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>

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>

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>

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>

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>

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>

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>

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>

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>

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>