1. A method of initialising an input/output interface for the control of, of the submission of tasks to, an accelerator that acts as a shared resource in a data processing system, wherein the data processing system comprises: one or more processors that each execute one or more operating systems, each operating system including one or more applications; an accelerator that provides a shared resource for a plurality of the applications; a storage area accessible by at least the one or more processors and the accelerator; and one or more input/output interfaces for the control of, or the submission of tasks to, the accelerator; the method comprising, to initialise one of the input/output interfaces: one of the one or more processors sending a first signal to the accelerator; the accelerator, in response to receiving the first signal, writing one or more selected pieces of information representative of one or more capabilities of the accelerator to the storage area, and sending a second signal to the processor; the processor, in response to receiving the second signal, reading the one or more selected pieces of information from the storage area; the processor sending a third signal to the accelerator; and the accelerator configuring the input/output interface in response to the third signal from the processor.