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=-15.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=unavailable 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 9154AC5519F for ; Wed, 18 Nov 2020 13:17:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C9AD241A6 for ; Wed, 18 Nov 2020 13:17:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726316AbgKRNRi (ORCPT ); Wed, 18 Nov 2020 08:17:38 -0500 Received: from mga05.intel.com ([192.55.52.43]:11571 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725772AbgKRNRh (ORCPT ); Wed, 18 Nov 2020 08:17:37 -0500 IronPort-SDR: 7x7JSKvVVOS42zK5J1dyplKbQulZOHM1wOSfOM4wKBoxWTE1EybgQbw4mUNi3YiZShOgfAvpdc ssL1eC+1bxCA== X-IronPort-AV: E=McAfee;i="6000,8403,9808"; a="255823626" X-IronPort-AV: E=Sophos;i="5.77,486,1596524400"; d="scan'208";a="255823626" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Nov 2020 05:17:33 -0800 IronPort-SDR: +TRcy0i38QNWJDPEf0ciTCwCc6WCnYewt9NBokqVOf0EmemeM2zpmmBIXQuk763RcOxgB7c5RV KrTFtTa8B8Qw== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.77,486,1596524400"; d="scan'208";a="532693442" Received: from marshy.an.intel.com (HELO [10.122.105.143]) ([10.122.105.143]) by fmsmga006.fm.intel.com with ESMTP; 18 Nov 2020 05:17:31 -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> <20201118054718.GB14665@yilunxu-OptiPlex-7050> From: Richard Gong Message-ID: <1713a966-5b0f-4e65-70ee-793d09e53cec@linux.intel.com> Date: Wed, 18 Nov 2020 07:38:31 -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: <20201118054718.GB14665@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-kernel@vger.kernel.org On 11/17/20 11:47 PM, Xu Yilun wrote: > On Tue, Nov 17, 2020 at 09:39:55AM -0600, Richard Gong wrote: >> >> >> 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. > > I'm thinking of the case of inband reprograming, that the QSPI flash > controller itself is embedded in FPGA soft logic, then maybe host still > need to access FPGA on authentication. We can decide whether we should update fpga_region_program_fpga() function when you update for inband reprogramming case. Regards, Richard > > Thanks, > Yilun > >>>> >>>>> 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