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=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 25A4DC433E0 for ; Wed, 27 May 2020 10:01:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id EC52F208FE for ; Wed, 27 May 2020 10:01:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="f/Eb/+on" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728153AbgE0KBb (ORCPT ); Wed, 27 May 2020 06:01:31 -0400 Received: from us-smtp-2.mimecast.com ([207.211.31.81]:38734 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729754AbgE0KB2 (ORCPT ); Wed, 27 May 2020 06:01:28 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590573687; 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: in-reply-to:in-reply-to:references:references; bh=p+Npb1oaA/q+RvOPe4v/x6Ts2XAyuVZ94IYNronv0pU=; b=f/Eb/+onXWlZ7T75FZOBq8O5sV5pEIRz+rfENaRJLvY9yASkiKaBz4tTMZVxuJsn0ZONYx NXvqd1DU+up6zG7rsilHXlEB5k81A7M/tDYX5rP1+XwAXj73Iap4X1Gx+gPkFFZbLTDtqn Q/balH5H/zn4F9tSein1LcRZy5CftzQ= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-419-wGgKYjScPnmb2jsXPtDdwA-1; Wed, 27 May 2020 06:01:25 -0400 X-MC-Unique: wGgKYjScPnmb2jsXPtDdwA-1 Received: by mail-ed1-f72.google.com with SMTP id f18so9924497eds.6 for ; Wed, 27 May 2020 03:01:25 -0700 (PDT) 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:in-reply-to:references:date :message-id:mime-version; bh=p+Npb1oaA/q+RvOPe4v/x6Ts2XAyuVZ94IYNronv0pU=; b=Q6yMX6+meLukVQzIXG4bF3wN4MxHLXL47cSh/0GQPgjF255+A4/XSm6z5Q1A260YHl U2qY13dIOaDfrLkUYSXJDX57vwvbOJgXrPECKCN26SWQZqUOEZIUBNZtRQQLxyNSZC0P 96LfLWSxcMgi+TyWpMSzoKZlU8nJkmM+VY7VR/GL+U0df4gHXrhfVrIvGp2ftRpGIBPp djY1rVUAQSpuCy+uCgMS6eO2vZFr2Q6/gX3l0jrStU5K+vKqWUrpIQz2AHqGUCaZdjvl 2ERajMWD3pBFcisbGdDZsW4OKg744LcygNNjEyeKS5v7gnlq6qKVfXXVi/josTorAxlK LNCQ== X-Gm-Message-State: AOAM531jDVp17X2+vHCSiPfZ1dHfhrvth/cEZS7Te4yOF63xBNieSMBb x9Kl2tKfitkI55hzwlaVlvFbfVQH6gWld7cAu2C4D95Bg4HWtREFRbINyYUzG8/sbLe9ywHylWO j6y8HeevuYhuXpBxP X-Received: by 2002:a17:906:7848:: with SMTP id p8mr5417793ejm.244.1590573683415; Wed, 27 May 2020 03:01:23 -0700 (PDT) X-Google-Smtp-Source: ABdhPJy5Xu/zdCY6KpNrSX/F4O4WzJirUlgGVX+ezeIKJeAMNHLVv3YFwK6xPvAH/J95xYbz8b91aQ== X-Received: by 2002:a17:906:7848:: with SMTP id p8mr5417750ejm.244.1590573683048; Wed, 27 May 2020 03:01:23 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([45.145.92.2]) by smtp.gmail.com with ESMTPSA id c23sm2255587ejm.116.2020.05.27.03.01.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 27 May 2020 03:01:22 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id B97471804EB; Wed, 27 May 2020 12:01:21 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: David Ahern , netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, brouer@redhat.com, daniel@iogearbox.net, john.fastabend@gmail.com, ast@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, andriin@fb.com, dsahern@gmail.com, David Ahern Subject: Re: [PATCH bpf-next 2/5] bpf: Add support to attach bpf program to a devmap entry In-Reply-To: <20200527010905.48135-3-dsahern@kernel.org> References: <20200527010905.48135-1-dsahern@kernel.org> <20200527010905.48135-3-dsahern@kernel.org> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 27 May 2020 12:01:21 +0200 Message-ID: <875zch3de6.fsf@toke.dk> MIME-Version: 1.0 Content-Type: text/plain Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org David Ahern writes: > Add BPF_XDP_DEVMAP attach type for use with programs associated with a > DEVMAP entry. > > DEVMAPs can associate a program with a device entry by setting the > value to pair. The program associated with the fd must have > type XDP with expected attach type BPF_XDP_DEVMAP. When a program is > associated with a device index, the program is run on an XDP_REDIRECT > and before the buffer is added to the per-cpu queue. At this point > rxq data is still valid; the next patch adds tx device information > allowing the prorgam to see both ingress and egress device indices. > > XDP generic is skb based and XDP programs do not work with skb's. Block > the use case by walking maps used by a program that is to be attached > via xdpgeneric and fail if any of them are DEVMAP / DEVMAP_HASH with > 8-bytes values. > > Block attach of BPF_XDP_DEVMAP programs to devices. > > Signed-off-by: David Ahern > --- > include/linux/bpf.h | 5 ++ > include/uapi/linux/bpf.h | 1 + > kernel/bpf/devmap.c | 92 ++++++++++++++++++++++++++++++---- > net/core/dev.c | 18 +++++++ > tools/include/uapi/linux/bpf.h | 1 + > 5 files changed, 108 insertions(+), 9 deletions(-) > > diff --git a/include/linux/bpf.h b/include/linux/bpf.h > index efe8836b5c48..088751bc09aa 100644 > --- a/include/linux/bpf.h > +++ b/include/linux/bpf.h > @@ -1242,6 +1242,7 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp, > struct net_device *dev_rx); > int dev_map_generic_redirect(struct bpf_dtab_netdev *dst, struct sk_buff *skb, > struct bpf_prog *xdp_prog); > +bool dev_map_can_have_prog(struct bpf_map *map); > > struct bpf_cpu_map_entry *__cpu_map_lookup_elem(struct bpf_map *map, u32 key); > void __cpu_map_flush(void); > @@ -1355,6 +1356,10 @@ static inline struct net_device *__dev_map_hash_lookup_elem(struct bpf_map *map > { > return NULL; > } > +static inline bool dev_map_can_have_prog(struct bpf_map *map) > +{ > + return false; > +} > > static inline void __dev_flush(void) > { > diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h > index 97e1fd19ff58..8c2c0d0c9a0e 100644 > --- a/include/uapi/linux/bpf.h > +++ b/include/uapi/linux/bpf.h > @@ -224,6 +224,7 @@ enum bpf_attach_type { > BPF_CGROUP_INET6_GETPEERNAME, > BPF_CGROUP_INET4_GETSOCKNAME, > BPF_CGROUP_INET6_GETSOCKNAME, > + BPF_XDP_DEVMAP, > __MAX_BPF_ATTACH_TYPE > }; > > diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c > index 95db6d8beebc..7658b3e2e7fc 100644 > --- a/kernel/bpf/devmap.c > +++ b/kernel/bpf/devmap.c > @@ -73,6 +73,7 @@ struct bpf_dtab_netdev { > struct net_device *dev; /* must be first member, due to tracepoint */ > struct hlist_node index_hlist; > struct bpf_dtab *dtab; > + struct bpf_prog *xdp_prog; > struct rcu_head rcu; > unsigned int idx; > struct dev_map_ext_val val; > @@ -231,6 +232,8 @@ static void dev_map_free(struct bpf_map *map) > > hlist_for_each_entry_safe(dev, next, head, index_hlist) { > hlist_del_rcu(&dev->index_hlist); > + if (dev->xdp_prog) > + bpf_prog_put(dev->xdp_prog); > dev_put(dev->dev); > kfree(dev); > } > @@ -245,6 +248,8 @@ static void dev_map_free(struct bpf_map *map) > if (!dev) > continue; > > + if (dev->xdp_prog) > + bpf_prog_put(dev->xdp_prog); > dev_put(dev->dev); > kfree(dev); > } > @@ -331,6 +336,16 @@ static int dev_map_hash_get_next_key(struct bpf_map *map, void *key, > return -ENOENT; > } > > +bool dev_map_can_have_prog(struct bpf_map *map) > +{ > + if ((map->map_type == BPF_MAP_TYPE_DEVMAP || > + map->map_type == BPF_MAP_TYPE_DEVMAP_HASH) && > + map->value_size != 4) > + return true; > + > + return false; > +} > + > static int bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags) > { > struct net_device *dev = bq->dev; > @@ -455,6 +470,35 @@ static inline int __xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, > return bq_enqueue(dev, xdpf, dev_rx); > } > > +static struct xdp_buff *dev_map_run_prog(struct net_device *dev, > + struct xdp_buff *xdp, > + struct bpf_prog *xdp_prog) > +{ > + u32 act; > + > + act = bpf_prog_run_xdp(xdp_prog, xdp); > + switch (act) { > + case XDP_DROP: > + fallthrough; > + case XDP_PASS: > + break; > + default: > + bpf_warn_invalid_xdp_action(act); > + fallthrough; > + case XDP_ABORTED: > + trace_xdp_exception(dev, xdp_prog, act); > + act = XDP_DROP; > + break; > + } > + > + if (act == XDP_DROP) { > + xdp_return_buff(xdp); > + xdp = NULL; > + } > + > + return xdp; > +} > + > int dev_xdp_enqueue(struct net_device *dev, struct xdp_buff *xdp, > struct net_device *dev_rx) > { > @@ -466,6 +510,11 @@ int dev_map_enqueue(struct bpf_dtab_netdev *dst, struct xdp_buff *xdp, > { > struct net_device *dev = dst->dev; > > + if (dst->xdp_prog) { > + xdp = dev_map_run_prog(dev, xdp, dst->xdp_prog); > + if (!xdp) > + return 0; > + } > return __xdp_enqueue(dev, xdp, dev_rx); > } Did you give any special consideration to where the hook should be? I'm asking because my immediate thought was that it should be on flush (i.e., in bq_xmit_all()), but now that I see this I'm so sure anymore. What were your thoughts around this? -Toke