Testing storage protection hardware in a secure virtual machine environment

A method for testing storage protection hardware includes receiving by a non-trusted entity that is executing on a host server, a request to dispatch a secure entity. It is determined, by a secure interface control of the host server, whether the host server is in an auxiliary-secure (AS) debug mode for testing an AS entity. Based on determining that the host server is in the AS debug mode, a secure guest entity state is loaded from a state descriptor for the secure entity into an AS entity state in hardware to test, upon dispatch of the secure entity, accesses to pages in a memory that are registered as secure and as belonging to the AS entity.