On Thu, Jul 07, 2016 at 02:43:49PM -0300, Eduardo Habkost wrote: > I see. If you have an useful use case for it, we may consider > that. But first I would like to see an actual case where a > feature was not added to GET_SUPPORTED_CPUID yet, but would not > crash and burn if forcibly enabled by QEMU. Ok. > I mean live migration to a different host (that normally has the > same CPU vendor). When you live-migrate or use savevm, you need > to send the machine state to the other host. This is implemented > using VMStateDescription structs describing the data to be > migrated. See vmstate_x86_cpu in target-i386/machine.c, for > example. > > You need additional migration sections if the feature introduces > additional state (e.g. CPU registers) that need to be migrated > too, to keep the feature working. If there's new state but no > migration support is implemented yet, you need to add the feature > to unmigratable_flags. > > For an example where no additional state is introduced by new > features, see: Thanks for the examples and the explanation - I see the deal now. Ok, I'll go through the features and see what kind of state the kernel programs in there and add them to a VMStateDescription thing. Hohumm, makes sense to me. Thanks. -- Regards/Gruss, Boris. ECO tip #101: Trim your mails when you reply. -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html