Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 323 insertions, 0 deletions

diff --git a/Documentation/dev-tools/kunit/run_wrapper.rst b/Documentation/dev-tools/kunit/run_wrapper.rst
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+.. 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.