Check if that page is defined; if it is, skip it in the metadata list. In such case, VMM should fill the page with the hashes content, or explicitly update it as a zero page (if kernel hashes are not used).
Is it an option to just skip the page unconditionally?
I think in the OvmfPkgX64 build the page is not used, so it probably doesn't matter whenever it is included or not, and it would make things a bit less confusing ...
