Linux kernels can output information to serial ports. This is useful for debugging kernel panics and hardware issues with video devices or headless servers.
To enable serial console output for KVM guests:
Ensure that the domain XML file of the guest includes configuration for the serial console. For example:
<target type='virtio' port='1'/>
On the host, you can then access the serial console with the following command, where guestname is the name of the guest virtual machine:
virsh console guestname
You can also use
virt-manager to display the virtual text console. In the guest console window, select Serial 1 in Text Consoles from the View menu.