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-rw-r--r--doc/guides/nics/netvsc.rst31
1 files changed, 22 insertions, 9 deletions
diff --git a/doc/guides/nics/netvsc.rst b/doc/guides/nics/netvsc.rst
index 345f393c..87fabf5b 100644
--- a/doc/guides/nics/netvsc.rst
+++ b/doc/guides/nics/netvsc.rst
@@ -28,19 +28,16 @@ In this release, the hyper PMD driver provides the basic functionality of packet
* VLAN tags are always stripped and presented in mbuf tci field.
-* The Hyper-V driver does not use or support Link State or Rx interrupt.
+* The Hyper-V driver does not use or support interrupts. Link state change
+ callback is done via change events in the packet ring.
* The maximum number of queues is limited by the host (currently 64).
When used with 4.16 kernel only a single queue is available.
-.. note::
- This driver is intended for use with **Hyper-V only** and is
- not recommended for use on Azure because accelerated Networking
- (SR-IOV) is not supported.
-
- On Azure, use the :doc:`vdev_netvsc` which
- automatically configures the necessary TAP and failsave drivers.
-
+* This driver supports SR-IOV network acceleration.
+ If SR-IOV is enabled then the driver will transparently manage the interface,
+ and send and receive packets using the VF path.
+ The VDEV_NETVSC and FAILSAFE drivers are *not* used when using netvsc PMD.
Installation
------------
@@ -103,3 +100,19 @@ The following prerequisites apply:
* Linux kernel support for UIO on vmbus is done with the uio_hv_generic driver.
Full support of multiple queues requires the 4.17 kernel. It is possible
to use the netvsc PMD with 4.16 kernel but it is limited to a single queue.
+
+
+Netvsc PMD arguments
+--------------------
+
+The user can specify below argument in devargs.
+
+#. ``latency``:
+
+ A netvsc device uses a mailbox page to indicate to the host that there
+ is something in the transmit queue. The host scans this page at a
+ periodic interval. This parameter allows adjusting the value that
+ is used by the host. Smaller values improve transmit latency, and larger
+ values save CPU cycles. This parameter is in microseconds.
+ If the value is too large or too small it will be
+ ignored by the host. (Default: 50)