From 4d2c729c62328d6841111d98396374476367ae83 Mon Sep 17 00:00:00 2001 From: Changbin Du Date: Tue, 14 May 2019 22:47:26 +0800 Subject: [PATCH] Documentation: PCI: convert pci-iov-howto.txt to reST Convert plain text documentation to reStructuredText format and add it to Sphinx TOC tree. No essential content change. Signed-off-by: Changbin Du Signed-off-by: Bjorn Helgaas Reviewed-by: Mauro Carvalho Chehab --- Documentation/PCI/index.rst | 1 + .../{pci-iov-howto.txt => pci-iov-howto.rst} | 175 ++++++++++-------- 2 files changed, 101 insertions(+), 75 deletions(-) rename Documentation/PCI/{pci-iov-howto.txt => pci-iov-howto.rst} (63%) diff --git a/Documentation/PCI/index.rst b/Documentation/PCI/index.rst index 79d6d75bbf28..0d9390298c4a 100644 --- a/Documentation/PCI/index.rst +++ b/Documentation/PCI/index.rst @@ -10,3 +10,4 @@ Linux PCI Bus Subsystem pci picebus-howto + pci-iov-howto diff --git a/Documentation/PCI/pci-iov-howto.txt b/Documentation/PCI/pci-iov-howto.rst similarity index 63% rename from Documentation/PCI/pci-iov-howto.txt rename to Documentation/PCI/pci-iov-howto.rst index d2a84151e99c..b9fd003206f1 100644 --- a/Documentation/PCI/pci-iov-howto.txt +++ b/Documentation/PCI/pci-iov-howto.rst @@ -1,14 +1,19 @@ - PCI Express I/O Virtualization Howto - Copyright (C) 2009 Intel Corporation - Yu Zhao +.. SPDX-License-Identifier: GPL-2.0 +.. include:: - Update: November 2012 - -- sysfs-based SRIOV enable-/disable-ment - Donald Dutile +==================================== +PCI Express I/O Virtualization Howto +==================================== -1. Overview +:Copyright: |copy| 2009 Intel Corporation +:Authors: - Yu Zhao + - Donald Dutile -1.1 What is SR-IOV +Overview +======== + +What is SR-IOV +-------------- Single Root I/O Virtualization (SR-IOV) is a PCI Express Extended capability which makes one physical device appear as multiple virtual @@ -23,9 +28,11 @@ Memory Space, which is used to map its register set. VF device driver operates on the register set so it can be functional and appear as a real existing PCI device. -2. User Guide +User Guide +========== -2.1 How can I enable SR-IOV capability +How can I enable SR-IOV capability +---------------------------------- Multiple methods are available for SR-IOV enablement. In the first method, the device driver (PF driver) will control the @@ -43,105 +50,123 @@ checks, e.g., check numvfs == 0 if enabling VFs, ensure numvfs <= totalvfs. The second method is the recommended method for new/future VF devices. -2.2 How can I use the Virtual Functions +How can I use the Virtual Functions +----------------------------------- The VF is treated as hot-plugged PCI devices in the kernel, so they should be able to work in the same way as real PCI devices. The VF requires device driver that is same as a normal PCI device's. -3. Developer Guide +Developer Guide +=============== -3.1 SR-IOV API +SR-IOV API +---------- To enable SR-IOV capability: -(a) For the first method, in the driver: + +(a) For the first method, in the driver:: + int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn); - 'nr_virtfn' is number of VFs to be enabled. -(b) For the second method, from sysfs: + +'nr_virtfn' is number of VFs to be enabled. + +(b) For the second method, from sysfs:: + echo 'nr_virtfn' > \ /sys/bus/pci/devices//sriov_numvfs To disable SR-IOV capability: -(a) For the first method, in the driver: + +(a) For the first method, in the driver:: + void pci_disable_sriov(struct pci_dev *dev); -(b) For the second method, from sysfs: + +(b) For the second method, from sysfs:: + echo 0 > \ /sys/bus/pci/devices//sriov_numvfs To enable auto probing VFs by a compatible driver on the host, run command below before enabling SR-IOV capabilities. This is the default behavior. +:: + echo 1 > \ /sys/bus/pci/devices//sriov_drivers_autoprobe To disable auto probing VFs by a compatible driver on the host, run command below before enabling SR-IOV capabilities. Updating this entry will not affect VFs which are already probed. +:: + echo 0 > \ /sys/bus/pci/devices//sriov_drivers_autoprobe -3.2 Usage example +Usage example +------------- Following piece of code illustrates the usage of the SR-IOV API. +:: -static int dev_probe(struct pci_dev *dev, const struct pci_device_id *id) -{ - pci_enable_sriov(dev, NR_VIRTFN); + static int dev_probe(struct pci_dev *dev, const struct pci_device_id *id) + { + pci_enable_sriov(dev, NR_VIRTFN); - ... - - return 0; -} - -static void dev_remove(struct pci_dev *dev) -{ - pci_disable_sriov(dev); - - ... -} - -static int dev_suspend(struct pci_dev *dev, pm_message_t state) -{ - ... - - return 0; -} - -static int dev_resume(struct pci_dev *dev) -{ - ... - - return 0; -} - -static void dev_shutdown(struct pci_dev *dev) -{ - ... -} - -static int dev_sriov_configure(struct pci_dev *dev, int numvfs) -{ - if (numvfs > 0) { - ... - pci_enable_sriov(dev, numvfs); - ... - return numvfs; - } - if (numvfs == 0) { - .... - pci_disable_sriov(dev); ... + return 0; } -} -static struct pci_driver dev_driver = { - .name = "SR-IOV Physical Function driver", - .id_table = dev_id_table, - .probe = dev_probe, - .remove = dev_remove, - .suspend = dev_suspend, - .resume = dev_resume, - .shutdown = dev_shutdown, - .sriov_configure = dev_sriov_configure, -}; + static void dev_remove(struct pci_dev *dev) + { + pci_disable_sriov(dev); + + ... + } + + static int dev_suspend(struct pci_dev *dev, pm_message_t state) + { + ... + + return 0; + } + + static int dev_resume(struct pci_dev *dev) + { + ... + + return 0; + } + + static void dev_shutdown(struct pci_dev *dev) + { + ... + } + + static int dev_sriov_configure(struct pci_dev *dev, int numvfs) + { + if (numvfs > 0) { + ... + pci_enable_sriov(dev, numvfs); + ... + return numvfs; + } + if (numvfs == 0) { + .... + pci_disable_sriov(dev); + ... + return 0; + } + } + + static struct pci_driver dev_driver = { + .name = "SR-IOV Physical Function driver", + .id_table = dev_id_table, + .probe = dev_probe, + .remove = dev_remove, + .suspend = dev_suspend, + .resume = dev_resume, + .shutdown = dev_shutdown, + .sriov_configure = dev_sriov_configure, + };