This represents a private communication channel between the host physical machine and the guest virtual machine and is manipulated by making changes to your guest virtual machine virtual machine using a management tool that results in changes made to the following section of the domain xml
... <devices> <channel type='unix'> <source mode='bind' path='/tmp/guestfwd'/> <target type='guestfwd' address='10.0.2.1' port='4600'/> </channel> <!-- KVM virtio channel --> <channel type='pty'> <target type='virtio' name='arbitrary.virtio.serial.port.name'/> </channel> <channel type='unix'> <source mode='bind' path='/var/lib/libvirt/qemu/f16x86_64.agent'/> <target type='virtio' name='org.qemu.guest_agent.0'/> </channel> <channel type='spicevmc'> <target type='virtio' name='com.redhat.spice.0'/> </channel> </devices> ...
Figure 20.63. Channel
This can be implemented in a variety of ways. The specific type of
<channel>is given in the
typeattribute of the
<target>element. Different channel types have different target attributes as follows:
guestfwd- Dictates that TCP traffic sent by the guest virtual machine to a given IP address and port is forwarded to the channel device on the host physical machine. The
targetelement must have address and port attributes.
virtio- Paravirtualized virtio channel.
<channel>is exposed in the guest virtual machine under
/dev/vport*, and if the optional element
/dev/virtio-ports/$name(for more info, see http://fedoraproject.org/wiki/Features/VirtioSerial). The optional element
addresscan tie the channel to a particular
type='virtio-serial'controller, documented above. With QEMU, if name is "org.qemu.guest_agent.0", then libvirt can interact with a guest virtual machine agent installed in the guest virtual machine, for actions such as guest virtual machine shutdown or file system quiescing.
spicevmc- Paravirtualized SPICE channel. The domain must also have a SPICE server as a graphics device, at which point the host physical machine piggy-backs messages across the main channel. The
targetelement must be present, with attribute
type='virtio';an optional attribute
namecontrols how the guest virtual machine will have access to the channel, and defaults to
name='com.redhat.spice.0'. The optional
<address>element can tie the channel to a particular