On 23 March 2011 16:27, Anthony Liguori <anth...@codemonkey.ws> wrote: > Migration uses the VMStateDescription name as a section identifier. The > section identifiers MUST be unique for a given device. Otherwise, if both > devices are present, migration fails miserably.
So how does it work if you have two devices of the same type in the system? I'd assumed that the unique identifier would be one based on the actually instantiated devices. > It also means that if the > wrong devices are created on the destination, instead of predictable > failure, you get unpredictable guest corruption. > > The Right Way to support what you're describing above is to have a single > VMStateField array and two VMStateDescriptions. IOW: This doesn't make sense because it's decoupling the information about minimum version ID etc (in the VMStateDescription) from the information about which fields are in which version (which is in the VMStateField array when it's initialised via VMSTATE_*_V() macros). So although you get to avoid duplicating all the fields in the arrangement you suggest you still end up with version_id, minimum_version_id etc being duplicated and needing to stay in sync. -- PMM
