ethdev: make device operations struct private

[dpdk.git] / doc / guides / linux_gsg / linux_drivers.rst

diff --git a/doc/guides/linux_gsg/linux_drivers.rst b/doc/guides/linux_gsg/linux_drivers.rst
index 371a817..1850740 100644 (file)
--- a/doc/guides/linux_gsg/linux_drivers.rst
+++ b/doc/guides/linux_gsg/linux_drivers.rst
@@ -36,6 +36,12 @@ be loaded as shown below:
     sudo modprobe uio
     sudo insmod kmod/igb_uio.ko
 
+.. note::
+
+   ``igb_uio`` module is disabled by default starting from ``DPDK v20.02``.
+   To build it, the config option ``CONFIG_RTE_EAL_IGB_UIO`` should be enabled.
+   It is planned to move ``igb_uio`` module to a different git repository.
+
 .. note::
 
     For some devices which lack support for legacy interrupts, e.g. virtual function
@@ -48,6 +54,13 @@ 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 aarch64 system.
+
 Since DPDK release 1.7 onward provides VFIO support, use of UIO is optional
 for platforms that support using VFIO.
 
@@ -65,11 +78,44 @@ Note that in order to use VFIO, your kernel must support it.
 VFIO kernel modules have been included in the Linux kernel since version 3.6.0 and are usually present by default,
 however please consult your distributions documentation to make sure that is the case.
 
+The ``vfio-pci`` module since Linux version 5.7 supports the creation of virtual
+functions. After the PF is bound to vfio-pci module, the user can create the VFs
+by sysfs interface, and these VFs are bound to vfio-pci module automatically.
+
+When the PF is bound to vfio-pci, it has initial VF token generated by random. For
+security reason, this token is write only, the user can't read it from the kernel
+directly. To access the VF, the user needs to start the PF with token parameter to
+setup a VF token in UUID format, then the VF can be accessed with this new token.
+
+Since the ``vfio-pci`` module uses the VF token as internal data to provide the
+collaboration between SR-IOV PF and VFs, so DPDK can use the same VF token for all
+PF devices which bound to one application. This VF token can be specified by the EAL
+parameter ``--vfio-vf-token``.
+
+.. code-block:: console
+
+    1. Generate the VF token by uuid command
+        14d63f20-8445-11ea-8900-1f9ce7d5650d
+
+    2. sudo modprobe vfio-pci enable_sriov=1
+
+    2. ./usertools/dpdk-devbind.py -b vfio-pci 0000:86:00.0
+
+    3. echo 2 > /sys/bus/pci/devices/0000:86:00.0/sriov_numvfs
+
+    4. Start the PF:
+        ./x86_64-native-linux-gcc/app/testpmd -l 22-25 -n 4 -w 86:00.0 \
+         --vfio-vf-token=14d63f20-8445-11ea-8900-1f9ce7d5650d --file-prefix=pf -- -i
+
+    5. Start the VF:
+        ./x86_64-native-linux-gcc/app/testpmd -l 26-29 -n 4 -w 86:02.0 \
+         --vfio-vf-token=14d63f20-8445-11ea-8900-1f9ce7d5650d --file-prefix=vf0 -- -i
+
 Also, to use VFIO, both kernel and BIOS must support and be configured to use IO virtualization (such as Intel® VT-d).
 
 .. note::
 
-    ``vfio-pci`` module doesn't support the creation of virtual functions.
+    ``vfio-pci`` module doesn't support the creation of virtual functions before Linux version 5.7.
 
 For proper operation of VFIO when running DPDK applications as a non-privileged user, correct permissions should also be set up.
 This can be done by using the DPDK setup script (called dpdk-setup.sh and located in the usertools directory).
@@ -78,6 +124,8 @@ This can be done by using the DPDK setup script (called dpdk-setup.sh and locate
 
     VFIO can be used without IOMMU. While this is just as unsafe as using UIO, it does make it possible for the user to keep the degree of device access and programming that VFIO has, in situations where IOMMU is not available.
 
+.. _bifurcated_driver:
+
 Bifurcated Driver
 -----------------
 
@@ -92,11 +140,14 @@ Such model has the following benefits:
  - It enables the user to use legacy linux tools such as ``ethtool`` or
    ``ifconfig`` while running DPDK application on the same network ports.
  - It enables the DPDK application to filter only part of the traffic,
-   While the rest will be directed and handled by the kernel driver.
+   while the rest will be directed and handled by the kernel driver.
+   The flow bifurcation is performed by the NIC hardware.
+   As an example, using :ref:`flow_isolated_mode` allows to choose
+   strictly what is received in DPDK.
 
 More about the bifurcated driver can be found in
 `Mellanox Bifurcated DPDK PMD
-<https://dpdksummit.com/Archive/pdf/2016Userspace/Day02-Session04-RonyEfraim-Userspace2016.pdf>`__.
+<https://www.dpdk.org/wp-content/uploads/sites/35/2016/10/Day02-Session04-RonyEfraim-Userspace2016.pdf>`__.
 
 .. _linux_gsg_binding_kernel: