QEMU guest agent

libvirt uses the QEMU guest agent which runs inside a Guest OS as a service. It acts as a communication channel between the hypervisor and the guest. Hypervisor uses this channel to fetch information of the Guest OS or issue commands to the Guest OS. The communication protocol used to issue commands to the Guest OS is Qemu Machine Protocol (QMP). For example, libvirt uses a guest agent to fetch network and filesystem details from the guest. The communication between the guest agent and hypervisor happens through a virtio-serial, or through an isa-serial channel named org.qemu.guest_agent.0. On the hypervisor side, a corresponding Linux socket file will also be created in /var/lib/libvirt/qemu/channel/target/.

For Fedora 22 it is as follows:

# file /var/lib/libvirt/qemu/channel/target/fedora22.org.qemu.guest_agent.0
/var/lib/libvirt/qemu/channel/target/fedora22.org.qemu.guest_agent.0: socket

The same socket file will be shared by multiple Fedora 22 instances. This means...