From mboxrd@z Thu Jan 1 00:00:00 1970 From: "tone.zhang" Subject: [PATCH v5] doc: Clarify IOMMU usage with "uio_pci_generic" kernel module Date: Tue, 25 Sep 2018 14:54:24 +0800 Message-ID: <1537858464-24913-1-git-send-email-tone.zhang@arm.com> References: <1537499262-22644-1-git-send-email-tone.zhang@arm.com> Cc: gavin.hu@arm.com, bruce.richardson@intel.com, bluca@debian.org, roszenrami@gmail.com, Honnappa.Nagarahalli@arm.com, nd@arm.com To: dev@dpdk.org Return-path: Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by dpdk.org (Postfix) with ESMTP id 0F4FE1AFF for ; Tue, 25 Sep 2018 08:54:34 +0200 (CEST) In-Reply-To: <1537499262-22644-1-git-send-email-tone.zhang@arm.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 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 --- 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