From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55787) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpICX-0006aS-6s for qemu-devel@nongnu.org; Mon, 04 May 2015 11:22:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YpICU-00084q-IA for qemu-devel@nongnu.org; Mon, 04 May 2015 11:22:33 -0400 Received: from e39.co.us.ibm.com ([32.97.110.160]:58428) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YpICU-00084E-8I for qemu-devel@nongnu.org; Mon, 04 May 2015 11:22:30 -0400 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Mon, 4 May 2015 09:22:28 -0600 Received: from b03cxnp08028.gho.boulder.ibm.com (b03cxnp08028.gho.boulder.ibm.com [9.17.130.20]) by d03dlp03.boulder.ibm.com (Postfix) with ESMTP id 36E1419D8026 for ; Mon, 4 May 2015 09:13:30 -0600 (MDT) Received: from d03av01.boulder.ibm.com (d03av01.boulder.ibm.com [9.17.195.167]) by b03cxnp08028.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id t44FM4bZ40960228 for ; Mon, 4 May 2015 08:22:04 -0700 Received: from d03av01.boulder.ibm.com (localhost [127.0.0.1]) by d03av01.boulder.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id t44FMPHw031049 for ; Mon, 4 May 2015 09:22:26 -0600 Message-ID: <55478EB1.3020500@linux.vnet.ibm.com> Date: Mon, 04 May 2015 11:22:25 -0400 From: Stefan Berger MIME-Version: 1.0 References: <1429137528-1069064-1-git-send-email-stefanb@linux.vnet.ibm.com> <20150416153506.3260becd@nial.brq.redhat.com> <552FC1AF.4030208@linux.vnet.ibm.com> <20150422090001.4191222f@nial.brq.redhat.com> <5537E60F.2050106@linux.vnet.ibm.com> <20150429110644.2000ebb8@nial.brq.redhat.com> <554109ED.7050500@linux.vnet.ibm.com> <20150504111602.079dc13b@nial.brq.redhat.com> In-Reply-To: <20150504111602.079dc13b@nial.brq.redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 0/5] Extend TPM support with a QEMU-external TPM List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Igor Mammedov Cc: safford@watson.ibm.com, Kevin O'Connor , qemu-devel@nongnu.org, quan.xu@intel.com, mst@redhat.com On 05/04/2015 05:16 AM, Igor Mammedov wrote: > On Wed, 29 Apr 2015 12:42:21 -0400 > > >> 2 choices now -- which one to take? > I'd try installing extra SSDT table first as a cleanest way (seabios only) > and if it fails fallback to TIS path. I did some experiment where I tried to use AML's Store() call to see whether it can read from some entry in another scope, similar to what the specs show on page 487, so that one could read the base address that is written elsewhere. The problem seems to be that there is no actual searching going on for accessing a scope during runtime, but this seems to be done during compile time. So something like Store(\_SB.I2C1.Y, BUFF) from the specs needs to have a SCOPE(\_SB.I2C1...) available during compile time. Otherwise I am not sure how to go about this. The only way I could think of would be to write a unique and 'recognizeable' address into the AML, something like 0x12345678, try to find it in SeaBIOS and replace it with the actual address. It doesn't seem right, tough. The next best choice would be to paravirtualize the TIS with bytes that survive a reset. Regards, Stefan