x86: allow using memory above 4 GiB
3 files changed
tree: d07d859fb17e355c9a61ef23850af73420a271d1
  1. api/
  2. arm/
  3. lib/
  4. powerpc/
  5. s390x/
  6. scripts/
  7. x86/
  8. .gitignore
  9. .gitlab-ci.yml
  10. .travis.yml
  11. configure
  13. errata.txt
  15. Makefile
  16. README.md
  17. run_tests.sh

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:


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:

make standalone
(send tests/some-test somewhere)
(go to somewhere)

‘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



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


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


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.

  1. 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

  2. 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.


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.


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


  • While the kernel standard requires 80 columns, we allow up to 120.


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:

    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.