Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756024AbcCPUh6 (ORCPT ); Wed, 16 Mar 2016 16:37:58 -0400 Received: from mga01.intel.com ([192.55.52.88]:7428 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752348AbcCPUhz (ORCPT ); Wed, 16 Mar 2016 16:37:55 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,346,1455004800"; d="scan'208";a="935435258" Date: Wed, 16 Mar 2016 22:37:50 +0200 From: Jarkko Sakkinen To: Jason Gunthorpe Cc: Stefan Berger , tpmdd-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-api@vger.kernel.org, dhowells@redhat.com Subject: Re: [PATCH v8 08/10] tpm: Proxy driver for supporting multiple emulated TPMs Message-ID: <20160316203750.GA23966@intel.com> References: <1457909680-14085-1-git-send-email-stefanb@linux.vnet.ibm.com> <1457909680-14085-9-git-send-email-stefanb@linux.vnet.ibm.com> <20160316120916.GA14820@intel.com> <20160316174904.GA6127@obsidianresearch.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160316174904.GA6127@obsidianresearch.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1015 Lines: 30 On Wed, Mar 16, 2016 at 11:49:04AM -0600, Jason Gunthorpe wrote: > On Wed, Mar 16, 2016 at 02:09:16PM +0200, Jarkko Sakkinen wrote: > > On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote: > > > Alternative to this would be to have /dev/vtpmx create: > > > > * /dev/vtpm0 for the server > > * /dev/tpm0 for the client > > > > This is how David Howell's PoC worked and that's why I want > > to make this alternative visible. > > > > The server could even respawn without container noticing it. > > This solution have better availability properties. > > Seriously, no, that doesn't make any sense. TPM is stateful, you can't > respawn the server side. > > If anyone is ever clever enough to make that workable then they just > go ahead and save the server fd with the other state. systemd for > instance already has everything needed to make that work. > > We don't need to have a server dev node and we certainly don't need > the leaking problem that leaves us with. Fair enough. > Jason /Jarkko