On 7/22/21 1:51 PM, Yu-cheng Yu wrote:

Linux distributions with CET are available now, and Intel processors with CET
are already on the market.  It would be nice if CET support can be accepted
into the kernel.

Changes in v28:
- Rebase to Linus tree v5.14-rc2.
- Patch #1: Update Document to indicate no-user-shstk also disables IBT.
- Patch #23: Update shstk_setup() with wrmsrl_safe().  Update return value.
- Patch #25: Split out copy_thread() changes.  Add support for old clone().
  Add comments.
- Add comments for get_xsave_addr() (Patch #25, #26).

Could you characterize where this whole thing is?

Are we at the point where the feedback is slowing down?  What kind of
feedback are you getting?  How stable is the ABI versus the last revision?