Virtual machine data processor

DETAILED DESCRIPTION Accordingly, it is an object of the present invention to provide a data processor which can support a virtual machine environment wherein a faulted instruction may be suspended while the cause of the fault is resolved, and thereafter resumed at the start of the access which had encountered the fault.
Another object of the present invention is to provide a virtual machine data processor wherein a faulted instruction is suspended while the cause of the fault is resolved and the faulted access performed, and then the faulted instruction is resumed as if the faulted access had been successful.
These and other objects of the present invention are achieved in a virtual machine data processor having an external access controller for providing access to a resource external to the data processor; an instruction execution controller for controlling the execution by the data processor of at least one instruction which requires at least one access to the resource via the external access controller; and an access fault recovery controller for storing information indicative of the state of the instruction execution controller as of the time an access fault is detected, and for restoring the state of the instruction execution controller using the stored state information after the access fault has been corrected.
In the present invention, the data processor includes an access rerun controller for enabling the external access controller to rerun the faulted access upon the access fault recovery controller enabling the instruction execution controller to resume execution of the instruction, except in response to a rerun signal indicating that the access should not be rerun.