On Wed, Feb 24, 2010 at 03:14:25AM +0000, Paul Brook wrote: > > vnet_hdr is IMHO a really bad example to copy from. > > > > vnet_hdr leaks into the migration state via n->has_vnet_hdr. What this > > means is that if you want to migrate from -net tap -net nic,model=virtio > > to -net user -net nic,model=virtio, it will fail. > > > > This is a hard problem to solve in qemu though because it would require > > that we implement software GSO which so far, no one has stepped up to do. > > Or make virtio-net pass this on to the guest, and have that deal with the > problem.
This is exacly what we do, via feature bits. > If you implement software GSO, then devices can assume it's always > present and don't need to probe. > > Paul
