Add PPIN support for Intel EMR cpu
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
linux (Ubuntu) |
Invalid
|
Undecided
|
Unassigned | ||
Jammy |
Fix Released
|
Medium
|
Roxana Nicolescu |
Bug Description
SRU Justification
[Impact]
Intel has introduced support for their new Emerald Rapids CPU.
It was backported to Jammy in #lp2015372 and in #lp2015855.
The remaining feature needed to fully support EMR is PPIN (the Protected Processor Inventory/
This was recently pushed to upstream in 6.4 in commit 36168bc061b4368
The change is very straightforward, it adds a new entry for EMERALDRAPIDS_X in the cpuids table where cpus that support ppin are listed. The table is then used in `ppin_init`.
In Jammy, this implementation is missing. Both Amd and Intel have their own implementation which is doing pretty much the same. Instead of a list of cpus supported, a switch case is used instead in their init functions (amd_detect_ppin and intel_ppin_init).
To reduce duplication of code and to help backport smoothly the new addition of EMR, commit 0dcab41d3487aca
“x86/cpu: Merge Intel and AMD ppin_init() functions” was backported too.
Thus commits:
- 0dcab41d3487aca
- 36168bc061b4368
are needed to support PPIN for EMR.
[Testing]
Kernel was built on cbd and boot tested on a VM.
[Regression potential]
Very low, it is a small refactor that removes duplication and it should not affect the functionality.
CVE References
Changed in linux (Ubuntu): | |
importance: | Undecided → Medium |
assignee: | nobody → Roxana Nicolescu (roxanan) |
status: | New → In Progress |
summary: |
- Enable PPIN for Intel EMR cpu + Add PPIN support for Intel EMR cpu |
Changed in linux (Ubuntu Jammy): | |
importance: | Undecided → Medium |
status: | New → In Progress |
Changed in linux (Ubuntu): | |
status: | In Progress → Invalid |
Changed in linux (Ubuntu Jammy): | |
assignee: | nobody → Roxana Nicolescu (roxanan) |
Changed in linux (Ubuntu): | |
assignee: | Roxana Nicolescu (roxanan) → nobody |
importance: | Medium → Undecided |
Changed in linux (Ubuntu Jammy): | |
status: | In Progress → Fix Committed |
tags: |
added: verification-done-jammy removed: verification-needed-jammy |
tags: |
added: verification-done-focal verification-done-jammy removed: verification-needed-focal verification-needed-jammy |
This bug is awaiting verification that the linux/5.15.0-74.81 kernel in -proposed solves the problem. Please test the kernel and update this bug with the results. If the problem is solved, change the tag 'verification- needed- jammy' to 'verification- done-jammy' . If the problem still exists, change the tag 'verification- needed- jammy' to 'verification- failed- jammy'.
If verification is not done by 5 working days from today, this fix will be dropped from the source code, and this bug will be closed.
See https:/ /wiki.ubuntu. com/Testing/ EnableProposed for documentation how to enable and use -proposed. Thank you!