[S] Change in coreboot[main]: cpu/x86/smm/smm_module_loader.c: Pass full SMRAM region info to SMM r...

[Benjamin Doron (Code Review)]

Attention is currently required from: Angel Pons, Arthur Heymans, Christian Walter, Felix Held, Fred Reitberger, Jason Glenesk, Jeff Daly, Johnny Lin, Jérémy Compostella, Lean Sheng Tan, Matt DeVillier, Shuo Liu, Tim Chu, Vanessa Eusebio.

Benjamin Doron has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/80703?usp=email )

Change subject: cpu/x86/smm/smm_module_loader.c: Pass full SMRAM region info to SMM runtime
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Patch Set 2:

(2 comments)

Commit Message:

https://review.coreboot.org/c/coreboot/+/80703/comment/2664e08a_cd5002e0 :
PS2, Line 17: integrity of the S3 resume path.
> I suppose the default region_overlaps_handler() cannot achieve this at the moment. […]

smm_region_overlaps_handler() consumes these fields. It's also the only consumer of them, so we don't have to worry about changing behaviour. By updating the value, smm_region_overlaps_handler() will protect the entire SMRAM.

https://review.coreboot.org/c/coreboot/+/80703/comment/681fbbca_750af248 :
PS2, Line 19: The consequences to overwriting the chipset-specific area are undefined.
> Could you please specify the definition here for 'chipset-specific' area?

This is common code, there is no specific definition. In practice, I've seen this area used as Intel's IED (Intel Enhanced Debug).