On 12/11/25 12:21 PM, Eelco Chaudron via dev wrote:
> 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 <[email protected]>
> ---
>  Documentation/intro/install/dpdk.rst |  4 ++++
>  Documentation/topics/dpdk/bridge.rst | 25 +++++++++++++++++++++++++
>  Documentation/topics/testing.rst     |  4 ++++
>  NEWS                                 |  6 +++++-
>  acinclude.m4                         |  8 ++++++++
>  5 files changed, 46 insertions(+), 1 deletion(-)

nit:  We normally use 'NEWS' as an area in the subject line, as that's
the actual name of the file.

> 
> diff --git a/Documentation/intro/install/dpdk.rst 
> b/Documentation/intro/install/dpdk.rst
> index af824239e..731a1ccc4 100644
> --- a/Documentation/intro/install/dpdk.rst
> +++ b/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.
> diff --git a/Documentation/topics/dpdk/bridge.rst 
> b/Documentation/topics/dpdk/bridge.rst
> index a077385e9..03c4dd4e3 100644
> --- a/Documentation/topics/dpdk/bridge.rst
> +++ b/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
> diff --git a/Documentation/topics/testing.rst 
> b/Documentation/topics/testing.rst
> index dbeaf2d93..ca6c9f2a0 100644
> --- a/Documentation/topics/testing.rst
> +++ b/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
> diff --git a/NEWS b/NEWS
> index f9a74df1a..0fc531a51 100644
> --- a/NEWS
> +++ b/NEWS
> @@ -16,7 +16,11 @@ Post-v3.6.0
>       * New ovsdb_idl_txn_assert_read_only() interface to mark transactions
>         as read-only and trigger assertion failure when application attempts
>         to modify the database data through this transaction.
> -

nit: Should keep two empty lines between sections.

> +   - Deprecation of support for running OVS with AVX512-specific features.
> +     * Deprecate AVX512-based optimized DPCLS lookups.
> +     * Deprecate AVX512-based optimized action handling.
> +     * Deprecate AVX512-based optimized miniflow extraction.
> +     * Deprecate AVX512-based optimized DPIF input processing.

Maybe it would be better to word these in a "X s now deprecated" form?
Or even, "The following AVX512-specific features are now deprecated: ..." ?

Best regards, Ilya Maximets.
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