Re: [PATCH] PCI: ACPI: Allow internal devices to be marked as untrusted

[Rafael J. Wysocki]

On Tue, Jan 25, 2022 at 11:59 AM Mika Westerberg
<mika.westerberg@xxxxxxxxxxxxxxx> wrote:
>
> On Mon, Jan 24, 2022 at 08:27:17AM +0200, Mika Westerberg wrote:
> > > > This patch introduces a new "UntrustedDevice" property that can be used
> > > > by the firmware to mark any device as untrusted.
> >
> > I think this new property should be documented somewhere too (also
> > explain when to use it instead of ExternalFacingPort). If not in the
> > next ACPI spec or some supplemental doc then perhaps in the DT bindings
> > under Documentation/devicetree/bindings.
>
> Actually Microsoft has similar already:
>
> https://docs.microsoft.com/en-us/windows-hardware/drivers/pci/dsd-for-pcie-root-ports#identifying-internal-pcie-ports-accessible-to-users-and-requiring-dma-protection
>
> I think we should use that too here.

Agreed.

This is what the platform firmware will need to use anyway for Windows
compatibility and OEMs may not care about running Linux on their
platforms.