Re: [virtio-comment] [PATCH] Add virtio rpmb device specification

["Michael S. Tsirkin" <mst@redhat.com>]

On Tue, Jul 30, 2019 at 12:33:17AM +0000, Huang, Yang wrote:
> 
> 
> > -----Original Message-----
> > From: virtio-comment@lists.oasis-open.org [mailto:virtio-comment@lists.oasis-
> > open.org] On Behalf Of Paolo Bonzini
> > Sent: Monday, July 29, 2019 17:19
> > To: Huang, Yang <yang.huang@intel.com>; virtio-dev@lists.oasis-open.org
> > Cc: virtio-comment@lists.oasis-open.org; mst@redhat.com; Zhu, Bing
> > <bing.zhu@intel.com>; Winkler, Tomas <tomas.winkler@intel.com>
> > Subject: Re: [virtio-comment] [PATCH] Add virtio rpmb device specification
> > 
> > On 29/07/19 09:48, Huang Yang wrote:
> > >
> > > But virtualization software like Qemu doesn't provide eMMC/UFS/NVMe
> > > RPMB emulation. It blocks the OS like Trusty or OP-TEE running in a
> > > virtualization environment. For instance, Google right now uses
> > > another way to work around RPMB emulation issue when running Trusty in
> > ARM Qemu:
> > > https://android.googlesource.com/trusty/external/trusty/+/refs/heads/m
> > > aster/test-runner/
> > >
> > > Virtio RPMB standardization will definitely benefit OP-TEE, Google
> > > Trusty TEE, Qemu, OVMF or other modules to develop the RPMB based
> > > secure storage in virtualization.
> > >
> > 
> > Is there any reason to use a new virtio-blk device, and not add this functionality
> > to virtio-blk?
> > 
> > Paolo
> 
> RPMB does not behave as a blk device. It doesn't have block device APIs.
> Current virtio blk features or definitions in spec are mostly useless or inapplicable to virtio rpmb.
> It performs a different behaviors from the operations on a blk device. 
> Key, writer counter or nonce are required to read/write on it.
> If add it to blk device, it will not only cause to a higher complexity, but also cause to two different behaviors on a same device.
> 


Well it seems that current RPMB implementations are all tied to
a storage device, like MMC or NVMe. Why is that and why doesn't
the same logic apply here?

-- 
MST