From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753417AbaHLO7f (ORCPT ); Tue, 12 Aug 2014 10:59:35 -0400 Received: from mga14.intel.com ([192.55.52.115]:18770 "EHLO mga14.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752687AbaHLO7d (ORCPT ); Tue, 12 Aug 2014 10:59:33 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.01,849,1400050800"; d="scan'208";a="575599061" Message-ID: <53EA2BD4.2040903@linux.intel.com> Date: Tue, 12 Aug 2014 07:59:32 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.7.0 MIME-Version: 1.0 To: Amit Shah CC: linux-kernel@vger.kernel.org, Rusty Russell , Virtualization List , kvm list , jgarzik@bitpay.com, duwe@lst.de, Amos Kong , ricardo.neri-calderon@linux.intel.com, tytso@mit.edu, herbert@gondor.apana.org.au Subject: Re: [PATCH 1/1] virtio: rng: add derating factor for use by hwrng core References: <6f2df652355d6e78da846d06e32489b7d9cdfcc2.1407782982.git.amit.shah@redhat.com> <53E93F77.9030305@linux.intel.com> <20140812052759.GI4184@grmbl.mre> In-Reply-To: <20140812052759.GI4184@grmbl.mre> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 08/11/2014 10:27 PM, Amit Shah wrote: > On (Mon) 11 Aug 2014 [15:11:03], H. Peter Anvin wrote: >> On 08/11/2014 11:49 AM, Amit Shah wrote: >>> The khwrngd thread is started when a hwrng device of sufficient >>> quality is registered. The virtio-rng device is backed by the >>> hypervisor, and we trust the hypervisor to provide real entropy. A >>> malicious hypervisor is a scenario that's ruled out, so we are certain >>> the quality of randomness we receive is perfectly trustworthy. Hence, >>> we use 100% for the factor, indicating maximum confidence in the source. >>> >>> Signed-off-by: Amit Shah >> >> It isn't "ruled out", it is just irrelevant: if the hypervisor is >> malicious, the quality of your random number source is the least of your >> problems. > > Yea; I meant ruled out in that sense. Should the commit msg be more > verbose? > Yes, as it is written it is misleading. -hpa