Stefan Hajnoczi has a nice summary:

http://blog.vmsplice.net/2019/04/whats-new-in-virtio-11.html

If you go here: https://docs.oasis-open.org/virtio/virtio/v1.1/cs01/ you will find a version with changes from v1.0 cs04 highlighted. In case you participated in a public review, changes since the public review draft are also listed in the specification itself.