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=-12.9 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,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 6D020C47082 for ; Thu, 3 Jun 2021 13:08:37 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3163A613B8 for ; Thu, 3 Jun 2021 13:08:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3163A613B8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xen.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.136441.252977 (Exim 4.92) (envelope-from ) id 1lon5E-0000FB-7G; Thu, 03 Jun 2021 13:08:24 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 136441.252977; Thu, 03 Jun 2021 13:08:24 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lon5E-0000F4-4B; Thu, 03 Jun 2021 13:08:24 +0000 Received: by outflank-mailman (input) for mailman id 136441; Thu, 03 Jun 2021 13:08:23 +0000 Received: from mail.xenproject.org ([104.130.215.37]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lon5D-0000Er-K7 for xen-devel@lists.xenproject.org; Thu, 03 Jun 2021 13:08:23 +0000 Received: from xenbits.xenproject.org ([104.239.192.120]) by mail.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lon5C-00067e-Im; Thu, 03 Jun 2021 13:08:22 +0000 Received: from [54.239.6.185] (helo=a483e7b01a66.ant.amazon.com) by xenbits.xenproject.org with esmtpsa (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1lon5C-0004fe-DC; Thu, 03 Jun 2021 13:08:22 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=xen.org; s=20200302mail; h=Content-Transfer-Encoding:Content-Type:In-Reply-To: MIME-Version:Date:Message-ID:From:References:Cc:To:Subject; bh=V/LOvSacPDdqLtqOw2ZfOKCaQmjRpIiS9k1Q71jKtt4=; b=54WZDv6fi7pkGFrXvFeXg7yVbt 3xL+WPLBmeyC29ndDdCB4KDEUC+pp765HipK7kQXrK34CrwNFzoviffsXnKWOlS5at3sOqiaDB0L8 /FpBHZvCZHhOG42D1cXKVJIKz93lD1W0zFFj2FI4fcDwaOuKJmXPVyVHNzDecr/Fbbz0=; Subject: Re: [XEN PATCH v2] libxl/arm: provide guests with random seed To: Sergiy Kibrik , xen-devel@lists.xenproject.org Cc: Ian Jackson , Wei Liu References: <20210527085233.69917-1-Sergiy_Kibrik@epam.com> From: Julien Grall Message-ID: <78b26e15-a3ca-e218-9afa-9f443e234260@xen.org> Date: Thu, 3 Jun 2021 14:08:20 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Thunderbird/78.10.2 MIME-Version: 1.0 In-Reply-To: <20210527085233.69917-1-Sergiy_Kibrik@epam.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 7bit Hi, On 27/05/2021 09:52, Sergiy Kibrik wrote: > Pass 128 bytes of random seed via FDT, so that guests' CRNGs are better seeded > early at boot. This is larger than ChaCha20 key size of 32, so each byte of > CRNG state will be mixed 4 times using this seed. There does not seem to be > advantage in larger seed though. > > Depending on its configuration Linux can use the seed as device randomness > or to just quickly initialize CRNG. > In either case this will provide extra randomness to further harden CRNG. > > CC: Julien Grall > Signed-off-by: Sergiy Kibrik Reviewed-by: Julien Grall Ian, Wei, can we get an ack for this patch? Cheers, -- Julien Grall