System, computer program product, and method embodiments for communication between a kernel operational on a storage subsystem and a key manager (KM) through a hardware management console (HMC) to provide encryption support are provided. In one embodiment, pursuant to a data request by the kernel to the KM, data including a data payload is sent by the KM to the kernel to provide encryption support, the data payload corresponding to an event flow suborder type selected by the kernel for an event flow.