| commit | 68fff3ac0013d4722aede8a9c8931b5ddc9310b5 | [log] [tgz] |
|---|---|---|
| author | Eric Auger <eric.auger@redhat.com> | Mon Nov 13 18:42:41 2023 +0100 |
| committer | Andrew Jones <andrew.jones@linux.dev> | Tue Nov 21 12:30:34 2023 +0100 |
| tree | 787738e665f1aaf86a8825bcd5ec176c86b2ffb7 | |
| parent | 60f5b29eb1bd8123768ea455eca4d822b400e80e [diff] |
arm: pmu-overflow-interrupt: Increase count values On some hardware, some pmu-overflow-interrupt failures can be observed. Although the even counter overflows, the interrupt is not seen as expected. This happens in the subtest after "promote to 64-b" comment. After analysis, the PMU overflow interrupt actually hits, ie. kvm_pmu_perf_overflow() gets called and KVM_REQ_IRQ_PENDING is set, as expected. However the PMCR.E is reset by the handle_exit path, at kvm_pmu_handle_pmcr() before the next guest entry and kvm_pmu_flush_hwstate/kvm_pmu_update_state subsequent call. There, since the enable bit has been reset, kvm_pmu_update_state() does not inject the interrupt into the guest. This does not seem to be a KVM bug but rather an unfortunate scenario where the test disables the PMCR.E too closely to the advent of the overflow interrupt. Since it looks like a benign and inlikely case, let's resize the number of iterations to prevent the PMCR enable bit from being resetted immediately at the same time as the actual overflow event. COUNT_INT is introduced, arbitrarily set to 1000 iterations and is used in this test. An alternative would be to let the PMU enabled and wait for the interrupt but those extra executions might disturb the counting. Reported-by: Jan Richter <jarichte@redhat.com> Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Shaoqin Huang <shahuang@redhat.com> Signed-off-by: Andrew Jones <andrew.jones@linux.dev>
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
NOTE: GCC cross-compiler is required for build on macOS.
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”, “hvf” or “tcg”, specify the ACCEL=name environment variable:
ACCEL=kvm ./x86-run ./x86/msr.flat
For running tests that involve migration from one QEMU instance to another you also need to have the “ncat” binary (from the nmap.org project) installed, otherwise the related tests will be skipped.
Check x86/efi/README.md.
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, hvf 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: general architecture neutral helper scripts for building and running tests ./scripts/<ARCH>: architecture dependent 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:
Header guards:
Please try to adhere to the following patterns when adding “#ifndef <...> #define <...>” header guards: ./lib: HEADER_H ./lib/: ARCH_HEADER_H ./lib//asm: ASMARCH_HEADER_H ./: ARCH_HEADER_H
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.
We strive to follow the Linux kernels coding style so it‘s recommended to run the kernel’s ./scripts/checkpatch.pl on new patches.