On Thu, Sep 30, 2021 at 4:03 AM Michael S. Tsirkin <mst@xxxxxxxxxx> wrote: > > On Wed, Sep 29, 2021 at 06:05:09PM -0700, Kuppuswamy Sathyanarayanan wrote: > > Confidential guest platforms like TDX have a requirement to allow > > only trusted devices. By default the confidential-guest core will > > arrange for all devices to default to unauthorized (via > > dev_default_authorization) in device_initialize(). Since virtio > > driver is already hardened against the attack from the un-trusted host, > > override the confidential computing default unauthorized state > > > > Reviewed-by: Dan Williams <dan.j.williams@xxxxxxxxx> > > Signed-off-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@xxxxxxxxxxxxxxx> > > Architecturally this all looks backwards. IIUC nothing about virtio > makes it authorized or trusted. The driver is hardened, > true, but this should be set at the driver not the device level. That's was my initial reaction to this proposal as well, and I ended up leading Sathya astray from what Greg wanted. Greg rightly points out that the "authorized" attribute from USB and Thunderbolt already exists [1] [2]. So the choice is find an awkward way to mix driver trust with existing bus-local "authorized" mechanisms, or promote the authorized capability to the driver-core. This patch set implements the latter to keep the momentum on the already shipping design scheme to not add to the driver-core maintenance burden. [1]: https://lore.kernel.org/all/YQuaJ78y8j1UmBoz@xxxxxxxxx/ [2]: https://lore.kernel.org/all/YQzF%2FutgrJfbZuHh@xxxxxxxxx/ > And in particular, not all virtio drivers are hardened - > I think at this point blk and scsi drivers have been hardened - so > treating them all the same looks wrong. My understanding was that they have been audited, Sathya?
