TOMOYO Linux Cross Reference
Linux/Documentation/dev-tools/kunit/run_wrapper.rst

   .. SPDX-License-Identifier: GPL-2.0
   
   =============================
   Running tests with kunit_tool
   =============================
   
   We can either run KUnit tests using kunit_tool or can run tests
   manually, and then use kunit_tool to parse the results. To run tests
   manually, see: Documentation/dev-tools/kunit/run_manual.rst.
  As long as we can build the kernel, we can run KUnit.
  
  kunit_tool is a Python script which configures and builds a kernel, runs
  tests, and formats the test results.
  
  Run command:
  
  .. code-block::
  
          ./tools/testing/kunit/kunit.py run
  
  We should see the following:
  
  .. code-block::
  
          Configuring KUnit Kernel ...
          Building KUnit kernel...
          Starting KUnit kernel...
  
  We may want to use the following options:
  
  .. code-block::
  
          ./tools/testing/kunit/kunit.py run --timeout=30 --jobs=`nproc --all`
  
  - ``--timeout`` sets a maximum amount of time for tests to run.
  - ``--jobs`` sets the number of threads to build the kernel.
  
  kunit_tool will generate a ``.kunitconfig`` with a default
  configuration, if no other ``.kunitconfig`` file exists
  (in the build directory). In addition, it verifies that the
  generated ``.config`` file contains the ``CONFIG`` options in the
  ``.kunitconfig``.
  It is also possible to pass a separate ``.kunitconfig`` fragment to
  kunit_tool. This is useful if we have several different groups of
  tests we want to run independently, or if we want to use pre-defined
  test configs for certain subsystems.
  
  To use a different ``.kunitconfig`` file (such as one
  provided to test a particular subsystem), pass it as an option:
  
  .. code-block::
  
          ./tools/testing/kunit/kunit.py run --kunitconfig=fs/ext4/.kunitconfig
  
  To view kunit_tool flags (optional command-line arguments), run:
  
  .. code-block::
  
          ./tools/testing/kunit/kunit.py run --help
  
  Creating a ``.kunitconfig`` file
  ================================
  
  If we want to run a specific set of tests (rather than those listed
  in the KUnit ``defconfig``), we can provide Kconfig options in the
  ``.kunitconfig`` file. For default .kunitconfig, see:
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/tools/testing/kunit/configs/default.config.
  A ``.kunitconfig`` is a ``minconfig`` (a .config
  generated by running ``make savedefconfig``), used for running a
  specific set of tests. This file contains the regular Kernel configs
  with specific test targets. The ``.kunitconfig`` also
  contains any other config options required by the tests (For example:
  dependencies for features under tests, configs that enable/disable
  certain code blocks, arch configs and so on).
  
  To create a ``.kunitconfig``, using the KUnit ``defconfig``:
  
  .. code-block::
  
          cd $PATH_TO_LINUX_REPO
          cp tools/testing/kunit/configs/default.config .kunit/.kunitconfig
  
  We can then add any other Kconfig options. For example:
  
  .. code-block::
  
          CONFIG_LIST_KUNIT_TEST=y
  
  kunit_tool ensures that all config options in ``.kunitconfig`` are
  set in the kernel ``.config`` before running the tests. It warns if we
  have not included the options dependencies.
  
  .. note:: Removing something from the ``.kunitconfig`` will
     not rebuild the ``.config file``. The configuration is only
     updated if the ``.kunitconfig`` is not a subset of ``.config``.
     This means that we can use other tools
     (For example: ``make menuconfig``) to adjust other config options.
     The build dir needs to be set for ``make menuconfig`` to
     work, therefore  by default use ``make O=.kunit menuconfig``.
 
 Configuring, building, and running tests
 ========================================
 
 If we want to make manual changes to the KUnit build process, we
 can run part of the KUnit build process independently.
 When running kunit_tool, from a ``.kunitconfig``, we can generate a
 ``.config`` by using the ``config`` argument:
 
 .. code-block::
 
         ./tools/testing/kunit/kunit.py config
 
 To build a KUnit kernel from the current ``.config``, we can use the
 ``build`` argument:
 
 .. code-block::
 
         ./tools/testing/kunit/kunit.py build
 
 If we already have built UML kernel with built-in KUnit tests, we
 can run the kernel, and display the test results with the ``exec``
 argument:
 
 .. code-block::
 
         ./tools/testing/kunit/kunit.py exec
 
 The ``run`` command discussed in section: **Running tests with kunit_tool**,
 is equivalent to running the above three commands in sequence.
 
 Parsing test results
 ====================
 
 KUnit tests output displays results in TAP (Test Anything Protocol)
 format. When running tests, kunit_tool parses this output and prints
 a summary. To see the raw test results in TAP format, we can pass the
 ``--raw_output`` argument:
 
 .. code-block::
 
         ./tools/testing/kunit/kunit.py run --raw_output
 
 If we have KUnit results in the raw TAP format, we 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
 
 Filtering tests
 ===============
 
 By passing a bash style glob filter to the ``exec`` or ``run``
 commands, we can run a subset of the tests built into a kernel . For
 example: if we only want to run KUnit resource tests, use:
 
 .. code-block::
 
         ./tools/testing/kunit/kunit.py run 'kunit-resource*'
 
 This uses the standard glob format with wildcard characters.
 
 .. _kunit-on-qemu:
 
 Running tests on QEMU
 =====================
 
 kunit_tool supports running tests on  qemu as well as
 via UML. To run tests on qemu, by default it requires two flags:
 
 - ``--arch``: Selects a configs collection (Kconfig, qemu config options
   and so on), that allow KUnit tests to be run on the specified
   architecture in a minimal way. The architecture argument is same as
   the option name passed to the ``ARCH`` variable used by Kbuild.
   Not all architectures currently support this flag, but we can use
   ``--qemu_config`` to handle it. If ``um`` is passed (or this flag
   is ignored), the tests will run via UML. Non-UML architectures,
   for example: i386, x86_64, arm and so on; run on qemu.
 
 - ``--cross_compile``: Specifies the Kbuild toolchain. It passes the
   same argument as 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 we have the sparc toolchain installed on
     our system.
 
   - ``$HOME/toolchains/microblaze/gcc-9.2.0-nolibc/microblaze-linux/bin/microblaze-linux``
     if we have downloaded the microblaze toolchain from the 0-day
     website to a directory in our home directory called toolchains.
 
 This means that for most architectures, running under qemu is as simple as:
 
 .. code-block:: bash
 
         ./tools/testing/kunit/kunit.py run --arch=x86_64
 
 When cross-compiling, we'll likely need to specify a different toolchain, for
 example:
 
 .. code-block:: bash
 
         ./tools/testing/kunit/kunit.py run \
                 --arch=s390 \
                 --cross_compile=s390x-linux-gnu-
 
 If we want to run KUnit tests on an architecture not supported by
 the ``--arch`` flag, or want to run KUnit tests on qemu using a
 non-default configuration; then we can write our own``QemuConfig``.
 These ``QemuConfigs`` are written in Python. They have an import line
 ``from..qemu_config import QemuArchParams`` at the top of the file.
 The file must contain a variable called ``QEMU_ARCH`` that has an
 instance of ``QemuArchParams`` assigned to it. See example in:
 ``tools/testing/kunit/qemu_configs/x86_64.py``.
 
 Once we have a ``QemuConfig``, we can pass it into kunit_tool,
 using the ``--qemu_config`` flag. When used, this flag replaces the
 ``--arch`` flag. For example: using
 ``tools/testing/kunit/qemu_configs/x86_64.py``, the invocation appear
 as
 
 .. code-block:: bash
 
         ./tools/testing/kunit/kunit.py run \
                 --timeout=60 \
                 --jobs=12 \
                 --qemu_config=./tools/testing/kunit/qemu_configs/x86_64.py
 
 Running command-line arguments
 ==============================
 
 kunit_tool has a number of other command-line arguments which can
 be useful for our test environment. Below are the most commonly used
 command line arguments:
 
 - ``--help``: Lists all available options. To list common options,
   place ``--help`` before the command. To list options specific to that
   command, place ``--help`` after the command.
 
   .. note:: Different commands (``config``, ``build``, ``run``, etc)
             have different supported options.
 - ``--build_dir``: Specifies kunit_tool build directory. It includes
   the ``.kunitconfig``, ``.config`` files and compiled kernel.
 
 - ``--make_options``: Specifies additional options to pass to make, when
   compiling a kernel (using ``build`` or ``run`` commands). For example:
   to enable compiler warnings, we can pass ``--make_options W=1``.
 
 - ``--alltests``: Enable a predefined set of options in order to build
   as many tests as possible.
 
   .. note:: The list of enabled options can be found in
             ``tools/testing/kunit/configs/all_tests.config``.
 
             If you only want to enable all tests with otherwise satisfied
             dependencies, instead add ``CONFIG_KUNIT_ALL_TESTS=y`` to your
             ``.kunitconfig``.
 
 - ``--kunitconfig``: Specifies the path or the directory of the ``.kunitconfig``
   file. For example:
 
   - ``lib/kunit/.kunitconfig`` can be the path of the file.
 
   - ``lib/kunit`` can be the directory in which the file is located.
 
   This file is used to build and run with a predefined set of tests
   and their dependencies. For example, to run tests for a given subsystem.
 
 - ``--kconfig_add``: Specifies additional configuration options to be
   appended to the ``.kunitconfig`` file. For example:
 
   .. code-block::
 
         ./tools/testing/kunit/kunit.py run --kconfig_add CONFIG_KASAN=y
 
 - ``--arch``: Runs tests on the specified architecture. The architecture
   argument is same as the Kbuild ARCH environment variable.
   For example, i386, x86_64, arm, um, etc. Non-UML architectures run on qemu.
   Default is `um`.
 
 - ``--cross_compile``: Specifies the Kbuild toolchain. It passes the
   same argument as passed to the ``CROSS_COMPILE`` variable used by
   Kbuild. This will be the prefix for the toolchain
   binaries such as GCC. For example:
 
   - ``sparc64-linux-gnu-`` if we have the sparc toolchain installed on
     our system.
 
   - ``$HOME/toolchains/microblaze/gcc-9.2.0-nolibc/microblaze-linux/bin/microblaze-linux``
     if we have downloaded the microblaze toolchain from the 0-day
     website to a specified path in our home directory called toolchains.
 
 - ``--qemu_config``: Specifies the path to a file containing a
   custom qemu architecture definition. This should be a python file
   containing a `QemuArchParams` object.
 
 - ``--qemu_args``: Specifies additional qemu arguments, for example, ``-smp 8``.
 
 - ``--jobs``: Specifies the number of jobs (commands) to run simultaneously.
   By default, this is set to the number of cores on your system.
 
 - ``--timeout``: Specifies the maximum number of seconds allowed for all tests to run.
   This does not include the time taken to build the tests.
 
 - ``--kernel_args``: Specifies additional kernel command-line arguments. May be repeated.
 
 - ``--run_isolated``: If set, boots the kernel for each individual suite/test.
   This is useful for debugging a non-hermetic test, one that
   might pass/fail based on what ran before it.
 
 - ``--raw_output``: If set, generates unformatted output from kernel. Possible options are:
 
    - ``all``: To view the full kernel output, use ``--raw_output=all``.
 
    - ``kunit``: This is the default option and filters to KUnit output. Use ``--raw_output`` or ``--raw_output=kunit``.
 
 - ``--json``: If set, stores the test results in a JSON format and prints to `stdout` or
   saves to a file if a filename is specified.
 
 - ``--filter``: Specifies filters on test attributes, for example, ``speed!=slow``.
   Multiple filters can be used by wrapping input in quotes and separating filters
   by commas. Example: ``--filter "speed>slow, module=example"``.
 
 - ``--filter_action``: If set to ``skip``, filtered tests will be shown as skipped
   in the output rather than showing no output.
 
 - ``--list_tests``: If set, lists all tests that will be run.
 
 - ``--list_tests_attr``: If set, lists all tests that will be run and all of their
   attributes.

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.