Hi Everyone,
The FEAT_MEC enablement patches have now been merged into RMM: https://github.com/TF-RMM/tf-rmm/commit/8819a19d048b273438690954c151c8333db4...
This marks the culmination of several months of work.
The patch series went through two major rewrites as we experimented with different implementation approaches. This also led to a re-design of the delegate scrub flow in RMM, which was merged earlier as a precursor to this work.
We also received design inputs from @Raghu K , which resulted in more fine-grained programming of the MEC registers. In addition, two extra hardening methods were implemented based on this feedback. These can be enabled via the RMM_MEM_SCRUB_METHOD build flag.
In the coming days, we plan to profile the three different scrub methods to determine a more suitable default.
The FEAT_MEC design in RMM and rationale for the hardening is explained here: https://github.com/TF-RMM/tf-rmm/wiki/RFC:-FEAT_MEC-Design-in-RMM
As usual, please let us know if you find any issues.
Best Regards Soby Mathew