Documentation: PCI: convert pci-iov-howto.txt to reST (4d2c729c) · Commits · 戴 / test

Documentation/PCI/index.rst

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		@@ -10,3 +10,4 @@ Linux PCI Bus Subsystem

		pci
		picebus-howto
		pci-iov-howto

Documentation/PCI/pci-iov-howto.txt→Documentation/PCI/pci-iov-howto.rst

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		.. SPDX-License-Identifier: GPL-2.0
		.. include:: <isonum.txt>

		====================================
		PCI Express I/O Virtualization Howto
		Copyright (C) 2009 Intel Corporation
		Yu Zhao <yu.zhao@intel.com>
		====================================

		Update: November 2012
		-- sysfs-based SRIOV enable-/disable-ment
		Donald Dutile <ddutile@redhat.com>
		:Copyright: \|copy\| 2009 Intel Corporation
		:Authors: - Yu Zhao <yu.zhao@intel.com>
		- Donald Dutile <ddutile@redhat.com>

		1. Overview
		Overview
		========

		1.1 What is SR-IOV
		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
		@@ -43,46 +50,64 @@ 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:

		(b) For the second method, from sysfs::

		echo 'nr_virtfn' > \
		/sys/bus/pci/devices/<DOMAIN:BUS:DEVICE.FUNCTION>/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/<DOMAIN:BUS:DEVICE.FUNCTION>/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/<DOMAIN:BUS:DEVICE.FUNCTION>/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/<DOMAIN:BUS:DEVICE.FUNCTION>/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)
		{

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