From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:51845) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1THjIt-0002dj-Dx for qemu-devel@nongnu.org; Fri, 28 Sep 2012 18:45:04 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1THjIs-0004NY-98 for qemu-devel@nongnu.org; Fri, 28 Sep 2012 18:45:03 -0400 Received: from e6.ny.us.ibm.com ([32.97.182.146]:43060) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1THjIs-0004Hi-4N for qemu-devel@nongnu.org; Fri, 28 Sep 2012 18:45:02 -0400 Received: from /spool/local by e6.ny.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Fri, 28 Sep 2012 18:44:36 -0400 Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay02.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q8SMhnCQ143314 for ; Fri, 28 Sep 2012 18:43:49 -0400 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q8SMhmcJ007595 for ; Fri, 28 Sep 2012 18:43:49 -0400 Message-ID: <50662824.6010203@linux.vnet.ibm.com> Date: Fri, 28 Sep 2012 18:43:48 -0400 From: Stefan Berger MIME-Version: 1.0 References: <1338838668-7544-1-git-send-email-stefanb@linux.vnet.ibm.com> <506469E0.90408@linux.vnet.ibm.com> In-Reply-To: <506469E0.90408@linux.vnet.ibm.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH V19 0/7] Qemu Trusted Platform Module (TPM) integration List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Andreas Niederl , Anthony Liguori , "Michael S. Tsirkin" On 09/27/2012 10:59 AM, Corey Bryant wrote: > > > I reviewed this series and have sent all my comments. In general the > patches look good to me other than the comments I've already made. Thanks for the review. > > The external interfaces (command line and monitor commands) look to be > in good shape. In particular -tpmdev can easily be modified to > support future backend vTPM implementations, such a software vTPM. > And the monitor commands are simple and straight forward (info TPM and > query-TPM with no arguments). > > I haven't had the chance to run any tests with the patch series, but I > plan to soon. In the mean time I have a couple of general questions: > > I understand that the passthrough driver won't support migration. What > happens on a migration attempt? Does it fail gracefully? QEMU refuses to migrate. > > What happens when a 2nd guest attempts to use the passthrough vTPM > after the 1st guest is already using it? Does it also fail gracefully? > Yes, if something blocks /dev/tpm0 then an error message is printed. I may adjust that error message suggesting that something else is using the device. > Are there any architecture dependencies for this support? > There are some specifics for x86: on Linux one has to do 'modprobe tpm_tis force=1' to due missing ACPI support in SeaBIOS so far. I have patches for SeaBIOS. I haven't tried the passthrough driver in VMs running on any other architectures, but I don't see reasons why it shouldn't work. Stefan