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 X-Spam-Level: X-Spam-Status: No, score=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7EFD1C47247 for ; Fri, 8 May 2020 01:59:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 574E5208E4 for ; Fri, 8 May 2020 01:59:45 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="E4TVMuBh" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726974AbgEHB7o (ORCPT ); Thu, 7 May 2020 21:59:44 -0400 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:50119 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726518AbgEHB7o (ORCPT ); Thu, 7 May 2020 21:59:44 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1588903183; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=uMn5kXEMwwk6mUv6PTZwumoxAF7POIcplX3ZxztB3/w=; b=E4TVMuBhItj+lmZEpOm8e/h3ystQ7Q0+Qp8oA9sZzKLP13YuyYzCeClnQ2HkzJCwB+Qj7l Yu5PXl4gXrP+67PumGouG39L3aF2hd4hGQkVoVY4Ww73uCmxwYfkhFWw2CaSdZwsZDYRvZ E8keP2HMUvHSmiBvE/CQvBpPctV6mxk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-26-3y5hWrAsPU-uIiXsi-giRw-1; Thu, 07 May 2020 21:59:41 -0400 X-MC-Unique: 3y5hWrAsPU-uIiXsi-giRw-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2DCBE80B72B; Fri, 8 May 2020 01:59:40 +0000 (UTC) Received: from [10.72.13.98] (ovpn-13-98.pek2.redhat.com [10.72.13.98]) by smtp.corp.redhat.com (Postfix) with ESMTP id 4300E579AD; Fri, 8 May 2020 01:59:31 +0000 (UTC) Subject: Re: [PATCH net-next 1/2] virtio-net: don't reserve space for vnet header for XDP To: "Michael S. Tsirkin" Cc: Jesper Dangaard Brouer , virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, bpf@vger.kernel.org, "Jubran, Samih" References: <20200506061633.16327-1-jasowang@redhat.com> <20200506102123.739f1233@carbon> <3ecb558b-5281-2497-db3c-6aae7d7f882b@redhat.com> <20200506054619-mutt-send-email-mst@kernel.org> From: Jason Wang Message-ID: Date: Fri, 8 May 2020 09:59:29 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.7.0 MIME-Version: 1.0 In-Reply-To: <20200506054619-mutt-send-email-mst@kernel.org> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2020/5/6 下午5:46, Michael S. Tsirkin wrote: >>> There >>> are a lot of unanswered questions on how this will be implemented. >>> Thus, I cannot layout how we are going to leverage this info yet, but >>> your patch are killing this info, which IHMO is going in the wrong >>> direction. >> I can copy vnet header ahead of data_hard_start, does it work for you? >> >> Thanks > That's likely to be somewhat expensive. Any better approach? Note that it's not the issue that is introduced in this patch. Anyhow the header adjustment may just overwrite the vnet header even without this patch. Thanks