Assuming that the guest VM is bridged and that both KVM hosts are in the same ethernet segment.
Shutdown guest VM.
Copy guest VM image from host B to host C.
b# scp /vm/vm2.qcow2 root@c:/vm
Dump XML definition and copy it to the destination host.
b# virsh dumpxml vm2 > vm2.xml b# scp vm2.xml root@c:/etc/libvirt/qemu
On host C (the destination host) define the quest xml definition.
c# virsh define /etc/libvirt/qemu/vm2.xml Domain vm2 defined from /etc/libvirt/qemu/vm2.xml
Start VM guest on the destination system.
c# virsh start vm2 Domain vm2 started
Disable autostart for the VM guest in B (the original host).
b# virsh autostart vm2 --disable Domain vm2 unmarked as autostarted
Enable autostart for the moved VM guest in C (the destination host).
c# virsh autostart vm2 Domain vm2 marked as autostarted
Move KVM guest to another Host