kernel/tools/testing/selftests/x86/xstate.h, branch linux-rolling-stable

selftests: complete kselftest include centralization

2025-11-27T22:24:31Z

This follow-up patch completes centralization of kselftest.h and ksefltest_harness.h includes in remaining seltests files, replacing all relative paths with a non-relative paths using shared -I include path in lib.mk Tested with gcc-13.3 and clang-18.1, and cross-compiled successfully on riscv, arm64, x86_64 and powerpc arch. [reddybalavignesh9979@gmail.com: add selftests include path for kselftest.h] Link: https://lkml.kernel.org/r/20251017090201.317521-1-reddybalavignesh9979@gmail.com Link: https://lkml.kernel.org/r/20251016104409.68985-1-reddybalavignesh9979@gmail.com Signed-off-by: Bala-Vignesh-Reddy Suggested-by: Andrew Morton Link: https://lore.kernel.org/lkml/20250820143954.33d95635e504e94df01930d0@linux-foundation.org/ Reviewed-by: Wei Yang Cc: David Hildenbrand Cc: David S. Miller Cc: Eric Dumazet Cc: Günther Noack Cc: Jakub Kacinski Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mickael Salaun Cc: Ming Lei Cc: Paolo Abeni Cc: Shuah Khan Cc: Simon Horman Cc: Suren Baghdasaryan Cc: Vlastimil Babka Signed-off-by: Andrew Morton

selftests/x86/apx: Add APX test

2025-04-16T07:44:14Z

The extended general-purpose registers for APX may contain random data, which is currently assumed by the xstate testing framework. This allows the testing of the new userspace feature using the common test code. Invoke the test entry function from apx.c after enumerating the state component and adding it to the support list Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Reviewed-by: Sohil Mehta Cc: Andy Lutomirski Cc: H. Peter Anvin Cc: Linus Torvalds Cc: Oleg Nesterov Link: https://lore.kernel.org/r/20250416021720.12305-6-chang.seok.bae@intel.com

selftests/x86/xstate: Consolidate test invocations into a single entry

2025-02-26T12:05:29Z

Currently, each of the three xstate tests runs as a separate invocation, requiring the xstate number to be passed and state information to be reconstructed repeatedly. This approach arose from their individual and isolated development, but now it makes sense to unify them. Introduce a wrapper function that first verifies feature availability from the kernel and constructs the necessary state information once. The wrapper then sequentially invokes all tests to ensure consistent execution. Update the AMX test to use this unified invocation. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-8-chang.seok.bae@intel.com

selftests/x86/xstate: Introduce signal ABI test

2025-02-26T12:05:29Z

With the refactored test cases, another xstate exposure to userspace is through signal delivery. While amx.c includes signal-related scenarios, its primary focus is on xstate permission management, which is largely specific to dynamic states. The remaining gap is testing xstate preservation and restoration across signal delivery. The kernel defines an ABI for presenting xstate in the signal frame, closely resembling the hardware XSAVE format, where xstate modification is also possible. Introduce a new test case to verify xstate preservation across signal delivery and return, that is ensuring ABI compatibility by: - Loading xstate before raising a signal. - Verifying correct exposure in the signal frame - Modifying xstate in the signal frame before returning. - Checking the state restoration upon signal return. Integrate this test into the AMX test suite as an initial usage site. Expected output: $ amx_64 ... [RUN] AMX Tile data: load xstate and raise SIGUSR1 [OK] 'magic1' is valid [OK] 'xfeatures' in SW reserved area is valid [OK] 'xfeatures' in XSAVE header is valid [OK] xstate delivery was successful [OK] 'magic2' is valid [RUN] AMX Tile data: load new xstate from sighandler and check it after sigreturn [OK] xstate was restored correctly Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-7-chang.seok.bae@intel.com

selftests/x86/xstate: Refactor ptrace ABI test

2025-02-26T12:05:29Z

Following the refactoring of the context switching test, the ptrace test is another component reusable for other xstate features. As part of this restructuring, add a missing check to validate the user_xstateregs->xstate_fx_sw field in the ABI. Also, replace err() and fatal_error() with ksft_exit_fail_msg() for consistency in error handling. Expected output: $ amx_64 ... [RUN] AMX Tile data: inject xstate via ptrace(). [OK] 'xfeatures' in SW reserved area was correctly written [OK] xstate was correctly updated. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-6-chang.seok.bae@intel.com

selftests/x86/xstate: Refactor context switching test

2025-02-26T12:05:29Z

The existing context switching and ptrace tests in amx.c are not specific to dynamic states, making them reusable for general xstate testing. As a first step, move the context switching test to xstate.c. Refactor the test code to allow specifying which xstate component being tested. To decouple the test from dynamic states, remove the permission request code. In fact, The permission request inside the test wrapper was redundant. Additionally, replace fatal_error() with ksft_exit_fail_msg() for consistency in error handling. Expected output: $ amx_64 ... [RUN] AMX Tile data: check context switches, 10 iterations, 5 threads. [OK] No incorrect case was found. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-5-chang.seok.bae@intel.com

selftests/x86/xstate: Enumerate and name xstate components

2025-02-26T12:05:28Z

After moving essential helpers from amx.c, the code remains neutral regarding which xstate components it handles. However, explicitly listing known components helps users identify which features are ready for testing. Enumerate xstate components to facilitate identification. Extend struct xstate_info to include a name field, providing a human-readable identifier. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-4-chang.seok.bae@intel.com

selftests/x86/xstate: Refactor XSAVE helpers for general use

2025-02-26T12:05:28Z

The AMX test introduced several XSAVE-related helper functions, but so far, it has been the only user of them. These helpers can be generalized for broader test of multiple xstate features. Move most XSAVE-related code into xsave.h, making it shareable. The restructuring includes: * Establishing low-level XSAVE helpers for saving and restoring register states, as well as handling XSAVE buffers. * Generalizing state data manipuldations: set_rand_data() * Introducing a generic feature query helper: get_xstate_info() While doing so, remove unused defines in amx.c. Signed-off-by: Chang S. Bae Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/20250226010731.2456-3-chang.seok.bae@intel.com