* Chang S. Bae chang.seok.bae@intel.com wrote:
Hi all,
This series proposes a rework of xstate-related tests to improve maintainability and expand test coverage.
== Motivation: Addressing Missing and New XSTATE Tests ==
With the introduction of AMX, a new test suite [1] was created to verify dynamic state handling by the kernel as observed from userspace. However, previous tests for non-dynamic states like AVX lacked ABI validation, leaving gaps in coverage. While these states currently function without major issues (following the alternate sigstack fix [2]), xstate testing in the x86 selftest suite has been largely overlooked.
Now, with Intel introducing another extended state, Advanced Performance Extensions (APX) [3], a correspondent test case is need. The APX enabling series will follow shortly and will leverage this refactored selftest framework.
== Selftest Code Rework ==
To ensure ABI validation and core functionality across various xstates, refactoring the test code is necessary. Without this, existing code from amx.c would need to be duplicated, compromising the structural quality of xstate tests.
This series introduces a shared test framework for extended state validation, applicable to both existing and new xstates. The test cases cover:
- Context switching
- ABI compatibility for signal handling
- ABI compatibility for ptrace interactions
== Patch Organization ==
The patchset is structured as follows:
- PATCH1: Preparatory cleanup — removing redundant signal handler registration code.
- PATCH2/3: Introduce low-level XSAVE helpers and xstate component enumeration.
- PATCH4/5: Refactor existing test code.
- PATCH6: Introduce a new signal test case.
- PATCH7/8: Consolidate test invocations and clarify the list of supported features.
- PATCH9: Add test coverage for AVX.
== Coverage and Future Work Considerations ==
Currently, these tests are aligned with 64-bit mode only. Support for 32-bit cases will be considered when necessary, but only after this phase of rework is finalized.
FWIW, the AMX TILECFG state is trivial, requiring almost constant values. Additionally, various PKRU tests are already established in tools/selftests/mm.
This series is based on the tip/master branch. You can also find it in the following repository: git://github.com/intel/apx.git selftest-xstate_v1
Thanks, Chang
[1] https://lore.kernel.org/all/20211026122523.AFB99C1F@davehans-spike.ostc.inte... [2] https://lore.kernel.org/lkml/20210518200320.17239-1-chang.seok.bae@intel.com... [3] https://www.intel.com/content/www/us/en/developer/articles/technical/advance...
Chang S. Bae (9): selftests/x86: Consolidate redundant signal helper functions selftests/x86/xstate: Refactor XSAVE helpers for general use selftests/x86/xstate: Enumerate and name xstate components selftests/x86/xstate: Refactor context switching test selftests/x86/xstate: Refactor ptrace ABI test selftests/x86/xstate: Introduce signal ABI test selftests/x86/xstate: Consolidate test invocations into a single entry selftests/x86/xstate: Clarify supported xstates selftests/x86/avx: Add AVX test
22 files changed, 753 insertions(+), 720 deletions(-)
Thank you very much for doing this - this series is a very big step forward in this area.
I've applied your series to tip:x86/fpu with minor edits to the changelogs, and if all goes fine it should all go upstream in the v6.15 merge window in a couple of weeks.
Thanks,
Ingo