cdemu-daemon receives SCSI commands from kernel module thorugh the
VHBA module and processes them, passing the requested data back to
the kernel. The daemon implements the actual virtual device; one
instance per each device registered by kernel module. It uses
libmirage for the image access (e.g. sector reading).
The daemon registers itself on D-BUS's system or session bus
(depending on the options passed to it) where it exposes an interface
that can be used by clients to control it.