Haciendo en casa una prueba con otra máquina virtual y examinando el log de
libvirt:
LC_ALL=C PATH=/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
HOME=/ QEMU_AUDIO_DRV=none /usr/bin/kvm -S -M pc-0.12 -enable-kvm -m 512
-smp 1,sockets=1,cores=1,threads=1 -name vm0 -uuid
44f38697-90a8-04b2-27e5-abd3a9f3c29d -nodefaults -chardev
socket,id=monitor,path=/var/lib/libvirt/qemu/vm0.monitor,server,nowait -mon
chardev=monitor,mode=readline -rtc base=utc -boot c -drive
file=/var/lib/libvirt/images/vdisk0.qcow2,if=none,id=drive-virtio-disk0,boot=on,format=qcow2
-device
virtio-blk-pci,bus=pci.0,addr=0x4,drive=drive-virtio-disk0,id=virtio-disk0
-device
virtio-net-pci,vlan=0,id=net0,mac=52:54:00:2a:8d:ae,bus=pci.0,addr=0x5 -net
tap,fd=36,vlan=0,name=hostnet0 -chardev pty,id=serial0 -device
isa-serial,chardev=serial0 -chardev tty,id=parallel0,path=/dev/parport0
-device isa-parallel,chardev=parallel0 -usb -device usb-tablet,id=input0
-vnc 127.0.0.1:0 -k es -vga cirrus -device
virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x3
char device redirected to /dev/pts/4
chardev: opening backend "tty" failed
