If you want to access the COM/serial port of your host machine from a KVM virtual machine in Proxmox VE, simply do the following :
where 104 is the ID of the VM
add “args: -serial /dev/ttyS0” to the end of the file
It should look like this :
name: testVM ide2: debian-500-i386-netinst.iso,media=cdrom smp: 1 vlan0: rtl8139=XX:XX:XX:XX:XX:XX bootdisk: ide0 ide0: vm-104-disk.qcow2 ostype: other memory: 256 args: -serial /dev/ttyS0
If the VM is already running, you may have to stop the VM completely and start it again for it to see the COM port. If you simply reboot the machine, it may not see it.
Proxmox VE : http://pve.proxmox.com/wiki/Main_Page