diff options
Diffstat (limited to 'Documentation/dev-tools/kunit/kunit-tool.rst')
| -rw-r--r-- | Documentation/dev-tools/kunit/kunit-tool.rst | 188 |
1 files changed, 180 insertions, 8 deletions
diff --git a/Documentation/dev-tools/kunit/kunit-tool.rst b/Documentation/dev-tools/kunit/kunit-tool.rst index 29ae2fee8123..c7ff9afe407a 100644 --- a/Documentation/dev-tools/kunit/kunit-tool.rst +++ b/Documentation/dev-tools/kunit/kunit-tool.rst @@ -22,14 +22,19 @@ not require any virtualization support: it is just a regular program. What is a .kunitconfig? ======================= -It's just a defconfig that kunit_tool looks for in the base directory. -kunit_tool uses it to generate a .config as you might expect. In addition, it -verifies that the generated .config contains the CONFIG options in the -.kunitconfig; the reason it does this is so that it is easy to be sure that a -CONFIG that enables a test actually ends up in the .config. +It's just a defconfig that kunit_tool looks for in the build directory +(``.kunit`` by default). kunit_tool uses it to generate a .config as you might +expect. In addition, it verifies that the generated .config contains the CONFIG +options in the .kunitconfig; the reason it does this is so that it is easy to +be sure that a CONFIG that enables a test actually ends up in the .config. -How do I use kunit_tool? -======================== +It's also possible to pass a separate .kunitconfig fragment to kunit_tool, +which is useful if you have several different groups of tests you wish +to run independently, or if you want to use pre-defined test configs for +certain subsystems. + +Getting Started with kunit_tool +=============================== If a kunitconfig is present at the root directory, all you have to do is: @@ -48,10 +53,177 @@ However, you most likely want to use it with the following options: .. note:: This command will work even without a .kunitconfig file: if no - .kunitconfig is present, a default one will be used instead. + .kunitconfig is present, a default one will be used instead. + +If you wish to use a different .kunitconfig file (such as one provided for +testing a particular subsystem), you can pass it as an option. + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py run --kunitconfig=fs/ext4/.kunitconfig For a list of all the flags supported by kunit_tool, you can run: .. code-block:: bash ./tools/testing/kunit/kunit.py run --help + +Configuring, Building, and Running Tests +======================================== + +It's also possible to run just parts of the KUnit build process independently, +which is useful if you want to make manual changes to part of the process. + +A .config can be generated from a .kunitconfig by using the ``config`` argument +when running kunit_tool: + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py config + +Similarly, if you just want to build a KUnit kernel from the current .config, +you can use the ``build`` argument: + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py build + +And, if you already have a built UML kernel with built-in KUnit tests, you can +run the kernel and display the test results with the ``exec`` argument: + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py exec + +The ``run`` command which is discussed above is equivalent to running all three +of these in sequence. + +All of these commands accept a number of optional command-line arguments. The +``--help`` flag will give a complete list of these, or keep reading this page +for a guide to some of the more useful ones. + +Parsing Test Results +==================== + +KUnit tests output their results in TAP (Test Anything Protocol) format. +kunit_tool will, when running tests, parse this output and print a summary +which is much more pleasant to read. If you wish to look at the raw test +results in TAP format, you can pass the ``--raw_output`` argument. + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py run --raw_output + +.. note:: + The raw output from test runs may contain other, non-KUnit kernel log + lines. + +If you have KUnit results in their raw TAP format, you can parse them and print +the human-readable summary with the ``parse`` command for kunit_tool. This +accepts a filename for an argument, or will read from standard input. + +.. code-block:: bash + + # Reading from a file + ./tools/testing/kunit/kunit.py parse /var/log/dmesg + # Reading from stdin + dmesg | ./tools/testing/kunit/kunit.py parse + +This is very useful if you wish to run tests in a configuration not supported +by kunit_tool (such as on real hardware, or an unsupported architecture). + +Filtering Tests +=============== + +It's possible to run only a subset of the tests built into a kernel by passing +a filter to the ``exec`` or ``run`` commands. For example, if you only wanted +to run KUnit resource tests, you could use: + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py run 'kunit-resource*' + +This uses the standard glob format for wildcards. + +Running Tests on QEMU +===================== + +kunit_tool supports running tests on QEMU as well as via UML (as mentioned +elsewhere). The default way of running tests on QEMU requires two flags: + +``--arch`` + Selects a collection of configs (Kconfig as well as QEMU configs + options, etc) that allow KUnit tests to be run on the specified + architecture in a minimal way; this is usually not much slower than + using UML. The architecture argument is the same as the name of the + option passed to the ``ARCH`` variable used by Kbuild. Not all + architectures are currently supported by this flag, but can be handled + by the ``--qemu_config`` discussed later. If ``um`` is passed (or this + this flag is ignored) the tests will run via UML. Non-UML architectures, + e.g. i386, x86_64, arm, um, etc. Non-UML run on QEMU. + +``--cross_compile`` + Specifies the use of a toolchain by Kbuild. The argument passed here is + the same passed to the ``CROSS_COMPILE`` variable used by Kbuild. As a + reminder this will be the prefix for the toolchain binaries such as gcc + for example ``sparc64-linux-gnu-`` if you have the sparc toolchain + installed on your system, or + ``$HOME/toolchains/microblaze/gcc-9.2.0-nolibc/microblaze-linux/bin/microblaze-linux-`` + if you have downloaded the microblaze toolchain from the 0-day website + to a directory in your home directory called ``toolchains``. + +In many cases it is likely that you may want to run an architecture which is +not supported by the ``--arch`` flag, or you may want to just run KUnit tests +on QEMU using a non-default configuration. For this use case, you can write +your own QemuConfig. These QemuConfigs are written in Python. They must have an +import line ``from ..qemu_config import QemuArchParams`` at the top of the file +and the file must contain a variable called ``QEMU_ARCH`` that has an instance +of ``QemuArchParams`` assigned to it. An example can be seen in +``tools/testing/kunit/qemu_configs/x86_64.py``. + +Once you have a QemuConfig you can pass it into kunit_tool using the +``--qemu_config`` flag; when used this flag replaces the ``--arch`` flag. If we +were to do this with the ``x86_64.py`` example from above, the invocation would +look something like this: + +.. code-block:: bash + + ./tools/testing/kunit/kunit.py run \ + --timeout=60 \ + --jobs=12 \ + --qemu_config=./tools/testing/kunit/qemu_configs/x86_64.py + +Other Useful Options +==================== + +kunit_tool has a number of other command-line arguments which can be useful +when adapting it to fit your environment or needs. + +Some of the more useful ones are: + +``--help`` + Lists all of the available options. Note that different commands + (``config``, ``build``, ``run``, etc) will have different supported + options. Place ``--help`` before the command to list common options, + and after the command for options specific to that command. + +``--build_dir`` + Specifies the build directory that kunit_tool will use. This is where + the .kunitconfig file is located, as well as where the .config and + compiled kernel will be placed. Defaults to ``.kunit``. + +``--make_options`` + Specifies additional options to pass to ``make`` when compiling a + kernel (with the ``build`` or ``run`` commands). For example, to enable + compiler warnings, you can pass ``--make_options W=1``. + +``--alltests`` + Builds a UML kernel with all config options enabled using ``make + allyesconfig``. This allows you to run as many tests as is possible, + but is very slow and prone to breakage as new options are added or + modified. In most cases, enabling all tests which have satisfied + dependencies by adding ``CONFIG_KUNIT_ALL_TESTS=1`` to your + .kunitconfig is preferable. + +There are several other options (and new ones are often added), so do check +``--help`` if you're looking for something not mentioned here. |