The KubeVirt system application in StarlingX includes: KubeVirt, Containerized Data Importer (CDI), and the Virtctl client tool.
KubeVirt is an open source project that allows VMs to be run and managed as pods inside a Kubernetes cluster. This is a particularly important innovation as traditional VM workloads can be moved into Kubernetes alongside already containerized workloads, thereby taking advantage of Kubernetes as an orchestration engine. Specifically, KubeVirt VM workloads and containerized workloads can exist on the same node/host; an advantage over the OpenStack solution in StarlingX where workloads can exist on same system/cluster but not on the same node/host.
The CDI is an open source project that provides facilities for enabling PVCs to be used as disks for KubeVirt VMs by way of DataVolumes.
The Virtctl client tool is an open source tool distributed with KubeVirt and required to use advanced features such as serial and graphical console access. It also provides convenience commands for starting/stopping VMs, live migrating VMs, canceling live migrations and uploading VM disk images.
See https://kubevirt.io/user-guide for more details.