APPARATUS AND METHOD FOR SECURE, EFFICIENT MICROCODE PATCHING

An apparatus and method for efficient microcode patching. For example, one embodiment of an apparatus comprises: a package comprising one or more integrated circuit dies, the one or more integrated circuit dies comprising: a plurality of cores; and a security controller coupled to the plurality of cores, a first core of the plurality of cores comprising: a decoder to decode a microcode patching instruction, the microcode patching instruction comprising an operand to be used to identify an address; and execution circuitry to execute the microcode patching instruction, wherein responsive to the microcode patching instruction, the execution circuitry and/or security controller are to: retrieve a microcode patch from a location in memory based on the address, validate the microcode patch, apply the microcode patch to update or replace microcode associated with the one or more integrated circuit dies, and transmit the microcode patch to a persistent storage device; wherein the microcode patch is to be subsequently retrieved from the persistent storage device by one or more external security controllers of one or more external integrated circuit dies, the one or more external security controllers to cause the microcode patch to be applied to update or replace microcode associated with the one or more external integrated circuit dies.