Re: [Qemu-devel] [PATCH v1 3/8] usb/ehci: seperate out PCIisms

[Gerd Hoffmann]

  Hi,

>> ... then you don't need to fiddle with the versions as the vmstate wire
>> format doesn't change then.
>>
> 
> Does that work considering you have turned one layer of VMSD into two?
> Can it equivocate machines saved with the old all-in-one vmsd with
> this new one that is structured in two layers?

I'm pretty sure it does as only for top-level vmsd name and version are
stuffed into the wire bytestream.  For sub-vmsds only the actual fields
are written.  So moving stuff from the toplevel vmsd into another one
which then gets referenced via VMSTATE_STRUCT doesn't change the format.

cheers,
  Gerd