On Thu, Aug 01, 2024 at 11:36:19AM -0400, Peter Xu wrote:
On Thu, Aug 01, 2024 at 01:51:00AM -0400, Michael S. Tsirkin wrote:
So I suggest a single command that dumps some description of host features, to be passed to qemu on destination. qemu then fails to start on destination if some of these do not work. The advantage is that this also helps things like -cpu host, and a bunch of other things like vdpa where we like to pass through config from kernel.
Something like that could work indeed. I'm thinking whether it shouldn't require a new QMP command; that sounds more work, and we also needs Libvirt cooperations so QEMU migration will still fail. I wonder whether we can integrate it into migration handshake that I referred previously in our TODO item here:
https://wiki.qemu.org/ToDo/LiveMigration#Migration_handshake
This is different. You can start migration on destination without touching source at all. This allows e.g. finding a destination that can support your source.