Greetings Has libvirt dedicated page cache area for guest ? If not - what is the difference between cache='none' and cache='directsync' ?

The optional cache attribute controls the cache mechanism, possible >values are "default", "none", "writethrough", "writeback", "directsync" >(like "writethrough", but it bypasses the host page cache) and >"unsafe" (host may cache all disk io, and sync requests from guest >are ignored). As I understand 'unsafe' - always remove flags O_SYNC|O_DIRECT fron guest level. What about other cache options - how it work ? Would be glad see any schema or description, if You have.

b.r. Maxim Kozin