6b321a3df5
There is a need to add some more fields to VirtIODevice that should be migrated (broken status, endianness). The problem is that we do not want to break compatibility while adding a new feature... This issue has been addressed in the generic VMState code with the use of optional subsections. As a *temporary* alternative to port the whole virtio migration code to VMState, this patch mimics a similar subsectionning ability for virtio, using the VMState code. Since each virtio device is streamed in its own section, the idea is to stream subsections between the end of the device section and the start of the next sections. This allows an older QEMU to complain and exit when fed with subsections: Unknown savevm section type 5 load of migration failed Suggested-by: Alexander Graf <agraf@suse.de> Signed-off-by: Greg Kurz <gkurz@linux.vnet.ibm.com> Reviewed-by: Alexander Graf <agraf@suse.de> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Read the documentation in qemu-doc.html or on http://wiki.qemu-project.org - QEMU team