System, apparatus and method for accessing multiple address spaces via a data mover

At least one computer readable storage medium having stored thereon instructions, which if performed by a machine cause the machine to perform a method comprising:

• receiving, in an offload engine, a first job descriptor from a first client, the first job descriptor comprising a first process address space identifier (PASID) associated with a first address space of the first client and a second PASID selector associated with an address space of a second client;
• accessing a permissions table using the second PASID selector to determine whether the first client is permitted to access the second address space;
• and
• in response to determining that the first client is permitted to access the second address space, performing, by the offload engine, a memory operation requested in the first job descriptor within the second address space, and thereafter writing a completion notification to the first address space.