On Tue, Feb 08, 2022 at 04:23:27PM -0800, Rajat Jain wrote: > Hello Folks, > > > On Tue, Feb 1, 2022 at 6:01 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" or the > > "external-facing" properties). > > > > However, currently there is no way for 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). > > > > Introduce a new "UntrustedDevice" property that can be used by the > > firmware to mark any device as untrusted. > > Just to unite the threads (from > https://www.spinics.net/lists/linux-pci/msg120221.html). I did reach > out to Microsoft but they haven't acknowledged my email. I also pinged > them again yesterday, but I suspect I may not be able to break the > ice. So this patch may be ready to go in my opinion. > > I don't see any outstanding comments on this patch, but please let me > know if you have any comments. > > Thanks & Best Regards, > > Rajat > > > > > > Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx> > > --- > > v2: * Also use the same property for device tree based systems. > > * Add documentation (next patch) > > > > drivers/pci/of.c | 2 ++ > > drivers/pci/pci-acpi.c | 1 + > > drivers/pci/pci.c | 9 +++++++++ > > drivers/pci/pci.h | 2 ++ > > 4 files changed, 14 insertions(+) > > > > diff --git a/drivers/pci/of.c b/drivers/pci/of.c > > index cb2e8351c2cc..e8b804664b69 100644 > > --- a/drivers/pci/of.c > > +++ b/drivers/pci/of.c > > @@ -24,6 +24,8 @@ void pci_set_of_node(struct pci_dev *dev) > > dev->devfn); > > if (dev->dev.of_node) > > dev->dev.fwnode = &dev->dev.of_node->fwnode; > > + > > + pci_set_untrusted(dev); > > } > > > > void pci_release_of_node(struct pci_dev *dev) > > diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c > > index a42dbf448860..2bffbd5c6114 100644 > > --- a/drivers/pci/pci-acpi.c > > +++ b/drivers/pci/pci-acpi.c > > @@ -1356,6 +1356,7 @@ void pci_acpi_setup(struct device *dev, struct acpi_device *adev) > > > > pci_acpi_optimize_delay(pci_dev, adev->handle); > > pci_acpi_set_external_facing(pci_dev); > > + pci_set_untrusted(pci_dev); > > pci_acpi_add_edr_notifier(pci_dev); > > > > pci_acpi_add_pm_notifier(adev, pci_dev); > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > > index 9ecce435fb3f..41e887c27004 100644 > > --- a/drivers/pci/pci.c > > +++ b/drivers/pci/pci.c > > @@ -6869,3 +6869,12 @@ static int __init pci_realloc_setup_params(void) > > return 0; > > } > > pure_initcall(pci_realloc_setup_params); > > + > > +void pci_set_untrusted(struct pci_dev *pdev) > > +{ > > + u8 val; > > + > > + if (!device_property_read_u8(&pdev->dev, "UntrustedDevice", &val) Please no, "Untrusted" does not really convey much, if anything here. You are taking an odd in-kernel-value and making it a user api. Where is this "trust" defined? Who defines it? What policy does the kernel impose on it? By putting this value in a firmware requirement like this, it better be documented VERY VERY well. thanks, greg k-h
