Storing Storage Protection Key Errors
Original Publication Date: 1984-Jun-01
Included in the Prior Art Database: 2005-Feb-04
This technique relates to configuring redundant key arrays in a running system to duplicate valid and invalid storage keys for system integrity. The configuring of new storage keys involves initializing the unused keys to zero with good parity (so they will be available for later assignment and configuration) and duplicating the good keys and the invalid keys on the oncoming side. The central processor (CP) microcode recognizes a valid storage key by checking a record which contains a bit indicative of each previously detected key error. CP microcode then writes a valid key to a redundant array with a special command, causing the array to invert the parity bit and to store the key which will cause a parity error on the next fetch.