From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B83DC29B8E0 for ; Thu, 13 Nov 2025 14:39:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.129.124 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763044784; cv=none; b=p1P/YrhxUSZw0H9cRnIVqLnW+LQBcgOOdpAdDmHR5F+YlCr1yinXqmlln+QaEUD0J7ecg7BpHab6128+Rc5U2KiRc2VL4tDC4w/Z2oMbJXZ0EGJb4+zl4Roam7KZcxb42Y1r/OKV23aS8qUbTpd2yXWgH55L3xzpkdJsqRtDRMY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763044784; c=relaxed/simple; bh=WZlXUh05gtlAY7ujomAKuF63JeA7BJis07HZSFeJXuU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=YR7Z7e/qCcNPFUIP2HP9ltZ7TgGNBtYuSVMWLy8UaTK7+6KChK5HH+mqxbxIsyIqjjzpv5iEM9L9KQCcCstZ1WqIo0P/Imhk6+XJIc0Mo66oVZ5lw8dWxUYSv2s6LtL9cgWP/aZU+OvRyc7yChUAnoPOqaW5WDgXsHM4c3mvrbE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=SRzAFso0; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b=c8KpH4BD; arc=none smtp.client-ip=170.10.129.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SRzAFso0"; dkim=pass (2048-bit key) header.d=redhat.com header.i=@redhat.com header.b="c8KpH4BD" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1763044780; 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=C6ZlE/8wFoMWAmPveb7rTnuh4QFvGSZOBJ0lkY75WHA=; b=SRzAFso0iznnitrCamVClU22g2/R8Z+KUoJ5VWefviUDPXb26pn51mYc3oYpC1UagfEy8w 50vHkjmtfhCHzJzbrcvVXXfb/wgBQ4pPXyaMkg0G6SEuFgjWfBu5Z9zDSmZf7yHuD2QeBP zGqlr92FlR1q8bfhz6U8gAuqq0GW2EY= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-443-bfnNUj_9O2erBz5HBFmufA-1; Thu, 13 Nov 2025 09:39:39 -0500 X-MC-Unique: bfnNUj_9O2erBz5HBFmufA-1 X-Mimecast-MFC-AGG-ID: bfnNUj_9O2erBz5HBFmufA_1763044778 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-40cfb98eddbso956206f8f.0 for ; Thu, 13 Nov 2025 06:39:39 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=google; t=1763044778; x=1763649578; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=C6ZlE/8wFoMWAmPveb7rTnuh4QFvGSZOBJ0lkY75WHA=; b=c8KpH4BDQAzXj5yndotz6K96d36bDlywY87h0nqY5QMDRgFs5GAAAX/T5fp3feof2m vkDWwEj2McYRXshkMgIgrF6DqeG7zD2XA05iT3stqcAXwW6WCRYM+0kAPYtn92HvvAYh vLkgdE51I4CHzaCeCE1nEWA4jGpWObCVsKNqEDAEJjH4M+2r/cwboTG+UV/kTMfRaqP6 vBJprNV2pkb6ifPQgK6R5PwUsdKiSeuB4e7tJEEmqLDbiplnkWAjQUkeLeY/2h5z5WGn u8O2UGmA2HNoUUA/nkHxqq3qdGrF1+oeb4PBKBLwsVfwMiyUDcRJIjNpsj1n6AP8ufub NGFA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1763044778; x=1763649578; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=C6ZlE/8wFoMWAmPveb7rTnuh4QFvGSZOBJ0lkY75WHA=; b=JGjlkVUqA3vJ/2gFOF1o6DQc32XNageLjs8cnr6BhDtfaVBd7X+acyW8y+xG7DJMF1 1Ze1azd/EZ/QcV8oqmuOFwJllzbp+wSEd94L+giNZyUXha5oXbD1aLlkF/eV949m5n4H K08Gm7FIAjnbqpDOUE+7mMafSAwCqnk7SC9RdtXymEaWfOvkPTEjxVEt0NXj3n6juY8N gItbKY+djBm5DPxbDJZWqtXFuV8e6wRuxJYNsGIHonwh1NWrjuTs0nZ07P/7K2OCuS3C HmbKFDOGo6QHW8wKwlEMNBCqlBEE5eUiMgcEFFlysqfIfV++1EsPOfoRxL11VG0OYvNg 6tWA== X-Forwarded-Encrypted: i=1; AJvYcCXTalOoNYyGdWel4TGCMWdy+YUBvnKn4rtVOEGTvnD26BvLPIaAHx9pT5TmWBmFqcYR/llz170=@vger.kernel.org X-Gm-Message-State: AOJu0Yw4oobmq9xw6saNLfHnbo/rpIcf4cnIlpEyEc+Kf/u35jTFFKpl 6+oqGkllA96SpCO/b5UBg/9PeFC+kv0NMcsO17fvdiJDCWyXFu3Uvlp4mW9rerfFKfp1J49l9ZL ZW7sDjvnhyawcXpSGv4uqbyPxPtotneK5iUJi9SOBB72TqblItVsFSSbLQA== X-Gm-Gg: ASbGncuHnT8Aj8rIyyiXt1eb0Uvadbj8lNR2iws+S2lVZi7tnxmrvnwBjb7MdKJA6lS 4na8zAtk4sAog0iPvmYL1zyKdVAuIm0W8VcNPyXP5b35Vow3d3SaMVrJPs+/9C/vnPtC/re/U8N FidYPnIsfXRuSC9OLwrust11ekGGBAnwlYN/Kh9sf3UKIIvUe0wDvGIi57GAr4ANW34xi8y2K5L SWWEJCPPtr1lmab69QMqnsNc2I+nup3ZwnE53nU1kOSsih+BEbVeBafv09t8LSd6eXQ3hyEkQXB vo3pegbHmSHS8chwpTvMUXtHfkeyd0bsjHBL6mq09ARwrowbJmj1uBHoqcH2rrwgpfHIhBYCpek KGPCFc1pBom8y X-Received: by 2002:a05:6000:2911:b0:429:cc35:7032 with SMTP id ffacd0b85a97d-42b52821778mr3447024f8f.23.1763044778211; Thu, 13 Nov 2025 06:39:38 -0800 (PST) X-Google-Smtp-Source: AGHT+IGec5SZJzkrdZIMQyF+gi07hDcBuVbPd+9nb9X5ZfZ31kZtvs0xZMBq40lgAX06ufK4If5sPw== X-Received: by 2002:a05:6000:2911:b0:429:cc35:7032 with SMTP id ffacd0b85a97d-42b52821778mr3446995f8f.23.1763044777793; Thu, 13 Nov 2025 06:39:37 -0800 (PST) Received: from [192.168.88.32] ([212.105.155.55]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-42b53f29c5fsm4196462f8f.46.2025.11.13.06.39.36 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 13 Nov 2025 06:39:37 -0800 (PST) Message-ID: <25b05194-63cd-4265-8d2c-e174d801fc3a@redhat.com> Date: Thu, 13 Nov 2025 15:39:35 +0100 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net v5 1/2] virtio-net: correct hdr_len handling for VIRTIO_NET_F_GUEST_HDRLEN To: Xuan Zhuo , netdev@vger.kernel.org Cc: Richard Weinberger , Anton Ivanov , Johannes Berg , Willem de Bruijn , Jason Wang , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , "Michael S. Tsirkin" , =?UTF-8?Q?Eugenio_P=C3=A9rez?= , Simon Horman , Jiri Pirko , Alvaro Karsz , linux-um@lists.infradead.org, virtualization@lists.linux.dev References: <20251111111212.102083-1-xuanzhuo@linux.alibaba.com> <20251111111212.102083-2-xuanzhuo@linux.alibaba.com> Content-Language: en-US From: Paolo Abeni In-Reply-To: <20251111111212.102083-2-xuanzhuo@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 11/11/25 12:12 PM, Xuan Zhuo wrote: > The commit be50da3e9d4a ("net: virtio_net: implement exact header length > guest feature") introduces support for the VIRTIO_NET_F_GUEST_HDRLEN > feature in virtio-net. > > This feature requires virtio-net to set hdr_len to the actual header > length of the packet when transmitting, the number of > bytes from the start of the packet to the beginning of the > transport-layer payload. > > However, in practice, hdr_len was being set using skb_headlen(skb), > which is clearly incorrect. This commit fixes that issue. > > Fixes: be50da3e9d4a ("net: virtio_net: implement exact header length guest feature") > Signed-off-by: Xuan Zhuo IMHO this looks like more a new feature - namely, VIRTIO_NET_F_GUEST_HDRLEN support - than a fix. [...] > @@ -2361,7 +2362,7 @@ static int tpacket_rcv(struct sk_buff *skb, struct net_device *dev, > if (vnet_hdr_sz && > virtio_net_hdr_from_skb(skb, h.raw + macoff - > sizeof(struct virtio_net_hdr), > - vio_le(), true, 0)) { > + vio_le(), true, false, 0)) { > if (po->tp_version == TPACKET_V3) > prb_clear_blk_fill_status(&po->rx_ring); > goto drop_n_account; To reduce the diffstat, what about creating a __virtio_net_hdr_from_skb() variant (please find a better name) allowing the extra `hdrlen_negotiated` argument, define virtio_net_hdr_from_skb() as a wrapper of such helper withthe extra arg == false, and use the helper in the few places that really could use hdrlen?