summaryrefslogtreecommitdiffstats
path: root/doc/guides/nics/vdev_netvsc.rst
diff options
context:
space:
mode:
authorLuca Boccassi <luca.boccassi@gmail.com>2018-02-19 11:16:57 +0000
committerLuca Boccassi <luca.boccassi@gmail.com>2018-02-19 11:17:28 +0000
commitca33590b6af032bff57d9cc70455660466a654b2 (patch)
tree0b68b090bd9b4a78a3614b62400b29279d76d553 /doc/guides/nics/vdev_netvsc.rst
parent169a9de21e263aa6599cdc2d87a45ae158d9f509 (diff)
New upstream version 18.02upstream/18.02
Change-Id: I89ed24cb2a49b78fe5be6970b99dd46c1499fcc3 Signed-off-by: Luca Boccassi <luca.boccassi@gmail.com>
Diffstat (limited to 'doc/guides/nics/vdev_netvsc.rst')
-rw-r--r--doc/guides/nics/vdev_netvsc.rst100
1 files changed, 100 insertions, 0 deletions
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.