We’ve confirmed with Dell Support that QLogic has identified a bug with the QLE82xx network driver (at least through version 5.3.12.0925) and Virtual Machine Queues (VMQ). As of August 15, 2014, QLogic reports that they have reproduced the issue, but have not resolved it.
We have a case open with Microsoft Hyper-V Support and that case number has been shared with Dell and QLogic to coordinate troubleshooting and support as the issue becomes more visible in the community. I’ll post updates as we have them. There is word of a beta driver at some point, which we’ve expressed interest in testing.