See the doc comments for a description of this new coroutine API.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: NFam Zheng <famz@redhat.com>
Message-id: 1474989516-18255-2-git-send-email-stefanha@redhat.com
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>