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Diffstat (limited to 'doc/guides/nics/netvsc.rst')
| -rw-r--r-- | doc/guides/nics/netvsc.rst | 31 |
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) |