Due to the nature of this bug, being very difficult to reproduce, real verification could take weeks instead of only days. However, one reporter has been running with a test kernel I built here https://launchpad.net/~ddstreet/+archive/ubuntu/lp1723127
which is the base 4.4.0-112 kernel plus the two patches from this bug. In their testing, running on 6 weeks now, the problem has not reproduced and they have seen no other issues. Of course, that test kernel doesn't have all the other patches that the -proposed kernel has, but that testing is likely the best verification we can get for this particular bug. I have also asked the same reporter to switch their testing from my test kernel over to the -proposed kernel, and to report any unexpected issues they see. If they do report any regression, I'll communicate that here. Based on that justification, I'll mark this bug as verified. ** Tags removed: verification-needed-artful verification-needed-xenial ** Tags added: verification-done-artful verification-done-xenial -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1723127 Title: Intel i40e PF reset due to incorrect MDD detection (continues...) Status in linux package in Ubuntu: Fix Released Status in linux source package in Trusty: Won't Fix Status in linux source package in Xenial: Fix Committed Status in linux source package in Artful: Fix Committed Status in linux source package in Bionic: Fix Released Bug description: [impact] The i40e driver sometimes causes a "malicious device" event that the firmware detects, which causes the firmware to reset the nic, causing an interruption in the network connection - which can cause further problems, e.g. if the interface is in a bond; the reset will at least cause a temporary interruption in network traffic. [fix] The upstream patch to fix this adjusts how the driver fragments TX data; the "malicious driver" detected by the firmware is a result of incorrectly crafted TX fragment descriptors (the firmware has specific complicated restrictions on this). The patch is from Intel, and they suggested this specific patch to address the problem; additionally I have checked with someone who reported this to me and provided a test kernel with the patch to them, and they have been able to run ~6 weeks so far without reproducing the issue; previously they could reproduce it as quickly as a day, but usually within 2-3 weeks. [test case] the bug is unfortunately very difficult to reproduce, but as shown in this (and previous) bug comments, some users of the i40e have traffic that can consistently reproduce the problem (although usually on the order of days, or longer, to reproduce). Reproducing is easily detected, as the nw traffic will be interrupted and the system logs will contain a message like: i40e 0000:02:00.1: TX driver issue detected, PF reset issued [regression potential] the patch for this alters how tx is fragmented by the driver, so a possible regression would likely cause problems in TX traffic and/or additional "malicious device detection" events. [original description] This is a continuation from bug 1713553; a patch was added in that bug to attempt to fix this, and it may have helped reduce the issue but appears not to have fixed it, based on more reports. The issue is the i40e driver, when TSO is enabled, sometimes sees the NIC firmware issue a "MDD event" where MDD is "Malicious Driver Detection". This is vaguely defined in the i40e spec, but with no way to tell what the NIC actually saw that it didn't like. So, the driver can do nothing but print an error message and reset the PF (or VF). Unfortunately, this resets the interface, which causes an interruption in network traffic flow while the PF is resetting. See bug 1713553 for more details. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1723127/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
