13 Aug
2025
13 Aug
'25
9:57 p.m.
On 2025-08-13 14:07, Dave Hansen wrote:
On 7/15/25 23:33, Xin Li (Intel) wrote:
The FRED specification has been changed in v9.0 to state that there is no need for FRED event handlers to begin with ENDBR64, because in the presence of supervisor indirect branch tracking, FRED event delivery does not enter the WAIT_FOR_ENDBRANCH state.
As a result, remove ENDBR64 from FRED entry points.
So, the spec is being updated or has been updated to reflect the new architecture, right?
Remind me, are there no FRED systems out in the wild today, so we don't have to worry about breaking anything?
Correct. The FRED v9 spec contains this change.
All production hardware and late pre-production hardware will have this.
-hpa