Comment 11 for bug 1274676

Finished bisecting the kernel today and found the culprit:

commit 56e94095efb3d4f749212bf7c0b151843d157f49
Author: Alexander Duyck <email address hidden>
Date: Fri Jul 20 08:10:03 2012 +0000

    ixgbevf: Add VF DCB + SR-IOV support

    This change adds support for DCB and SR-IOV from the VF. With this change
    in place the VF will correctly use a traffic class other than 0 in the case
    that the PF is configured with the default user priority belonging to a
    traffic class other than 0.

    Cc: Greg Rose <email address hidden>
    Signed-off-by: Alexander Duyck <email address hidden>
    Tested-by: Sibai Li <email address hidden>
    Signed-off-by: Jeff Kirsher <email address hidden>

The challenge is that this commit is stacked on 53 additional patches to the driver in 12.04 which is a massive delta.

I am not recommending back-porting this large set of driver patches to the precise kernel. The correct solution would be to install the 'linux-image-generic-lts-saucy' and then modify the ec2 instance attributes to enable SR-IOV. This hardware enablement kernel brings the necessary features for this driver in a supported fashion (https://wiki.ubuntu.com/Kernel/LTSEnablementStack).