[libvirt-users] acceptable SASL mechanisms/can libvirt authenticate against PAM

I was playing with SASL authentication a bit today and I wasn't able to get libvirt to authenticate against PAM (or anything else except the sasldb, although I didn't try Kerberos). Does anybody know off the top of their head what mechanisms/password check options work? I'm trying to figure out if I'm attempting the impossible. Dave