From 5af3be004bc11f81582ef57cd01ed3f0811cb407 Mon Sep 17 00:00:00 2001 From: Bruce Richardson Date: Mon, 23 Mar 2015 16:19:50 +0000 Subject: [PATCH] doc: add note on needing igb_uio for VF devices Since the uio_pci_generic module requires that the device to which it is being bound supports legacy interrupts, there can be problems using it with VF devices. Add a note to the GSG doc to document this fact, and provide information on loading igb_uio as a replacement. Signed-off-by: Bruce Richardson Acked-by: Bernard Iremonger Acked-by: Siobhan Butler --- doc/guides/linux_gsg/build_dpdk.rst | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/doc/guides/linux_gsg/build_dpdk.rst b/doc/guides/linux_gsg/build_dpdk.rst index 255d6dc62c..5f0f3aeda2 100644 --- a/doc/guides/linux_gsg/build_dpdk.rst +++ b/doc/guides/linux_gsg/build_dpdk.rst @@ -166,7 +166,7 @@ Loading Modules to Enable Userspace IO for DPDK ----------------------------------------------- To run any DPDK application, a suitable uio module can be loaded into the running kernel. -In most cases, the standard uio_pci_generic module included in the linux kernel +In many cases, the standard uio_pci_generic module included in the linux kernel can provide the uio capability. This module can be loaded using the command .. code-block:: console @@ -174,7 +174,18 @@ can provide the uio capability. This module can be loaded using the command sudo modprobe uio_pci_generic As an alternative to the uio_pci_generic, the DPDK also includes the igb_uio -module which can be found in the kmod subdirectory referred to above. +module which can be found in the kmod subdirectory referred to above. It can +be loaded as shown below: + +.. code-block:: console + + sudo modprobe uio + sudo insmod kmod/igb_uio.ko + +.. note:: + + For some devices which lack support for legacy interrupts, e.g. virtual function + (VF) devices, the igb_uio module may be needed in place of uio_pci_generic. Since DPDK release 1.7 onward provides VFIO support, use of UIO is optional for platforms that support using VFIO. -- 2.20.1