From patchwork Mon Jun 28 11:47:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Kumar Kartikeya Dwivedi X-Patchwork-Id: 12347763 X-Patchwork-Delegate: bpf@iogearbox.net 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 2A773C2B9F4 for ; Mon, 28 Jun 2021 11:50:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 03159619BF for ; Mon, 28 Jun 2021 11:49:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232905AbhF1LwW (ORCPT ); Mon, 28 Jun 2021 07:52:22 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56968 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232884AbhF1LwS (ORCPT ); Mon, 28 Jun 2021 07:52:18 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 26DE6C061767; Mon, 28 Jun 2021 04:49:52 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id x16so13835384pfa.13; Mon, 28 Jun 2021 04:49:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=4LVtRPMedXBwPU8Fk0Itdr6whKyCNEJkD3pIe5JJLNQ=; b=g7lRsDvLtdacPq4bg/6/YTm9WcBJzO7i01WVPfC3CCGwVsKdrV9ncawxZJmtF3w7Pi u0x2f11HWXtQsRvxnpLavpqY68OXTlAFu1VcAaDTNO78XqVrXAwRA2ad1mNcAFGXz2RJ CZXG/qm1rH5kJyMiXAoFJ2Cqp1HT/Z54gt0O19LsCT9seoy4C+NGuVvh3Sh/SdT6bGYN 0osY9AGuQG4+5F1Y8RiAi241h10UxD4Hh73UCVCOY2gM+Egxdg62jWlsJBBLJRJ3yZp3 Huoeb16HueJsqMSFep7RuvlARxnRQUt4mlO8fJX2yGreuId/o0l7waY4Rzq/INmHOmqL E98A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=4LVtRPMedXBwPU8Fk0Itdr6whKyCNEJkD3pIe5JJLNQ=; b=c3K8aDa7oCUBzrBdOqGEdY8YSKhszPSVg0YSOy9haOnJZ//CYW6vH0Fm4JoIO7KpX4 nZbo2+eBdG1/Ob9JW2k8YlTwZpLOpkrILiNJZTToYKYj7sGpjtGvwrWIpdvcIboSlYTI 9OoPErHQMEsIH5GPgvT/Nh/FiDGORKNWJ7D0rbxBb3fKBT5/sqAtocEE/441uyOUTwFm XmaYNLRVffuRyh942nMh55sYSBKECOmS25eFg4/CQj8D/zoQbqkH+p0v1+W2h9YIgaga vJOtMNHbaMjIl+pU/cF9yX7BaSQyu0x1WWEBQnT96g86bNWRjL75H5LjMx4vQcgoxjyN ZzNg== X-Gm-Message-State: AOAM530WEUnKDVP0wPgR15TgabHNn9PeCm8AHeCalJpXz2g8tf7qBGlM 07xBmn+RbU75nZy30VFvZCafcIrCw5k= X-Google-Smtp-Source: ABdhPJxjR4B2gayujr9Nq1Cr3XxbPk4iv0RA+DgWABqFqe0rYL66XBbRtpvXB7kyYotIGupFdQ8Ofg== X-Received: by 2002:aa7:88d6:0:b029:300:6247:8141 with SMTP id k22-20020aa788d60000b029030062478141mr24241024pff.47.1624880991491; Mon, 28 Jun 2021 04:49:51 -0700 (PDT) Received: from localhost ([2402:3a80:11da:c590:f80e:952e:84ac:ba3d]) by smtp.gmail.com with ESMTPSA id t13sm14189358pfq.4.2021.06.28.04.49.50 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 28 Jun 2021 04:49:51 -0700 (PDT) From: Kumar Kartikeya Dwivedi To: netdev@vger.kernel.org Cc: Kumar Kartikeya Dwivedi , =?utf-8?q?Toke_H=C3=B8iland-?= =?utf-8?q?J=C3=B8rgensen?= , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Jesper Dangaard Brouer , "David S. Miller" , Jakub Kicinski , John Fastabend , Martin KaFai Lau , bpf@vger.kernel.org Subject: [PATCH net-next v4 3/5] bpf: cpumap: implement generic cpumap Date: Mon, 28 Jun 2021 17:17:44 +0530 Message-Id: <20210628114746.129669-4-memxor@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210628114746.129669-1-memxor@gmail.com> References: <20210628114746.129669-1-memxor@gmail.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: kuba@kernel.org This change implements CPUMAP redirect support for generic XDP programs. The idea is to reuse the cpu map entry's queue that is used to push native xdp frames for redirecting skb to a different CPU. This will match native XDP behavior (in that RPS is invoked again for packet reinjected into networking stack). To be able to determine whether the incoming skb is from the driver or cpumap, we reuse skb->redirected bit that skips generic XDP processing when it is set. To always make use of this, CONFIG_NET_REDIRECT guard on it has been lifted and it is always available. From the redirect side, we add the skb to ptr_ring with its lowest bit set to 1. This should be safe as skb is not 1-byte aligned. This allows kthread to discern between xdp_frames and sk_buff. On consumption of the ptr_ring item, the lowest bit is unset. In the end, the skb is simply added to the list that kthread is anyway going to maintain for xdp_frames converted to skb, and then received again by using netif_receive_skb_list. Bulking optimization for generic cpumap is left as an exercise for a future patch for now. Since cpumap entry progs are now supported, also remove check in generic_xdp_install for the cpumap. Reviewed-by: Toke Høiland-Jørgensen Signed-off-by: Kumar Kartikeya Dwivedi --- include/linux/bpf.h | 9 +++- include/linux/skbuff.h | 10 +--- kernel/bpf/cpumap.c | 115 +++++++++++++++++++++++++++++++++++------ net/core/dev.c | 3 +- net/core/filter.c | 6 ++- 5 files changed, 115 insertions(+), 28 deletions(-) diff --git a/include/linux/bpf.h b/include/linux/bpf.h index f309fc1509f2..095aaa104c56 100644 --- a/include/linux/bpf.h +++ b/include/linux/bpf.h @@ -1513,7 +1513,8 @@ bool dev_map_can_have_prog(struct bpf_map *map); void __cpu_map_flush(void); int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, struct net_device *dev_rx); -bool cpu_map_prog_allowed(struct bpf_map *map); +int cpu_map_generic_redirect(struct bpf_cpu_map_entry *rcpu, + struct sk_buff *skb); /* Return map's numa specified by userspace */ static inline int bpf_map_attr_numa_node(const union bpf_attr *attr) @@ -1710,6 +1711,12 @@ static inline int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, return 0; } +static inline int cpu_map_generic_redirect(struct bpf_cpu_map_entry *rcpu, + struct sk_buff *skb) +{ + return -EOPNOTSUPP; +} + static inline bool cpu_map_prog_allowed(struct bpf_map *map) { return false; diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index b2db9cd9a73f..f19190820e63 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -863,8 +863,8 @@ struct sk_buff { __u8 tc_skip_classify:1; __u8 tc_at_ingress:1; #endif -#ifdef CONFIG_NET_REDIRECT __u8 redirected:1; +#ifdef CONFIG_NET_REDIRECT __u8 from_ingress:1; #endif #ifdef CONFIG_TLS_DEVICE @@ -4664,17 +4664,13 @@ static inline __wsum lco_csum(struct sk_buff *skb) static inline bool skb_is_redirected(const struct sk_buff *skb) { -#ifdef CONFIG_NET_REDIRECT return skb->redirected; -#else - return false; -#endif } static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress) { -#ifdef CONFIG_NET_REDIRECT skb->redirected = 1; +#ifdef CONFIG_NET_REDIRECT skb->from_ingress = from_ingress; if (skb->from_ingress) skb->tstamp = 0; @@ -4683,9 +4679,7 @@ static inline void skb_set_redirected(struct sk_buff *skb, bool from_ingress) static inline void skb_reset_redirect(struct sk_buff *skb) { -#ifdef CONFIG_NET_REDIRECT skb->redirected = 0; -#endif } static inline bool skb_csum_is_sctp(struct sk_buff *skb) diff --git a/kernel/bpf/cpumap.c b/kernel/bpf/cpumap.c index a1a0c4e791c6..274353e2cd70 100644 --- a/kernel/bpf/cpumap.c +++ b/kernel/bpf/cpumap.c @@ -16,6 +16,7 @@ * netstack, and assigning dedicated CPUs for this stage. This * basically allows for 10G wirespeed pre-filtering via bpf. */ +#include #include #include #include @@ -168,6 +169,49 @@ static void put_cpu_map_entry(struct bpf_cpu_map_entry *rcpu) } } +static void cpu_map_bpf_prog_run_skb(struct bpf_cpu_map_entry *rcpu, + struct list_head *listp, + struct xdp_cpumap_stats *stats) +{ + struct sk_buff *skb, *tmp; + struct xdp_buff xdp; + u32 act; + int err; + + if (!rcpu->prog) + return; + + list_for_each_entry_safe(skb, tmp, listp, list) { + act = bpf_prog_run_generic_xdp(skb, &xdp, rcpu->prog); + switch (act) { + case XDP_PASS: + break; + case XDP_REDIRECT: + skb_list_del_init(skb); + err = xdp_do_generic_redirect(skb->dev, skb, &xdp, + rcpu->prog); + if (unlikely(err)) { + kfree_skb(skb); + stats->drop++; + } else { + stats->redirect++; + } + return; + default: + bpf_warn_invalid_xdp_action(act); + fallthrough; + case XDP_ABORTED: + trace_xdp_exception(skb->dev, rcpu->prog, act); + fallthrough; + case XDP_DROP: + skb_list_del_init(skb); + kfree_skb(skb); + stats->drop++; + return; + } + } +} + static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, void **frames, int n, struct xdp_cpumap_stats *stats) @@ -179,8 +223,6 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, if (!rcpu->prog) return n; - rcu_read_lock_bh(); - xdp_set_return_frame_no_direct(); xdp.rxq = &rxq; @@ -227,17 +269,34 @@ static int cpu_map_bpf_prog_run_xdp(struct bpf_cpu_map_entry *rcpu, } } + xdp_clear_return_frame_no_direct(); + + return nframes; +} + +#define CPUMAP_BATCH 8 + +static int cpu_map_bpf_prog_run(struct bpf_cpu_map_entry *rcpu, void **frames, + int xdp_n, struct xdp_cpumap_stats *stats, + struct list_head *list) +{ + int nframes; + + rcu_read_lock_bh(); + + nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, xdp_n, stats); + if (stats->redirect) - xdp_do_flush_map(); + xdp_do_flush(); - xdp_clear_return_frame_no_direct(); + if (unlikely(!list_empty(list))) + cpu_map_bpf_prog_run_skb(rcpu, list, stats); - rcu_read_unlock_bh(); /* resched point, may call do_softirq() */ + rcu_read_unlock_bh(); return nframes; } -#define CPUMAP_BATCH 8 static int cpu_map_kthread_run(void *data) { @@ -254,9 +313,9 @@ static int cpu_map_kthread_run(void *data) struct xdp_cpumap_stats stats = {}; /* zero stats */ unsigned int kmem_alloc_drops = 0, sched = 0; gfp_t gfp = __GFP_ZERO | GFP_ATOMIC; + int i, n, m, nframes, xdp_n; void *frames[CPUMAP_BATCH]; void *skbs[CPUMAP_BATCH]; - int i, n, m, nframes; LIST_HEAD(list); /* Release CPU reschedule checks */ @@ -280,9 +339,20 @@ static int cpu_map_kthread_run(void *data) */ n = __ptr_ring_consume_batched(rcpu->queue, frames, CPUMAP_BATCH); - for (i = 0; i < n; i++) { + for (i = 0, xdp_n = 0; i < n; i++) { void *f = frames[i]; - struct page *page = virt_to_page(f); + struct page *page; + + if (unlikely(__ptr_test_bit(0, &f))) { + struct sk_buff *skb = f; + + __ptr_clear_bit(0, &skb); + list_add_tail(&skb->list, &list); + continue; + } + + frames[xdp_n++] = f; + page = virt_to_page(f); /* Bring struct page memory area to curr CPU. Read by * build_skb_around via page_is_pfmemalloc(), and when @@ -292,7 +362,7 @@ static int cpu_map_kthread_run(void *data) } /* Support running another XDP prog on this CPU */ - nframes = cpu_map_bpf_prog_run_xdp(rcpu, frames, n, &stats); + nframes = cpu_map_bpf_prog_run(rcpu, frames, xdp_n, &stats, &list); if (nframes) { m = kmem_cache_alloc_bulk(skbuff_head_cache, gfp, nframes, skbs); if (unlikely(m == 0)) { @@ -330,12 +400,6 @@ static int cpu_map_kthread_run(void *data) return 0; } -bool cpu_map_prog_allowed(struct bpf_map *map) -{ - return map->map_type == BPF_MAP_TYPE_CPUMAP && - map->value_size != offsetofend(struct bpf_cpumap_val, qsize); -} - static int __cpu_map_load_bpf_program(struct bpf_cpu_map_entry *rcpu, int fd) { struct bpf_prog *prog; @@ -696,6 +760,25 @@ int cpu_map_enqueue(struct bpf_cpu_map_entry *rcpu, struct xdp_buff *xdp, return 0; } +int cpu_map_generic_redirect(struct bpf_cpu_map_entry *rcpu, + struct sk_buff *skb) +{ + int ret; + + __skb_pull(skb, skb->mac_len); + skb_set_redirected(skb, false); + __ptr_set_bit(0, &skb); + + ret = ptr_ring_produce(rcpu->queue, skb); + if (ret < 0) + goto trace; + + wake_up_process(rcpu->kthread); +trace: + trace_xdp_cpumap_enqueue(rcpu->map_id, !ret, !!ret, rcpu->cpu); + return ret; +} + void __cpu_map_flush(void) { struct list_head *flush_list = this_cpu_ptr(&cpu_map_flush_list); diff --git a/net/core/dev.c b/net/core/dev.c index ad5ab33cbd39..8521936414f2 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5665,8 +5665,7 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp) * have a bpf_prog installed on an entry */ for (i = 0; i < new->aux->used_map_cnt; i++) { - if (dev_map_can_have_prog(new->aux->used_maps[i]) || - cpu_map_prog_allowed(new->aux->used_maps[i])) { + if (dev_map_can_have_prog(new->aux->used_maps[i])) { mutex_unlock(&new->aux->used_maps_mutex); return -EINVAL; } diff --git a/net/core/filter.c b/net/core/filter.c index 0b13d8157a8f..4a21fde3028f 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4038,8 +4038,12 @@ static int xdp_do_generic_redirect_map(struct net_device *dev, goto err; consume_skb(skb); break; + case BPF_MAP_TYPE_CPUMAP: + err = cpu_map_generic_redirect(fwd, skb); + if (unlikely(err)) + goto err; + break; default: - /* TODO: Handle BPF_MAP_TYPE_CPUMAP */ err = -EBADRQC; goto err; }