Description of problem:
Failed to start domain with a tcp type interface , the following error 
occurs
# virsh start rhel6.5
error: Failed to start domain rhel6.5
error: internal error Process exited while reading console log output: char device redirected to /dev/pts/4
2014-08-15T05:59:17.348271Z qemu-kvm: -netdev socket,listen=(null):5558,id=hostnet0: Device 'socket' could not be initialized

http://libvirt.org/formatdomain.html#elementsNICSTCP

Version-Release number of selected component (if applicable):
kernel-2.6.32-486.el6.x86_64
libvirt-0.10.2-43.el6.x86_64
qemu-kvm-0.12.1.2-2.427.el6.x86_64


How reproducible:
100%

Steps to Reproduce:
# virsh dumpxml rhel6.5
<domain type='kvm'>
   <name>rhel6.5</name>
  .......
   <devices>
     <emulator>/usr/libexec/qemu-kvm</emulator>
     <disk type='file' device='disk'>
       <driver name='qemu' type='qcow2' cache='none'/>
       <source file='/var/lib/libvirt/images/kvm-rhel6.5-x86_64-qcow2.img'/>
       <target dev='hda' bus='ide'/>
       <address type='drive' controller='0' bus='0' target='0' unit='0'/>
     </disk>
     <controller type='usb' index='0' model='ich9-ehci1'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x05' 
function='0x7'/>
     </controller>
     <controller type='usb' index='0' model='ich9-uhci1'>
       <master startport='0'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x05' 
function='0x0' multifunction='on'/>
     </controller>
     <controller type='usb' index='0' model='ich9-uhci2'>
       <master startport='2'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x05' 
function='0x1'/>
     </controller>
     <controller type='usb' index='0' model='ich9-uhci3'>
       <master startport='4'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x05' 
function='0x2'/>
     </controller>
     <controller type='ide' index='0'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x01' 
function='0x1'/>
     </controller>
    <interface type='server'>  <===== Config a tcp type interface
      <source port='5558'/>
     </interface>
     <serial type='pty'>
       <target port='0'/>
     </serial>
     <console type='pty'>
       <target type='serial' port='0'/>
     </console>
     <input type='mouse' bus='ps2'/>
     <graphics type='vnc' port='-1' autoport='yes'/>
     <sound model='ich6'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x04' 
function='0x0'/>
     </sound>
     <video>
       <model type='cirrus' vram='9216' heads='1'/>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x02' 
function='0x0'/>
     </video>
     <memballoon model='virtio'>
       <address type='pci' domain='0x0000' bus='0x00' slot='0x06' 
function='0x0'/>
     </memballoon>
   </devices>
</domain>

# virsh start rhel6.5
error: Failed to start domain rhel6.5
error: internal error Process exited while reading console log output: char device redirected to /dev/pts/4
2014-08-15T05:59:17.348271Z qemu-kvm: -netdev socket,listen=(null):5558,id=hostnet0: Device 'socket' could not be initialized


Actual results:
Failed to start domain with a tcp type interface 

Expected results:
Successfully start the domain 

Additional info:
It works fine in rhel7.From the qemu-kvm manual , it should be supported in rhel6.

man qemu-kvm
......
       -net socket[,vlan=n][,name=name][,fd=h][,listen=[host]:port][,connect=host:port]
           Connect the VLAN n to a remote VLAN in another QEMU virtual machine using a TCP socket connection. If listen is specified, QEMU waits for incoming
           connections on port (host is optional). connect is used to connect to another QEMU instance using the listen option. fd=h specifies an already opened
           TCP socket.

           Example:

                   # launch a first QEMU instance
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:56 \
                   -net socket,listen=:1234
                   # connect the VLAN 0 of this instance to the VLAN 0
                   # of the first instance
                   qemu linux.img -net nic,macaddr=52:54:00:12:34:57 \
                   -net socket,connect=127.0.0.1:1234