From ca33590b6af032bff57d9cc70455660466a654b2 Mon Sep 17 00:00:00 2001 From: Luca Boccassi Date: Mon, 19 Feb 2018 11:16:57 +0000 Subject: New upstream version 18.02 Change-Id: I89ed24cb2a49b78fe5be6970b99dd46c1499fcc3 Signed-off-by: Luca Boccassi --- doc/guides/nics/vdev_netvsc.rst | 100 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 100 insertions(+) create mode 100644 doc/guides/nics/vdev_netvsc.rst (limited to 'doc/guides/nics/vdev_netvsc.rst') diff --git a/doc/guides/nics/vdev_netvsc.rst b/doc/guides/nics/vdev_netvsc.rst new file mode 100644 index 00000000..55d130a3 --- /dev/null +++ b/doc/guides/nics/vdev_netvsc.rst @@ -0,0 +1,100 @@ +.. SPDX-License-Identifier: BSD-3-Clause + Copyright 2017 6WIND S.A. + Copyright 2017 Mellanox Technologies, Ltd. + +VDEV_NETVSC driver +================== + +The VDEV_NETVSC driver (librte_pmd_vdev_netvsc) provides support for NetVSC +interfaces and associated SR-IOV virtual function (VF) devices found in +Linux virtual machines running on Microsoft Hyper-V_ (including Azure) +platforms. + +.. _Hyper-V: https://docs.microsoft.com/en-us/windows-hardware/drivers/network/overview-of-hyper-v + +Implementation details +---------------------- + +Each instance of this driver effectively needs to drive two devices: the +NetVSC interface proper and its SR-IOV VF (referred to as "physical" from +this point on) counterpart sharing the same MAC address. + +Physical devices are part of the host system and cannot be maintained during +VM migration. From a VM standpoint they appear as hot-plug devices that come +and go without prior notice. + +When the physical device is present, egress and most of the ingress traffic +flows through it; only multicasts and other hypervisor control still flow +through NetVSC. Otherwise, NetVSC acts as a fallback for all traffic. + +To avoid unnecessary code duplication and ensure maximum performance, +handling of physical devices is left to their original PMDs; this virtual +device driver (also known as *vdev*) manages other PMDs as summarized by the +following block diagram:: + + .------------------. + | DPDK application | + `--------+---------' + | + .------+------. + | DPDK ethdev | + `------+------' Control + | | + .------------+------------. v .--------------------. + | failsafe PMD +---------+ vdev_netvsc driver | + `--+-------------------+--' `--------------------' + | | + | .........|......... + | : | : + .----+----. : .----+----. : + | tap PMD | : | any PMD | : + `----+----' : `----+----' : <-- Hot-pluggable + | : | : + .------+-------. : .-----+-----. : + | NetVSC-based | : | SR-IOV VF | : + | netdevice | : | device | : + `--------------' : `-----------' : + :.................: + + +This driver implementation may be temporary and should be improved or removed +either when hot-plug will be fully supported in EAL and bus drivers or when +a new NetVSC driver will be integrated. + +Build options +------------- + +- ``CONFIG_RTE_LIBRTE_VDEV_NETVSC_PMD`` (default ``y``) + + Toggle compilation of this driver. + +Run-time parameters +------------------- + +This driver is invoked automatically in Hyper-V VM systems unless the user +invoked it by command line using ``--vdev=net_vdev_netvsc`` EAL option. + +The following device parameters are supported: + +- ``iface`` [string] + + Provide a specific NetVSC interface (netdevice) name to attach this driver + to. Can be provided multiple times for additional instances. + +- ``mac`` [string] + + Same as ``iface`` except a suitable NetVSC interface is located using its + MAC address. + +- ``force`` [int] + + If nonzero, forces the use of specified interfaces even if not detected as + NetVSC or detected as routed NETVSC. + +- ``ignore`` [int] + + If nonzero, ignores the driver runnig (actually used to disable the + auto-detection in Hyper-V VM). + +Not specifying either ``iface`` or ``mac`` makes this driver attach itself to +all unrouted NetVSC interfaces found on the system. -- cgit 1.2.3-korg