On Fri, Feb 22, 2019 at 09:31:56PM +0200, Jarkko Sakkinen
wrote:> On Fri, Feb 22, 2019 at 10:23:02AM -0500, Michael S. Tsirkin wrote:
> > On Fri, Feb 22, 2019 at 12:26:10PM +0200, Jarkko Sakkinen wrote:
> > > On Thu, Feb 21, 2019 at 06:14:02PM -0800, David Tolnay wrote:
> > > > Add a config TCG_VIRTIO_VTPM which enables a driver
providing the guest
> > > > kernel side of TPM over virtio.
> > > >
> > > > Use case: TPM support is needed for performing trusted work
from within
> > > > a virtual machine launched by Chrome OS.
> > > >
> > > > Tested inside crosvm, the Chrome OS virtual machine monitor.
Crosvm's
> > > > implementation of the virtio TPM device can be found in
these two source
> > > > files:
> > > >
> > > > -
https://chromium.googlesource.com/chromiumos/platform/crosvm/+/18ce5713e6cb99c40aafec52b67c28ba12a44f31/devices/src/virtio/tpm.rs
> > > > -
https://chromium.googlesource.com/chromiumos/platform/crosvm/+/18ce5713e6cb99c40aafec52b67c28ba12a44f31/tpm2/src/lib.rs
> > >
> > > These files/links do not make sense for kernel testing. Please
remove
> > > them from the next version.
> >
> > To clarify generally for a virtio device we want
> > - guest support
> > - device support
> > - spec
> >
> > If the device is implemented in qemu and guest in linux kernel,
> > then there are lots of people familiar with these
> > programming environments, so sometimes we merge
> > guest and host code even if spec isn't written up at all.
> >
> > If you don't want to do that there's a small number of people
who can
> > properly review code, e.g. I don't think lots of people on this
list are
> > familiar with crosvm. One way to address this would be to build a
QEMU
> > implementation. Another would be to write up a spec. You can do both
> > too :)
>
> I don't really understand your arguments.
>
> /Jarkko
Jarkko, I am not making any argument at all.
I am trying to suggest ways for this driver to get upstream.
And I am saying that while I agree availability of an implementation in
crosvm isn't sufficient, availability of a software device
implementation in QEMU is not an absolute prerequisite for including a
virtio driver in Linux. If there's a virtio spec explaining how to
write one, that can be enough.
--
MST
