Index: lnt/tests/test_suite.py
===================================================================
--- lnt/tests/test_suite.py
+++ lnt/tests/test_suite.py
@@ -471,6 +471,9 @@
         if self.opts.run_under:
             defs['TEST_SUITE_RUN_UNDER'] = \
                 self._unix_quote_args(self.opts.run_under)
+        if self.opts.subdirs:
+            defs['TEST_SUITE_SUBDIRS'] = \
+                self._unix_quote_args(self.opts.subdirs)
         if self.opts.benchmarking_only:
             defs['TEST_SUITE_BENCHMARKING_ONLY'] = 'ON'
         if self.opts.only_compile:
@@ -1078,6 +1081,10 @@
 @click.option("--only-test", "only_test", metavar="PATH",
               type=click.UNPROCESSED, default=None,
               help="Only run tests under PATH")
+@click.option("--subdirs", "subdirs", metavar="String",
+              type=click.UNPROCESSED, default=None,
+              help="Semicolon separated list of directories with "
+                   "CMakeLists.txt to include")
 # Test Execution
 @click.option("--only-compile", "only_compile",
               help="Don't run the tests, just compile them.", is_flag=True)