x86_64-default-cpu-tcg-pc-4.2.xml

<domain type='qemu'>
  <name>guest</name>
  <uuid>1ccfd97d-5eb4-478a-bbe6-88d254c16db7</uuid>
  <memory>4194304</memory>
  <currentMemory>4194304</currentMemory>
  <vcpu>4</vcpu>
  <os>
    <type arch='x86_64' machine='pc-i440fx-4.2'>hvm</type>
    <boot dev='hd'/>
  </os>
  <features>
    <acpi/>
    <apic/>
  </features>
  <clock offset='utc'/>
  <devices>
    <emulator>/usr/bin/qemu-system-x86_64</emulator>
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/guest.qcow2'/>
      <target dev='vda' bus='virtio'/>
    </disk>
  </devices>
</domain>