> On Fri, Jan 18, 2013 at 12:34:57PM -0500, Paolo Bonzini wrote: > > > > version_id and minimum_version_id should be changed to 2, as the > > > > comment indicates. > > > > > > But won't that mean we have to carry that patch forever, and > > > while we carry > > > that patch we can never migrate from Fedora qemu to an upstream > > > qemu instance? > > > I'd like to avoid carrying any incompatibility forward, if > > > possible. > > > > To some extent you have to choose between backwards- and forwards- > > compatibility. But I think that you can achieve what you want > > by leaving version_id to 3, while setting minimum_version_id to 2. > > What about > > "Problem is it uses acpi_load_old, when reading from qemu-kvm 1.2 (which > advertises format as V2), which reads 4*16 bits (instead of 16 bits) > for en/sts fields. So it can corrupt incoming migration data."
That's if minimum_version_id==3. But if you set minimum_version_id==2, you fix incoming migration from qemu-kvm 1.2 (and break it from upstream QEMU 1.2). acpi_load_old will only be called for version 1. At the same time, because version_id==3 you will still have working migration to upstream QEMU 1.3 and future releases (and break backwards migration to qemu-kvm 1.2, but that's not a problem). Paolo
