Hi Rajat,
On Wed, Jan 19, 2022 at 4:04 PM Rajat Jain <rajatja@xxxxxxxxxx> wrote:
>
> Today the pci_dev->untrusted is set for any devices sitting downstream
> an external facing port (determined via "ExternalFacingPort" property).
> This however, disallows any internal devices to be marked as untrusted.
>
> There are use-cases though, where a platform would like to treat an
> internal device as untrusted (perhaps because it runs untrusted
> firmware, or offers an attack surface by handling untrusted network
> data etc).
>
> This patch introduces a new "UntrustedDevice" property that can be used
> by the firmware to mark any device as untrusted.
>
> Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx>
> ---
> drivers/pci/pci-acpi.c | 13 +++++++++++++
> 1 file changed, 13 insertions(+)
>
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index a42dbf448860..3d9e5fa49451 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -1350,12 +1350,25 @@ static void pci_acpi_set_external_facing(struct pci_dev *dev)
> dev->external_facing = 1;
> }
>
> +static void pci_acpi_set_untrusted(struct pci_dev *dev)
> +{
> + u8 val;
> +
> + if (device_property_read_u8(&dev->dev, "UntrustedDevice", &val))
> + return;
> +
> + /* These PCI devices are not trustworthy */
> + if (val)
> + dev->untrusted = 1;
Should this all be replaced with:
dev->untrusted = device_property_read_bool(&dev->dev, "UntrustedDevice");
?
Also, is this ACPI-specific? Why won't we need this for DT systems (or
do we already have this)?.
Thanks,
Dmitry
