Welcome to kvm-unit-tests
See http://www.linux-kvm.org/page/KVM-unit-tests for a high-level description of this project, as well as running tests and adding tests HOWTOs.
Building the tests
This directory contains sources for a kvm test suite.
To create the test images do:
./configure
make
in this directory. Test images are created in .//*.flat
Standalone tests
The tests can be built as standalone To create and use standalone tests do:
./configure
make standalone
(send tests/some-test somewhere)
(go to somewhere)
./some-test
'make install' will install all tests in PREFIX/share/kvm-unit-tests/tests, each as a standalone test.
Running the tests
Then use the runner script to detect the correct invocation and invoke the test:
./x86-run ./x86/msr.flat
or:
./run_tests.sh
to run them all.
To select a specific qemu binary, specify the QEMU= environment variable:
QEMU=/tmp/qemu/x86_64-softmmu/qemu-system-x86_64 ./x86-run ./x86/msr.flat
To select an accelerator, for example "kvm" or "tcg", specify the ACCEL= environment variable:
ACCEL=kvm ./x86-run ./x86/msr.flat
Unit test inputs
Unit tests use QEMU's '-append <args...>' parameter for command line inputs, i.e. all args will be available as argv strings in main(). Additionally a file of the form
KEY=VAL KEY2=VAL ...
may be passed with '-initrd ' to become the unit test's environ, which can then be accessed in the usual ways, e.g. VAL = getenv("KEY") Any key=val strings can be passed, but some have reserved meanings in the framework. The list of reserved environment variables is below
QEMU_ACCEL ... either kvm or tcg
QEMU_VERSION_STRING ... string of the form qemu -h | head -1
KERNEL_VERSION_STRING ... string of the form uname -r
Additionally these self-explanatory variables are reserved
QEMU_MAJOR, QEMU_MINOR, QEMU_MICRO, KERNEL_VERSION, KERNEL_PATCHLEVEL, KERNEL_SUBLEVEL, KERNEL_EXTRAVERSION
Guarding unsafe tests
Some tests are not safe to run by default, as they may crash the host. kvm-unit-tests provides two ways to handle tests like those.
-
Adding 'nodefault' to the groups field for the unit test in the unittests.cfg file. When a unit test is in the nodefault group it is only run when invoked
a) independently, arch-run arch/test b) by specifying any other non-nodefault group it is in, groups = nodefault,mygroup : ./run_tests.sh -g mygroup c) by specifying all tests should be run, ./run_tests.sh -a
-
Making the test conditional on errata in the code, if (ERRATA(abcdef012345)) { do_unsafe_test(); }
With the errata condition the unsafe unit test is only run when
a) the ERRATA_abcdef012345 environ variable is provided and 'y' b) the ERRATA_FORCE environ variable is provided and 'y' c) by specifying all tests should be run, ./run_tests.sh -a (The -a switch ensures the ERRATA_FORCE is provided and set to 'y'.)
The errata.txt file provides a mapping of the commits needed by errata conditionals to their respective minimum kernel versions. By default, when the user does not provide an environ, then an environ generated from the errata.txt file and the host's kernel version is provided to all unit tests.
Contributing
Directory structure
.: configure script, top-level Makefile, and run_tests.sh
./scripts: helper scripts for building and running tests
./lib: general architecture neutral services for the tests
./lib/<ARCH>: architecture dependent services for the tests
./<ARCH>: the sources of the tests and the created objects/images
See /README for architecture specific documentation.
Style
Currently there is a mix of indentation styles so any changes to existing files should be consistent with the existing style. For new files:
- C: please use standard linux-with-tabs, see Linux kernel doc Documentation/process/coding-style.rst
- Shell: use TABs for indentation
Exceptions:
- While the kernel standard requires 80 columns, we allow up to 120.
Patches
Patches are welcome at the KVM mailing list kvm@vger.kernel.org.
Please prefix messages with: [kvm-unit-tests PATCH]
You can add the following to .git/config to do this automatically for you:
[format]
subjectprefix = kvm-unit-tests PATCH
Additionally it's helpful to have a common order of file types in patches.
Our chosen order attempts to place the more declarative files before
the code files. We also start with common code and finish with unit test
code. git-diff's orderFile feature allows us to specify the order in a
file. The orderFile we use is scripts/git.difforder
. Adding the config
with git config diff.orderFile scripts/git.difforder
enables it.