kunit: tool: Print UML command

As for the Qemu command, print the command used to run tests with UML.

Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@google.com>
Signed-off-by: Mickaël Salaün <mic@digikod.net>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: Add command line interface to filter and report attributes

Add ability to kunit.py to filter attributes and report a list of tests
including attributes without running tests.

Add flag "--filter" to input filters on test attributes. Tests will be
filtered out if they do not match all inputted filters.

Example: --filter speed=slow (This filter would run only the tests that are
marked as slow)

Filters have operations: <, >, <=, >=, !=, and =. But note that the
characters < and > are often interpreted by the shell, so they may need to
be quoted or escaped.

Example: --filter "speed>slow" or --filter speed\>slow (This filter would
run only the tests that have the speed faster than slow.

Additionally, multiple filters can be used.

Example: --filter "speed=slow, module!=example" (This filter would run
only the tests that have the speed slow and are not in the "example"
module)

Note if the user wants to skip filtered tests instead of not
running/showing them use the "--filter_action=skip" flag instead.

Expose the output of kunit.action=list option with flag "--list_tests" to
output a list of tests. Additionally, add flag "--list_tests_attr" to
output a list of tests and their attributes. These flags are useful to see
tests and test attributes without needing to run tests.

Example of the output of "--list_tests_attr":
example
example.test_1
example.test_2
# example.test_2.speed: slow

This output includes a suite, example, with two test cases, test_1 and
test_2. And in this instance test_2 has been marked as slow.

Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Rae Moar <rmoar@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: undo type subscripts for subprocess.Popen

Writing `subprocess.Popen[str]` requires python 3.9+.
kunit.py has an assertion that the python version is 3.7+, so we should
try to stay backwards compatible.

This conflicts a bit with commit 1da2e6220e11 ("kunit: tool: fix
pre-existing `mypy --strict` errors and update run_checks.py"), since
mypy complains like so
> kunit_kernel.py:95: error: Missing type parameters for generic type "Popen" [type-arg]

Note: `mypy --strict --python-version 3.7` does not work.

We could annotate each file with comments like
`# mypy: disable-error-code="type-arg"
but then we might still get nudged to break back-compat in other files.

This patch adds a `mypy.ini` file since it seems like the only way to
disable specific error codes for all our files.

Note: run_checks.py doesn't need to specify `--config_file mypy.ini`,
but I think being explicit is better, particularly since most kernel
devs won't be familiar with how mypy works.

Fixes: 695e26030858 ("kunit: tool: add subscripts for type annotations where appropriate")
Reported-by: SeongJae Park <sj@kernel.org>
Link: https://lore.kernel.org/linux-kselftest/20230501171520.138753-1-sj@kernel.org
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Tested-by: SeongJae Park <sj@kernel.org>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: Add support for overriding the QEMU serial port

On some platforms, the console is not the first serial port. To make
this work, the first serial port in QEMU must be set to "null".

Add support for this by adding an optional "serial" parameter, which
defaults to "stdio", and can be overridden by platform-specific
configuration.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix pre-existing `mypy --strict` errors and update run_checks.py

Basically, get this command to be happy and make run_checks.py happy
$ mypy --strict --exclude '_test.py$' --exclude qemu_configs/ ./tools/testing/kunit/

Primarily the changes are
* add `-> None` return type annotations
* add all the missing argument type annotations

Previously, we had false positives from mypy in `main()`, see commit
09641f7c7d8f ("kunit: tool: surface and address more typing issues").
But after commit 2dc9d6ca52a4 ("kunit: kunit.py extract handlers")
refactored things, the variable name reuse mypy hated is gone.

Note: mypy complains we don't annotate the types the unused args in our
signal handler. That's silly.
But to make it happy, I've copy-pasted an appropriate annotation from
https://github.com/python/typing/discussions/1042#discussioncomment-2013595.

Reported-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/linux-kselftest/9a172b50457f4074af41fe1dc8e55dcaf4795d7e.camel@sipsolutions.net/
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: remove unused imports and variables

We don't run a linter regularly over kunit.py code (the default settings
on most don't like kernel style, e.g. tabs) so some of these imports
didn't get removed when they stopped being used.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: add subscripts for type annotations where appropriate

E.g. for subprocess.Popen, it can be opened in `text=True` mode where it
returns strings, or `text=False` where it returns bytes.
To differentiate, you can annotate types as `Popen[str]` or
`Popen[bytes]`.

This patch should add subscripts in all the places we were missing them.

Reported-by: Johannes Berg <johannes.berg@intel.com>
Link: https://lore.kernel.org/linux-kselftest/20230315105055.9b2be0153625.I7a2cb99b95dff216c0feed4604255275e0b156a7@changeid/
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: rename all_test_uml.config, use it for --alltests

Context:
1. all_tests_uml.config used to be UML specific back when users to
manually specify CONFIG_VIRTIO_UML=y to enable CONFIG_PCI=y.
2. --alltests used allyesconfig along with a curated list of options to
disable. It's only ever worked for brief periods of time and has
perennially been broken due to compile issues.

Now all_tests_uml.config should work across ~all architectures.
Let's instead use this to implement --alltests.

Note: if anyone was using all_tests_uml.config, this change breaks them.
I think that's unlikely since it was added in 5.19 and was a lot to
type: --kunitconfig=tools/testing/kunit/configs/all_tests_uml.config.
We could make it a symlink to the new name, but I don't think the
caution is warranted here.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: add kunit.enable to enable/disable KUnit test

This patch adds the kunit.enable module parameter that will need to be
set to true in addition to KUNIT being enabled for KUnit tests to run.
The default value is true giving backwards compatibility. However, for
the production+testing use case the new config option
KUNIT_DEFAULT_ENABLED can be set to N requiring the tester to opt-in
by passing kunit.enable=1 to the kernel.

Signed-off-by: Joe Fradley <joefradley@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: Enable virtio/PCI by default on UML

There are several tests which depend on PCI, and hence need a bunch of
extra options to run under UML. This makes it awkward to give
configuration instructions (whether in documentation, or as part of a
.kunitconfig file), as two separate, incompatible sets of config options
are required for UML and "most other architectures".

For non-UML architectures, it's possible to add default kconfig options
via the qemu_config python files, but there's no equivalent for UML. Add
a new tools/testing/kunit/configs/arch_uml.config file containing extra
kconfig options to use on UML.

Tested-by: José Expósito <jose.exposito89@gmail.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: make --kunitconfig repeatable, blindly concat

It's come up a few times that it would be useful to have --kunitconfig
be repeatable [1][2].

This could be done before with a bit of shell-fu, e.g.
$ find fs/ -name '.kunitconfig' -exec cat {} + | \
./tools/testing/kunit/kunit.py run --kunitconfig=/dev/stdin
or equivalently:
$ cat fs/ext4/.kunitconfig fs/fat/.kunitconfig | \
./tools/testing/kunit/kunit.py run --kunitconfig=/dev/stdin

But this can be fairly clunky to use in practice.

And having explicit support in kunit.py opens the door to having more
config fragments of interest, e.g. options for PCI on UML [1], UML
coverage [2], variants of tests [3].
There's another argument to be made that users can just use multiple
--kconfig_add's, but this gets very clunky very fast (e.g. [2]).

Note: there's a big caveat here that some kconfig options might be
incompatible. We try to give a clearish error message in the simple case
where the same option appears multiple times with conflicting values,
but more subtle ones (e.g. mutually exclusive options) will be
potentially very confusing for the user. I don't know we can do better.

Note 2: if you want to combine a --kunitconfig with the default, you
either have to do to specify the current build_dir
> --kunitconfig=.kunit --kunitconfig=additional.config
or
> --kunitconfig=tools/testing/kunit/configs/default.config --kunitconifg=additional.config
each of which have their downsides (former depends on --build_dir,
doesn't work if you don't have a .kunitconfig yet), etc.

Example with conflicting values:
> $ ./tools/testing/kunit/kunit.py config --kunitconfig=lib/kunit --kunitconfig=/dev/stdin <<EOF
> CONFIG_KUNIT_TEST=n
> CONFIG_KUNIT=m
> EOF
> ...
> kunit_kernel.ConfigError: Multiple values specified for 2 options in kunitconfig:
> CONFIG_KUNIT=y
> vs from /dev/stdin
> CONFIG_KUNIT=m
>
> CONFIG_KUNIT_TEST=y
> vs from /dev/stdin
> # CONFIG_KUNIT_TEST is not set

[1] https://lists.freedesktop.org/archives/dri-devel/2022-June/357616.html
[2] https://lore.kernel.org/linux-kselftest/CAFd5g45f3X3xF2vz2BkTHRqOC4uW6GZxtUUMaP5mwwbK8uNVtA@mail.gmail.com/
[3] https://lore.kernel.org/linux-kselftest/CANpmjNOdSy6DuO6CYZ4UxhGxqhjzx4tn0sJMbRqo2xRFv9kX6Q@mail.gmail.com/

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: refactor internal kconfig handling, allow overriding

Currently, you cannot ovewrwrite what's in your kunitconfig via
--kconfig_add.
Nor can you override something in a qemu_config via either means.

This patch makes it so we have this level of priority
* --kconfig_add
* kunitconfig file (the default or the one from --kunitconfig)
* qemu_config

The rationale for this order is that the more "dynamic" sources of
kconfig options should take priority.

--kconfig_add is obviously the most dynamic.
And for kunitconfig, users probably tweak the file manually or specify
--kunitconfig more often than they delve into qemu_config python files.

And internally, we convert the kconfigs from a python list into a set or
dict fairly often. We should just use a dict internally.
We exposed the set transform in the past since we didn't define __eq__,
so also take the chance to shore up the kunit_kconfig.Kconfig interface.

Example
=======

Let's consider the unrealistic example where someone would want to
disable CONFIG_KUNIT.
I.e. they run
$ ./tools/testing/kunit/kunit.py config --kconfig_add=CONFIG_KUNIT=n

Before
------
We'd write the following
> # CONFIG_KUNIT is not set
> CONFIG_KUNIT_ALL_TESTS=y
> CONFIG_KUNIT_TEST=y
> CONFIG_KUNIT=y
> CONFIG_KUNIT_EXAMPLE_TEST=y

And we'd error out with
> ERROR:root:Not all Kconfig options selected in kunitconfig were in the generated .config.
> This is probably due to unsatisfied dependencies.
> Missing: # CONFIG_KUNIT is not set

After
-----
We'd write the following
> # CONFIG_KUNIT is not set
> CONFIG_KUNIT_TEST=y
> CONFIG_KUNIT_ALL_TESTS=y
> CONFIG_KUNIT_EXAMPLE_TEST=y

And we'd error out with
> ERROR:root:Not all Kconfig options selected in kunitconfig were in the generated .config.
> This is probably due to unsatisfied dependencies.
> Missing: CONFIG_KUNIT_EXAMPLE_TEST=y, CONFIG_KUNIT_TEST=y, CONFIG_KUNIT_ALL_TESTS=y

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: introduce --qemu_args

Example usage:
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 \
--kconfig_add=CONFIG_SMP=y --qemu_args='-smp 8'

Looking in the test.log, one can see
> smp: Bringing up secondary CPUs ...
> .... node #0, CPUs: #1 #2 #3 #4 #5 #6 #7
> smp: Brought up 1 node, 8 CPUs

This flag would allow people to make tweaks like this without having to
create custom qemu_config files.

For consistency with --kernel_args, we allow users to repeat this
argument, e.g. you can tack on a --qemu_args='-m 2048', or you could
just append it to the first string ('-smp 8 -m 2048').

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: simplify creating LinuxSourceTreeOperations

Drop get_source_tree_ops() and just call what used to be
get_source_tree_ops_from_qemu_config() in both cases.

Also rename the functions to have shorter names and add a "_" prefix to
note they're not meant to be used outside this function.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: cosmetic: don't specify duplicate kernel cmdline options

Context:
When using a non-UML arch, kunit.py will boot the test kernel with
options like these by default (this is x86_64):
> mem=1G console=tty kunit_shutdown=halt console=ttyS0 kunit_shutdown=reboot

The first three options are added unconditionally but are only intended
for UML.

1. 'mem=1G' is redundant with the '-m 1024' that we hard-code into the
qemu commandline.

2. We specify a 'console' for all tools/testing/kunit/qemu_configs/*.py
already, so 'console=tty' gets overwritten.

3. For QEMU, we need to use 'reboot', and for UML we need to use 'halt'.
If you switch them, kunit.py will hang until the --timeout expires.

This patch:
Having these duplicate options is a bit noisy.
Switch so we only add UML-specific options for UML.

I.e. we now get
UML: 'mem=1G console=tty kunit_shutdown=halt' (unchanged)
x86_64: 'console=ttyS0 kunit_shutdown=reboot'

Side effect: you can't overwrite these options on UML w/ --kernel_arg.
But you already couldn't for QEMU (console, kunit_shutdown), and why
would you want to?

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: refactoring printing logic into kunit_printer.py

Context:
* kunit_kernel.py is importing kunit_parser.py just to use the
print_with_timestamp() function
* the parser is directly printing to stdout, which will become an issue
if we ever try to run multiple kernels in parallel

This patch introduces a kunit_printer.py file and migrates callers of
kunit_parser.print_with_timestamp() to call
kunit_printer.stdout.print_with_timestamp() instead.

Future changes:
If we want to support showing results for parallel runs, we could then
create new Printer's that don't directly write to stdout and refactor
the code to pass around these Printer objects.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: drop unused load_config argument

It's always set to true except in one test case.
And in that test case it can safely be set to true anyways.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: misc cleanups

This primarily comes from running pylint over kunit tool code and
ignoring some warnings we don't care about.
If we ever got a fully clean setup, we could add this to run_checks.py,
but we're not there yet.

Fix things like
* Drop unused imports
* check `is None`, not `== None` (see PEP 8)
* remove redundant parens around returns
* remove redundant `else` / convert `elif` to `if` where appropriate
* rename make_arch_qemuconfig() param to base_kunitconfig (this is the
name used in the subclass, and it's a better one)
* kunit_tool_test: check the exit code for SystemExit (could be 0)

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: stop using a shell to run kernel under QEMU

Note: this potentially breaks custom qemu_configs if people are using
them! But the fix for them is simple, don't specify multiple arguments
in one string and don't add on a redundant ''.

It feels a bit iffy to be using a shell in the first place.

There's the usual shenanigans where people could pass in arbitrary shell
commands via --kernel_arg (since we're just adding '' around the
kernel_cmdline) or via a custom qemu_config.
This isn't too much of a concern given the nature of this script (and
the qemu_config file is in python, you can do w/e you want already).

But it does have some other drawbacks.

One example of a kunit-specific pain point:
If the relevant qemu binary is missing, we get output like this:
> /bin/sh: line 1: qemu-system-aarch64: command not found
This in turn results in our KTAP parser complaining about
missing/invalid KTAP, but we don't directly show the error!
It's even more annoying to debug when you consider --raw_output only
shows KUnit output by default, i.e. you need --raw_output=all to see it.

Whereas directly invoking the binary, Python will raise a
FileNotFoundError for us, which is a noisier but more clear.

Making this change requires
* splitting parameters like ['-m 256'] into ['-m', '256'] in
kunit/qemu_configs/*.py
* change [''] to [] in kunit/qemu_configs/*.py since otherwise
QEMU fails w/ 'Device needs media, but drive is empty'
* dropping explicit quoting of the kernel cmdline
* using shlex.quote() when we print what command we're running
so the user can copy-paste and run it

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: properly report the used arch for --json, or '' if not known

Before, kunit.py always printed "arch": "UM" in its json output, but...
1. With `kunit.py parse`, we could be parsing output from anywhere, so
we can't say that.
2. Capitalizing it is probably wrong, as it's `ARCH=um`
3. Commit 87c9c1631788 ("kunit: tool: add support for QEMU") made it so
kunit.py could knowingly run a different arch, yet we'd still always
claim "UM".

This patch addresses all of those. E.g.

1.
$ ./tools/testing/kunit/kunit.py parse .kunit/test.log --json | grep -o '"arch.*' | sort -u
"arch": "",

2.
$ ./tools/testing/kunit/kunit.py run --json | ...
"arch": "um",

3.
$ ./tools/testing/kunit/kunit.py run --json --arch=x86_64 | ...
"arch": "x86_64",

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: simplify code since build_dir can't be None

--build_dir is set to a default of '.kunit' since commit ddbd60c779b4
("kunit: use --build_dir=.kunit as default"), but even before then it
was explicitly set to ''.

So outside of one unit test, there was no way for the build_dir to be
ever be None, and we can simplify code by fixing the unit test and
enforcing that via updated type annotations.

E.g. this lets us drop `get_file_path()` since it's now exactly
equivalent to os.path.join().

Note: there's some `if build_dir` checks that also fail if build_dir is
explicitly set to '' that just guard against passing "O=" to make.
But running `make O=` works just fine, so drop these checks.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: Import missing importlib.abc

Python 3.10.0 contains:
9e09849d20 ("bpo-41006: importlib.util no longer imports typing (GH-20938)")

It causes importlib.util to no longer import importlib.abs, which leads
to the following error when trying to use kunit with qemu:
AttributeError: module 'importlib' has no attribute 'abc'. Did you mean: '_abc'?

Add the missing import.

Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix newly introduced typechecker errors

After upgrading mypy and pytype from pip, we see 2 new errors when
running ./tools/testing/kunit/run_checks.py.

Error #1: mypy and pytype
They now deduce that importlib.util.spec_from_file_location() can return
None and note that we're not checking for this.

We validate that the arch is valid (i.e. the file exists) beforehand.
Add in an `asssert spec is not None` to appease the checkers.

Error #2: pytype bug https://github.com/google/pytype/issues/1057
It doesn't like `from datetime import datetime`, specifically that a
type shares a name with a module.

We can workaround this by either
* renaming the import or just using `import datetime`
* passing the new `--fix-module-collisions` flag to pytype.

We pick the first option for now because
* the flag is quite new, only in the 2021.11.29 release.
* I'd prefer if people can just run `pytype <file>`

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: reconfigure when the used kunitconfig changes

Problem: currently, if you remove something from your kunitconfig,
kunit.py will not regenerate the .config file.
The same thing happens if you did --kunitconfig_add=CONFIG_KASAN=y [1]
and then ran again without it. Your new run will still have KASAN.

The reason is that kunit.py won't regenerate the .config file if it's a
superset of the kunitconfig. This speeds it up a bit for iterating.

This patch adds an additional check that forces kunit.py to regenerate
the .config file if the current kunitconfig doesn't match the previous
one.

What this means:
* deleting entries from .kunitconfig works as one would expect
* dropping a --kunitconfig_add also triggers a rebuild
* you can still edit .config directly to turn on new options

We implement this by creating a `last_used_kunitconfig` file in the
build directory (so .kunit, by default) after we generate the .config.
When comparing the kconfigs, we compare python sets, so duplicates and
permutations don't trip us up.

The majority of this patch is adding unit tests for the existing logic
and for the new case where `last_used_kunitconfig` differs.

[1] https://lore.kernel.org/linux-kselftest/20211106013058.2621799-2-dlatypov@google.com/

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: revamp message for invalid kunitconfig

The current error message is precise, but not very clear if you don't
already know what it's talking about, e.g.

> $ make ARCH=um olddefconfig O=.kunit
> ERROR:root:Provided Kconfig is not contained in validated .config. Following fields found in kunitconfig, but not in .config: CONFIG_DRM=y

Try to reword the error message so that it's
* your missing options usually have unsatisified dependencies
* if you're on UML, that might be the cause (it is, in this example)

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: add --kconfig_add to allow easily tweaking kunitconfigs

E.g. run tests but with KASAN
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kconfig_add=CONFIG_KASAN=y

This also works with --kunitconfig
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kunitconfig=fs/ext4 --kconfig_add=CONFIG_KASAN=y

This flag is inspired by TuxMake's --kconfig-add, see
https://gitlab.com/Linaro/tuxmake#examples.

Our version just uses "_" as the delimiter for consistency with
pre-existing flags like --build_dir, --make_options, --kernel_args, etc.

Note: this does make it easier to run into a pre-existing edge case:
$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --kconfig_add=CONFIG_KASAN=y
$ ./tools/testing/kunit/kunit.py run --arch=x86_64
This second invocation ^ still has KASAN enabled!

kunit.py won't call olddefconfig if our current .config is already a
superset of the provided kunitconfig.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: move Kconfig read_from_file/parse_from_string to package-level

read_from_file() clears its `self` Kconfig object and parses a config
file.

It is a way to construct Kconfig objects more so than an operation on
Kconfig objects. This is reflected in the fact its only ever used as:
kconfig = kunit_config.Kconfig()
kconfig.read_from_file(path)

So clean this up and simplify callers by replacing it with
kconfig = kunit_config.parse_file(path)

Do the same thing for the related parse_from_string() function as well.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix typecheck errors about loading qemu configs

Currently, we have these errors:
$ mypy ./tools/testing/kunit/*.py
tools/testing/kunit/kunit_kernel.py:213: error: Item "_Loader" of "Optional[_Loader]" has no attribute "exec_module"
tools/testing/kunit/kunit_kernel.py:213: error: Item "None" of "Optional[_Loader]" has no attribute "exec_module"
tools/testing/kunit/kunit_kernel.py:214: error: Module has no attribute "QEMU_ARCH"
tools/testing/kunit/kunit_kernel.py:215: error: Module has no attribute "QEMU_ARCH"

exec_module
===========

pytype currently reports no errors, but that's because there's a comment
disabling it on 213.

This is due to https://github.com/python/typeshed/pull/2626.
The fix is to assert the loaded module implements the ABC
(abstract base class) we want which has exec_module support.

QEMU_ARCH
=========

pytype is fine with this, but mypy is not:
https://github.com/python/mypy/issues/5059

Add a check that the loaded module does indeed have QEMU_ARCH.
Note: this is not enough to appease mypy, so we also add a comment to
squash the warning.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: continue past invalid utf-8 output

kunit.py currently crashes and fails to parse kernel output if it's not
fully valid utf-8.

This can come from memory corruption or just inadvertently printing
out binary data as strings.

E.g. adding this line into a kunit test
pr_info("\x80")
will cause this exception
UnicodeDecodeError: 'utf-8' codec can't decode byte 0x80 in position
1961: invalid start byte

We can tell Python how to handle errors, see
https://docs.python.org/3/library/codecs.html#error-handlers

Unfortunately, it doesn't seem like there's a way to specify this in
just one location, so we need to repeat ourselves quite a bit.

Specify `errors='backslashreplace'` so we instead:
* print out the offending byte as '\x80'
* try and continue parsing the output.
* as long as the TAP lines themselves are valid, we're fine.

Fixed spelling/grammar in commit log:
Shuah Khan <<skhan@linuxfoundation.org>

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: yield output from run_kernel in real time

Currently, `run_kernel()` dumps all the kernel output to a file
(.kunit/test.log) and then opens the file and yields it to callers.
This made it easier to respect the requested timeout, if any.

But it means that we can't yield the results in real time, either to the
parser or to stdout (if --raw_output is set).

This change spins up a background thread to enforce the timeout, which
allows us to yield the kernel output in real time, while also copying it
to the .kunit/test.log file.
It's also careful to ensure that the .kunit/test.log file is complete,
even in the kunit_parser throws an exception/otherwise doesn't consume
every line, see the new `finally` block and unit test.

For example:

$ ./tools/testing/kunit/kunit.py run --arch=x86_64 --raw_output
<configure + build steps>
...
<can now see output from QEMU in real time>

This does not currently have a visible effect when --raw_output is not
passed, as kunit_parser.py currently only outputs everything at the end.
But that could change, and this patch is a necessary step towards
showing parsed test results in real time.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: show list of valid --arch options when invalid

Consider this attempt to run KUnit in QEMU:
$ ./tools/testing/kunit/kunit.py run --arch=x86

Before you'd get this error message:
kunit_kernel.ConfigError: x86 is not a valid arch

After:
kunit_kernel.ConfigError: x86 is not a valid arch, options are ['alpha', 'arm', 'arm64', 'i386', 'powerpc', 'riscv', 's390', 'sparc', 'x86_64']

This should make it a bit easier for people to notice when they make
typos, etc. Currently, one would have to dive into the python code to
figure out what the valid set is.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: misc fixes (unused vars, imports, leaked files)

Drop some variables in unit tests that were unused and/or add assertions
based on them.

For ExitStack, it was imported, but the `es` variable wasn't used so it
didn't do anything, and we were leaking the file objects.
Refactor it to just use nested `with` statements to properly close them.

And drop the direct use of .close() on file objects in the kunit tool
unit test, as these can be leaked if test assertions fail.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: remove unnecessary "annotations" import

The import was working around the fact "tuple[T]" was used instead of
typing.Tuple[T].

Convert it to use type.Tuple to be consistent with how the rest of the
code is anotated.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Move default config from arch/um -> tools/testing/kunit

The default .kunitconfig file is currently kept in
arch/um/configs/kunit_defconfig, but -- with the impending QEMU patch
-- will no-longer be exclusively used for UML-based kernels.

Move it alongside the other KUnit configs in
tools/testing/kunit/configs, and give it a name which matches the
existing all_tests.config and broken_on_uml.config files.

Also update the Getting Started documentation to point to the new file.

Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: add support for QEMU

Add basic support to run QEMU via kunit_tool. Add support for i386,
x86_64, arm, arm64, and a bunch more.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: David Gow <davidgow@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Add 'kunit_shutdown' option

Add a new kernel command-line option, 'kunit_shutdown', which allows the
user to specify that the kernel poweroff, halt, or reboot after
completing all KUnit tests; this is very handy for running KUnit tests
on UML or a VM so that the UML/VM process exits cleanly immediately
after running all tests without needing a special initramfs.

Signed-off-by: David Gow <davidgow@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Tested-By: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: make --kunitconfig accept dirs, add lib/kunit fragment

TL;DR
$ ./tools/testing/kunit/kunit.py run --kunitconfig=lib/kunit

Per suggestion from Ted [1], we can reduce the amount of typing by
assuming a convention that these files are named '.kunitconfig'.

In the case of [1], we now have
$ ./tools/testing/kunit/kunit.py run --kunitconfig=fs/ext4

Also add in such a fragment for kunit itself so we can give that as an
example more close to home (and thus less likely to be accidentally
broken).

[1] https://lore.kernel.org/linux-ext4/YCNF4yP1dB97zzwD@mit.edu/

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix unintentional statefulness in run_kernel()

This is a bug that has been present since the first version of this
code.
Using [] as a default parameter is dangerous, since it's mutable.

Example using the REPL:
>>> def bad(param = []):
... param.append(len(param))
... print(param)
...
>>> bad()
[0]
>>> bad()
[0, 1]

This wasn't a concern in the past since it would just keep appending the
same values to it.

E.g. before, `args` would just grow in size like:
[mem=1G', 'console=tty']
[mem=1G', 'console=tty', mem=1G', 'console=tty']

But with now filter_glob, this is more dangerous, e.g.
run_kernel(filter_glob='my-test*') # default modified here
run_kernel() # filter_glob still applies here!
That earlier `filter_glob` will affect all subsequent calls that don't
specify `args`.

Note: currently the kunit tool only calls run_kernel() at most once, so
it's not possible to trigger any negative side-effects right now.

Fixes: 6ebf5866f2e8 ("kunit: tool: add Python wrappers for running KUnit tests")
Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: add support for filtering suites by glob

This allows running different subsets of tests, e.g.

$ ./tools/testing/kunit/kunit.py build
$ ./tools/testing/kunit/kunit.py exec 'list*'
$ ./tools/testing/kunit/kunit.py exec 'kunit*'

This passes the "kunit_filter.glob" commandline option to the UML
kernel, which currently only supports filtering by suite name.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: make kunit_tool accept optional path to .kunitconfig fragment

Currently running tests via KUnit tool means tweaking a .kunitconfig
file, which you'd keep around locally and never commit.
This changes makes it so users can pass in a path to a kunitconfig.

One of the imagined use cases is having kunitconfig fragments in-tree
to formalize interesting sets of tests for features/subsystems, e.g.
$ ./tools/testing/kunit/kunit.py run --kunticonfig=fs/ext4/kunitconfig

For now, this hypothetical fs/ext4/kunitconfig would contain
CONFIG_KUNIT=y
CONFIG_EXT4_FS=y
CONFIG_EXT4_KUNIT_TESTS=y

At the moment, it's not hard to manually whip up this file, but as more
and more tests get added, this will get tedious.

It also opens the door to documenting how to run all the tests relevant
to a specific subsystem or feature as a simple one-liner.

This can be seen as an analogue to tools/testing/selftests/*/config
But in the case of KUnit, the tests live in the same directory as the
code-under-test, so it feels more natural to allow the kunitconfig
fragments to live anywhere. (Though, people could create a separate
directory if wanted; this patch imposes no restrictions on the path).

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: move kunitconfig parsing into __init__, make it optional

LinuxSourceTree will unceremoniously crash if the user doesn't call
read_kunitconfig() first in a number of functions.

And currently every place we create an instance, the caller also calls
create_kunitconfig() and read_kunitconfig().
Move these instead into __init__() so they can't be forgotten and to
reduce copy-paste.

The https://github.com/google/pytype type-checker complained that
_config wasn't initialized. With this, kunit_tool now type checks
under both pytype and mypy.

Add an optional boolean that can be used to disable this for use cases
in the future where we might not need/want to load the config.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: surface and address more typing issues

The authors of this tool were more familiar with a different
type-checker, https://github.com/google/pytype.

That's open source, but mypy seems more prevalent (and runs faster).
And unlike pytype, mypy doesn't try to infer types so it doesn't check
unanotated functions.

So annotate ~all functions in kunit tool to increase type-checking
coverage.
Note: per https://www.python.org/dev/peps/pep-0484/, `__init__()` should
be annotated as `-> None`.

Doing so makes mypy discover a number of new violations.
Exclude main() since we reuse `request` for the different types of
requests, which mypy isn't happy about.

This commit fixes all but one error, where `TestSuite.status` might be
None.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: Force the use of the 'tty' console for UML

kunit_tool relies on the UML console outputting printk() output to the
tty in order to get results. Since the default console driver could
change, pass 'console=tty' to the kernel.

This is triggered by a change[1] to use ttynull as a fallback console
driver which -- by chance or by design -- seems to have changed the
default console output on UML, breaking kunit_tool. While this may be
fixed, we should be less fragile to such changes in the default.

[1]:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=757055ae8dedf5333af17b3b5b4b70ba9bc9da4e

Signed-off-by: David Gow <davidgow@google.com>
Fixes: 757055ae8ded ("init/console: Use ttynull as a fallback when there is no console")
Reported-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Introduce get_file_path() helper

Helper allows to derive file names depending on --build_dir argument.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: print out stderr from make (like build warnings)

Currently the tool redirects make stdout + stderr, and only shows them
if the make command fails.
This means build warnings aren't shown to the user.

This change prints the contents of stderr even if make succeeds, under
the assumption these are only build warnings or other messages the user
likely wants to see.

We drop stdout from the raised exception since we can no longer easily
collate stdout and stderr and just showing the stderr seems fine.

Example with a warning:

[14:56:35] Building KUnit Kernel ...
../lib/kunit/kunit-test.c: In function ‘kunit_test_successful_try’:
../lib/kunit/kunit-test.c:19:6: warning: unused variable ‘unused’ [-Wunused-variable]
19 | int unused;
| ^~~~~~

[14:56:40] Starting KUnit Kernel ...

Note the stderr has a trailing \n, and since we use print, we add
another, but it helps separate make and kunit.py output.

Example with a build error:

[15:02:45] Building KUnit Kernel ...
ERROR:root:../lib/kunit/kunit-test.c: In function ‘kunit_test_successful_try’:
../lib/kunit/kunit-test.c:19:2: error: unknown type name ‘invalid_type’
19 | invalid_type *test = data;
| ^~~~~~~~~~~~
...

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Do not pollute source directory with generated files (test.log)

When --build_dir is provided use it and do not pollute source directory
which even can be mounted over network or read-only.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Do not pollute source directory with generated files (.kunitconfig)

When --build_dir is provided use it and do not pollute source directory
which even can be mounted over network or read-only.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix display of make errors

CalledProcessError stores the output of the failed process as `bytes`,
not a `str`.

So when we log it on build error, the make output is all crammed into
one line with "\n" instead of actually printing new lines.

After this change, we get readable output with new lines, e.g.
> CC lib/kunit/kunit-example-test.o
> In file included from ../lib/kunit/test.c:9:
> ../include/kunit/test.h:22:1: error: unknown type name ‘invalid_type_that_causes_compile’
> 22 | invalid_type_that_causes_compile errors;
> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> make[3]: *** [../scripts/Makefile.build:283: lib/kunit/test.o] Error 1

Secondly, trying to concat exceptions to strings will fail with
> TypeError: can only concatenate str (not "OSError") to str
so fix this with an explicit cast to str.

Signed-off-by: Daniel Latypov <dlatypov@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: fix --alltests flag

Alltests flag evidently stopped working when run from outside of the
root of the source tree, so fix that. Also add an additional broken
config to the broken_on_uml config.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: capture stderr on all make subprocess calls

Direct stderr to subprocess.STDOUT so error messages get included in the
subprocess.CalledProcessError exceptions output field. This results in
more meaningful error messages for the user.

This is already being done in the make_allyesconfig method. Do the same
for make_mrproper, make_olddefconfig, and make methods.

With this, failures on unclean trees [1] will give users an error
message that includes:
"The source tree is not clean, please run 'make ARCH=um mrproper'"

[1] https://bugzilla.kernel.org/show_bug.cgi?id=205219

Signed-off-by: Will Chen <chenwi@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: add --make_options

The kunit.py utility builds an ARCH=um kernel and then runs it. Add
optional --make_options flag to kunit.py allowing for the operator to
specify extra build options.

This allows use of the clang compiler for kunit:
tools/testing/kunit/kunit.py run --defconfig \
--make_options CC=clang --make_options HOSTCC=clang

Signed-off-by: Greg Thelen <gthelen@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: David Gow <davidgow@google.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Run all KUnit tests through allyesconfig

Implemented the functionality to run all KUnit tests through kunit_tool
by specifying an --alltests flag, which builds UML with allyesconfig
enabled, and consequently runs every KUnit test. A new function was
added to kunit_kernel: make_allyesconfig.
Firstly, if --alltests is specified, kunit.py triggers build_um_kernel
which call make_allyesconfig. This function calls the make command,
disables the broken configs that would otherwise prevent UML from
building, then starts the kernel with all possible configurations
enabled. All stdout and stderr is sent to test.log and read from there
then fed through kunit_parser to parse the tests to the user. Also added
a signal_handler in case kunit is interrupted while running.
Tested: Run under different conditions such as testing with
--raw_output, testing program interrupt then immediately running kunit
again without --alltests and making sure to clean the console.

Signed-off-by: Heidi Fahim <heidifahim@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: test: Improve error messages for kunit_tool when kunitconfig is invalid

Previous error message for invalid kunitconfig was vague. Added to it so
that it lists invalid fields and prompts for them to be removed. Added
validate_config function returning whether or not this kconfig is valid.

Signed-off-by: Heidi Fahim <heidifahim@google.com>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Rename 'kunitconfig' to '.kunitconfig'

This commit renames 'kunitconfig' to '.kunitconfig' so that it can be
automatically ignored by git and do not disturb people who want to type
'kernel/' by pressing only the 'k' and then 'tab' key.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Place 'test.log' under the 'build_dir'

'kunit' writes the 'test.log' under the kernel source directory even
though a 'build_dir' option is given. As users who use the option might
expect the outputs to be placed under the specified directory, this
commit modifies the logic to write the log file under the 'build_dir'.

Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: Create default config in '--build_dir'

If both '--build_dir' and '--defconfig' are given, the handling of
'--defconfig' ignores '--build_dir' option. This commit modifies the
behavior to respect '--build_dir' option.

Reported-by: Brendan Higgins <brendanhiggins@google.com>
Suggested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: SeongJae Park <sjpark@amazon.de>
Reviewed-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Brendan Higgins <brendanhiggins@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: defconfig: add defconfigs for building KUnit tests

Add defconfig for UML and a fragment that can be used to configure other
architectures for building KUnit tests. Add option to kunit_tool to use
a defconfig to create the kunitconfig.

Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>

kunit: tool: add Python wrappers for running KUnit tests

The ultimate goal is to create minimal isolated test binaries; in the
meantime we are using UML to provide the infrastructure to run tests, so
define an abstract way to configure and run tests that allow us to
change the context in which tests are built without affecting the user.
This also makes pretty and dynamic error reporting, and a lot of other
nice features easier.

kunit_config.py:
- parse .config and Kconfig files.

kunit_kernel.py: provides helper functions to:
- configure the kernel using kunitconfig.
- build the kernel with the appropriate configuration.
- provide function to invoke the kernel and stream the output back.

kunit_parser.py: parses raw logs returned out by kunit_kernel and
displays them in a user friendly way.

test_data/*: samples of test data for testing kunit.py, kunit_config.py,
etc.

Signed-off-by: Felix Guo <felixguoxiuping@gmail.com>
Signed-off-by: Brendan Higgins <brendanhiggins@google.com>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>