Here is the relevant log snippet:
journal: libvirt version: 1.2.8, package: 16.el7_1.3 (CentOS BuildSystem
, 2015-05-12-20:12:58, worker1.bsys.CentOS.org)
journal: failed to connect to monitor socket: No such process
journal: internal error: process exited while connecting to monitor:
((null):1937): Spice-Warning **: reds.c:3036:reds_init_socket:
getaddrinfo(127.0.0.1,5900): Address family for hostname not supported
qemu–kvm: failed to initialize spice server
If I remove graphics devices from the VM it saves/resumes properly on host restart.
I feel like this is an issue of libvirt starting before networking, but I am a fish out of water with systemd.