[libvirt-users] Has libvirt guest pagecache level ?

[mxs kolo]

 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