MemoryBacking options

Hi, Is there any documentation that states which options can be used together with each other. <domain> ... <memoryBacking> <hugepages> <page size="1" unit="G" nodeset="0-3,5"/> <page size="2" unit="M" nodeset="4"/> </hugepages> <nosharepages/> <locked/> <source type="file|anonymous|memfd"/> <access mode="shared|private"/> <allocation mode="immediate|ondemand" threads='8'/> <discard/> </memoryBacking> ... </domain>