The virtio CCW transport device driver
The virtio CCW transport device driver handles the virtual channel command word (CCW) devices that are provided by the KVM hypervisor.
Virtio CCW devices are accessed through a virtual channel subsystem.
The virtio CCW transport device driver is part of a module stack that also includes device drivers for handling particular device types. If a module is not loaded automatically, you must load it before you can work with the corresponding devices. Loading a supporting module with the modprobe command automatically loads the base module if needed.
Virtio devices
The KVM hypervisor hides some of the specifics of the devices it virtualizes. For example, the hypervisor can virtualize both disk devices and plain files in the host file system as block devices. The KVM guest cannot differentiate block devices according to their nature on the host.
As a user of Linux on KVM, you must work with the virtual devices at the abstraction level with which they are presented. You cannot perform all actions against virtual devices that you can perform against real devices.