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[RFC,v1,00/10] roadtest: a driver testing framework

Message ID 20220311162445.346685-1-vincent.whitchurch@axis.com
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Series roadtest: a driver testing framework | expand

Message

Vincent Whitchurch March 11, 2022, 4:24 p.m. UTC
This patchset proposes roadtest, a device-driver testing framework.  Drivers
are tested under User Mode Linux (UML) and interact with mocked/modelled
hardware.  The tests and hardware models are written in Python, the former
using Python's built-in unittest framework.

Drivers are tested via their userspace interfaces.  The hardware models allow
tests to inject values into registers and assert that drivers control the
hardware in the right way and react as expected to stimuli.

Roadtest is meant to be used for relatively simple drivers, such as the ones
part of the IIO, regulator and RTC subsystems.

Questions and answers:

= Why do we need this?

There are a large amount of these kind of drivers in the kernel.  Most of the
hardware is not available in current CI systems so most drivers can only, at
best, be build-tested there.  Even basic soundness such as a driver
successfully probing and binding to the devices it tries to be support cannot
be tested.  Drivers cannot be easily regression-tested to ensure that bugs
fixed once do not get reintroduced.

Many drivers support multiple related hardware variants, and far from all patch
submitters have access to all the variants which the driver that they are
patching supports, so there is no way for them to easily verify that they
haven't broken something basic on a variant which they do not own.

Furthermore, hardware can be used in many different configurations with drivers
supporting many different devicetree properties, so even just having access to
all the variants would be insufficient.

On top of that, some of the chips measure environmental conditions such as
temperature, so testing extreme cases may not be simple even if one has access
to the hardware.

All this makes development, modification, maintenance, and reviewing of these
drivers harder than it necessarily needs to be.  Roadtest hopes to make some of
these things slightly easier by providing a framework to create hardware
models/mocks and to write testcases which exercise drivers using these models.

= Do you have some specific examples of the kind of code this could be used to
  test?

Here is an example of a patch which can easily be regression-tested using
roadtest (in fact, this series includes such a regression test) but is much
harder to do so automatically with real hardware since it requires specific
environmental conditions:

 iio: light: opt3001: Fixed timeout error when 0 lux
 https://lore.kernel.org/lkml/20210920125351.6569-1-valek@2n.cz/

Here is another example.  This driver has code which correctly parses a
documented devicetree property (amstaos,proximity-diodes) but which then fails
to actually communicate this setting to the hardware in any way.  Such code can
be easily tested with roadtest since the framework integrates devicetree
support and provides functions to assert that drivers writes expected registers
with expected values:

 drivers/iio/light/tsl2772.c tsl2772_read_prox_diodes()

(Both the above examples happen to be from the same subsystem but that should
in no way be taken to imply that such issues are unique to that subsystem or
that that subsystem has more of them.)

= How does this relate to kselftests?

Tests in kselftests also test kernel code using the userspace interfaces, but
that's about what's common between the frameworks.  kselftests has other goals
and does not provide any kind of mechanism for hardware mocking.

= How does this relate to kunit?

Kunit is for unit testing of functions in kernel code, and is not meant for
testing kernel code via userspace interfaces.  It could in theory be used to
test some of the simple drivers too, but that would require (1) a large amount
of mocking code in various kernel frameworks, and, more importantly, (2)
refactoring of the drivers to be tested.

This can be contrasted with roadtest which works with mostly unmodified drivers
and which mocks the hardware at the lowest level without having to change
kernel frameworks.

= How do I use it?

See Documentation/dev-tools/roadtest.rst added by the documentation patch for
more information about running and writing tests using this framework.

= What's included in the patchset?

The current framework allows developing tests for hardware which uses the I2C
bus.  Hardware models can also control GPIOs and use them to trigger
interrupts.

This series includes tests for some IIO, regulator and RTC drivers.  The
regulator and RTC tests depend on a few driver patches which are either in
review or in linux-next.  These are noted in the commit messages.

The entire patch set, including the required dependencies, is also available in
a git tree:

 https://github.com/vwax/linux/commits/roadtest/rfc-v1

Cc: linux-kernel@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-um@lists.infradead.org

Cc: shuah@kernel.org
Cc: brendanhiggins@google.com
Cc: linux-kselftest@vger.kernel.org

Cc: jic23@kernel.org
Cc: linux-iio@vger.kernel.org

Cc: lgirdwood@gmail.com
Cc: broonie@kernel.org

Cc: a.zummo@towertech.it
Cc: alexandre.belloni@bootlin.com
Cc: linux-rtc@vger.kernel.org

Cc: corbet@lwn.net
Cc: linux-doc@vger.kernel.org

Vincent Whitchurch (10):
  roadtest: import libvhost-user from QEMU
  roadtest: add C backend
  roadtest: add framework
  roadtest: add base config
  roadtest: add build files
  roadtest: add documentation
  iio: light: opt3001: add roadtest
  iio: light: vcnl4000: add roadtest
  regulator: tps62864: add roadtest
  rtc: pcf8563: add roadtest

 Documentation/dev-tools/index.rst             |    1 +
 Documentation/dev-tools/roadtest.rst          |  669 ++++
 tools/testing/roadtest/.gitignore             |    2 +
 tools/testing/roadtest/Dockerfile             |   25 +
 tools/testing/roadtest/Makefile               |   84 +
 tools/testing/roadtest/init.sh                |   19 +
 tools/testing/roadtest/pyproject.toml         |   10 +
 tools/testing/roadtest/requirements.txt       |    4 +
 tools/testing/roadtest/roadtest/__init__.py   |    2 +
 .../roadtest/roadtest/backend/__init__.py     |    0
 .../roadtest/roadtest/backend/backend.py      |   32 +
 .../testing/roadtest/roadtest/backend/gpio.py |  111 +
 .../testing/roadtest/roadtest/backend/i2c.py  |  123 +
 .../testing/roadtest/roadtest/backend/main.py |   13 +
 .../testing/roadtest/roadtest/backend/mock.py |   20 +
 .../roadtest/roadtest/backend/test_gpio.py    |   98 +
 .../roadtest/roadtest/backend/test_i2c.py     |   84 +
 .../testing/roadtest/roadtest/cmd/__init__.py |    0
 tools/testing/roadtest/roadtest/cmd/main.py   |  146 +
 tools/testing/roadtest/roadtest/cmd/remote.py |   48 +
 .../roadtest/roadtest/core/__init__.py        |    0
 .../testing/roadtest/roadtest/core/control.py |   52 +
 .../roadtest/roadtest/core/devicetree.py      |  155 +
 .../roadtest/roadtest/core/hardware.py        |   94 +
 tools/testing/roadtest/roadtest/core/log.py   |   42 +
 .../testing/roadtest/roadtest/core/modules.py |   38 +
 .../testing/roadtest/roadtest/core/opslog.py  |   35 +
 tools/testing/roadtest/roadtest/core/proxy.py |   48 +
 tools/testing/roadtest/roadtest/core/suite.py |  286 ++
 tools/testing/roadtest/roadtest/core/sysfs.py |   77 +
 .../roadtest/roadtest/core/test_control.py    |   35 +
 .../roadtest/roadtest/core/test_devicetree.py |   31 +
 .../roadtest/roadtest/core/test_hardware.py   |   41 +
 .../roadtest/roadtest/core/test_log.py        |   54 +
 .../roadtest/roadtest/core/test_opslog.py     |   27 +
 .../roadtest/roadtest/tests/__init__.py       |    0
 .../roadtest/roadtest/tests/base/config       |   84 +
 .../roadtest/roadtest/tests/iio/__init__.py   |    0
 .../roadtest/roadtest/tests/iio/config        |    1 +
 .../roadtest/roadtest/tests/iio/iio.py        |  112 +
 .../roadtest/tests/iio/light/__init__.py      |    0
 .../roadtest/roadtest/tests/iio/light/config  |    2 +
 .../roadtest/tests/iio/light/test_opt3001.py  |   95 +
 .../roadtest/tests/iio/light/test_vcnl4000.py |  132 +
 .../roadtest/tests/iio/light/test_vcnl4010.py |  282 ++
 .../roadtest/tests/iio/light/test_vcnl4040.py |  104 +
 .../roadtest/tests/iio/light/test_vcnl4200.py |   96 +
 .../roadtest/tests/regulator/__init__.py      |    0
 .../roadtest/roadtest/tests/regulator/config  |    4 +
 .../roadtest/tests/regulator/test_tps62864.py |  187 ++
 .../roadtest/roadtest/tests/rtc/__init__.py   |    0
 .../roadtest/roadtest/tests/rtc/config        |    1 +
 .../roadtest/roadtest/tests/rtc/rtc.py        |   73 +
 .../roadtest/tests/rtc/test_pcf8563.py        |  348 ++
 tools/testing/roadtest/src/.gitignore         |    1 +
 tools/testing/roadtest/src/backend.c          |  884 +++++
 .../src/libvhost-user/include/atomic.h        |  310 ++
 .../src/libvhost-user/libvhost-user.c         | 2885 +++++++++++++++++
 .../src/libvhost-user/libvhost-user.h         |  691 ++++
 59 files changed, 8798 insertions(+)
 create mode 100644 Documentation/dev-tools/roadtest.rst
 create mode 100644 tools/testing/roadtest/.gitignore
 create mode 100644 tools/testing/roadtest/Dockerfile
 create mode 100644 tools/testing/roadtest/Makefile
 create mode 100755 tools/testing/roadtest/init.sh
 create mode 100644 tools/testing/roadtest/pyproject.toml
 create mode 100644 tools/testing/roadtest/requirements.txt
 create mode 100644 tools/testing/roadtest/roadtest/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/backend.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/gpio.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/i2c.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/main.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/mock.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/test_gpio.py
 create mode 100644 tools/testing/roadtest/roadtest/backend/test_i2c.py
 create mode 100644 tools/testing/roadtest/roadtest/cmd/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/cmd/main.py
 create mode 100644 tools/testing/roadtest/roadtest/cmd/remote.py
 create mode 100644 tools/testing/roadtest/roadtest/core/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/core/control.py
 create mode 100644 tools/testing/roadtest/roadtest/core/devicetree.py
 create mode 100644 tools/testing/roadtest/roadtest/core/hardware.py
 create mode 100644 tools/testing/roadtest/roadtest/core/log.py
 create mode 100644 tools/testing/roadtest/roadtest/core/modules.py
 create mode 100644 tools/testing/roadtest/roadtest/core/opslog.py
 create mode 100644 tools/testing/roadtest/roadtest/core/proxy.py
 create mode 100644 tools/testing/roadtest/roadtest/core/suite.py
 create mode 100644 tools/testing/roadtest/roadtest/core/sysfs.py
 create mode 100644 tools/testing/roadtest/roadtest/core/test_control.py
 create mode 100644 tools/testing/roadtest/roadtest/core/test_devicetree.py
 create mode 100644 tools/testing/roadtest/roadtest/core/test_hardware.py
 create mode 100644 tools/testing/roadtest/roadtest/core/test_log.py
 create mode 100644 tools/testing/roadtest/roadtest/core/test_opslog.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/base/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/iio.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_opt3001.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4000.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4010.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4040.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4200.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/regulator/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/regulator/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/regulator/test_tps62864.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/__init__.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/config
 create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/rtc.py
 create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/test_pcf8563.py
 create mode 100644 tools/testing/roadtest/src/.gitignore
 create mode 100644 tools/testing/roadtest/src/backend.c
 create mode 100644 tools/testing/roadtest/src/libvhost-user/include/atomic.h
 create mode 100644 tools/testing/roadtest/src/libvhost-user/libvhost-user.c
 create mode 100644 tools/testing/roadtest/src/libvhost-user/libvhost-user.h

Comments

Johannes Berg March 24, 2022, 1 p.m. UTC | #1
On Fri, 2022-03-11 at 17:24 +0100, Vincent Whitchurch wrote:
> Import the libvhost-user from QEMU for use in the implementation of the
> virtio devices in the roadtest backend.
> 

So hm, I wonder if this is the sensible thing to do?

Not that I mind importing qemu code, but:

 1) the implementation is rather complex in some places, and has support
    for a LOT of virtio/vhost-user features that are really not needed
    in these cases, for performance etc. It's also close to 4k LOC.

 2) the implementation doesn't support time-travel mode which might come
    in handy

We have another implementation that might be simpler:
https://github.com/linux-test-project/usfstl/blob/main/src/vhost.c

but it probably has dependencies on other things in this library, but
vhost.c itself is only ~1k LOC. (But I need to update it, I'm sure we
have some unpublished bugfixes etc. in this code)

johannes
Vincent Whitchurch April 5, 2022, 1:54 p.m. UTC | #2
On Thu, Mar 24, 2022 at 02:00:10PM +0100, Johannes Berg wrote:
> On Fri, 2022-03-11 at 17:24 +0100, Vincent Whitchurch wrote:
> > Import the libvhost-user from QEMU for use in the implementation of the
> > virtio devices in the roadtest backend.
> 
> So hm, I wonder if this is the sensible thing to do?
> 
> Not that I mind importing qemu code, but:
> 
>  1) the implementation is rather complex in some places, and has support
>     for a LOT of virtio/vhost-user features that are really not needed
>     in these cases, for performance etc. It's also close to 4k LOC.

Is this really a problem given that the code is imported as-is?  The
intention is not to have to make a lot of local modifications to it in
the kernel tree.  The code is stable and presumably well-tested
upstream, and upstream maintains it as a separate library (in the QEMU
source tree though) to encourage reuse.

>  2) the implementation doesn't support time-travel mode which might come
>     in handy

True, but I don't see the external time-travel controller stuff being
too useful for the kinds of tests this framework is targeting.
Jonathan Cameron April 18, 2022, 7:44 p.m. UTC | #3
On Fri, 11 Mar 2022 17:24:35 +0100
Vincent Whitchurch <vincent.whitchurch@axis.com> wrote:

> This patchset proposes roadtest, a device-driver testing framework.  Drivers
> are tested under User Mode Linux (UML) and interact with mocked/modelled
> hardware.  The tests and hardware models are written in Python, the former
> using Python's built-in unittest framework.
> 
> Drivers are tested via their userspace interfaces.  The hardware models allow
> tests to inject values into registers and assert that drivers control the
> hardware in the right way and react as expected to stimuli.
> 
> Roadtest is meant to be used for relatively simple drivers, such as the ones
> part of the IIO, regulator and RTC subsystems.

Hi All,

Just wanted to very briefly report back on my experience of using this framework.

Given I wanted a suitable job to try out it's usefulness when doing refactoring
/development, I decided to tidy up one of the remaining IIO drivers in staging
and see how things went in developing tests to hit the particular code I was
modifying.  At some point I might extend this to a more comprehensive test suite
for that driver, but for now it does basic channel reading and a few other things
+ verifies some of the register state changes seen on the hardware side of things.

Whilst my python could be said to be decidedly rusty (last time I recall writing
some was for an intern project 20 years back), it was fairly easy to get something
working using the docs in this series and the fine engineering tool of cut and paste.

Road test worked very well.

Was it easier than my existing hacked up QEMU board emulation that lets me
instantiate minimal emulation pretty quickly?

Pretty similar on balance but big advantage here is I'm not having to ask people
to go fetch a tree and build QEMU just to sanity check the driver changes.
Also note I'm doing a lot of QEMU work for the day job at the moment, so it's not
really a fair comparison if the question is what would most kernel driver
developers find useful.

So for now I'll probably mix and match depending on the complexity of the device
I'm emulating, but roadtest is definitely a good addition to the toolkit.

Note this is putting aside all the advantages of having tests in tree and the
much lighter amount of infrastructure needed to run those over QEMU CI.

If anyone is curious patch set with tests and the staging graduation of
the AD7746 CDC driver.

https://lore.kernel.org/all/20220418192907.763933-18-jic23@kernel.org/

Great work Vincent. I'm looking forward to using this more.

Thanks,

Jonathan

> 
> Questions and answers:
> 
> = Why do we need this?
> 
> There are a large amount of these kind of drivers in the kernel.  Most of the
> hardware is not available in current CI systems so most drivers can only, at
> best, be build-tested there.  Even basic soundness such as a driver
> successfully probing and binding to the devices it tries to be support cannot
> be tested.  Drivers cannot be easily regression-tested to ensure that bugs
> fixed once do not get reintroduced.
> 
> Many drivers support multiple related hardware variants, and far from all patch
> submitters have access to all the variants which the driver that they are
> patching supports, so there is no way for them to easily verify that they
> haven't broken something basic on a variant which they do not own.
> 
> Furthermore, hardware can be used in many different configurations with drivers
> supporting many different devicetree properties, so even just having access to
> all the variants would be insufficient.
> 
> On top of that, some of the chips measure environmental conditions such as
> temperature, so testing extreme cases may not be simple even if one has access
> to the hardware.
> 
> All this makes development, modification, maintenance, and reviewing of these
> drivers harder than it necessarily needs to be.  Roadtest hopes to make some of
> these things slightly easier by providing a framework to create hardware
> models/mocks and to write testcases which exercise drivers using these models.
> 
> = Do you have some specific examples of the kind of code this could be used to
>   test?
> 
> Here is an example of a patch which can easily be regression-tested using
> roadtest (in fact, this series includes such a regression test) but is much
> harder to do so automatically with real hardware since it requires specific
> environmental conditions:
> 
>  iio: light: opt3001: Fixed timeout error when 0 lux
>  https://lore.kernel.org/lkml/20210920125351.6569-1-valek@2n.cz/
> 
> Here is another example.  This driver has code which correctly parses a
> documented devicetree property (amstaos,proximity-diodes) but which then fails
> to actually communicate this setting to the hardware in any way.  Such code can
> be easily tested with roadtest since the framework integrates devicetree
> support and provides functions to assert that drivers writes expected registers
> with expected values:
> 
>  drivers/iio/light/tsl2772.c tsl2772_read_prox_diodes()
> 
> (Both the above examples happen to be from the same subsystem but that should
> in no way be taken to imply that such issues are unique to that subsystem or
> that that subsystem has more of them.)
> 
> = How does this relate to kselftests?
> 
> Tests in kselftests also test kernel code using the userspace interfaces, but
> that's about what's common between the frameworks.  kselftests has other goals
> and does not provide any kind of mechanism for hardware mocking.
> 
> = How does this relate to kunit?
> 
> Kunit is for unit testing of functions in kernel code, and is not meant for
> testing kernel code via userspace interfaces.  It could in theory be used to
> test some of the simple drivers too, but that would require (1) a large amount
> of mocking code in various kernel frameworks, and, more importantly, (2)
> refactoring of the drivers to be tested.
> 
> This can be contrasted with roadtest which works with mostly unmodified drivers
> and which mocks the hardware at the lowest level without having to change
> kernel frameworks.
> 
> = How do I use it?
> 
> See Documentation/dev-tools/roadtest.rst added by the documentation patch for
> more information about running and writing tests using this framework.
> 
> = What's included in the patchset?
> 
> The current framework allows developing tests for hardware which uses the I2C
> bus.  Hardware models can also control GPIOs and use them to trigger
> interrupts.
> 
> This series includes tests for some IIO, regulator and RTC drivers.  The
> regulator and RTC tests depend on a few driver patches which are either in
> review or in linux-next.  These are noted in the commit messages.
> 
> The entire patch set, including the required dependencies, is also available in
> a git tree:
> 
>  https://github.com/vwax/linux/commits/roadtest/rfc-v1
> 
> Cc: linux-kernel@vger.kernel.org
> Cc: devicetree@vger.kernel.org
> Cc: linux-um@lists.infradead.org
> 
> Cc: shuah@kernel.org
> Cc: brendanhiggins@google.com
> Cc: linux-kselftest@vger.kernel.org
> 
> Cc: jic23@kernel.org
> Cc: linux-iio@vger.kernel.org
> 
> Cc: lgirdwood@gmail.com
> Cc: broonie@kernel.org
> 
> Cc: a.zummo@towertech.it
> Cc: alexandre.belloni@bootlin.com
> Cc: linux-rtc@vger.kernel.org
> 
> Cc: corbet@lwn.net
> Cc: linux-doc@vger.kernel.org
> 
> Vincent Whitchurch (10):
>   roadtest: import libvhost-user from QEMU
>   roadtest: add C backend
>   roadtest: add framework
>   roadtest: add base config
>   roadtest: add build files
>   roadtest: add documentation
>   iio: light: opt3001: add roadtest
>   iio: light: vcnl4000: add roadtest
>   regulator: tps62864: add roadtest
>   rtc: pcf8563: add roadtest
> 
>  Documentation/dev-tools/index.rst             |    1 +
>  Documentation/dev-tools/roadtest.rst          |  669 ++++
>  tools/testing/roadtest/.gitignore             |    2 +
>  tools/testing/roadtest/Dockerfile             |   25 +
>  tools/testing/roadtest/Makefile               |   84 +
>  tools/testing/roadtest/init.sh                |   19 +
>  tools/testing/roadtest/pyproject.toml         |   10 +
>  tools/testing/roadtest/requirements.txt       |    4 +
>  tools/testing/roadtest/roadtest/__init__.py   |    2 +
>  .../roadtest/roadtest/backend/__init__.py     |    0
>  .../roadtest/roadtest/backend/backend.py      |   32 +
>  .../testing/roadtest/roadtest/backend/gpio.py |  111 +
>  .../testing/roadtest/roadtest/backend/i2c.py  |  123 +
>  .../testing/roadtest/roadtest/backend/main.py |   13 +
>  .../testing/roadtest/roadtest/backend/mock.py |   20 +
>  .../roadtest/roadtest/backend/test_gpio.py    |   98 +
>  .../roadtest/roadtest/backend/test_i2c.py     |   84 +
>  .../testing/roadtest/roadtest/cmd/__init__.py |    0
>  tools/testing/roadtest/roadtest/cmd/main.py   |  146 +
>  tools/testing/roadtest/roadtest/cmd/remote.py |   48 +
>  .../roadtest/roadtest/core/__init__.py        |    0
>  .../testing/roadtest/roadtest/core/control.py |   52 +
>  .../roadtest/roadtest/core/devicetree.py      |  155 +
>  .../roadtest/roadtest/core/hardware.py        |   94 +
>  tools/testing/roadtest/roadtest/core/log.py   |   42 +
>  .../testing/roadtest/roadtest/core/modules.py |   38 +
>  .../testing/roadtest/roadtest/core/opslog.py  |   35 +
>  tools/testing/roadtest/roadtest/core/proxy.py |   48 +
>  tools/testing/roadtest/roadtest/core/suite.py |  286 ++
>  tools/testing/roadtest/roadtest/core/sysfs.py |   77 +
>  .../roadtest/roadtest/core/test_control.py    |   35 +
>  .../roadtest/roadtest/core/test_devicetree.py |   31 +
>  .../roadtest/roadtest/core/test_hardware.py   |   41 +
>  .../roadtest/roadtest/core/test_log.py        |   54 +
>  .../roadtest/roadtest/core/test_opslog.py     |   27 +
>  .../roadtest/roadtest/tests/__init__.py       |    0
>  .../roadtest/roadtest/tests/base/config       |   84 +
>  .../roadtest/roadtest/tests/iio/__init__.py   |    0
>  .../roadtest/roadtest/tests/iio/config        |    1 +
>  .../roadtest/roadtest/tests/iio/iio.py        |  112 +
>  .../roadtest/tests/iio/light/__init__.py      |    0
>  .../roadtest/roadtest/tests/iio/light/config  |    2 +
>  .../roadtest/tests/iio/light/test_opt3001.py  |   95 +
>  .../roadtest/tests/iio/light/test_vcnl4000.py |  132 +
>  .../roadtest/tests/iio/light/test_vcnl4010.py |  282 ++
>  .../roadtest/tests/iio/light/test_vcnl4040.py |  104 +
>  .../roadtest/tests/iio/light/test_vcnl4200.py |   96 +
>  .../roadtest/tests/regulator/__init__.py      |    0
>  .../roadtest/roadtest/tests/regulator/config  |    4 +
>  .../roadtest/tests/regulator/test_tps62864.py |  187 ++
>  .../roadtest/roadtest/tests/rtc/__init__.py   |    0
>  .../roadtest/roadtest/tests/rtc/config        |    1 +
>  .../roadtest/roadtest/tests/rtc/rtc.py        |   73 +
>  .../roadtest/tests/rtc/test_pcf8563.py        |  348 ++
>  tools/testing/roadtest/src/.gitignore         |    1 +
>  tools/testing/roadtest/src/backend.c          |  884 +++++
>  .../src/libvhost-user/include/atomic.h        |  310 ++
>  .../src/libvhost-user/libvhost-user.c         | 2885 +++++++++++++++++
>  .../src/libvhost-user/libvhost-user.h         |  691 ++++
>  59 files changed, 8798 insertions(+)
>  create mode 100644 Documentation/dev-tools/roadtest.rst
>  create mode 100644 tools/testing/roadtest/.gitignore
>  create mode 100644 tools/testing/roadtest/Dockerfile
>  create mode 100644 tools/testing/roadtest/Makefile
>  create mode 100755 tools/testing/roadtest/init.sh
>  create mode 100644 tools/testing/roadtest/pyproject.toml
>  create mode 100644 tools/testing/roadtest/requirements.txt
>  create mode 100644 tools/testing/roadtest/roadtest/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/backend.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/gpio.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/i2c.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/main.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/mock.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/test_gpio.py
>  create mode 100644 tools/testing/roadtest/roadtest/backend/test_i2c.py
>  create mode 100644 tools/testing/roadtest/roadtest/cmd/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/cmd/main.py
>  create mode 100644 tools/testing/roadtest/roadtest/cmd/remote.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/control.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/devicetree.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/hardware.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/log.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/modules.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/opslog.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/proxy.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/suite.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/sysfs.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/test_control.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/test_devicetree.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/test_hardware.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/test_log.py
>  create mode 100644 tools/testing/roadtest/roadtest/core/test_opslog.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/base/config
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/config
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/iio.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/config
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_opt3001.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4000.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4010.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4040.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/iio/light/test_vcnl4200.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/regulator/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/regulator/config
>  create mode 100644 tools/testing/roadtest/roadtest/tests/regulator/test_tps62864.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/__init__.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/config
>  create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/rtc.py
>  create mode 100644 tools/testing/roadtest/roadtest/tests/rtc/test_pcf8563.py
>  create mode 100644 tools/testing/roadtest/src/.gitignore
>  create mode 100644 tools/testing/roadtest/src/backend.c
>  create mode 100644 tools/testing/roadtest/src/libvhost-user/include/atomic.h
>  create mode 100644 tools/testing/roadtest/src/libvhost-user/libvhost-user.c
>  create mode 100644 tools/testing/roadtest/src/libvhost-user/libvhost-user.h
>