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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B7AA4C433EF for ; Sun, 9 Jan 2022 23:18:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237465AbiAIXSg (ORCPT ); Sun, 9 Jan 2022 18:18:36 -0500 Received: from mail.netfilter.org ([217.70.188.207]:42124 "EHLO mail.netfilter.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237460AbiAIXRG (ORCPT ); Sun, 9 Jan 2022 18:17:06 -0500 Received: from localhost.localdomain (unknown [78.30.32.163]) by mail.netfilter.org (Postfix) with ESMTPSA id 37FD864692; Mon, 10 Jan 2022 00:14:16 +0100 (CET) From: Pablo Neira Ayuso To: netfilter-devel@vger.kernel.org Cc: davem@davemloft.net, netdev@vger.kernel.org, kuba@kernel.org Subject: [PATCH net-next 27/32] netfilter: nf_tables: add register tracking infrastructure Date: Mon, 10 Jan 2022 00:16:35 +0100 Message-Id: <20220109231640.104123-28-pablo@netfilter.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220109231640.104123-1-pablo@netfilter.org> References: <20220109231640.104123-1-pablo@netfilter.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org This patch adds new infrastructure to skip redundant selector store operations on the same register to achieve a performance boost from the packet path. This is particularly noticeable in pure linear rulesets but it also helps in rulesets which are already heaving relying in maps to avoid ruleset linear inspection. The idea is to keep data of the most recurrent store operations on register to reuse them with cmp and lookup expressions. This infrastructure allows for dynamic ruleset updates since the ruleset blob reduction happens from the kernel. Userspace still needs to be updated to maximize register utilization to cooperate to improve register data reuse / reduce number of store on register operations. Signed-off-by: Pablo Neira Ayuso --- include/net/netfilter/nf_tables.h | 12 ++++++++++++ net/netfilter/nf_tables_api.c | 11 +++++++++++ 2 files changed, 23 insertions(+) diff --git a/include/net/netfilter/nf_tables.h b/include/net/netfilter/nf_tables.h index 515e5db97e01..1c37ce61daea 100644 --- a/include/net/netfilter/nf_tables.h +++ b/include/net/netfilter/nf_tables.h @@ -122,6 +122,16 @@ struct nft_regs { }; }; +struct nft_regs_track { + struct { + const struct nft_expr *selector; + const struct nft_expr *bitwise; + } regs[NFT_REG32_NUM]; + + const struct nft_expr *cur; + const struct nft_expr *last; +}; + /* Store/load an u8, u16 or u64 integer to/from the u32 data register. * * Note, when using concatenations, register allocation happens at 32-bit @@ -886,6 +896,8 @@ struct nft_expr_ops { int (*validate)(const struct nft_ctx *ctx, const struct nft_expr *expr, const struct nft_data **data); + bool (*reduce)(struct nft_regs_track *track, + const struct nft_expr *expr); bool (*gc)(struct net *net, const struct nft_expr *expr); int (*offload)(struct nft_offload_ctx *ctx, diff --git a/net/netfilter/nf_tables_api.c b/net/netfilter/nf_tables_api.c index 2317429ea35e..83ce82212cbb 100644 --- a/net/netfilter/nf_tables_api.c +++ b/net/netfilter/nf_tables_api.c @@ -8259,6 +8259,7 @@ EXPORT_SYMBOL_GPL(nf_tables_trans_destroy_flush_work); static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *chain) { const struct nft_expr *expr, *last; + struct nft_regs_track track = {}; unsigned int size, data_size; void *data, *data_boundary; struct nft_rule_dp *prule; @@ -8298,7 +8299,17 @@ static int nf_tables_commit_chain_prepare(struct net *net, struct nft_chain *cha if (WARN_ON_ONCE(data > data_boundary)) return -ENOMEM; + size = 0; + track.last = last; nft_rule_for_each_expr(expr, last, rule) { + track.cur = expr; + + if (expr->ops->reduce && + expr->ops->reduce(&track, expr)) { + expr = track.cur; + continue; + } + if (WARN_ON_ONCE(data + expr->ops->size > data_boundary)) return -ENOMEM; -- 2.30.2