Apparatus and method for role-based register protection for TDX-IO

Apparatus and method for role-based register protection. For example, one embodiment of an apparatus comprises: one or more processor cores to execute instructions and process data, the one or more processor cores to execute one or more security instructions to protect a virtual machine or trusted application from a virtual machine monitor (VMM) or operating system (OS); an interconnect fabric to couple the one or more processor cores to a device; and security hardware logic to determine whether to allow a read or write transaction directed to a protected register to proceed over the interconnect fabric, the security hardware logic to evaluate one or more security attributes associated with an initiator of the transaction to make the determination.