Geoff Chappell, Software Analyst
The HviGetDebugDeviceOptions function reads a Microsoft hypervisor’s model-specific register 0x400000FF.
VOID HviGetDebugDeviceOptions (ULONGLONG *);
The one argument provides the address at which to receive the 64-bit register.
The HviGetDebugDeviceOptions function is exported by name from the kernel in version 10.0 and higher.
The HviGetDebugDeviceOptions function is not documented. Neither is 0x400000FF among the synthetic MSRs that Microsoft documents in the Hypervisor Top-Level Functional Specification.
If a hypervisor is present and the vendor is “Microsoft Hv”—see HviIsHypervisorVendorMicrosoft—the function reads the model-specific register 0x400000FF to the given address.
Otherwise, the function sets 0 at the given address.