On 04/11/2014 12:49 AM, Peter Maydell wrote: > On 10 April 2014 15:35, Alexey Kardashevskiy <a...@ozlabs.ru> wrote: >> Then what is the purpose of many, many VMSTATE_.*_EQUAL? > > Often it's backwards compatibility with a previous vmstate > or save/load function set which incorrectly sent data it didn't > need to. > >> And I do not want to send configuration by the proposed patch, I want to >> make sure that the new guest is able to continue. Why exactly is this bad? > > It's not bad, but as several people have now pointed out to you, > you're trying to fix a tiny tiny corner of the real, larger > problem, in a way which isn't going to generalise to actually > fixing the larger problem. So if we took your change then > (a) we still wouldn't be able to support detection of migration > between two systems with mismatched configuration, so it doesn't > really achieve anything > (b) if we ever did manage to fix that we'd have to remove your > change (because that bit of config checking would now be handled > via whatever generic mechanism we implemented), except we probably > couldn't remove it since that would break migration version > compatibility, so we'd end up with a wart we have to carry > around forever
Ok, understood. Thanks. ps. yeah, I do not often see the bigger picture, I know :( -- Alexey
