Comment 13 for bug 578527

franz-unix (franz-unix) wrote :

First sorry for the bad english. I have a similar problem with Ubuntu Lucid 10.04 amd64 Desktop edition using KVM.
Any virtual machine with a serial port (host device /dev/ttyS0) configured fails to start. Removing the serial port the VM works very well.
I use virt manager for the creation and management of the virtual machines .

This is the configuration file of the VM running Ubuntu Lucid 10.04 amd64 (like the host) but server edition

<domain type='kvm'>
    <type arch='x86_64' machine='pc-0.12'>hvm</type>
    <boot dev='hd'/>
  <clock offset='utc'/>
    <disk type='block' device='disk'>
      <driver name='qemu' type='raw' cache='none'/>
      <source dev='/dev/lvmforkvm/deluge'/>
      <target dev='vda' bus='virtio'/>
    <disk type='file' device='cdrom'>
      <driver name='qemu' type='raw'/>
      <target dev='hdc' bus='ide'/>
    <interface type='bridge'>
      <mac address='00:54:00:35:b8:12'/>
      <source bridge='br0'/>
      <model type='virtio'/>
    <serial type='dev'>
      <source path='/dev/ttyS0'/>
      <target port='0'/>
    <console type='dev'>
      <source path='/dev/ttyS0'/>
      <target port='0'/>
    <input type='mouse' bus='ps2'/>
    <graphics type='vnc' port='-1' autoport='yes'/>
      <model type='cirrus' vram='9216' heads='1'/>

And this is the error message that virt manager shows

Traceback (most recent call last):
  File "/usr/share/virt-manager/virtManager/", line 588, in run_domain
  File "/usr/share/virt-manager/virtManager/", line 150, in startup
  File "/usr/lib/python2.6/dist-packages/", line 300, in create
    if ret == -1: raise libvirtError ('virDomainCreate() failed', dom=self)
libvirtError: monitor socket did not show up.: Connection refused

I agree with Fjodor, the importance should be heightened. Without serial port virtualization a lot of functionalities could be lost. For example i need the serial port for the installation of a fax server (hylafax) that is using a modem connected to the host's physical serial port (/dev/ttyS0).
If you need to do some tests I can do that