commit | 8feb8cfb0e31fe2ad7ebd101828a4d957ee52739 | [log] [tgz] |
---|---|---|
author | Sean Christopherson <sean.j.christopherson@intel.com> | Tue Apr 28 16:11:35 2020 -0700 |
committer | Paolo Bonzini <pbonzini@redhat.com> | Mon May 04 12:34:55 2020 -0400 |
tree | 652132fb188853498d1858431e7f7595004c8818 | |
parent | 149c2513efc820a4d4a8dd1a3827f8310e95d5be [diff] |
x86: msr: Don't test bits 63:32 of SYSENTER MSRs on 32-bit builds Squish the "address" stuffed into SYSENTER_EIP/ESP into an unsigned long so as to drop bits 63:32 on 32-bit builds. VMX diverges from bare metal in the sense that the associated VMCS fields are natural width fields, whereas the actual MSRs hold 64-bit values, even on CPUs that don't support 64-bit mode. This causes the tests to fail if bits 63:32 are non-zero and a VM-Exit/VM-Enter occurs on and/or between WRMSR/RDMSR, e.g. when running the tests in L1 or deeper. Don't bother trying to actually test that bits 63:32 are dropped, the behavior depends on the (virtual) CPU capabilities, not the build, and the behavior is specific to VMX as both SVM and bare metal preserve the full 64-bit values. And because practically no one cares about 32-bit KVM, let alone an obscure architectural quirk that doesn't affect real world kernels. Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com> Message-Id: <20200428231135.12903-1-sean.j.christopherson@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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.
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 ./ARCH/*.flat
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.
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.
By default the runner script searches for a suitable QEMU binary in the system. To select a specific QEMU binary though, specify the QEMU=path/to/binary 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=name environment variable:
ACCEL=kvm ./x86-run ./x86/msr.flat
The test case may need specific runtime configurations, for example, extra QEMU parameters and time to execute limited, the runner script reads those information from a configuration file found at ./ARCH/unittests.cfg.
The configuration file also contain the groups (if any) each test belong to. So that a given group can be executed by specifying its name in the runner's -g option.
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 file’ 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
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 environment variable is provided and ‘y’
b) the ERRATA_FORCE environment 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.
.: 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 ./ARCH/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:
Exceptions:
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.