Openwrt under QEMU networking

I have OpenWRT 86_64 running under QEMU on Ubuntu. I can ssh into the QEMU session from my laptop, but I can't for the life of me connect from the OpenWRT session to the internet. I've tried about a dozen different ways to do this and none have worked.

Basically, while I can connect from the host to the virtual and back, when I try to connect from the virtual to anywhere else no packets appear to be sent; at least tcpdump shows nothing.

Can someone please post a working QEMU network config, both on the host and virtual sides?