From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by dpdk.org (Postfix) with ESMTP id 95F3B8062 for ; Fri, 12 Dec 2014 11:41:32 +0100 (CET) Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga101.jf.intel.com with ESMTP; 12 Dec 2014 02:41:31 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,563,1413270000"; d="scan'208";a="652793281" Received: from irvmail001.ir.intel.com ([163.33.26.43]) by orsmga002.jf.intel.com with ESMTP; 12 Dec 2014 02:41:25 -0800 Received: from sivswdev02.ir.intel.com (sivswdev02.ir.intel.com [10.237.217.46]) by irvmail001.ir.intel.com (8.14.3/8.13.6/MailSET/Hub) with ESMTP id sBCAfOOu024843 for ; Fri, 12 Dec 2014 10:41:25 GMT Received: from sivswdev02.ir.intel.com (localhost [127.0.0.1]) by sivswdev02.ir.intel.com with ESMTP id sBCAfOET006918 for ; Fri, 12 Dec 2014 10:41:24 GMT Received: (from smonroy@localhost) by sivswdev02.ir.intel.com with id sBCAfOG4006914 for dev@dpdk.org; Fri, 12 Dec 2014 10:41:24 GMT From: Sergio Gonzalez Monroy To: dev@dpdk.org Date: Fri, 12 Dec 2014 10:41:24 +0000 Message-Id: <1418380884-6875-1-git-send-email-sergio.gonzalez.monroy@intel.com> X-Mailer: git-send-email 1.8.5.4 MIME-Version: 1.0 Content-Type: text/plain; charset=y Content-Transfer-Encoding: 8bit Subject: [dpdk-dev] [PATCH] doc: Add known issue for iommu and igb_uio X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 12 Dec 2014 10:41:33 -0000 Known issue regarding iommu/VT-d and igb_uio on Linux kernel version 3.15 to 3.17 where unbinding the device from the driver removes the 1:1 mapping for the device on the iommu resulting in memory access errors. Signed-off-by: Sergio Gonzalez Monroy --- doc/guides/rel_notes/known_issues.rst | 32 ++++++++++++++++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/doc/guides/rel_notes/known_issues.rst b/doc/guides/rel_notes/known_issues.rst index 8ef654a..72bd0de 100644 --- a/doc/guides/rel_notes/known_issues.rst +++ b/doc/guides/rel_notes/known_issues.rst @@ -1026,3 +1026,35 @@ Stopping the port does not down the link on Intel® 40G ethernet controller | Driver/Module | Poll Mode Driver (PMD) | | | | +--------------------------------+--------------------------------------------------------------------------------------+ + +Devices bound to igb_uio with VT-d enabled do not work on Linux* kernel 3.15-3.17 +--------------------------------------------------------------------------------- + ++--------------------------------+--------------------------------------------------------------------------------------+ +| Title | Devices bound to igb_uio with VT-d enabled do not work on Linux* kernel 3.15-3.17 | +| | | ++================================+======================================================================================+ +| Reference # | IXA00373938 | +| | | ++--------------------------------+--------------------------------------------------------------------------------------+ +| Description | When VT-d is enabled (iommu=pt intel_iommu=on), devices are 1:1 mapped. | +| | In the Linux* kernel unbinding devices from drivers removes that mapping which | +| | result in IOMMU errors. | +| | | ++--------------------------------+--------------------------------------------------------------------------------------+ +| Implication | Devices will not be allowed to access memory. | +| | | ++--------------------------------+--------------------------------------------------------------------------------------+ +| Resolution/ Workaround | Use earlier or later kernel versions, or avoid driver binding on boot by | +| | blacklisting the driver modules. | +| | ie. in the case of ixgbe, we can pass the kernel command line option: | +| | modprobe.blacklist=ixgbe | +| | This way we do not need to unbind the device to bind it to igb_uio. | +| | | ++--------------------------------+--------------------------------------------------------------------------------------+ +| Affected Environment/ Platform | Linux* systems with kernel versions 3.15 to 3.17 | +| | | ++--------------------------------+--------------------------------------------------------------------------------------+ +| Driver/Module | igb_uio module | +| | | ++--------------------------------+--------------------------------------------------------------------------------------+ -- 1.9.3