Virtualised interface functions

A data processing system comprising:

• a memory addressable by a range of physical memory addresses;
• at least one first software domain having a first privilege level;
• a plurality of second software domains each having a privilege level which is below the first privilege level and each having a virtual memory address space;
• a memory management unit operable to perform virtual address translation of a virtual memory address into a physical memory address;
• and
• an input and/or output device supporting a plurality of virtualised interfaces, each virtualised interface being associated with a respective one of the non-privileged software domains, the input and/or output device further comprising at least one operation management unit operable to perform virtual address translation in one or more of the virtual memory address spaces;
• wherein, for I/O operations requested by a virtualised interface of the input and/or output device, the input and/or output device is configured to invoke the operation management unit to perform virtual address translation for those I/O operations meeting one or more predefined first criteria and to invoke the memory management unit to perform virtual address translation for those I/O operations which do not meet the one or more predefined first criteria.