And ssh-via-AF_VSOCK is precisely what we are doing in systemd v256: a small new unit generator (i.e. a plugin that extends systemd's unit tree dynamically) detects if AF_VSOCK is available and sshd is installed, and if so binds AF_VSOCK/port 22 to sshd, via socket activation. Or in other words: in environments where AF_VSOCK is a thing, sshd will now just work, without any extra configuration and at minimal cost of resources (because lazy socket activation rocks).
bugaevc