Comment 7 for bug 1755153

As assumed this can be triggered on x86 as well:
  <maxMemory slots='4' unit='KiB'>2097152</maxMemory>
  <memory unit='KiB'>524288</memory>
  <currentMemory unit='KiB'>524288</currentMemory>
...
  <cpu>
    <numa>
      <cell id='0' cpus='0' memory='524288' unit='KiB'/>
    </numa>
  </cpu>

hp512m.xml
<memory model='dimm'>
        <target>
                <size unit='KiB'>524288</size>
                <node>0</node>
        </target>
</memory>

root@b:~# virsh attach-device b-test hp512.xml --live
error: Failed to attach device from hp512.xml
error: this function is not supported by the connection driver: virSecurityManagerSetMemoryLabel