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=-6.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 EF418C4338F for ; Wed, 4 Aug 2021 07:37:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D252160EBC for ; Wed, 4 Aug 2021 07:37:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235817AbhHDHiB (ORCPT ); Wed, 4 Aug 2021 03:38:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:40756 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235791AbhHDHiA (ORCPT ); Wed, 4 Aug 2021 03:38:00 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 2B2AE60F14; Wed, 4 Aug 2021 07:37:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1628062668; bh=4pPeoZ7MZ2pz0sj8Up9qlptXqfQp3ZBRA9x2+/LZVvU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=YZa9m2sSkGFugCyKTUbUPV4zqRnRTmJRsGUpETkXV/LiPPi3/OAcoBLM7sURJLGAR DTfaxKN0/DWzw2Hzl4OOpcAQ/p1/zuRXP72noYlS8fadv+oKc2rfDHtcq2UAjAgtG8 UPUCHvN0zipyF/P6KrN7HI+avlZfsjL2qOPk21U0= Date: Wed, 4 Aug 2021 09:37:45 +0200 From: Greg KH To: Russ Weight Cc: Tom Rix , Moritz Fischer , linux-fpga@vger.kernel.org, moritzf@google.com Subject: Re: [PATCH 02/12] fpga: sec-mgr: enable secure updates Message-ID: References: <20210517023200.52707-1-mdf@kernel.org> <20210517023200.52707-3-mdf@kernel.org> <5d0552ce-d2bd-cca1-006e-8f11991fd378@intel.com> <85cd4801-ca1f-4482-6999-3d2e648b24e5@intel.com> <3ba35b3c-3c85-394b-f404-130968587a6f@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3ba35b3c-3c85-394b-f404-130968587a6f@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-fpga@vger.kernel.org On Tue, Aug 03, 2021 at 12:02:24PM -0700, Russ Weight wrote: > > > On 8/2/21 10:49 PM, Greg KH wrote: > >> If the request_firmware() implementation is not acceptable, then would > >> you agree that an IOCTL implementation is our best option? > > There is no difference in the end between using an ioctl, or a sysfs > > file, to provide the filename of your firmware, don't get hung up on > > that. > > I meant to suggest that passing file data (not a filename) through an > IOCTL might be better for this use case than trying to use request_firmware. > We have to, somehow, allow the user to point us to the desired image > data (which could be a root-entry-hash, or an FPGA image). We can't > really use a fixed filename modified by device version as many of > the devices do. Ah, yes, a "normal" write command might be best for this as that can be properly containerized and controlled. > > By providing a "filename", you are going around all of the namespace and > > other "container" protection that the kernel provides, and allowing > > processes to potentially load files that are normally outside of their > > scope to the hardware. If you are willing to allow that security > > "escape", wonderful, but you better document the heck out of it and > > explain why this is allowed for your special hardware and use case. > > > > As you are expecting this to work "in the cloud", I do not think that > > the operators of such hardware are really going to be all that happy to > > see this type of interface given these reasons. > > > > What is wrong with the current fpga firmware api that somehow is lacking > > for your special hardware, that other devices do not have to worry > > about? > The existing framework wants to update the live image in the FPGA, > whereas for this device, we are passing signed data to BMC firmware > which will store it in FLASH to be loaded on a subsequent boot of > the card. > > The existing framework needs to manage FPGA state, whereas for this > device, it is just a transfer of signed data. We also have to handle > a total transfer/authentication time of up to 45 minutes, so we are > using a kernel worker thread for the update. > > Perhaps the name, fpga security manager, is wrong? Maybe something > like fpga_sec_image_xfer is better? It does not sound like this has anything to do with "security", and rather is just a normal firmware upload, so "fpga_image_upload()" perhaps? naming is hard, greg k-h