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diff --git a/Documentation/dev-tools/kunit/kunit-tool.rst b/Documentation/dev-tools/kunit/kunit-tool.rst deleted file mode 100644 index ae52e0f489f9..000000000000 --- a/Documentation/dev-tools/kunit/kunit-tool.rst +++ /dev/null @@ -1,232 +0,0 @@ -.. SPDX-License-Identifier: GPL-2.0 - -================= -kunit_tool How-To -================= - -What is kunit_tool? -=================== - -kunit_tool is a script (``tools/testing/kunit/kunit.py``) that aids in building -the Linux kernel as UML (`User Mode Linux -<http://user-mode-linux.sourceforge.net/>`_), running KUnit tests, parsing -the test results and displaying them in a user friendly manner. - -kunit_tool addresses the problem of being able to run tests without needing a -virtual machine or actual hardware with User Mode Linux. User Mode Linux is a -Linux architecture, like ARM or x86; however, unlike other architectures it -compiles the kernel as a standalone Linux executable that can be run like any -other program directly inside of a host operating system. To be clear, it does -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 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. - -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: - -.. code-block:: bash - - ./tools/testing/kunit/kunit.py run - -However, you most likely want to use it with the following options: - -.. code-block:: bash - - ./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all` - -- ``--timeout`` sets a maximum amount of time to allow tests to run. -- ``--jobs`` sets the number of threads to use to build the kernel. - -.. note:: - This command will work even without a .kunitconfig file: if no - .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 - -The raw output from test runs may contain other, non-KUnit kernel log -lines. You can see just KUnit output with ``--raw_output=kunit``: - -.. code-block:: bash - - ./tools/testing/kunit/kunit.py run --raw_output=kunit - -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. |