build: fix meson check for binutils 2.30

[dpdk.git] / doc / guides / nics / i40e.rst

diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst
index 5d8500c..6aceb53 100644 (file)
--- a/doc/guides/nics/i40e.rst
+++ b/doc/guides/nics/i40e.rst
@@ -129,13 +129,16 @@ Please note that enabling debugging options may affect system performance.
 Runtime Config Options
 ~~~~~~~~~~~~~~~~~~~~~~
 
-- ``Number of Queues per VF`` (default ``4``)
+- ``Reserved number of Queues per VF`` (default ``4``)
+
+  The number of reserved queue per VF is determined by its host PF. If the
+  PCI address of an i40e PF is aaaa:bb.cc, the number of reserved queues per
+  VF can be configured with EAL parameter like -w aaaa:bb.cc,queue-num-per-vf=n.
+  The value n can be 1, 2, 4, 8 or 16. If no such parameter is configured, the
+  number of reserved queues per VF is 4 by default. If VF request more than
+  reserved queues per VF, PF will able to allocate max to 16 queues after a VF
+  reset.
 
-  The number of queue per VF is determined by its host PF. If the PCI address
-  of an i40e PF is aaaa:bb.cc, the number of queues per VF can be configured
-  with EAL parameter like -w aaaa:bb.cc,queue-num-per-vf=n. The value n can be
-  1, 2, 4, 8 or 16. If no such parameter is configured, the number of queues
-  per VF is 4 by default.
 
 - ``Support multiple driver`` (default ``disable``)
 
@@ -163,6 +166,22 @@ Runtime Config Options
   Currently hot-plugging of representor ports is not supported so all required
   representors must be specified on the creation of the PF.
 
+- ``Use latest supported vector`` (default ``disable``)
+
+  Latest supported vector path may not always get the best perf so vector path was
+  recommended to use only on later platform. But users may want the latest vector path
+  since it can get better perf in some real work loading cases. So ``devargs`` param
+  ``use-latest-supported-vec`` is introduced, for example::
+
+  -w 84:00.0,use-latest-supported-vec=1
+
+Vector RX Pre-conditions
+~~~~~~~~~~~~~~~~~~~~~~~~
+For Vector RX it is assumed that the number of descriptor rings will be a power
+of 2. With this pre-condition, the ring pointer can easily scroll back to the
+head after hitting the tail without a conditional check. In addition Vector RX
+can use this assumption to do a bit mask using ``ring_size - 1``.
+
 Driver compilation and testing
 ------------------------------
 
@@ -424,6 +443,9 @@ steering can be used with rte_flow API.
 GTPv1 package is released, and it can be downloaded from
 https://downloadcenter.intel.com/download/27587.
 
+PPPoE package is released, and it can be downloaded from
+https://downloadcenter.intel.com/download/28040.
+
 Load a profile which supports GTP and store backup profile:
 
 .. code-block:: console