qemu/docs/devel/acpi-bits.rst
Ani Sinha 1b7a07c441 acpi/tests/avocado/bits: some misc fixes
Most of the changes are trivial. The bits test timeout has now been increased
to 200 seconds in order to accommodate slower systems and fewer unnecessary
failures. Removed of the reference to non-existent README file in docs. Some
minor corrections in the doc file.

Signed-off-by: Ani Sinha <ani@anisinha.ca>
Message-Id: <20221117053644.516649-1-ani@anisinha.ca>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
2022-11-17 09:58:22 +01:00

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=============================================================================
ACPI/SMBIOS avocado tests using biosbits
=============================================================================
Biosbits is a software written by Josh Triplett that can be downloaded
from https://biosbits.org/. The github codebase can be found
`here <https://github.com/biosbits/bits/tree/master>`__. It is a software that executes
the bios components such as acpi and smbios tables directly through acpica
bios interpreter (a freely available C based library written by Intel,
downloadable from https://acpica.org/ and is included with biosbits) without an
operating system getting involved in between.
There are several advantages to directly testing the bios in a real physical
machine or VM as opposed to indirectly discovering bios issues through the
operating system. For one thing, the OSes tend to hide bios problems from the
end user. The other is that we have more control of what we wanted to test
and how by directly using acpica interpreter on top of the bios on a running
system. More details on the inspiration for developing biosbits and its real
life uses can be found in [#a]_ and [#b]_.
For QEMU, we maintain a fork of bios bits in gitlab along with all the
dependent submodules here: https://gitlab.com/qemu-project/biosbits-bits
This fork contains numerous fixes, a newer acpica and changes specific to
running this avocado QEMU tests using bits. The author of this document
is the sole maintainer of the QEMU fork of bios bits repo.
Under the directory ``tests/avocado/``, ``acpi-bits.py`` is a QEMU avocado
test that drives all this.
A brief description of the various test files follows.
Under ``tests/avocado/`` as the root we have:
::
├── acpi-bits
│ ├── bits-config
│ │ └── bits-cfg.txt
│ ├── bits-tests
│ ├── smbios.py2
│ ├── testacpi.py2
│ └── testcpuid.py2
├── acpi-bits.py
* ``tests/avocado``:
``acpi-bits.py``:
This is the main python avocado test script that generates a
biosbits iso. It then spawns a QEMU VM with it, collects the log and reports
test failures. This is the script one would be interested in if they wanted
to add or change some component of the log parsing, add a new command line
to alter how QEMU is spawned etc. Test writers typically would not need to
modify this script unless they wanted to enhance or change the log parsing
for their tests. In order to enable debugging, you can set **V=1**
environment variable. This enables verbose mode for the test and also dumps
the entire log from bios bits and more information in case failure happens.
In order to run this test, please perform the following steps from the QEMU
build directory:
::
$ make check-venv (needed only the first time to create the venv)
$ ./tests/venv/bin/avocado run -t acpi tests/avocado
The above will run all acpi avocado tests including this one.
In order to run the individual tests, perform the following:
::
$ ./tests/venv/bin/avocado run tests/avocado/acpi-bits.py --tap -
The above will produce output in tap format. You can omit "--tap -" in the
end and it will produce output like the following:
::
$ ./tests/venv/bin/avocado run tests/avocado/acpi-bits.py
Fetching asset from tests/avocado/acpi-bits.py:AcpiBitsTest.test_acpi_smbios_bits
JOB ID : eab225724da7b64c012c65705dc2fa14ab1defef
JOB LOG : /home/anisinha/avocado/job-results/job-2022-10-10T17.58-eab2257/job.log
(1/1) tests/avocado/acpi-bits.py:AcpiBitsTest.test_acpi_smbios_bits: PASS (33.09 s)
RESULTS : PASS 1 | ERROR 0 | FAIL 0 | SKIP 0 | WARN 0 | INTERRUPT 0 | CANCEL 0
JOB TIME : 39.22 s
You can inspect the log file for more information about the run or in order
to diagnoze issues. If you pass V=1 in the environment, more diagnostic logs
would be found in the test log.
* ``tests/avocado/acpi-bits/bits-config``:
This location contains biosbits configuration files that determine how the
software runs the tests.
``bits-config.txt``:
This is the biosbits config file that determines what tests
or actions are performed by bits. The description of the config options are
provided in the file itself.
* ``tests/avocado/acpi-bits/bits-tests``:
This directory contains biosbits python based tests that are run from within
the biosbits environment in the spawned VM. New additions of test cases can
be made in the appropriate test file. For example, new acpi tests can go
into testacpi.py2 and one would call testsuite.add_test() to register the new
test so that it gets executed as a part of the ACPI tests.
It might be occasionally necessary to disable some subtests or add a new
test that belongs to a test suite not already present in this directory. To
do this, please clone the bits source from
https://gitlab.com/qemu-project/biosbits-bits/-/tree/qemu-bits.
Note that this is the "qemu-bits" branch and not the "bits" branch of the
repository. "qemu-bits" is the branch where we have made all the QEMU
specific enhancements and we must use the source from this branch only.
Copy the test suite/script that needs modification (addition of new tests
or disabling them) from python directory into this directory. For
example, in order to change cpuid related tests, copy the following
file into this directory and rename it with .py2 extension:
https://gitlab.com/qemu-project/biosbits-bits/-/blob/qemu-bits/python/testcpuid.py
Then make your additions and changes here. Therefore, the steps are:
(a) Copy unmodified test script to this directory from bits source.
(b) Add a SPDX license header.
(c) Perform modifications to the test.
Commits (a), (b) and (c) should go under separate commits so that the original
test script and the changes we have made are separated and clear.
The test framework will then use your modified test script to run the test.
No further changes would be needed. Please check the logs to make sure that
appropriate changes have taken effect.
The tests have an extension .py2 in order to indicate that:
(a) They are python2.7 based scripts and not python 3 scripts.
(b) They are run from within the bios bits VM and is not subjected to QEMU
build/test python script maintenance and dependency resolutions.
(c) They need not be loaded by avocado framework when running tests.
Author: Ani Sinha <ani@anisinha.ca>
References:
-----------
.. [#a] https://blog.linuxplumbersconf.org/2011/ocw/system/presentations/867/original/bits.pdf
.. [#b] https://www.youtube.com/watch?v=36QIepyUuhg