From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=56300 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1Q7GMr-0006Ko-23 for qemu-devel@nongnu.org; Tue, 05 Apr 2011 20:13:05 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Q7GMp-0000Tx-T6 for qemu-devel@nongnu.org; Tue, 05 Apr 2011 20:13:04 -0400 Received: from e5.ny.us.ibm.com ([32.97.182.145]:40704) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Q7GMp-0000Tr-OG for qemu-devel@nongnu.org; Tue, 05 Apr 2011 20:13:03 -0400 Received: from d01dlp01.pok.ibm.com (d01dlp01.pok.ibm.com [9.56.224.56]) by e5.ny.us.ibm.com (8.14.4/8.13.1) with ESMTP id p35NlJuv014686 for ; Tue, 5 Apr 2011 19:47:19 -0400 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp01.pok.ibm.com (Postfix) with ESMTP id 5F59938C8038 for ; Tue, 5 Apr 2011 20:12:53 -0400 (EDT) Received: from d01av01.pok.ibm.com (d01av01.pok.ibm.com [9.56.224.215]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id p360CxZh187774 for ; Tue, 5 Apr 2011 20:13:01 -0400 Received: from d01av01.pok.ibm.com (loopback [127.0.0.1]) by d01av01.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p360CwW4013658 for ; Tue, 5 Apr 2011 20:12:59 -0400 Message-ID: <4D9BB00A.5040808@linux.vnet.ibm.com> Date: Tue, 05 Apr 2011 20:12:58 -0400 From: Stefan Berger MIME-Version: 1.0 Subject: Re: [Qemu-devel] [PATCH V2 4/9] Add tpm_tis driver to build process References: <20110330194211.732385449@linux.vnet.ibm.com> <20110330194237.138721858@linux.vnet.ibm.com> <4D962E1C.2000203@linux.vnet.ibm.com> <4D9A79B2.2010502@linux.vnet.ibm.com> <4D9B606C.2090105@linux.vnet.ibm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Blue Swirl Cc: qemu-devel@nongnu.org On 04/05/2011 02:55 PM, Blue Swirl wrote: > On Tue, Apr 5, 2011 at 9:33 PM, Stefan Berger > wrote: >> On 04/05/2011 01:45 PM, Blue Swirl wrote: >>> On Tue, Apr 5, 2011 at 5:08 AM, Stefan Berger >>> wrote: >>>> On 04/03/2011 05:20 AM, Blue Swirl wrote: >>>>> On Fri, Apr 1, 2011 at 10:57 PM, Stefan Berger >>>>> wrote: >>>>>> On 04/01/2011 02:14 PM, Blue Swirl wrote: >>>>>> >>>>>> At this point there is no compile test needed since all code is >>>>>> 'there'. >>>>>> It's merely adding the front-end,i.e., the TPM TIS emulation to be >>>>>> compiled. >>>>> If the basic device (without the tpms-devel library) can be built on >>>>> any OS, the flag should go to default-configs/*86*-softmmu.mak. >>>>> >>>> It can be built on any OS, but it is of no use since the backend >>>> (libtpms) >>>> is only available on Linux and we don't support it on another OS. Unless >>>> someone else wants to port it to other OSes, I'd say that the test for >>>> Linux >>>> is useful. >>>> I'd actually also only compile the TIS if libtpms could be found, and >>>> terminate with an error message otherwise. I would add this restriction >>>> only >>>> in the last patch, so that in patch 4 at least for now the TIS can be >>>> built. >>>> Does that sound reasonable? >>> It should be possible to emulate the device (to some degree) without >>> relying on backend. See for example the recently committed smart card >>> device. >>> >> In case of a TPM, the specs are huge and translate into multiple 10k lines >> of code. If there was to be a dummy backend, all it could send back would be >> error messages... > Then how about emulating the library instead so that all calls return failure? That device would be of no use for a user and only serve the purpose of test-compiling it if it was for detecting bit rot. > If a device is built only in special circumstances, it will be more > prone to bit rot. We have a few such devices though, so it's not so > big deal. > I'll be following the project and there is interest to keep this device working. Stefan