I was in a similar situation as the author: for quite a while I had to build my own Redhat kernel for a very obscure case: by pass RMRR check to pass GPU to a windows VM. (similar to https://github.com/kiler129/relax-intel-rmrr ; not my repo)

The root issue can only be addressed by ROM updates from the manufacturer but I'm running an old DL360 that's no longer supported by HPE.

The patch itself is only one line change but updating the kernel is a pain since I have to : - get SRPM (there's no git repo) - unpack SRPM, apply patch - rebuild and install