NEWS: Deprecate support for AVX512-optimized features.

The AVX512-optimized datapath features, including DPCLS lookups,
action handling, miniflow extraction, and DPIF input processing, are
being deprecated.

These features have not been actively maintained upstream and there is
no automated testing coverage for them.

This notice deprecates support as of the v3.7 release, with the
intention to remove it in the v3.8 release.

Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Kevin Traynor <ktraynor@redhat.com>

Author: chaudron

Documentation/intro/install/dpdk.rst

@@ -155,6 +155,10 @@ has to be configured to build against the DPDK library (``--with-dpdk``).
      While ``--with-dpdk`` is required, you can pass any other configuration
      option described in :ref:`general-configuring`.
 
+   .. note::
+     The AVX512 Datapath Classifier Performance feature is deprecated and will
+     be removed in a future release.
+
    It is strongly recommended to build OVS with at least ``-msse4.2`` and
    ``-mpopcnt`` optimization flags. If these flags are not enabled, the AVX512
    optimized DPCLS implementation is not available in the resulting binary.

Documentation/topics/dpdk/bridge.rst

@@ -165,6 +165,11 @@ To turn on SMC::
 Datapath Classifier Performance
 -------------------------------
 
+.. note::
+
+   The AVX512 Datapath Classifier Performance feature is deprecated and will be
+   removed in a future release.
+
 The datapath classifier (dpcls) performs wildcard rule matching, a compute
 intensive process of matching a packet ``miniflow`` to a rule ``miniflow``. The
 code that does this compute work impacts datapath performance, and optimizing
@@ -214,6 +219,11 @@ result in lower performance when these mitigations are enabled.
 Optimizing Specific Subtable Search
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+.. note::
+
+   The AVX512 Optimizing Specific Subtable Search feature is deprecated and
+   will be removed in a future release.
+
 During the packet classification, the datapath can use specialized lookup
 tables to optimize the search.  However, not all situations are optimized.  If
 you see a message like the following one in the OVS logs, it means that there
@@ -247,6 +257,11 @@ the output of the ``dp-extra-info:miniflow_bits(4,1)`` values.
 Datapath Interface Performance
 ------------------------------
 
+.. note::
+
+   The AVX512 Datapath Interface Performance feature is deprecated and will be
+   removed in a future release.
+
 The datapath interface (DPIF) is responsible for taking packets through the
 major components of the userspace datapath; such as packet parsing, caches and
 datapath classifier lookups.
@@ -274,6 +289,11 @@ name::
 Packet parsing performance
 --------------------------
 
+.. note::
+
+   The AVX512 Packet parsing performance feature is deprecated and will be
+   removed in a future release.
+
 Open vSwitch performs parsing of the raw packets and extracts the important
 header information into a compressed miniflow structure.  This miniflow is
 composed of bits and blocks where the bits signify which blocks are set or have
@@ -331,6 +351,11 @@ following command::
 Actions Implementations (Experimental)
 --------------------------------------
 
+.. note::
+
+   The AVX512 Actions Implementations feature is deprecated and will be
+   removed in a future release.
+
 Actions describe what processing or modification should be performed on a
 packet when it matches a given flow. Similar to the datapath interface,
 DPCLS and MFEX (see above), the implementation of these actions can be

Documentation/topics/testing.rst

@@ -366,6 +366,10 @@ testsuite.
 Userspace datapath: Testing and Validation of CPU-specific Optimizations
 ''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''''
 
+.. note::
+  The AVX512 CPU-specific optimization features are deprecated and will be
+  removed in a future release.
+
 As multiple versions of the datapath classifier, packet parsing functions and
 actions can co-exist, each with different CPU ISA optimizations, it is
 important to validate that they all give the exact same results.  To easily

NEWS

@@ -30,6 +30,11 @@ Post-v3.6.0
      * The OOT kernel module: was deprecated in v2.15; was last present in
        the v2.17 release; and is no longer present in any supported release
        since v2.17 went EOL when v3.5 was released.
+   - The following AVX512-specific features are now deprecated:
+     * AVX512-optimized DPCLS lookups.
+     * AVX512-optimized action handling.
+     * AVX512-optimized miniflow extraction.
+     * AVX512-optimized DPIF input processing.
 
 
 v3.6.0 - 18 Aug 2025

acinclude.m4

@@ -30,6 +30,8 @@ AC_DEFUN([OVS_CHECK_ACTIONS_AUTOVALIDATOR], [
     AC_DEFINE([ACTIONS_AUTOVALIDATOR_DEFAULT], [1],
               [Autovalidator for actions is a default implementation.])
     AC_MSG_RESULT([yes])
+    AC_MSG_WARN(
+      [Explicit AVX512 feature support will be deprecated in the next release.])
   fi
 ])
 
@@ -50,6 +52,8 @@ AC_DEFUN([OVS_CHECK_MFEX_AUTOVALIDATOR], [
     AC_DEFINE([MFEX_AUTOVALIDATOR_DEFAULT], [1],
               [Autovalidator for miniflow_extract is a default implementation.])
     AC_MSG_RESULT([yes])
+    AC_MSG_WARN(
+      [Explicit AVX512 feature support will be deprecated in the next release.])
   fi
 ])
 
@@ -70,6 +74,8 @@ AC_DEFUN([OVS_CHECK_DPCLS_AUTOVALIDATOR], [
               [Autovalidator for the userspace datapath classifier is a
                default implementation.])
     AC_MSG_RESULT([yes])
+    AC_MSG_WARN(
+      [Explicit AVX512 feature support will be deprecated in the next release.])
   fi
 ])
 
@@ -88,6 +94,8 @@ AC_DEFUN([OVS_CHECK_DPIF_AVX512_DEFAULT], [
               [DPIF AVX512 is a default implementation of the userspace
                datapath interface.])
     AC_MSG_RESULT([yes])
+    AC_MSG_WARN(
+      [Explicit AVX512 feature support will be deprecated in the next release.])
   fi
 ])