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=-11.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 A4987C2D0E4 for ; Tue, 17 Nov 2020 15:18:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 713ED2465E for ; Tue, 17 Nov 2020 15:18:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728855AbgKQPS5 (ORCPT ); Tue, 17 Nov 2020 10:18:57 -0500 Received: from mga06.intel.com ([134.134.136.31]:54003 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728430AbgKQPS5 (ORCPT ); Tue, 17 Nov 2020 10:18:57 -0500 IronPort-SDR: itqlG4WL4UZc5DRnwBM02PouqFGQTeu81tGC8nbNOYHGSu662oyB1sYqmciugFzHZ+pzh0V1zO e0XRpHyTqvPw== X-IronPort-AV: E=McAfee;i="6000,8403,9808"; a="232558367" X-IronPort-AV: E=Sophos;i="5.77,485,1596524400"; d="scan'208";a="232558367" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 17 Nov 2020 07:18:56 -0800 IronPort-SDR: QnxcYKp0ZsxrXN3O9Up2pMA+5XVfSYi3dreEgkW7vxPfhQ2IbUo9/j9vCsfOix0Tpo8P1ei+Hm IZR2yoZKQd8A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,485,1596524400"; d="scan'208";a="532252459" Received: from marshy.an.intel.com (HELO [10.122.105.143]) ([10.122.105.143]) by fmsmga006.fm.intel.com with ESMTP; 17 Nov 2020 07:18:55 -0800 Subject: Re: [PATCHv1 3/4] dt-bindings: fpga: add authenticate-fpga-config property To: Xu Yilun Cc: Moritz Fischer , trix@redhat.com, linux-fpga@vger.kernel.org, linux-kernel@vger.kernel.org, dinguyen@kernel.org, sridhar.rajagopal@intel.com, Richard Gong References: <1605204403-6663-1-git-send-email-richard.gong@linux.intel.com> <1605204403-6663-4-git-send-email-richard.gong@linux.intel.com> <20201115192106.GB283592@epycbox.lan> <20201116024758.GA6810@yilunxu-OptiPlex-7050> <20201117022453.GA12837@yilunxu-OptiPlex-7050> From: Richard Gong Message-ID: Date: Tue, 17 Nov 2020 09:39:55 -0600 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201117022453.GA12837@yilunxu-OptiPlex-7050> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On 11/16/20 8:24 PM, Xu Yilun wrote: > On Mon, Nov 16, 2020 at 08:14:52AM -0600, Richard Gong wrote: >> >> Hi Yilun, >> >> On 11/15/20 8:47 PM, Xu Yilun wrote: >>> On Sun, Nov 15, 2020 at 11:21:06AM -0800, Moritz Fischer wrote: >>>> Hi Richard, >>>> >>>> On Thu, Nov 12, 2020 at 12:06:42PM -0600, richard.gong@linux.intel.com wrote: >>>>> From: Richard Gong >>>>> >>>>> Add authenticate-fpga-config property for FPGA bitstream authentication. >>>>> >>>>> Signed-off-by: Richard Gong >>>>> --- >>>>> Documentation/devicetree/bindings/fpga/fpga-region.txt | 1 + >>>>> 1 file changed, 1 insertion(+) >>>>> >>>>> diff --git a/Documentation/devicetree/bindings/fpga/fpga-region.txt b/Documentation/devicetree/bindings/fpga/fpga-region.txt >>>>> index e811cf8..7a512bc 100644 >>>>> --- a/Documentation/devicetree/bindings/fpga/fpga-region.txt >>>>> +++ b/Documentation/devicetree/bindings/fpga/fpga-region.txt >>>>> @@ -187,6 +187,7 @@ Optional properties: >>>>> - external-fpga-config : boolean, set if the FPGA has already been configured >>>>> prior to OS boot up. >>>>> - encrypted-fpga-config : boolean, set if the bitstream is encrypted >>>>> +- authenticate-fpga-config : boolean, set if do bitstream authentication >>>> It is unclear to me from the description whether this entails >>>> authentication + reconfiguration or just authentication. >>>> >>>> If the latter is the case this should probably be described as such. >>> >>> If it is just authentication, do we still need to disable bridges in >>> fpga_region_program_fpga? >>> >> >> Yes. >> >> Except for the actual configuration of the device, the authentication >> feature is the same as FPGA configuration. > > FPGA Bridges gate bus signals between a host and FPGA. So the FPGA > region could not be accessed by host when doing configuration. But for > this authentication, we are just writing the flash, we don't actually > touch the FPGA soft logic. The host should still be able to operate on > the old logic before reboot, is it? > Yes, it's feasible in theory but doesn't make much sense in practice. I prefer to keep fpga_region_program_fpga() unchanged. Regards, Richard > Thanks, > Yilun > >> >> Regards, >> Richard >> >>> I'm wondering if the FPGA functionalities could still be working when >>> the authenticating is ongoing, or when the authenticating is failed. >>> >> >> >> >>> Thanks, >>> Yilun >>> >>>> >>>>> - region-unfreeze-timeout-us : The maximum time in microseconds to wait for >>>>> bridges to successfully become enabled after the region has been >>>>> programmed. >>>>> -- >>>>> 2.7.4 >>>>> >>>> >>>> Thanks