Messages in this thread | | | From | Rajat Jain <> | Date | Thu, 20 Jan 2022 07:08:06 -0800 | Subject | Re: [PATCH] PCI: ACPI: Allow internal devices to be marked as untrusted |
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Hi Dmitry, Bjorn,
Thanks for your review and comments.
On Wed, Jan 19, 2022 at 6:25 PM Dmitry Torokhov <dtor@google.com> wrote: > > Hi Rajat, > > On Wed, Jan 19, 2022 at 4:04 PM Rajat Jain <rajatja@google.com> 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@google.com> > > --- > > 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"); > > ?
Ack, yes, I will do this.
> > Also, is this ACPI-specific? Why won't we need this for DT systems (or > do we already have this)?.
Good point. Ack, Yes, I don't mind doing this for DT systems also. I wanted to get some feedback and acceptance within the PCI subsystem on the general idea of this property though. Bjorn?
Thanks & Best Regards,
Rajat
> > Thanks, > Dmitry
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