Comment 22 for bug 1317811

Playing around with this, I actually found an even simpler way to trigger the issue:

PV guest #1: Install redis-server (and enable eth0 ip in config)
PV guest #2: Install redis-tools and run 'redis-benchmark -q -h <PV guest #1 IP> -d 1000'

The MTU size turns out to be irrelevant, this even happens with 1500 during the batch request tests. What does make a difference is to prevent scatter gather as it was reported in another bug about this (on any host that sees the "rides the rocket" message:

sudo ethtool -K eth0 sg off

I discussed the issue upstream and the driver should handle this case without dropping the request. It might be a bit complicated so I cannot give an ETA on the fix right now.