I have configured the kvm and edit the xml as below, however there are an error when I want to run the guest.  The error as follows:

virsh create libvirt.xml

error: Failed to create domain from libvirt-test.xml
error: XML description for unknown target type for character device: virtio is not well formed or invalid


Please help me to solve this problem.

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<domain type='kvm'>
    <name>i-5E36098H</name>
    <os>
    <type>hvm</type>
          <kernel>/opt/eucalyptus-data/suria/i-5E36098H/kernel</kernel>
        <initrd>/opt/eucalyptus-data/suria/i-5E36098H/ramdisk</initrd>
 <cmdline>root=LABEL=root console=ttyS0</cmdline>
    </os>
    <features>
        <acpi/>
    </features>
    <memory>13107200</memory>
    <vcpu>1</vcpu>
    <devices>
        <emulator>/usr/bin/kvm</emulator>
        <disk type='file'>
            <source file='/opt/eucalyptus-data/suria/i-5E36098H/disk'/>
            <target dev='vda' bus='virtio'/>
        </disk>

        <interface type='network'>
            <source network='default'/>
            <mac address='d0:0d:45:D2:08:01'/>
            <model type='virtio'/>
        </interface>

        <controller type='ide' index='0'/>
                <controller type='virtio-serial' index='0' ports='16' vectors='4'/>
                <controller type='virtio-serial' index='1'>
                <address type='pci' domain='0x0000' bus='0x00' slot='0x0a' function='0x0'/>
        </controller>

        <parallel type='pty'>
                <source path='/dev/pts/2'/>
                <target port='0'/>
        </parallel>

        <serial type='pty'>
                <source path='/dev/pts/3'/>
                <!-- <source mode='bind' path='/var/lib/libvirt/qemu/va-i-5E36098H-isa.sock'/>-->
                <target type='virtio' port='0'/>
        </serial>

        <console type='pty'>
                <source path='/dev/pts/4'/>
                <target type='virtio' port='0'/>
        </console>

        <channel type='pty'>
                <source mode='bind' path='/var/lib/libvirt/qemu/va-i5E36098H-virtio.sock'/>
                <target type='virtio' name='org.qemu.guest_agent.0'/>
                <address type='virtio-serial' controller='0' bus='0' port='0'/>
        </channel>

         <graphics type='vnc' port='-1' autoport='yes' keymap='en-us'/>
    </devices>

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