An apparatus and method for supporting communication during error handling in a computing system. A computing system includes a first partition and a second partition, each capable of performing error management based on a respective machine check architecture (MCA). The first partition includes a host processor that executes an exception handler for managing reported errors. A message converter unit of the second partition assists in generating messages based on detected errors in the second partition. The message converter unit receives requests from hardware components of the second partition for handling errors and translates MCA addresses between the first partition and the second partition. To support the message converter unit, during an earlier bootup operation, the second partition communicates the hardware topology of the second partition to the host processor, and the host processor sends address translation information.