From patchwork Wed Oct 10 13:09:58 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Campbell X-Patchwork-Id: 190638 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id D12F32C008B for ; Thu, 11 Oct 2012 00:10:10 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756100Ab2JJNKF (ORCPT ); Wed, 10 Oct 2012 09:10:05 -0400 Received: from smtp.eu.citrix.com ([62.200.22.115]:16114 "EHLO SMTP.EU.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755832Ab2JJNKD (ORCPT ); Wed, 10 Oct 2012 09:10:03 -0400 X-IronPort-AV: E=Sophos;i="4.80,564,1344211200"; d="scan'208";a="15075181" Received: from lonpmailmx01.citrite.net ([10.30.203.162]) by LONPIPO01.EU.CITRIX.COM with ESMTP/TLS/RC4-MD5; 10 Oct 2012 13:09:59 +0000 Received: from [10.80.2.42] (10.80.2.42) by LONPMAILMX01.citrite.net (10.30.203.162) with Microsoft SMTP Server id 8.3.279.1; Wed, 10 Oct 2012 14:09:59 +0100 Message-ID: <1349874598.10070.39.camel@zakaz.uk.xensource.com> Subject: Re: [Xen-devel] compound skb frag pages appearing in start_xmit From: Ian Campbell To: Eric Dumazet CC: "netdev@vger.kernel.org" , Eric Dumazet , xen-devel , "Konrad Rzeszutek Wilk" , Sander Eikelenboom Date: Wed, 10 Oct 2012 14:09:58 +0100 In-Reply-To: <1349863984.10070.26.camel@zakaz.uk.xensource.com> References: <1349790467.21847.185.camel@zakaz.uk.xensource.com> <1349790863.21172.4406.camel@edumazet-glaptop> <1349792241.21847.199.camel@zakaz.uk.xensource.com> <1349792847.21172.4479.camel@edumazet-glaptop> <1349793630.21847.208.camel@zakaz.uk.xensource.com> <1349863984.10070.26.camel@zakaz.uk.xensource.com> Organization: Citrix Systems, Inc. X-Mailer: Evolution 3.4.3-1 MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, 2012-10-10 at 11:13 +0100, Ian Campbell wrote: > I haven't tackled netfront yet. I seem to be totally unable to reproduce the equivalent issue on the netfront xmit side, even though it seems like the loop in xennet_make_frags ought to be obviously susceptible to it. Konrad, Sander, are either of you able to repro, e.g. with: My repro for netback was just to netcat a wodge of data from dom0->domU but going the other way doesn't seem to trigger. --- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index b06ef81..8a3f770 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -462,6 +462,8 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); + BUG_ON(PageCompound(skb_frag_page(frag))); + mfn = pfn_to_mfn(page_to_pfn(skb_frag_page(frag))); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly);