I have put the LLDB changes for this into review. We are tracking SME only support in this issue: https://github.com/llvm/llvm-project/issues/138717
The PRs that relate to these kernel changes are listed in this comment: https://github.com/llvm/llvm-project/issues/138717#issuecomment-3456979166
LLDB's use case for this new ptrace feature is to restore process state after expression evaluation takes a process from non-streaming to streaming mode. We have a specific code path to handle that restoration, and it was not a problem to integrate this new ptrace feature.
I have proven with testcases that LLDB can restore any streaming mode/ZA/streaming vector length combination, starting from any other combination.
The LLDB changes will remain in review until if/when these kernel changes are accepted. I expect LLDB reviewers will be ok approving changes on the condition that I wait for the kernel side before merging.
I expect LLDB review to take some time, likely a month, due to the availability of reviewers at this time.
Reviewed-by: David Spickett david.spickett@linaro.org