From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C754C8BF3 for ; Tue, 4 Jul 2023 23:54:23 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7346B1B6 for ; Tue, 4 Jul 2023 16:54:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1688514861; 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=PORwtyRFGlG4lvPZI8qM6TQsPqsUfbHMoOVfE2D1XLI=; b=W7TWEHf1FgBXwx+m2ziG39ABk7FQHxxNKl2TFsLhqe1EKV/kM+LzWeXjaTfnPBui4wLmqz 9WCsggVEXmOfl4QqvBIpv1spM3aDzrqqxK3oQPzyasVo/Ca6areOugBm+Eq3iS/RdewQDJ CL/IP8dGlEhMyP2NCx2/FdMgfmt/6aU= Received: from mail-wr1-f69.google.com (mail-wr1-f69.google.com [209.85.221.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-144-j5UYF0qeP6GuV5lVep_3UA-1; Tue, 04 Jul 2023 19:54:20 -0400 X-MC-Unique: j5UYF0qeP6GuV5lVep_3UA-1 Received: by mail-wr1-f69.google.com with SMTP id ffacd0b85a97d-30e3ee8a42eso3508135f8f.1 for ; Tue, 04 Jul 2023 16:54:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1688514859; x=1691106859; h=mime-version:message-id:date:references:in-reply-to:subject:cc:to :from:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=PORwtyRFGlG4lvPZI8qM6TQsPqsUfbHMoOVfE2D1XLI=; b=l0wMrwh1Ha7PXWQTZQDaoMoldS2RF+KHiwl9rUdBx7X0HbHMdKOEWzZ3m7FBpCj2nL mohQlQclZ9k12KYh9KI0q3To3FlqJuTIvsBUsWlxBqkfI4ArzQdP4wsXf/vrOVhMX+nN 8cRvEoaj+jF2YoL020F0msJrYgrBTSx0r0OBq7HHqpAsYcZOOFQVtr2F0kMxJwLpik2j tyBOG1yuWQyX/vdGGBEGaJ1kJiXffsU1wrkcbtnOLF66y+LSvf6TvNqspV5efhYsWvdW Ar49ibUOSby4Ko+ZF7CRIWTOqOfasvn6s6/iNWxHlv9vSHSgGhSdLH+e6mh04gXlr9rA e5hw== X-Gm-Message-State: AC+VfDyVcK8IzbPbIFgHAZXDtgGHQPXUPwkvh4buX7M+TwvfTGaXWP9q WKlm5+fOArd2L4gkAl7nVowi7thPZnHyGYZLMHUkrDH+atV++rKA4ieERLCuwLQCXDzkV4guRAP 3SDGoMyT7/cgYU6YE X-Received: by 2002:a05:600c:3787:b0:3fa:8c67:fc43 with SMTP id o7-20020a05600c378700b003fa8c67fc43mr12744032wmr.32.1688514859029; Tue, 04 Jul 2023 16:54:19 -0700 (PDT) X-Google-Smtp-Source: ACHHUZ7tq90DzBUFgJTJaEJ4Ac9MVzBo9lw3N89KMFWnG6tpF5auyzg3GBH2U3SFnJuMDfeVAFVYtw== X-Received: by 2002:a05:600c:3787:b0:3fa:8c67:fc43 with SMTP id o7-20020a05600c378700b003fa8c67fc43mr12744017wmr.32.1688514858642; Tue, 04 Jul 2023 16:54:18 -0700 (PDT) Received: from alrua-x1.borgediget.toke.dk ([2a0c:4d80:42:443::2]) by smtp.gmail.com with ESMTPSA id k15-20020a7bc40f000000b003fbaf9abf2fsm457745wmi.23.2023.07.04.16.54.17 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 04 Jul 2023 16:54:18 -0700 (PDT) Received: by alrua-x1.borgediget.toke.dk (Postfix, from userid 1000) id 45C8BBC118E; Wed, 5 Jul 2023 01:54:17 +0200 (CEST) From: Toke =?utf-8?Q?H=C3=B8iland-J=C3=B8rgensen?= To: Andrew Lunn , wei.fang@nxp.com Cc: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ast@kernel.org, daniel@iogearbox.net, hawk@kernel.org, john.fastabend@gmail.com, shenwei.wang@nxp.com, xiaoning.wang@nxp.com, netdev@vger.kernel.org, linux-imx@nxp.com, linux-kernel@vger.kernel.org, bpf@vger.kernel.org Subject: Re: [PATCH net 1/3] net: fec: dynamically set the NETDEV_XDP_ACT_NDO_XMIT feature of XDP In-Reply-To: <5b1182d5-a147-4bfd-9ac8-b33462e97b10@lunn.ch> References: <20230704082916.2135501-1-wei.fang@nxp.com> <20230704082916.2135501-2-wei.fang@nxp.com> <5b1182d5-a147-4bfd-9ac8-b33462e97b10@lunn.ch> X-Clacks-Overhead: GNU Terry Pratchett Date: Wed, 05 Jul 2023 01:54:17 +0200 Message-ID: <87mt0bb5cm.fsf@toke.dk> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4,RCVD_IN_MSPIKE_WL,SPF_HELO_NONE,SPF_NONE, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Andrew Lunn writes: > On Tue, Jul 04, 2023 at 04:29:14PM +0800, wei.fang@nxp.com wrote: >> From: Wei Fang >> >> When a XDP program is installed or uninstalled, fec_restart() will >> be invoked to reset MAC and buffer descriptor rings. It's reasonable >> not to transmit any packet during the process of reset. However, the >> NETDEV_XDP_ACT_NDO_XMIT bit of xdp_features is enabled by default, >> that is to say, it's possible that the fec_enet_xdp_xmit() will be >> invoked even if the process of reset is not finished. In this case, >> the redirected XDP frames might be dropped and available transmit BDs >> may be incorrectly deemed insufficient. So this patch disable the >> NETDEV_XDP_ACT_NDO_XMIT feature by default and dynamically configure >> this feature when the bpf program is installed or uninstalled. > > I don't know much about XDP, so please excuse what might be a stupid > question. > > Is this a generic issue? Should this > xdp_features_clear_redirect_target(dev) / > xdp_features_set_redirect_target(dev, false) be done in the core? No, because not all drivers require an XDP program to be attached to support being a redirect target (which is one of the reasons we introduced these feature bits in the first place :)). -Toke