From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga04.intel.com ([192.55.52.120]:31637 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725833AbgFCLLf (ORCPT ); Wed, 3 Jun 2020 07:11:35 -0400 Date: Wed, 3 Jun 2020 13:07:26 +0200 From: Maciej Fijalkowski Subject: Re: XDP_REDIRECT with xsks_map and dev_map Message-ID: <20200603110726.GA55184@ranger.igk.intel.com> References: <87d06hzvr8.fsf@toke.dk> <877dwpmp7f.fsf@toke.dk> <87lfl4l8zu.fsf@toke.dk> <20200603104833.GA14391@ranger.igk.intel.com> <87ftbcl86e.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <87ftbcl86e.fsf@toke.dk> Sender: xdp-newbies-owner@vger.kernel.org List-ID: To: Toke =?iso-8859-1?Q?H=F8iland-J=F8rgensen?= Cc: maharishi bhargava , xdp-newbies@vger.kernel.org On Wed, Jun 03, 2020 at 01:07:05PM +0200, Toke Høiland-Jørgensen wrote: > Maciej Fijalkowski writes: > > > On Wed, Jun 03, 2020 at 12:49:25PM +0200, Toke Høiland-Jørgensen wrote: > >> maharishi bhargava writes: > >> > >> > On Tue, Jun 2, 2020 at 9:31 PM Toke Høiland-Jørgensen wrote: > >> >> > >> >> maharishi bhargava writes: > >> >> > >> >> > On Tue 2 Jun, 2020, 14:31 Toke Høiland-Jørgensen, wrote: > >> >> >> > >> >> >> maharishi bhargava writes: > >> >> >> > >> >> >> > Hi, in my XDP program, I want to redirect some packets using AF_XDP > >> >> >> > and redirect other packets directly from driver space. > >> >> >> > Redirection through AF_XDP works fine, but redirection through dev map > >> >> >> > stops after some packets are processed. > >> >> >> > >> >> >> Do you mean it stops even if you are *only* redirecting to a devmap, or > >> >> >> if you are first redirecting a few packets to AF_XDP, then to devmap? > >> >> >> > >> >> >> Also, which driver(s) are the physical NICs you're redirecting to/from > >> >> >> using, and which kernel version are you on? > >> >> >> > >> >> >> -Toke > >> >> > > >> >> > > >> >> > > >> >> > Currently, I'm trying to redirect packets only using devmap. But also > >> >> > have code for redirection using AF_XDP(only when a given condition is > >> >> > satisfied). A DPDK program is running in userspace which will receive > >> >> > packets from AF_XDP. > >> >> > >> >> Right, so it's just devmap redirect that breaks. What do you mean > >> >> 'redirection stops', exactly? How are you seeing this? Does xdp_monitor > >> >> (from samples/bpf) report any exceptions? > >> >> > >> >> -Toke > >> >> > >> > So, In my setup, there are three systems, Let's Assume A, B, C. System > >> > B is acting as a forwarder between A and C. So I can see the number of > >> > packets received at system C. To be specific, only 1024 packets are > >> > received. If I remove the xsks_map part from the code and don't run > >> > DPDK in userspace. This problem does not occur. Also if I forward all > >> > the packets using AF_XDP, there is no such issue. > >> > >> I thought you said you were seeing the problem when only redirecting to > >> a devmap? So why does the xsk_map code impact this? I think you may have > >> to share some code... > > > > Isn't the case here that either xsk_map or dev_map consumes the frame and > > therefore the latter doesn't see it? so cloning might be needed here? > > Yeah, certainly you can't redirect *the same packet* to both xsk_map and > devmap - but that wasn't what I understood was the use case here? Maybe the best would be if Maharishi shared the code as you requested :) > > -Toke >