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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 E903CC3B1B9 for ; Fri, 14 Feb 2020 18:31:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BCCA82168B for ; Fri, 14 Feb 2020 18:31:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=android.com header.i=@android.com header.b="I2psfdBn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729430AbgBNSbV (ORCPT ); Fri, 14 Feb 2020 13:31:21 -0500 Received: from mail-pj1-f65.google.com ([209.85.216.65]:51909 "EHLO mail-pj1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729479AbgBNSbV (ORCPT ); Fri, 14 Feb 2020 13:31:21 -0500 Received: by mail-pj1-f65.google.com with SMTP id fa20so4217285pjb.1 for ; Fri, 14 Feb 2020 10:31:20 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=android.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding:content-language; bh=b2tZd1tExc8HDMdHBE3vQFxVxr8Zxh1LCSwV2NCLKvA=; b=I2psfdBnjWffVVztPHbsuO6CJ1Wik63YRMJ7O0UZnYqwXbM0XbThRNVDNh7GFGt4JL m70CeLxJ8CHuU6pM7QNVUuzZizPkY/avCoYD7zSwwE4x6KERh6m95jrh0i4ikiCd8XRY WPcezJytnnIzv3FYja0Zv8mEzFdsDTKHCRBxPwmbEHB6K0wZDWc1FXRkYuX/iM//beDU yN/oHf2wS9u+UmOZVh4lDTXPJZQvK/E35/Q6KyJ6dosvdc0edZzptawqkbxSHv2j2X/X mEMwuXWsi9Hdw6P8gXgL3ZHPcW9ZTVJHBKjYEyVIO6W9jvKmpjrXxVlrsKStqjIQQGfG xOCQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding :content-language; bh=b2tZd1tExc8HDMdHBE3vQFxVxr8Zxh1LCSwV2NCLKvA=; b=fzmL/+2XhgQdNXBzxXLeoyJLfAYbjTJhwTFa0w8uzo8C/zWPBeUNGnQqq5W4HjPVA0 dG7d5Hogbbt8xOz3c96lB2VEeZgFzJF/QUMdKxw8SBnrUiCX1GMzQhDNT+9ujoi2MSSV 1o7MRD4vAaFQYeXSebtVep8B+ScjcANnIWeheqEPeIDNMsW9Dar68VhJY1uueAs+bXuP 6hAWNQls0UdQwMP4TtahQhAYNO9IKBBZrPa7SxdZIv9wTteLGr4iNT8z/LfUXLhu9EPl fiscjTchBRtXp4MZOMeuifKpTIKw3O6a78S5ZnttVCEakOMD8H84Qck0YzJ8GsSLOSwy Jz3w== X-Gm-Message-State: APjAAAW91gzaxryq852HmPZQM7QHoXFvW0/66QXB4EqisablDOTdLljB tJw8zgzkVQgSSRsVlCe5rqz7U4IPFE4= X-Google-Smtp-Source: APXvYqweRvrbcGI+TN/E706xtY2309e9rucgMW2XIhqLYDDV+p9y1XPcO+Pq087xKSbHaBwFV0buhg== X-Received: by 2002:a17:902:a616:: with SMTP id u22mr4596187plq.173.1581705080166; Fri, 14 Feb 2020 10:31:20 -0800 (PST) Received: from nebulus.mtv.corp.google.com ([2620:15c:211:200:5404:91ba:59dc:9400]) by smtp.googlemail.com with ESMTPSA id a10sm782832pgk.71.2020.02.14.10.31.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 14 Feb 2020 10:31:19 -0800 (PST) Subject: Re: [PATCH 0/3] random: add random.rng_seed to bootconfig entry To: Rob Herring Cc: Masami Hiramatsu , "linux-kernel@vger.kernel.org" , Android Kernel Team , Theodore Ts'o , Arnd Bergmann , Greg Kroah-Hartman , Richard Henderson , Mark Brown , Kees Cook , Hsin-Yi Wang , Vasily Gorbik , Andrew Morton , Steven Rostedt , Mike Rapoport , Arvind Sankar , Dominik Brodowski , Thomas Gleixner , Alexander Potapenko , Jonathan Corbet , Mauro Carvalho Chehab , Josh Poimboeuf , Pawan Gupta , Juergen Gross , Linux Doc Mailing List References: <158166060044.9887.549561499483343724.stgit@devnote2> <1694f42c-bfc9-570a-64d2-3984965c8940@android.com> From: Mark Salyzyn Message-ID: <7882e5d2-dd4d-cdfb-2aab-9a3d910882d4@android.com> Date: Fri, 14 Feb 2020 10:31:18 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-GB Sender: linux-doc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On 2/14/20 10:14 AM, Rob Herring wrote: > On Fri, Feb 14, 2020 at 11:00 AM Mark Salyzyn wrote: >> On 2/14/20 5:49 AM, Rob Herring wrote: >>> On Fri, Feb 14, 2020 at 12:10 AM Masami Hiramatsu wrote: >>>> Hi, >>>> >>>> The following series is bootconfig based implementation of >>>> the rng_seed option patch originally from Mark Salyzyn. >>>> Note that I removed unrelated command line fixes from this >>>> series. >>> Why do we need this? There's already multiple other ways to pass >>> random seed and this doesn't pass the "too complex for the command >>> line" argument you had for needing bootconfig. >>> >>> Rob >> Android is the use case I can vouch for. But also KVM. . . . > I'm familiar with Cuttlefish somewhat. Guess who got virtio-gpu > working on Android[1]. :) I assume DT doesn't work for you because you > need x86 builds, but doesn't QEMU use UEFI in that case which also has > a mechanism for passing entropy. IDK, will have to ask the Cuttlefish Team why UEFI not being used, will get back to you. > > To clarify my question: Why do we need random seed in bootconfig > rather than just the kernel command line? I'm not understanding why > things changed from your original patch. Command line was identified as the simplest for them to implement generically for the x86 and arm64 Cuttlefish instances and hence my original patch series. However, it also is limited in the size of the entropy string that can be provided, so we flipped a coin and decided to accept the bootconfig mechanism as a viable alternative; that BTW appeared to be simpler to implement (mainly because rubbing out the entropy command line argument is not easy). -- Mark