From patchwork Tue Nov 20 11:40:06 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ian Campbell X-Patchwork-Id: 200307 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 BD7602C0093 for ; Tue, 20 Nov 2012 22:40:12 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753079Ab2KTLkJ (ORCPT ); Tue, 20 Nov 2012 06:40:09 -0500 Received: from smtp.citrix.com ([66.165.176.89]:28329 "EHLO SMTP.CITRIX.COM" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752996Ab2KTLkI (ORCPT ); Tue, 20 Nov 2012 06:40:08 -0500 X-IronPort-AV: E=Sophos;i="4.83,285,1352073600"; d="scan'208";a="45145457" Received: from ftlpmailmx02.citrite.net ([10.13.107.66]) by FTLPIPO01.CITRIX.COM with ESMTP/TLS/RC4-MD5; 20 Nov 2012 11:40:07 +0000 Received: from ukmail1.uk.xensource.com (10.80.16.128) by smtprelay.citrix.com (10.13.107.66) with Microsoft SMTP Server id 8.3.279.1; Tue, 20 Nov 2012 06:40:06 -0500 Received: from cosworth.uk.xensource.com ([10.80.16.52] ident=ianc) by ukmail1.uk.xensource.com with esmtp (Exim 4.69) (envelope-from ) id 1TamBS-0000C1-Ep; Tue, 20 Nov 2012 11:40:06 +0000 From: Ian Campbell To: netdev@vger.kernel.org CC: Ian Campbell , xen-devel@lists.xen.org, Eric Dumazet , Konrad Rzeszutek Wilk , ANNIE LI , Sander Eikelenboom , Stefan Bader Subject: [PATCH] xen/netfront: handle compound page fragments on transmit Date: Tue, 20 Nov 2012 11:40:06 +0000 Message-ID: <1353411606-15940-1-git-send-email-ian.campbell@citrix.com> X-Mailer: git-send-email 1.7.2.5 In-Reply-To: <1353403286.18229.159.camel@zakaz.uk.xensource.com> References: <1353403286.18229.159.camel@zakaz.uk.xensource.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org An SKB paged fragment can consist of a compound page with order > 0. However the netchannel protocol deals only in PAGE_SIZE frames. Handle this in xennet_make_frags by iterating over the frames which make up the page. This is the netfront equivalent to 6a8ed462f16b for netback. Signed-off-by: Ian Campbell Cc: netdev@vger.kernel.org Cc: xen-devel@lists.xen.org Cc: Eric Dumazet Cc: Konrad Rzeszutek Wilk Cc: ANNIE LI Cc: Sander Eikelenboom Cc: Stefan Bader Tested-by: Stefan Bader Acked-by: Eric Dumazet --- drivers/net/xen-netfront.c | 58 +++++++++++++++++++++++++++++++++---------- 1 files changed, 44 insertions(+), 14 deletions(-) diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c index caa0110..a12b99a 100644 --- a/drivers/net/xen-netfront.c +++ b/drivers/net/xen-netfront.c @@ -452,24 +452,54 @@ static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, /* Grant backend access to each skb fragment page. */ for (i = 0; i < frags; i++) { skb_frag_t *frag = skb_shinfo(skb)->frags + i; + struct page *page = skb_frag_page(frag); + unsigned long size = skb_frag_size(frag); + unsigned long offset = frag->page_offset; - tx->flags |= XEN_NETTXF_more_data; + /* Data must not cross a page boundary. */ + BUG_ON(size + offset > PAGE_SIZE<tx_skb_freelist, np->tx_skbs); - np->tx_skbs[id].skb = skb_get(skb); - tx = RING_GET_REQUEST(&np->tx, prod++); - tx->id = id; - ref = gnttab_claim_grant_reference(&np->gref_tx_head); - BUG_ON((signed short)ref < 0); + /* Skip unused frames from start of page */ + page += offset >> PAGE_SHIFT; + offset &= ~PAGE_MASK; - mfn = pfn_to_mfn(page_to_pfn(skb_frag_page(frag))); - gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, - mfn, GNTMAP_readonly); + while (size > 0) { + unsigned long bytes; - tx->gref = np->grant_tx_ref[id] = ref; - tx->offset = frag->page_offset; - tx->size = skb_frag_size(frag); - tx->flags = 0; + BUG_ON(offset >= PAGE_SIZE); + + bytes = PAGE_SIZE - offset; + if (bytes > size) + bytes = size; + + tx->flags |= XEN_NETTXF_more_data; + + id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); + np->tx_skbs[id].skb = skb_get(skb); + tx = RING_GET_REQUEST(&np->tx, prod++); + tx->id = id; + ref = gnttab_claim_grant_reference(&np->gref_tx_head); + BUG_ON((signed short)ref < 0); + + mfn = pfn_to_mfn(page_to_pfn(page)); + gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, + mfn, GNTMAP_readonly); + + tx->gref = np->grant_tx_ref[id] = ref; + tx->offset = offset; + tx->size = bytes; + tx->flags = 0; + + offset += bytes; + size -= bytes; + + /* Next frame */ + if (offset == PAGE_SIZE && size) { + BUG_ON(!PageCompound(page)); + page++; + offset = 0; + } + } } np->tx.req_prod_pvt = prod;