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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham 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 1912BC43381 for ; Tue, 19 Feb 2019 10:24:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DB3CE2177E for ; Tue, 19 Feb 2019 10:24:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727752AbfBSKYF (ORCPT ); Tue, 19 Feb 2019 05:24:05 -0500 Received: from mx1.redhat.com ([209.132.183.28]:33640 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727023AbfBSKYF (ORCPT ); Tue, 19 Feb 2019 05:24:05 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 63D2D883BC; Tue, 19 Feb 2019 10:24:04 +0000 (UTC) Received: from firesoul.localdomain (ovpn-200-20.brq.redhat.com [10.40.200.20]) by smtp.corp.redhat.com (Postfix) with ESMTP id EBD0A102490D; Tue, 19 Feb 2019 10:24:01 +0000 (UTC) Received: from [10.1.2.1] (localhost [IPv6:::1]) by firesoul.localdomain (Postfix) with ESMTP id 849E131256FC5; Tue, 19 Feb 2019 11:24:00 +0100 (CET) Subject: [PATCH bpf-next] bpf: add skb->queue_mapping write access from tc clsact From: Jesper Dangaard Brouer To: netdev@vger.kernel.org, Daniel Borkmann , Alexei Starovoitov Cc: Jesper Dangaard Brouer Date: Tue, 19 Feb 2019 11:24:00 +0100 Message-ID: <155057184028.20935.11848804617158437103.stgit@firesoul> User-Agent: StGit/0.17.1-dirty MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.26]); Tue, 19 Feb 2019 10:24:04 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The skb->queue_mapping already have read access, via __sk_buff->queue_mapping. This patch allow BPF tc qdisc clsact write access to the queue_mapping via tc_cls_act_is_valid_access. It is already possible to change this via TC filter action skbedit tc-skbedit(8). Due to the lack of TC examples, lets show one: # tc qdisc add dev ixgbe1 handle ffff: ingress # tc filter add dev ixgbe1 parent ffff: matchall action skbedit queue_mapping 5 # tc filter list dev ixgbe1 parent ffff: The most common mistake is that XPS (Transmit Packet Steering) takes precedence over setting skb->queue_mapping. XPS is configured per DEVICE via /sys/class/net/DEVICE/queues/tx-*/xps_cpus via a CPU hex mask. To disable set mask=00. The purpose of changing skb->queue_mapping is to influence the selection of the net_device "txq" (struct netdev_queue), which influence selection of the qdisc "root_lock" (via txq->qdisc->q.lock) and txq->_xmit_lock. When using the MQ qdisc the txq->qdisc points to different qdiscs and associated locks, and HARD_TX_LOCK (txq->_xmit_lock), allowing for CPU scalability. Due to lack of TC examples, lets show howto attach clsact BPF programs: # tc qdisc add dev ixgbe2 clsact # tc filter replace dev ixgbe2 egress bpf da obj XXX_kern.o sec tc_qmap2cpu # tc filter list dev ixgbe2 egress Signed-off-by: Jesper Dangaard Brouer --- net/core/filter.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 353735575204..d05ae8d05397 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -6238,6 +6238,7 @@ static bool tc_cls_act_is_valid_access(int off, int size, case bpf_ctx_range(struct __sk_buff, tc_classid): case bpf_ctx_range_till(struct __sk_buff, cb[0], cb[4]): case bpf_ctx_range(struct __sk_buff, tstamp): + case bpf_ctx_range(struct __sk_buff, queue_mapping): break; default: return false; @@ -6642,9 +6643,16 @@ static u32 bpf_convert_ctx_access(enum bpf_access_type type, break; case offsetof(struct __sk_buff, queue_mapping): - *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, - bpf_target_off(struct sk_buff, queue_mapping, 2, - target_size)); + if (type == BPF_WRITE) + *insn++ = BPF_STX_MEM(BPF_H, si->dst_reg, si->src_reg, + bpf_target_off(struct sk_buff, + queue_mapping, + 2, target_size)); + else + *insn++ = BPF_LDX_MEM(BPF_H, si->dst_reg, si->src_reg, + bpf_target_off(struct sk_buff, + queue_mapping, + 2, target_size)); break; case offsetof(struct __sk_buff, vlan_present):