From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Michael S. Tsirkin" Subject: Re: [PATCH net-next RFC WIP] Patch for XDP support for virtio_net Date: Wed, 26 Oct 2016 19:36:45 +0300 Message-ID: <20161026185743-mutt-send-email-mst@kernel.org> References: <1477109243-29520-1-git-send-email-shrijeet@gmail.com> <20161026155202.5d99d935@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Shrijeet Mukherjee , tom@herbertland.com, netdev@vger.kernel.org, shm@cumulusnetworks.com, roopa@cumulusnetworks.com, nikolay@cumulusnetworks.com To: Jesper Dangaard Brouer Return-path: Received: from mx1.redhat.com ([209.132.183.28]:41202 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932275AbcJZQgv (ORCPT ); Wed, 26 Oct 2016 12:36:51 -0400 Content-Disposition: inline In-Reply-To: <20161026155202.5d99d935@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, Oct 26, 2016 at 03:52:02PM +0200, Jesper Dangaard Brouer wrote: > On Sat, 22 Oct 2016 04:07:23 +0000 > Shrijeet Mukherjee wrote: > > > This patch adds support for xdp ndo and also inserts the xdp program > > call into the merged RX buffers and big buffers paths > > I really appreciate you are doing this for virtio_net. > > My first question is: Is the (packet) page data writable? > (MST might be able to answer?) > > As this is currently an XDP requirement[1]. I'm not sure I understand what does writable mean. Could you explain a bit more pls? We do copy data into skb ATM but I plan to change that. > > > * The small packet skb receive is skipped for now > > * No TX for now > > I do see more and more valid use-cases for only implementing XDP_DROP > and not necessarily also implementing XDP_TX. This does requires that > we implement some kind of feature/capabilities negotiation mechanism[2]. > > > [1] https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/design/requirements.html#write-access-to-packet-data > > [2] https://prototype-kernel.readthedocs.io/en/latest/networking/XDP/design/design.html#capabilities-negotiation > > -- > Best regards, > Jesper Dangaard Brouer > MSc.CS, Principal Kernel Engineer at Red Hat > Author of http://www.iptv-analyzer.org > LinkedIn: http://www.linkedin.com/in/brouer