From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 69550C25B75 for ; Wed, 15 May 2024 12:20:47 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 1244940B3F; Wed, 15 May 2024 12:20:47 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id ewR-MLm6K6pB; Wed, 15 May 2024 12:20:46 +0000 (UTC) X-Comment: SPF check N/A for local connections - client-ip=140.211.166.34; helo=ash.osuosl.org; envelope-from=intel-wired-lan-bounces@osuosl.org; receiver= DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org 1954440B76 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osuosl.org; s=default; t=1715775646; bh=5gdxnNNc90LFgI4BQOkZuwRwsM/ENvTlh/dXZy4UcbY=; h=Date:From:To:References:In-Reply-To:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: Cc:From; b=Cr5A1FRfvaw9DVB06mkeji99S4rLppWZoBvRN/9wVbpuZcTx3vnQaBBlasf1PEUzR YeEuCq9dP+CDt3A+ELIAkTJ4bDxCv+WDbEUaiQPaS7XsgKszRzOwt0ZNIQnHt5pt/f aIHME9NGRZZe2g0X4PU10pPEFPUfV5MF4Ty5WG0B5k7KZT5YsYXMQqjijGLUMMGZsg 4MKEUlo9OkDarHhFKSSlkw2FW4VIZMIzGAnqdKCy++lMV7fN3YKFaWeUM6xg3Adbhh 4/lvoUjzQ/Pbdy9wTkUxGaUB0YsDou9k74AC+hElE1RLwhwt2h1ge0L7IYfEcYLRNr SNp5f+u0pGp+w== Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by smtp2.osuosl.org (Postfix) with ESMTP id 1954440B76; Wed, 15 May 2024 12:20:46 +0000 (UTC) Received: from smtp2.osuosl.org (smtp2.osuosl.org [140.211.166.133]) by ash.osuosl.org (Postfix) with ESMTP id 8E3421BF3A4 for ; Wed, 15 May 2024 12:20:44 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp2.osuosl.org (Postfix) with ESMTP id 86A5340B76 for ; Wed, 15 May 2024 12:20:44 +0000 (UTC) X-Virus-Scanned: amavis at osuosl.org Received: from smtp2.osuosl.org ([127.0.0.1]) by localhost (smtp2.osuosl.org [127.0.0.1]) (amavis, port 10024) with ESMTP id UpwwyDnLZ0e8 for ; Wed, 15 May 2024 12:20:43 +0000 (UTC) X-Greylist: delayed 1485 seconds by postgrey-1.37 at util1.osuosl.org; Wed, 15 May 2024 12:20:42 UTC DMARC-Filter: OpenDMARC Filter v1.4.2 smtp2.osuosl.org A68D840B3F DKIM-Filter: OpenDKIM Filter v2.11.0 smtp2.osuosl.org A68D840B3F Received-SPF: Pass (mailfrom) identity=mailfrom; client-ip=2001:780:45:1d:225:90ff:fe52:c662; helo=ganesha.gnumonks.org; envelope-from=laforge@gnumonks.org; receiver= Received: from ganesha.gnumonks.org (ganesha.gnumonks.org [IPv6:2001:780:45:1d:225:90ff:fe52:c662]) by smtp2.osuosl.org (Postfix) with ESMTPS id A68D840B3F for ; Wed, 15 May 2024 12:20:42 +0000 (UTC) Received: from uucp by ganesha.gnumonks.org with local-bsmtp (Exim 4.94.2) (envelope-from ) id 1s7DEb-00D1eo-Ak; Wed, 15 May 2024 13:55:49 +0200 Received: from laforge by localhost.localdomain with local (Exim 4.97) (envelope-from ) id 1s7DEV-00000003YLY-056H; Wed, 15 May 2024 13:55:43 +0200 Date: Wed, 15 May 2024 13:55:42 +0200 From: Harald Welte To: Alexander Lobakin Message-ID: References: <20240327152358.2368467-1-aleksander.lobakin@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240327152358.2368467-1-aleksander.lobakin@intel.com> X-Mailman-Original-Authentication-Results: smtp2.osuosl.org; dmarc=none (p=none dis=none) header.from=gnumonks.org Subject: Re: [Intel-wired-lan] [PATCH net-next v6 00/21] ice: add PFCP filter support X-BeenThere: intel-wired-lan@osuosl.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Wired Ethernet Linux Kernel Driver Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Wojciech Drewek , netdev@vger.kernel.org, intel-wired-lan@lists.osuosl.org, linux-kernel@vger.kernel.org Errors-To: intel-wired-lan-bounces@osuosl.org Sender: "Intel-wired-lan" Daer Alexander, Wojciech, forgive me for being late to the party, but I just saw the PFCP support hitting Linus'' git repo in 1b294a1f35616977caddaddf3e9d28e576a1adbc and was trying to figure out what it is all about. Is there some kind of article, kernel documentation or other explanation about it? I have a prehistoric background in Linux kernel networking, and have been spending much of the last two decades in creating open source implemenmtations of 3GPP specifications. So I'm very familiar with what PFCP is, and what it does, and how it is used as a protocol by the 3GPP control plane to control the user/data plane. Conceptually it seems very odd to me to have something like *pfcp net-devices*. PFCP is just a control plane protocol, not a tunnel mechanism. >From the Kconfig: > +config PFCP > + tristate "Packet Forwarding Control Protocol (PFCP)" > + depends on INET > + select NET_UDP_TUNNEL > + help > + This allows one to create PFCP virtual interfaces that allows to > + set up software and hardware offload of PFCP packets. I'm curious to understand why are *pfcp* packets hardware offloaded? PFCP is just the control plane, similar to you can consider netlink the control plane by which userspace programs control the data plane. I can fully understand that GTP-U packets are offloaded to kernel space or hardware, and that then some control plane mechanism like PFCP is needed to control that data plane. But offloading packets of that control protocol? I also see the following in the patch: > +MODULE_DESCRIPTION("Interface driver for PFCP encapsulated traffic"); PFCP is not an encapsulation protocol for user plane traffic. It is not a tunneling protocol. GTP-U is the tunneling protocol, whose implementations (typically UPFs) are remote-controlled by PFCP. > + Note that this module does not support PFCP protocol in the kernel space. > + There is no support for parsing any PFCP messages. If I may be frank, why do we introduce something called "pfcp" to the kernel, if it doesn't actually implement any of the PFCP specification 3GPP TS 29.244 (which is specifying a very concrete protocol)? Once again, I just try to understand what you're trying to do here. It's very much within my professional field, but I somehow cannot align what I see within this patch set with my existing world view of what PFCP is and how it works. If anyone else has a better grasp of the architecture of this kernel PFCP support, or has any pointers, I'd be very happy to follow up on that. Thanks for your time, Harald -- - Harald Welte https://laforge.gnumonks.org/ ============================================================================ "Privacy in residential applications is a desirable marketing option." (ETSI EN 300 175-7 Ch. A6)