From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760962AbYEPU3j (ORCPT ); Fri, 16 May 2008 16:29:39 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752830AbYEPU3a (ORCPT ); Fri, 16 May 2008 16:29:30 -0400 Received: from terminus.zytor.com ([198.137.202.10]:57935 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755375AbYEPU3a (ORCPT ); Fri, 16 May 2008 16:29:30 -0400 Message-ID: <482DEDA5.9080309@zytor.com> Date: Fri, 16 May 2008 13:25:09 -0700 From: "H. Peter Anvin" User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Johannes Berg CC: Rusty Russell , virtualization@lists.linux-foundation.org, Jeff Garzik , Herbert Xu , Christian Borntraeger , LKML Subject: Re: [PATCH 2/2] lguest: virtio-rng support References: <482C8595.5030509@garzik.org> <200805160943.08788.rusty@rustcorp.com.au> <200805161531.44725.rusty@rustcorp.com.au> <200805161539.59739.rusty@rustcorp.com.au> <1210934981.6381.1.camel@johannes.berg> In-Reply-To: <1210934981.6381.1.camel@johannes.berg> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Johannes Berg wrote: >> + >> +/* Our random number generator device reads from /dev/urandom into the Guest's >> + * input buffers. The usual case is that the Guest doesn't want random numbers >> + * and so has no buffers although /dev/urandom is still readable, whereas >> + * console is the reverse. > > Is it really a good idea to use the hosts /dev/urandom to fill the > guests /dev/random? Only if you have an entropy estimate to go with it. It's still dubious, though: the guests own pool will do its own mixing, so you might as well pull from /dev/random in the host as being a genuine entropy source and only add what entropy is available. -hpa