Interestingly, we thought we had just been seeing this on the second
nic. However, we've went back through some older logs and realized that
it's been happening on the first nic as well, though it's presenting
itself slightly differently there (ping just says "Destination Host
Unreachable").
We've been running into a fairly persistent issue where virtio_net
adapters will suddenly stop sending packets when running under KVM.
This has persisted through several qemu versions, and a large number of
guest kernel upgrades.
What we end up seeing is the guest continuing to receive packet
