Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966608AbcCPMLU (ORCPT ); Wed, 16 Mar 2016 08:11:20 -0400 Received: from mga02.intel.com ([134.134.136.20]:41364 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965880AbcCPMLS (ORCPT ); Wed, 16 Mar 2016 08:11:18 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.24,344,1455004800"; d="scan'208";a="67409396" Date: Wed, 16 Mar 2016 14:09:16 +0200 From: Jarkko Sakkinen To: Stefan Berger Cc: tpmdd-devel@lists.sourceforge.net, jgunthorpe@obsidianresearch.com, 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: <20160316120916.GA14820@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1457909680-14085-9-git-send-email-stefanb@linux.vnet.ibm.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: 1112 Lines: 29 On Sun, Mar 13, 2016 at 06:54:38PM -0400, Stefan Berger wrote: > This patch implements a proxy driver for supporting multiple emulated TPMs > in a system. > > The driver implements a device /dev/vtpmx that is used to created > a client device pair /dev/tpmX (e.g., /dev/tpm10) and a server side that > is accessed using a file descriptor returned by an ioctl. > The device /dev/tpmX is the usual TPM device created by the core TPM > driver. Applications or kernel subsystems can send TPM commands to it > and the corresponding server-side file descriptor receives these > commands and delivers them to an emulated TPM. > > Signed-off-by: Stefan Berger > CC: linux-kernel@vger.kernel.org > CC: linux-doc@vger.kernel.org > CC: linux-api@vger.kernel.org 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. /Jarkko