On Fri, Feb 22, 2019 at 04:16:01PM -0500, Michael S. Tsirkin wrote: > On Fri, Feb 22, 2019 at 07:30:16AM -0800, James Bottomley wrote: > > On Thu, 2019-02-21 at 18:14 -0800, David Tolnay wrote: > > > Add a config TCG_VIRTIO_VTPM which enables a driver providing the > > > guest kernel side of TPM over virtio. > > > > What's the use case for using this over the current non-virtio vTPM?. > > I always thought virtio was about guest to host transport efficiency, > > but the phsical TPM, being connected over a very slow bus, is about as > > inefficient as you can get in that regard, so why do we need to use > > virtio to drive the virtual one? > > I can't say for sure about TPM. > > But generally there are many reasons to do virtio rather than emulating > a hardware device. We already have a xen 'virtioish' TPM driver, so I don't think there is a good reason to block a virtio driver if someone cares about it. There are enough good reasons to prefer virtio to other options, IMHO. Provided it meets the general requirements for new virtio stuff you outlined. Jason
