7.14.

$ oc edit pvc <pvc_name>

apiVersion: v1
kind: PersistentVolumeClaim
metadata:
   name: vm-disk-expand
spec:
  accessModes:
     - ReadWriteMany
  resources:
    requests:
       storage: 3Gi 1
# ...

$ oc create -f <blank-image-datavolume>.yaml

apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: <vm_name>
spec:
  template:
# ...
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: virtio
            name: rootdisk
            disk1: disk_one 1
          - disk:
              bus: virtio
            name: cloudinitdisk
            disk2: disk_two
            shareable: true 2
          interfaces:
          - masquerade: {}
            name: default

apiVersion: kubevirt.io/v1
kind: VirtualMachine
metadata:
  name: vm-0
spec:
  template:
    spec:
      domain:
        devices:
          disks:
          - disk:
              bus: sata
            name: rootdisk
          - errorPolicy: report
            lun: 1
              bus: scsi
              reservation: true 2
            name: na-shared
            serial: shared1234
      volumes:
      - dataVolume:
          name: vm-0
        name: rootdisk
      - name: na-shared
        persistentVolumeClaim:
          claimName: pvc-na-share