1. A method of enabling accelerator functionality in a coherent computer system when an accelerator functional unit (AFU) is unavailable, the coherent computer system comprising a memory shared by a processor and a coherent accelerator device (CAD) comprising the AFU, the memory comprising a work queue directly accessible by the AFU and the processor utilizing the same effective addresses, the method comprising: loading, with the CAD, AFU logic to the AFU and reading the AFU logic descriptor to determine whether the loaded AFU logic is a most recent version; implementing, with the processor, an AFU virtual machine (AFU VM) emulating the AFU invoking the most recent version of AFU logic if the loaded AFU logic is not the most recent version and the AFU is unavailable, and; sharing the work queue with the processor and the AFU VM, the work queue directly accessible by the AFU VM and the processor utilizing the same effective addresses.