A method of managing memory mapped input output operations to an alternate address space comprising: executing a first instruction directed to a first memory mapped input output alternate address space of a machine associated with a first adapter to allocate a resource associated with the first adapter to a process in accordance with a definition of a z/Architecture; wherein a selected process issues at least one of a load and a store instruction executed in a problem state of the machine to a selected address location of a selected resource. The method further includes ensuring that the selected resource corresponds with the allocated resource and determining that the selected process corresponds with the process to which the resource is allocated.