CentOS virt - Sep 2014 - libvirt/kvm changes /dev/ttyS0

A new kvm guest on a CentOS6.5 x84_64 host is set up to make use of the serial
 port (virt-install ... --serial dev,path=/dev/ttyS0)

    <serial type='dev'>
      <source path='/dev/ttyS0'/>
      <target port='0'/>
    </serial>
    <console type='dev'>
      <source path='/dev/ttyS0'/>
      <target type='serial' port='0'/>
    </console>

 When I launch the vm, setroubleshootd goes into overdrive and creates massive
 logs, and /var/log/messages starts growing significantly also. The reason is
 that as soon as the vm starts, ownership and context of /dev/ttyS0 on the host
 are being reset. Why is that, and how can I prevent it from happening?

 Should be:

crw-rw----. root dialout system_u:object_r:tty_device_t:s0 /dev/ttyS0

 Changes to:

crw-rw----. qemu qemu unconfined_u:object_r:svirt_image_t:s0:c9,c796 /dev/ttyS0

>  When I launch the vm, setroubleshootd goes into overdrive and creates
massive
>  logs, and /var/log/messages starts growing significantly also. The reason
is
>  that as soon as the vm starts, ownership and context of /dev/ttyS0 on the
host
>  are being reset. Why is that, and how can I prevent it from happening?
> 
>  Should be:
> 
> crw-rw----. root dialout system_u:object_r:tty_device_t:s0 /dev/ttyS0
> 
>  Changes to:
> 
> crw-rw----. qemu qemu unconfined_u:object_r:svirt_image_t:s0:c9,c796
/dev/ttyS0
  
 One way of doing this: https://bugzilla.redhat.com/show_bug.cgi?id=596553#c4
 (no. 1). This avoids resetting of group ownership to root instead of dialout.

 In addition, I had to add qemu to the disk group to access the /dev/dm* device
 that serves as vm disk.

 Also found qemu_use_comm and set it to on, for what it's worth ...