Kevin Wolf wrote: > Am 10.05.2010 23:51, schrieb Alexander Graf: > >> Usually the guest can tell the host to flush data to disk. In some cases we >> don't want to flush though, but try to keep everything in cache. >> >> So let's add a new parameter to -drive that allows us to set the flushing >> behavior to "on" or "off", defaulting to enabling the guest to flush. >> >> Signed-off-by: Alexander Graf <ag...@suse.de> >> > > What about another cache=... value instead of adding more options? I'm > quite sure you'll only ever need this with writeback caching. So we > could have cache=none|writethrough|writeback|wb-noflush or something > like that. > >
Yes, cache=volatile seems reasonable. Or cache=unsafe. >> --- >> block/raw-posix.c | 13 +++++++++++++ >> > > This is obviously wrong. If you want to introduce new behaviour to the > block layer, you must do it consistently and not just for one block > driver. So these changes should be made to the generic functions in > block.c instead. > How so? The callback functions are called using bdrv->drv->xxx. If I modify that pointer, I end up affecting all other virtual disks as well. Alex
