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 AD395C77B7C for ; Fri, 5 May 2023 16:57:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231326AbjEEQ5b (ORCPT ); Fri, 5 May 2023 12:57:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45234 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229717AbjEEQ53 (ORCPT ); Fri, 5 May 2023 12:57:29 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id ED4FA19925 for ; Fri, 5 May 2023 09:57:21 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id d9443c01a7336-1aad5245632so14368655ad.3 for ; Fri, 05 May 2023 09:57:21 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=networkplumber-org.20221208.gappssmtp.com; s=20221208; t=1683305841; x=1685897841; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=MRnH3Cqyhep5CEq8cjj0HvIYZ//rx8xK1w3m3boBFtg=; b=Cyf/IQwjmN9nQoPYngzzVl136RZUda/4n2mxEslQE6sZXsNPA8HPj7FUmIk4yH/+Ul CGE5+hMHUuhvWiMrdhcQ/HHILkaTdCVWE2E1FFRP15KyTbmDfuaSgT46WsKX6jjnhdCc qZN4gR2llEQKeHIA3LEIWEO2NOvJd0J2Yv2QhCa8uDlEG4Z6y2RzMgVkL01DBdbuaqoE t7wEXYL4RYq3GDXOjJ5w3vEJguzJSKRMLOSN65oWtMlSTHjTj4gmbgwHmETw67ZtZINV 88UsYbpmdrEPjoEyvb7s9l3l5iSdgBRIPPuuERshVM37DqaUym8OWO4n72s9AR5DfuMD 4w1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1683305841; x=1685897841; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=MRnH3Cqyhep5CEq8cjj0HvIYZ//rx8xK1w3m3boBFtg=; b=hp3ZxUkTrXVs26tmRyncyObYLQJtWjOX/jviUYz5hfjki7xhKpBnCPJcRgNplTa9iy YCWihf4esCYNmPW9TKnTVTCZ96W27OGp9ek/l1qbPtDWu2pEk2RZ1FoIiH87bCf/n7cD UaV8q3idfULUloBPuIWR2NXEfK4l0ReAyDGtIrDqNJwPGL0M6/7SBh1m0LQcsbRers6g hSQ6g/HRF/Ebvb2CJx55Mc2cytX7HPFV9yAkx/LzNWS78L5LHF0N8VfVY9V4f7NpIWt5 NyLRkKXTsmPdhKrgCiFonVGCzZPAqYICnYXJ8JDLcLLgVX/fqo5UOtQUrSgr9W7F9ERl HivQ== X-Gm-Message-State: AC+VfDzAubqDpbBFNzojUPRqfLyedlb2GXQS83hhGb1Igocy7Zk7mBN5 P0IQGJ41vqKajmBDEmrdrtLzxw== X-Google-Smtp-Source: ACHHUZ7LKP3CgdJgRxrVJzoZS412nCrFH/uVDLZE6eaj78oMi5iMd/a/L1rEOrB3ZxMOJ5q/i06cTg== X-Received: by 2002:a17:902:be01:b0:1a8:1c9a:f68 with SMTP id r1-20020a170902be0100b001a81c9a0f68mr1814959pls.36.1683305841239; Fri, 05 May 2023 09:57:21 -0700 (PDT) Received: from hermes.local (204-195-120-218.wavecable.com. [204.195.120.218]) by smtp.gmail.com with ESMTPSA id w1-20020a170902904100b001a69c1c78e7sm2017229plz.71.2023.05.05.09.57.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 May 2023 09:57:20 -0700 (PDT) Date: Fri, 5 May 2023 09:57:17 -0700 From: Stephen Hemminger To: Chuck Lever Cc: netdev@vger.kernel.org, linux-rdma@vger.kernel.org, BMT@zurich.ibm.com, tom@talpey.com Subject: Re: [PATCH RFC 2/3] net/lo: Ensure lo devices have a MAC address Message-ID: <20230505095717.6ad2b4ca@hermes.local> In-Reply-To: <168330135435.5953.3471584034284499194.stgit@oracle-102.nfsv4bat.org> References: <168330051600.5953.11366152375575299483.stgit@oracle-102.nfsv4bat.org> <168330135435.5953.3471584034284499194.stgit@oracle-102.nfsv4bat.org> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On Fri, 05 May 2023 11:42:44 -0400 Chuck Lever wrote: > From: Chuck Lever > > A non-zero MAC address enables a network device to be assigned as > the underlying device for a virtual RDMA device. Without a non- > zero MAC address, cma_acquire_dev_by_src_ip() is unable to find the > underlying egress device that corresponds to a source IP address, > and rdma_resolve_address() fails. > > Signed-off-by: Chuck Lever > --- > drivers/net/loopback.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/net/loopback.c b/drivers/net/loopback.c > index f6d53e63ef4e..1ce4f19d8065 100644 > --- a/drivers/net/loopback.c > +++ b/drivers/net/loopback.c > @@ -192,6 +192,8 @@ static void gen_lo_setup(struct net_device *dev, > dev->needs_free_netdev = true; > dev->priv_destructor = dev_destructor; > > + eth_hw_addr_random(dev); > + > netif_set_tso_max_size(dev, GSO_MAX_SIZE); > } > > > > This enough of a change, it will probably break somebody. If you need dummy endpoint (ie multiple loopback), a common way is to use dummy devices for that.