If you have a non-GPU device that you wish to assign to a guest in KVM and are using the machine type of PC (not Q35), you can use this XML and skip the <qemu:cmd> arguments at the end. This goes in between the <devices> and </devices> tags in your domain XML.
<hostdev mode='subsystem' type='pci' managed='yes'>
<driver name='vfio'/>
<source>
<address domain='0x0000' bus='0x02' slot='0x00' function='0x1'/>
</source