selftests: Warn about skipped tests in result summary

Update the functions that print the test totals at the end of a selftest
to include a warning message when skipped tests are detected. The
message advises users that skipped tests may indicate missing
configuration options and suggests enabling them to improve coverage.

Link: https://lore.kernel.org/r/20241126093710.13314-1-laura.nao@collabora.com
Signed-off-by: Laura Nao <laura.nao@collabora.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

Author: laura-nao

tools/testing/selftests/kselftest.h

@@ -149,6 +149,11 @@ static inline void ksft_set_plan(unsigned int plan)
 
 static inline void ksft_print_cnts(void)
 {
+	if (ksft_cnt.ksft_xskip > 0)
+		printf(
+			"# %u skipped test(s) detected. Consider enabling relevant config options to improve coverage.\n",
+			ksft_cnt.ksft_xskip
+		);
 	if (ksft_plan != ksft_test_num())
 		printf("# Planned tests != run tests (%u != %u)\n",
 			ksft_plan, ksft_test_num());

tools/testing/selftests/kselftest/ksft.py

@@ -27,6 +27,9 @@ def set_plan(num_tests):
 
 
 def print_cnts():
+    if ksft_cnt['skip'] > 0:
+        print(f"# {ksft_cnt['skip']} skipped test(s) detected. Consider enabling relevant config options to improve coverage.")
+
     print(
         f"# Totals: pass:{ksft_cnt['pass']} fail:{ksft_cnt['fail']} xfail:0 xpass:0 skip:{ksft_cnt['skip']} error:0"
     )

tools/testing/selftests/kselftest/ktap_helpers.sh

@@ -107,5 +107,9 @@ ktap_finished() {
 }
 
 ktap_print_totals() {
+	if [ "$KTAP_CNT_SKIP" -gt 0 ]; then
+		echo "# $KTAP_CNT_SKIP skipped test(s) detected. " \
+			"Consider enabling relevant config options to improve coverage."
+	fi
 	echo "# Totals: pass:$KTAP_CNT_PASS fail:$KTAP_CNT_FAIL xfail:0 xpass:0 skip:$KTAP_CNT_SKIP error:0"
 }