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 435C9C433E0 for ; Fri, 22 May 2020 12:08:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 113DE2072C for ; Fri, 22 May 2020 12:08:56 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="e9kuM+5H" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730027AbgEVMIz (ORCPT ); Fri, 22 May 2020 08:08:55 -0400 Received: from us-smtp-1.mimecast.com ([207.211.31.81]:60819 "EHLO us-smtp-delivery-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1730010AbgEVMIy (ORCPT ); Fri, 22 May 2020 08:08:54 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1590149332; 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=u/HlAcXKy6POHIGIcLRkxndzZPc/CF+My2FFUK06Fks=; b=e9kuM+5HSm/KhhOl5An971C/OVWf379T+/FI5XYMzcBqiwgGfwxRRxKuj5/N6V+DChIAwD MCdTK+Gs99beKANJBtDcqDma0kFI6lMHcrquDjBPslWAzwff5fAf0fZ5yyZ3WON0Fo5lC2 GTiFJorb+j/oSHIvImbinBraYl2AdaQ= 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-165-Aep6l-uhO124_mFr6GBV8Q-1; Fri, 22 May 2020 08:08:50 -0400 X-MC-Unique: Aep6l-uhO124_mFr6GBV8Q-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 8842C8018A2; Fri, 22 May 2020 12:08:48 +0000 (UTC) Received: from carbon (unknown [10.40.208.9]) by smtp.corp.redhat.com (Postfix) with ESMTP id 62ABE19167; Fri, 22 May 2020 12:08:07 +0000 (UTC) Date: Fri, 22 May 2020 14:08:05 +0200 From: Jesper Dangaard Brouer To: David Ahern Cc: netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org, toke@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, brouer@redhat.com, Lorenzo Bianconi Subject: Re: [PATCH RFC bpf-next 1/4] bpf: Handle 8-byte values in DEVMAP and DEVMAP_HASH Message-ID: <20200522140805.045b8823@carbon> In-Reply-To: <20200522010526.14649-2-dsahern@kernel.org> References: <20200522010526.14649-1-dsahern@kernel.org> <20200522010526.14649-2-dsahern@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Thu, 21 May 2020 19:05:23 -0600 David Ahern wrote: > Add support to DEVMAP and DEVMAP_HASH to support 8-byte values as a > pair. To do this, a new struct is needed in > bpf_dtab_netdev to hold the values to return on lookup. I would like to see us leverage BTF instead of checking on the size attr->value_size. E.g do the sanity check based on BTF. Given I don't know the exact details on how this should be done, I will look into it... I already promised Lorenzo, as we have already discussed this on IRC. So, you can Lorenzo can go ahead with this approach, and test the use-case. And I'll try to figure out if-and-how we can leverage BTF here. Input from BTF experts will be much appreciated. > Signed-off-by: David Ahern > --- > kernel/bpf/devmap.c | 53 ++++++++++++++++++++++++++++++++++----------- > 1 file changed, 40 insertions(+), 13 deletions(-) > > diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c > index a51d9fb7a359..2c01ce434306 100644 > --- a/kernel/bpf/devmap.c > +++ b/kernel/bpf/devmap.c > @@ -60,12 +60,19 @@ struct xdp_dev_bulk_queue { > unsigned int count; > }; > > +/* devmap value can be dev index or dev index + prog id */ > +struct dev_map_ext_val { > + u32 ifindex; /* must be first for compat with 4-byte values */ > + u32 prog_id; > +}; > + > 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 rcu_head rcu; > unsigned int idx; > + struct dev_map_ext_val val; > }; > > struct bpf_dtab { > @@ -108,9 +115,13 @@ static int dev_map_init_map(struct bpf_dtab *dtab, union bpf_attr *attr) > u64 cost = 0; > int err; > > - /* check sanity of attributes */ > + /* check sanity of attributes. 2 value sizes supported: > + * 4 bytes: ifindex > + * 8 bytes: ifindex + prog id > + */ > if (attr->max_entries == 0 || attr->key_size != 4 || > - attr->value_size != 4 || attr->map_flags & ~DEV_CREATE_FLAG_MASK) > + (attr->value_size != 4 && attr->value_size != 8) || > + attr->map_flags & ~DEV_CREATE_FLAG_MASK) > return -EINVAL; > > /* Lookup returns a pointer straight to dev->ifindex, so make sure the [...] > static int __dev_map_update_elem(struct net *net, struct bpf_map *map, > @@ -568,8 +579,16 @@ static int __dev_map_update_elem(struct net *net, struct bpf_map *map, > { > struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); > struct bpf_dtab_netdev *dev, *old_dev; > - u32 ifindex = *(u32 *)value; > u32 i = *(u32 *)key; > + u32 ifindex; > + > + if (map->value_size == 4) { > + ifindex = *(u32 *)value; > + } else { > + struct dev_map_ext_val *val = value; > + > + ifindex = val->ifindex; > + } > > if (unlikely(map_flags > BPF_EXIST)) > return -EINVAL; > @@ -609,10 +628,18 @@ static int __dev_map_hash_update_elem(struct net *net, struct bpf_map *map, > { > struct bpf_dtab *dtab = container_of(map, struct bpf_dtab, map); > struct bpf_dtab_netdev *dev, *old_dev; > - u32 ifindex = *(u32 *)value; > u32 idx = *(u32 *)key; > unsigned long flags; > int err = -EEXIST; > + u32 ifindex; > + > + if (map->value_size == 4) { > + ifindex = *(u32 *)value; > + } else { > + struct dev_map_ext_val *val = value; > + > + ifindex = val->ifindex; > + } > > if (unlikely(map_flags > BPF_EXIST || !ifindex)) > return -EINVAL; -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer