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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 482D4C2BA1A for ; Wed, 8 Apr 2020 11:50:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1C12F20780 for ; Wed, 8 Apr 2020 11:50:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="Xz7woTJY" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728634AbgDHLux (ORCPT ); Wed, 8 Apr 2020 07:50:53 -0400 Received: from us-smtp-2.mimecast.com ([205.139.110.61]:27686 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728492AbgDHLux (ORCPT ); Wed, 8 Apr 2020 07:50:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586346652; 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=2eXzQtSYdeTw5pRT+LOtyhNeBfnI40tGkZtZgT4bf9k=; b=Xz7woTJYGKU2lQcsrUd+uZQ2qSVuyQppVs8V7fBxvQg8XHtDi3yfLIeFFQg9Pfvrm+hbeK 8AA3GuLu1jg18qBHUTQVg0+Nd3mY3ZwJDZGptzFZ3zN1PP/OoZYqe8EJHrtGAzUtvPUvCU AkGgE47p8dVIY/h9FQyTuu4f9QEVedU= 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-252-SEAr8W1PMYCDNEoc6BDj9A-1; Wed, 08 Apr 2020 07:50:48 -0400 X-MC-Unique: SEAr8W1PMYCDNEoc6BDj9A-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 97FA8801E66; Wed, 8 Apr 2020 11:50:46 +0000 (UTC) Received: from firesoul.localdomain (unknown [10.40.208.40]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5EF5060BF7; Wed, 8 Apr 2020 11:50:40 +0000 (UTC) Received: from [192.168.42.3] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 6BA77300020FB; Wed, 8 Apr 2020 13:50:39 +0200 (CEST) Subject: [PATCH RFC v2 01/33] xdp: add frame size to xdp_buff From: Jesper Dangaard Brouer To: sameehj@amazon.com Cc: Jesper Dangaard Brouer , netdev@vger.kernel.org, bpf@vger.kernel.org, zorik@amazon.com, akiyano@amazon.com, gtzalik@amazon.com, =?utf-8?q?Toke_H=C3=B8iland-J=C3=B8rgensen?= , Daniel Borkmann , Alexei Starovoitov , John Fastabend , Alexander Duyck , Jeff Kirsher , David Ahern , Willem de Bruijn , Ilias Apalodimas , Lorenzo Bianconi , Saeed Mahameed Date: Wed, 08 Apr 2020 13:50:39 +0200 Message-ID: <158634663936.707275.3156718045905620430.stgit@firesoul> In-Reply-To: <158634658714.707275.7903484085370879864.stgit@firesoul> References: <158634658714.707275.7903484085370879864.stgit@firesoul> User-Agent: StGit/0.19 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org XDP have evolved to support several frame sizes, but xdp_buff was not updated with this information. The frame size (frame_sz) member of xdp_buff is introduced to know the real size of the memory the frame is delivered in. When introducing this also make it clear that some tailroom is reserved/required when creating SKBs using build_skb(). It would also have been an option to introduce a pointer to data_hard_end (with reserved offset). The advantage with frame_sz is that (like rxq) drivers only need to setup/assign this value once per NAPI cycle. Due to XDP-generic (and some drivers) it's not possible to store frame_sz inside xdp_rxq_info, because it's varies per packet as it can be based/depend on packet length. Signed-off-by: Jesper Dangaard Brouer --- include/net/xdp.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/include/net/xdp.h b/include/net/xdp.h index 40c6d3398458..99f4374f6214 100644 --- a/include/net/xdp.h +++ b/include/net/xdp.h @@ -6,6 +6,8 @@ #ifndef __LINUX_NET_XDP_H__ #define __LINUX_NET_XDP_H__ +#include /* skb_shared_info */ + /** * DOC: XDP RX-queue information * @@ -70,8 +72,23 @@ struct xdp_buff { void *data_hard_start; unsigned long handle; struct xdp_rxq_info *rxq; + u32 frame_sz; /* frame size to deduct data_hard_end/reserved tailroom*/ }; +/* Reserve memory area at end-of data area. + * + * This macro reserves tailroom in the XDP buffer by limiting the + * XDP/BPF data access to data_hard_end. Notice same area (and size) + * is used for XDP_PASS, when constructing the SKB via build_skb(). + */ +#define xdp_data_hard_end(xdp) \ + ((xdp)->data_hard_start + (xdp)->frame_sz - \ + SKB_DATA_ALIGN(sizeof(struct skb_shared_info))) + +/* Like skb_shinfo */ +#define xdp_shinfo(xdp) ((struct skb_shared_info *)(xdp_data_hard_end(xdp))) +// XXX: Above likely belongs in later patch + struct xdp_frame { void *data; u16 len;