Anyone use PG with kvm/virtio? Any gotchas or recommended settings?

[bubba postgres <bubba.postgres@xxxxxxxxx>]

Looks like the recommended settings are using the virtio interface, cache=none, and raw partitions (not qcow2).
Anyone else run into any problems with kvm or virtio?

We currently have a setup using qcow2, virtio, and the default cache settings, and experienced some data corruption (not preceded by crashes or restarts of postgres), and we are wondering if that might be the culprit.