From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Graf Subject: Re: [ovs-dev] [RFC: add openvswitch actions using BPF 2/2] openvswitch: implements the BPF_PROG action in datapath Date: Thu, 5 Feb 2015 16:07:33 +0100 Message-ID: <20150205150733.GG5546@pox.localdomain> References: <1423090122-19807-1-git-send-email-azhou@nicira.com> <1423090122-19807-3-git-send-email-azhou@nicira.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: dev@openvswitch.com, netdev@vger.kernel.org To: Andy Zhou Return-path: Received: from mail-wg0-f53.google.com ([74.125.82.53]:48757 "EHLO mail-wg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757790AbbBEPHg (ORCPT ); Thu, 5 Feb 2015 10:07:36 -0500 Received: by mail-wg0-f53.google.com with SMTP id a1so8059976wgh.12 for ; Thu, 05 Feb 2015 07:07:35 -0800 (PST) Content-Disposition: inline In-Reply-To: <1423090122-19807-3-git-send-email-azhou@nicira.com> Sender: netdev-owner@vger.kernel.org List-ID: On 02/04/15 at 02:48pm, Andy Zhou wrote: > BPF_PROG action allows an action to be implemented in eBPF language and > downloaded by the userspace at runtime. > > Signed-off-by: Andy Zhou Thanks a lot for putting this together Andy and Joe and everybody else who was involved. This is much further than what I expected as a first step. One slight open from my side is the avoidance of versioning help of helpers. We want to avoid v2, v3, ... helpers if the need should arise to extend an existing helper. I think it should be doable with BPF to have the verifier accept if a helper is called with less args than expected, to initialize those to 0. This would allow for helpers to support additional arguments. I think this needs to be documented and expectations should be clear. Other than that I'm very very happy with where this is going. It seems very doable to also allow for a BPF prog to be registered upon flow table miss.