Software Architecture

This section describes the logical context structure of the CCA Kit, including its modules and functions. Figure 1 shows its software architecture.

Figure 1 Software architecture of the CCA Kit

The software architecture includes the Realm Management Monitor (RMM) (S-EL2), Realm Management Monitor Dispatcher (RMMD) (EL3), and also the Kernel-based Virtual Machine (KVM) running in the normal world. Table 1 describes their functions.

**Table 1** Functions of each module
Module	Function
RMM	It isolates the Realm world based on stage 2 page tables, manages the Realm execution for the host, and provides interfaces for the Realm world.
RMMD	Running in Arm trusted firmware (ATF) at EL3, it forwards messages and manages context switching between the rich execution environment (REE) and the Realm.
Kernel-based Virtual Machine (KVM)	By applying patches to KVM, it now supports issuing RMI calls to the RMM, enabling lifecycle management for cVMs.

Parent topic: Feature Description