@@ -262,3 +262,169 @@ other code executed during boot, e.g.
# Reset coverage counters before running the test.
$ echo 0 > /sys/kernel/debug/gcov/reset
$ modprobe kunit-example-test
+
+
+Test Attributes and Filtering
+=============================
+
+Test suites and cases can be marked with test attributes, such as speed of
+test. These attributes will later be printed in test output and can be used to
+filter test execution.
+
+Marking Test Attributes
+-----------------------
+
+Tests are marked with an attribute by including a ``kunit_attributes`` object
+in the test definition.
+
+Test cases can be marked using the ``KUNIT_CASE_ATTR(test_name, attributes)``
+macro to define the test case instead of ``KUNIT_CASE(test_name)``.
+
+.. code-block:: c
+
+ static const struct kunit_attributes example_attr = {
+ .speed = KUNIT_VERY_SLOW,
+ };
+
+ static struct kunit_case example_test_cases[] = {
+ KUNIT_CASE_ATTR(example_test, example_attr),
+ };
+
+.. note::
+ To mark a test case as slow, you can also use ``KUNIT_CASE_SLOW(test_name)``.
+ This is a helpful macro as the slow attribute is the most commonly used.
+
+Test suites can be marked with an attribute by setting the "attr" field in the
+suite definition.
+
+.. code-block:: c
+
+ static const struct kunit_attributes example_attr = {
+ .speed = KUNIT_VERY_SLOW,
+ };
+
+ static struct kunit_suite example_test_suite = {
+ ...,
+ .attr = example_attr,
+ };
+
+.. note::
+ Not all attributes need to be set in a ``kunit_attributes`` object. Unset
+ attributes will remain uninitialized and act as though the attribute is set
+ to 0 or NULL. Thus, if an attribute is set to 0, it is treated as unset.
+ These unset attributes will not be reported and may act as a default value
+ for filtering purposes.
+
+Reporting Attributes
+--------------------
+
+When a user runs tests, attributes will be present in the raw kernel output (in
+KTAP format). Note that attributes will be hidden by default in kunit.py output
+for all passing tests but the raw kernel output can be accessed using the
+``--raw_output`` flag. This is an example of how test attributes for test cases
+will be formatted in kernel output:
+
+.. code-block:: none
+
+ # example_test.speed: slow
+ ok 1 example_test
+
+This is an example of how test attributes for test suites will be formatted in
+kernel output:
+
+.. code-block:: none
+
+ KTAP version 2
+ # Subtest: example_suite
+ # module: kunit_example_test
+ 1..3
+ ...
+ ok 1 example_suite
+
+Additionally, users can output a full attribute report of tests with their
+attributes, using the command line flag ``--list_tests_attr``:
+
+.. code-block:: bash
+
+ kunit.py run "example" --list_tests_attr
+
+.. note::
+ This report can be accessed when running KUnit manually by passing in the
+ module_param ``kunit.action=list_attr``.
+
+Filtering
+---------
+
+Users can filter tests using the ``--filter`` command line flag when running
+tests. As an example:
+
+.. code-block:: bash
+
+ kunit.py run --filter speed=slow
+
+
+You can also use the following operations on filters: "<", ">", "<=", ">=",
+"!=", and "=". Example:
+
+.. code-block:: bash
+
+ kunit.py run --filter "speed>slow"
+
+This example will run all tests with speeds faster than slow. Note that the
+characters < and > are often interpreted by the shell, so they may need to be
+quoted or escaped, as above.
+
+Additionally, you can use multiple filters at once. Simply separate filters
+using commas. Example:
+
+.. code-block:: bash
+
+ kunit.py run --filter "speed>slow, module=kunit_example_test"
+
+.. note::
+ You can use this filtering feature when running KUnit manually by passing
+ the filter as a module param: ``kunit.filter="speed>slow, speed<=normal"``.
+
+Filtered tests will not run or show up in the test output. You can use the
+``--filter_action=skip`` flag to skip filtered tests instead. These tests will be
+shown in the test output in the test but will not run. To use this feature when
+running KUnit manually, use the module param ``kunit.filter_action=skip``.
+
+Rules of Filtering Procedure
+----------------------------
+
+Since both suites and test cases can have attributes, there may be conflicts
+between attributes during filtering. The process of filtering follows these
+rules:
+
+- Filtering always operates at a per-test level.
+
+- If a test has an attribute set, then the test's value is filtered on.
+
+- Otherwise, the value falls back to the suite's value.
+
+- If neither are set, the attribute has a global "default" value, which is used.
+
+List of Current Attributes
+--------------------------
+
+``speed``
+
+This attribute indicates the speed of a test's execution (how slow or fast the
+test is).
+
+This attribute is saved as an enum with the following categories: "normal",
+"slow", or "very_slow". The assumed default speed for tests is "normal". This
+indicates that the test takes a relatively trivial amount of time (less than
+1 second), regardless of the machine it is running on. Any test slower than
+this could be marked as "slow" or "very_slow".
+
+The macro ``KUNIT_CASE_SLOW(test_name)`` can be easily used to set the speed
+of a test case to "slow".
+
+``module``
+
+This attribute indicates the name of the module associated with the test.
+
+This attribute is automatically saved as a string and is printed for each suite.
+Tests can also be filtered using this attribute.