1.473.g83b2b277ed-goog