* Daniel P. Berrange (berra...@redhat.com) wrote: > On Tue, May 02, 2017 at 03:35:48PM -0400, Stefan Berger wrote: > > On 05/02/2017 02:50 PM, Marc-André Lureau wrote: > > > Hi > > > > > > On Tue, May 2, 2017 at 10:25 PM Patrick Ohly <patrick.o...@intel.com > > > <mailto:patrick.o...@intel.com>> wrote: > > > > > > On Tue, 2017-05-02 at 13:19 -0400, Stefan Berger wrote: > > > > On 05/02/2017 01:09 PM, Marc-André Lureau wrote: > > > > > On Tue, May 2, 2017 at 8:59 PM Stefan Berger > > > <stef...@linux.vnet.ibm.com <mailto:stef...@linux.vnet.ibm.com>> > > > > > wrote: > > > > > > > > > >> And who is going to implement that qemu-swtpm? Obviously this > > > discussion > > > > >> doesn't contribute to progress if nobody is doing that in the > > > end. > > > > >> > > > > > The same persons who try to push for that emulated TPM code. > > > The easiest > > > > > approach would be to copy/adapt the swtpm code in qemu, if the > > > licence is > > > > > compatible. I can help with that if there is a consensus it's > > > a better > > > > > approach. > > > > > > > > > > > > It's a matter of time and at least I don't have time for that. > > > > > > Neither do I, and nor (I believe) does Amarnath. The approach with > > > using > > > the existing swtpm project seemed attractive to us exactly because it > > > avoids having to write and maintain more than just the glue code > > > between > > > the two projects. > > > > > > > > > The main argument is not about having more or less code in qemu to > > > maintain, but yes this is a concern (although giving up that maintenance > > > to a seperate project with mostly Stefan-alone isn't a much better > > > alternative). btw, is the project actually used by something else than > > > qemu? (I am not talking about developpers/testing). If not, then it > > > makes sense to make it part of qemu. > > > > The intention would be to use it for RunC as well (plus higher layers > > afterwards): https://github.com/opencontainers/runc/pull/1082 > > > > > > > > But it's mostly a technical reason, to avoid having to rely on a foreign > > > protocol and project with all the compatibility constrains. > > > > I understand. Ideally swtpm-0.1 would be equivalent to 1.0 with all features > > available and no further protocol extensions necessary. In practice that may > > look different. > > > > > > > > In the end, we may decide to start with a separate project, and change > > > it in the future if it's problematic (that would break some cases, such > > > as being able to freely switch the helper). Tbh, I am not so happy with > > > the code quality of swtpm, and I haven't looked closely at libtpms. > > > Having a qemu-swtpm as part of qemu would probably help improve it too, > > > and bring a few more developers for maintainance... > > > > libtpms combines a few source codes with some glue around it. The coding > > style is different for TPM 1.2 and TPM 2 code for example and the code bases > > are in the 10s of thousands of line. In the case of TPM 2 it 'lives from' > > TCG code drops and thus there is no reformatting of source code etc. > > > > If someone wants to get started on qemu-swtpm that's certainly cool but over > > the years it's just been quite difficult to find developers for it to share > > the burden. All that said, someone should state whether this series is a go > > or no-go because of the external project it requires. > > I think it is *good* that it uses the external swtpm project and do not > want to see it reimplemented inside QEMU, particularly with the interest > for swtpm to be used in container contexts via RunC. Such common > infrastructure > for both containers & QEMU will be important given the increasing convergance > of technology across containers & VMs.
I agree; there aren't that many people who understand the details of TPMs, reimplementing one in QEMU isn't something you'd want to do. Dave > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| > -- Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
