On Fri, Mar 29, 2019 at 09:51:06AM +0800, Yi Sun wrote: > On 19-03-28 18:49:32, Peter Xu wrote: > > When introducing the initial support for scalable mode we added a > > new field into vmstate however we blindly migrate that field without > > notice. That'll break migration no matter forward or backward. > > > Just curious, what is the scenario to break migration? From latest > qemu integrated scalable mode patches to an old qemu without scalable > mode?
Yes, just try to fetch/build a 3.1 QEMU and migrate that to a latest QEMU with -M pc-q35-3.1 and it'll crash with the iommu device. > > The changes look good to me. Thanks for the fix! > > Reviewed-by: Yi Sun <yi.y....@linux.intel.com> Thanks, -- Peter Xu
