MEM2GC
cp->ring.vm_base = MEM2GC( memory_type, offset );
cp->feedback.head_vm_address = MEM2GC( memory_type, cp->feedback.head_mem_offset );
cp->feedback.scratch_vm_start = MEM2GC( memory_type, cp->feedback.scratch_mem_offset );
cp->buffers.vm_start = MEM2GC( memory_type, cp->buffers.mem_offset );