1. A computer program product for providing access to adapters in a computing environment, the computer program product comprising: a computer readable storage medium readable by a processing circuit and storing instructions for execution by the processing circuit for performing a method comprising: executing, by a processor, a guest instruction issued by a guest processor, the guest instruction comprising a request to access an adapter of the computing environment, and the guest processor being hosted by a host operating system; determining whether the guest instruction is permitted to directly access the adapter; based on the guest instruction being permitted to directly access the adapter, the execution directly accessing one or more address spaces of the adapter without host intervention of the host operating system; and based on the guest instruction not being permitted to directly access the adapter, the execution causing an intercept to the host operating system.