doc: add limitation for ConnectX-4 with L2 in mlx5 guide

[dpdk.git] / doc / guides / nics / mlx5.rst

diff --git a/doc/guides/nics/mlx5.rst b/doc/guides/nics/mlx5.rst
index 220c6e5..5b4bb13 100644 (file)
--- a/doc/guides/nics/mlx5.rst
+++ b/doc/guides/nics/mlx5.rst
@@ -124,6 +124,11 @@ Limitations
     - IPv4/UDP with CVLAN filtering
     - Unicast MAC filtering
 
+  - Additional rules are supported from WinOF2 version 2.70:
+
+    - IPv4/TCP with CVLAN filtering
+    - L4 steering rules for port RSS of UDP, TCP and IP
+
 - For secondary process:
 
   - Forked secondary process not supported.
@@ -695,6 +700,13 @@ 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
@@ -1496,7 +1508,7 @@ Performance tuning
    for better performance. For VMs, verify that the right CPU
    and NUMA node are pinned according to the above. Run::
 
-        lstopo-no-graphics
+        lstopo-no-graphics --merge
 
    to identify the NUMA node to which the PCIe adapter is connected.