From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:58688) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cv5s0-0007Df-BA for qemu-devel@nongnu.org; Mon, 03 Apr 2017 13:34:25 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cv5rw-0003x8-TM for qemu-devel@nongnu.org; Mon, 03 Apr 2017 13:34:24 -0400 Received: from mx1.redhat.com ([209.132.183.28]:57628) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1cv5rw-0003wP-NH for qemu-devel@nongnu.org; Mon, 03 Apr 2017 13:34:20 -0400 Date: Mon, 3 Apr 2017 18:34:15 +0100 From: "Dr. David Alan Gilbert" Message-ID: <20170403173415.GC2112@work-vm> References: <1490965817-16913-1-git-send-email-amarnath.valluri@intel.com> <20170403170738.GC2768@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170403170738.GC2768@redhat.com> Subject: Re: [Qemu-devel] [PATCH 0/7] Provide support for the software TPM emulator List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Daniel P. Berrange" Cc: Amarnath Valluri , patrick.ohly@intel.com, qemu-devel@nongnu.org, stefanb@linux.vnet.ibm.com * Daniel P. Berrange (berrange@redhat.com) wrote: > On Fri, Mar 31, 2017 at 04:10:09PM +0300, Amarnath Valluri wrote: > > Briefly, Theses set of patches introduces: > > - new TPM backend driver to support software TPM emulators(swtpm(1)). > > - and few supported fixes/enhancements/cleanup to existing tpm backend code. > > > > The similar idea was initiated earliar(2) by Stefan Berger(CCed) with slightly > > different approach, using CUSE. As swtpm has excellent support for unix domain > > sockets, hence this implementation uses unix domain sockets to communicate with > > swtpm. > > > > When Qemu is configured with 'emulator' tpm backend, it spawns 'swtpm' and > > communicates its via Unix domain sockets. > > I'm not convinced that having QEMU spawning swtpm itself is a desirable > approach, as it means QEMU needs to have all the privileges that swtpm > will need, so that swtpm can inherit them. At the very least I think we > need to have a way to disable this spawning, so it can connect to a > pre-existing swtpm process that's been spawned ahead of time. This will > let us have stricter privilege separation. I agree, just letting something external start the swtpm and using a chardev to talk to it would seem to work wouldn't it? However, generally I prefer this mechanism of avoiding CUSE. Dave > Regards, > Daniel > -- > |: http://berrange.com -o- http://www.flickr.com/photos/dberrange/ :| > |: http://libvirt.org -o- http://virt-manager.org :| > |: http://entangle-photo.org -o- http://search.cpan.org/~danberr/ :| > -- Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK