1. A method for implementing coherent accelerator function isolation for virtualization in an input/output (IO) adapter in a computer system, said computer system including a processor; and a hypervisor managing functions associated with the hardware I/O adapter; said method comprising: providing the I/O adapter with a coherent accelerator including an interface services layer providing Partitionable Endpoint (PE) functions and multiple accelerator function units (AFUs) ; enabling each AFU to operate independently of the other AFUs to perform a computing task; enabling each AFU to access system memory bound to an application and to make one or more copies of said system memory bound to the application within the AFU; enabling each AFU to maintain synchronization between AFU memory-cache and processor memory-cache.