From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by dpdk.org (Postfix) with ESMTP id 3CD905F36 for ; Wed, 26 Sep 2018 07:08:57 +0200 (CEST) Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id EDF2118A; Tue, 25 Sep 2018 22:08:55 -0700 (PDT) Received: from wls-arm-softiron03.shanghai.arm.com (wls-arm-softiron03.shanghai.arm.com [10.169.40.43]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 7FB8E3F5B7; Tue, 25 Sep 2018 22:08:54 -0700 (PDT) From: "tone.zhang" To: dev@dpdk.org Cc: gavin.hu@arm.com, bruce.richardson@intel.com, bluca@debian.org, roszenrami@gmail.com, Honnappa.Nagarahalli@arm.com, stephen@networkplumber.org, nd@arm.com Date: Wed, 26 Sep 2018 13:08:47 +0800 Message-Id: <1537938527-14474-1-git-send-email-tone.zhang@arm.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1537858464-24913-1-git-send-email-tone.zhang@arm.com> References: <1537858464-24913-1-git-send-email-tone.zhang@arm.com> Subject: [dpdk-dev] [PATCH v6] doc: Clarify IOMMU usage with "uio_pci_generic" kernel module X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Sep 2018 05:08:57 -0000 If the devices used for DPDK are bound to the "uio_pci_generic" kernel module, the IOMMU should be disabled in order not to break the IO transmission because of the virtual / physical address mapping. The patch clarifies the IOMMU configurations on both x86_64 and arm64 systems. Signed-off-by: tone.zhang Reviewed-by: Honnappa Nagarahalli Reviewed-by: Stephen Hemminger Reviewed-by: Rami Rosen Acked-by: Gavin Hu Acked-by: Bruce Richardson Acked-by: Luca Boccassi --- doc/guides/linux_gsg/linux_drivers.rst | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/doc/guides/linux_gsg/linux_drivers.rst b/doc/guides/linux_gsg/linux_drivers.rst index 371a817..8da6a31 100644 --- a/doc/guides/linux_gsg/linux_drivers.rst +++ b/doc/guides/linux_gsg/linux_drivers.rst @@ -48,6 +48,13 @@ be loaded as shown below: ``vfio-pci`` kernel module rather than ``igb_uio`` or ``uio_pci_generic``. For more details see :ref:`linux_gsg_binding_kernel` below. +.. note:: + + If the devices used for DPDK are bound to the ``uio_pci_generic`` kernel module, + please make sure that the IOMMU is disabled or passthrough. One can add + ``intel_iommu=off`` or ``amd_iommu=off`` or ``intel_iommu=on iommu=pt``in GRUB + command line on x86_64 systems, or add ``iommu.passthrough=1`` on arm64 system. + Since DPDK release 1.7 onward provides VFIO support, use of UIO is optional for platforms that support using VFIO. -- 2.7.4