This bug is missing log files that will aid in diagnosing the problem. While running an Ubuntu kernel (not a mainline or third-party kernel) please enter the following command in a terminal window:
apport-collect 1697053 and then change the status of the bug to 'Confirmed'. If, due to the nature of the issue you have encountered, you are unable to run this command, please add a comment stating that fact and change the bug status to 'Confirmed'. This change has been made by an automated script, maintained by the Ubuntu Kernel Team. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- 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/1697053 Title: Missing IOTLB flush causes DMAR errors with SR-IOV Status in linux package in Ubuntu: Incomplete Bug description: SRU Justification: Impact: Using SR-IOV with Intel IOMMUs can observe DMAR errors of the following type: [606483.223009] DMAR:[fault reason 05] PTE Write access is not set [606484.071974] dmar: DRHD: handling fault status reg 402 [606484.077121] dmar: DMAR:[DMA Write] Request device [d8:0a.1] fault addr 35c6e000 The DMAR error causes, at a minimum, loss of network traffic because the request being serviced is lost. Network cards were also observed to experience transmit timeouts after a DMAR fault. In this case, these errors arise from a race condition in the IOTLB management; this race is described (and fixed) in upstream commit: commit ea8ea460c9ace60bbb5ac6e5521d637d5c15293d Author: David Woodhouse <david.woodho...@intel.com> Date: Wed Mar 5 17:09:32 2014 +0000 iommu/vt-d: Clean up and fix page table clear/free behaviour This commit first appeared in mainline 3.15. This issue affects only the Ubuntu 3.13 kernel series. Fix: The race avoidance portion of the above was backported to 3.14-stable, but was never incorporated into the Ubuntu 3.13 kernel series. commit 51d20e1096a711f8cfa9d98a3ac2dd2c7c0fc20c Author: David Woodhouse <dw...@infradead.org> Date: Mon Jun 9 14:09:53 2014 +0100 iommu/vt-d: Fix missing IOTLB flush in intel_iommu_unmap() Based on commit ea8ea460c9ace60bbb5ac6e5521d637d5c15293d upstream This 3.14-stable patch was tested by the customer and observed to resolve the issue in their environment. Testcase: In this case, the issue occurs on very recent Intel based servers using two different SR-IOV network cards (i40e and bnxt) at a customer site. The customer has tested the patch in their environment and confirmed that it resolves the issue. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1697053/+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