On Fri, May 17, 2024 at 3:54 PM Fiona Ebner <f.eb...@proxmox.com> wrote: > > Migration from an 8.2 or 9.0 binary to an 8.1 binary with machine > version 8.1 can fail with: > > > kvm: Features 0x1c0010130afffa7 unsupported. Allowed features: 0x10179bfffe7 > > kvm: Failed to load virtio-net:virtio > > kvm: error while loading state for instance 0x0 of device > > '0000:00:12.0/virtio-net' > > kvm: load of migration failed: Operation not permitted > > The series > > 53da8b5a99 virtio-net: Add support for USO features > 9da1684954 virtio-net: Add USO flags to vhost support. > f03e0cf63b tap: Add check for USO features > 2ab0ec3121 tap: Add USO support to tap device. > > only landed in QEMU 8.2, so the compatibility flags should be part of > machine version 8.1. > > Moving the flags unfortunately breaks forward migration with machine > version 8.1 from a binary without this patch to a binary with this > patch. > > Fixes: 53da8b5a99 ("virtio-net: Add support for USO features") > Signed-off-by: Fiona Ebner <f.eb...@proxmox.com>
Acked-by: Jason Wang <jasow...@redhat.com> Thanks