Re: [Qemu-devel] [PATCH 1/2] intel_iommu: Fix root_scalable migration breakage

[Peter Xu]

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 <address@hidden>

Thanks,

-- 
Peter Xu