This issue has been identified and fixed for SMM before: https://github.com/tianocore/edk2/commit/026e2ca2c315ea0d19be5f72b89009bdcf5f10c8 Despite the fact that the DXE and SMM cores have basically the same code for the MAT split logic, this fix was never ported to the DXE code, which still assumes any non-PE memory is data[1]. Ideally, the PE memory covers the entire range and this does not matter. However, if this is agreed upon, this must be properly and consistently ensured. [1] https://github.com/tianocore/edk2/blob/2072c22a0d63c780b0cc6377f6d4ffb116ad6144/MdeModulePkg/Core/Dxe/Misc/MemoryAttributesTable.c#L772-L788
Marvin, you can continue to provide the proposal.
