From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([140.186.70.92]:55342) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RaSkk-0002y0-2q for qemu-devel@nongnu.org; Tue, 13 Dec 2011 08:50:42 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1RaSki-0003Jl-ON for qemu-devel@nongnu.org; Tue, 13 Dec 2011 08:50:42 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24699) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1RaSki-0003JU-Hd for qemu-devel@nongnu.org; Tue, 13 Dec 2011 08:50:40 -0500 Date: Tue, 13 Dec 2011 15:51:35 +0200 From: "Michael S. Tsirkin" Message-ID: <20111213135135.GC13107@redhat.com> References: <1323717136-21661-1-git-send-email-stefanb@linux.vnet.ibm.com> <4EE68DFF.6050908@codemonkey.ws> <4EE6987F.1000100@linux.vnet.ibm.com> <201112130451.44284.paul@codesourcery.com> <4EE74A45.8000306@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4EE74A45.8000306@linux.vnet.ibm.com> Subject: Re: [Qemu-devel] [PATCH V13 6/7] Introduce --enable-tpm-passthrough configure option List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Stefan Berger Cc: andreas.niederl@iaik.tugraz.at, Paul Brook , qemu-devel@nongnu.org On Tue, Dec 13, 2011 at 07:51:17AM -0500, Stefan Berger wrote: > On 12/12/2011 11:51 PM, Paul Brook wrote: > >>>>+tpm_passthrough="no" > >>>Same as before, please probe for existence. > >>We would be probing for /dev/tpm0. Is that really what we want that this > >>driver only gets compiled if /dev/tpm0 is (currently) available? > >If what you say is true then this code should always be enabled. > > > Michael Tsirkin previously requested that there be an option for the > TPM passthrough driver to be selectively enabled since at least > using /dev/tpm0 may not be what everybody wants. The passthrough > driver at some point will also be able to use sockets to communicate > with a TPM when a file descriptor is passed to Qemu, so maybe that > changes then? > > > Stefan The passthrough as it is, is pretty easy to misuse. This is a hardware problem, not software, and I don't think it's fixable. So I do not think all downstreams will want to support this mode, making it easy to disable this is IMO important. -- MST