Each processor of a plurality of processors is configured to execute an interrupt message instruction. A message filtering unit includes storage circuitry configured to store captured identifier information from each processor. In response to a processor of the plurality of processors executing an interrupt message instruction, the processor is configured to provide a message type and a message payload to the message filtering unit. The message filtering unit is configured to use the captured identifier information to determine a recipient processor indicated by the message payload and, in response thereto, provides an interrupt request indicated by the message type to the recipient processor.