[roll] Roll fuchsia [kernel][x86] Spectre V2/RETBLEED: Don't enable STIBP if SMT isn't present

STIBP is 'single-thread indirect branch predictor' mode, a mode that
prevents code running on one hyperthread from influencing branch
predictions on its paired hyperthread. On some processors, fully
mitigating Spectre V2 or RETBLEED requires STIBP to be set. STIBP is not
required if hyperthreading/SMT isn't present or enabled.

Don't bother enabling STIBP for Spectre V2 or RETBLEED mitigations if
hyperthreading is not present or enabled; this avoids unnecessary
performance impacts from STIBP.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/747663
Original-Revision: a796173a572228cac35e773592d43ced21ce6682
GitOrigin-RevId: f23fa6479133906aca7e35ff83c8958ff2b80be1
Change-Id: Ie1358eedf200e818f937b03c288d0bf0531c3c77
1 file changed
tree: f38711b5530322901208ed3c3a93591206a4c4dc
  1. git-hooks/
  2. infra/
  3. third_party/
  4. cts
  5. firmware
  6. flower
  7. jiri.lock
  8. minimal
  9. prebuilts
  10. README.md
  11. stem
  12. test_durations
  13. toolchain
README.md

Integration

This repository contains Fuchsia's Global Integration manifest files.

Making changes

All changes should be made to the internal version of this repository. Our infrastructure automatically updates this version when the internal one changes.

Currently all changes must be made by a Google employee. Non-Google employees wishing to make a change can ask for assistance via the IRC channel #fuchsia on Freenode.

Obtaining the source

First install Jiri.

Next run:

$ jiri init
$ jiri import minimal https://fuchsia.googlesource.com/integration
$ jiri update

Third party

Third party projects should have their own subdirectory in ./third_party.