On 12/17/12 15:47, Hans de Goede wrote: > Hi, > > On 12/17/2012 03:39 PM, Gerd Hoffmann wrote: >> On 12/17/12 15:23, Hans de Goede wrote: >>> Hi, >>> >>> On 12/17/2012 02:16 PM, Gerd Hoffmann wrote: >>>> On 12/14/12 14:35, Hans de Goede wrote: >>>>> Note that a shadow variable is used instead of changing frindex to >>>>> uframe accuracy because we must send a frindex which is a multiple >>>>> of 8 >>>>> during migration for migration compatibility, and rounding it down to >>>>> a multiple of 8 pre-migration, can lead to frindex going backwards >>>>> from >>>>> the guest pov. >>>> >>>> Jumping forward instead? >>> >>> You mean rounding the send frindex up pre-migration, I didn't really >>> consider >>> that as it will cause us skipping processing an entry in the periodic >>> frame >>> list. I guess doing that on migration isn't too bad. OTOH giving the >>> guest >>> only frame accuracy like we've been doing till now also works fine... >>> >>> Your choice :) >> >> I'm looking for a way to avoid the shadow variable, but of course >> without breaking migration. giving the guest only frame accuracy looks >> good to me. > > Ok, but then we need the shadow variable, iow then the patch stays as is > ...
Can't we (a) switch frindex to microframe resolution, (b) round to frame resolution in pre_save and (c) return frindex & ~7 on guest register reads? cheers, Gerd
