Then I guess it's empty. I guess I'll just redo the server, and chalk this up as a one in a million file corruption, for which we didn't have the proper OS backup to counteract. We do have backups of the VMs anyway.
Thanks for the help! We didn't get this fixed, but I did learn a lot! This is our first Xenserver/XCP host.
If you know exactly what's checked in the driver (CPU vendor, ACPI tables, BIOS info, SMI?), we might be able to dig into the right direction. It's just that I won't spend a lot of resources without knowing if our modifications are useful or not.