[dpdk-stable] patch 'doc: add limitation for ConnectX-4 with L2 in mlx5 guide' has been queued to stable release 20.11.3

[luca.boccassi at gmail.com]

Hi,

FYI, your patch has been queued to stable release 20.11.3

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 07/14/21. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/bluca/dpdk-stable

This queued commit can be viewed at:
https://github.com/bluca/dpdk-stable/commit/222e82452dad164d61a97f7767c2aafbbaa0e4f7

Thanks.

Luca Boccassi

---
>From 222e82452dad164d61a97f7767c2aafbbaa0e4f7 Mon Sep 17 00:00:00 2001
From: Dmitry Kozlyuk <dkozlyuk at nvidia.com>
Date: Wed, 30 Jun 2021 10:01:06 +0300
Subject: [PATCH] doc: add limitation for ConnectX-4 with L2 in mlx5 guide

[ upstream commit e60561cc955ac01512a35ca309793e351cef3c9b ]

ConnectX-4 and ConnectX-4 Lx NICs require all L2 headers of transmitted
packets to be inlined. By default only first 18 bytes are inlined,
which is insufficient if additional encapsulation is used, like Q-in-Q.
Thus, default settings caused such traffic to be dropepd on Tx.
Document a recommendation to increase inlined data size in such cases.

Fixes: 505f1fe426d3 ("net/mlx5: add Tx devargs")

Signed-off-by: Dmitry Kozlyuk <dkozlyuk at nvidia.com>
Reviewed-by: Viacheslav Ovsiienko <viacheslavo at nvidia.com>
---
 doc/guides/nics/mlx5.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 24d5a69227..78bf829fe5 100644
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -591,6 +591,13 @@ Driver options
   it is not recommended and may prevent NIC from sending packets over
   some configurations.
 
+  For ConnectX-4 and ConnectX-4 Lx NICs, automatically configured value
+  is insufficient for some traffic, because they require at least all L2 headers
+  to be inlined. For example, Q-in-Q adds 4 bytes to default 18 bytes
+  of Ethernet and VLAN, thus ``txq_inline_min`` must be set to 22.
+  MPLS would add 4 bytes per label. Final value must account for all possible
+  L2 encapsulation headers used in particular environment.
+
   Please, note, this minimal data inlining disengages eMPW feature (Enhanced
   Multi-Packet Write), because last one does not support partial packet inlining.
   This is not very critical due to minimal data inlining is mostly required
-- 
2.30.2

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2021-07-12 13:41:41.481244720 +0100
+++ 0095-doc-add-limitation-for-ConnectX-4-with-L2-in-mlx5-gu.patch	2021-07-12 13:41:36.794128943 +0100
@@ -1 +1 @@
-From e60561cc955ac01512a35ca309793e351cef3c9b Mon Sep 17 00:00:00 2001
+From 222e82452dad164d61a97f7767c2aafbbaa0e4f7 Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit e60561cc955ac01512a35ca309793e351cef3c9b ]
+
@@ -13 +14,0 @@
-Cc: stable at dpdk.org
@@ -22 +23 @@
-index 0d96eec2bb..5b4bb13914 100644
+index 24d5a69227..78bf829fe5 100644
@@ -25 +26 @@
-@@ -700,6 +700,13 @@ Driver options
+@@ -591,6 +591,13 @@ Driver options