@@ -4735,7 +4735,7 @@ static inline bool has_untrusted_dev(void)
struct pci_dev *pdev = NULL;
for_each_pci_dev(pdev)
- if (pdev->untrusted)
+ if (pdev->untrusted || pdev->external_facing)
return true;
return false;
@@ -42,7 +42,7 @@ void pci_set_bus_of_node(struct pci_bus *bus)
} else {
node = of_node_get(bus->self->dev.of_node);
if (node && of_property_read_bool(node, "external-facing"))
- bus->self->untrusted = true;
+ bus->self->external_facing = true;
}
bus->dev.of_node = node;
@@ -1213,22 +1213,23 @@ static void pci_acpi_optimize_delay(struct pci_dev *pdev,
ACPI_FREE(obj);
}
-static void pci_acpi_set_untrusted(struct pci_dev *dev)
+static void pci_acpi_set_external_facing(struct pci_dev *dev)
{
u8 val;
- if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT)
+ if (pci_pcie_type(dev) != PCI_EXP_TYPE_ROOT_PORT &&
+ pci_pcie_type(dev) != PCI_EXP_TYPE_DOWNSTREAM)
return;
if (device_property_read_u8(&dev->dev, "ExternalFacingPort", &val))
return;
/*
- * These root ports expose PCIe (including DMA) outside of the
- * system so make sure we treat them and everything behind as
+ * These root/down ports expose PCIe (including DMA) outside of the
+ * system so make sure we treat everything behind them as
* untrusted.
*/
if (val)
- dev->untrusted = 1;
+ dev->external_facing = 1;
}
static void pci_acpi_setup(struct device *dev)
@@ -1240,7 +1241,7 @@ static void pci_acpi_setup(struct device *dev)
return;
pci_acpi_optimize_delay(pci_dev, adev->handle);
- pci_acpi_set_untrusted(pci_dev);
+ pci_acpi_set_external_facing(pci_dev);
pci_acpi_add_edr_notifier(pci_dev);
pci_acpi_add_pm_notifier(adev, pci_dev);
@@ -1552,7 +1552,7 @@ static void set_pcie_untrusted(struct pci_dev *dev)
* untrusted as well.
*/
parent = pci_upstream_bridge(dev);
- if (parent && parent->untrusted)
+ if (parent && (parent->untrusted || parent->external_facing))
dev->untrusted = true;
}
@@ -432,6 +432,14 @@ struct pci_dev {
* mappings to make sure they cannot access arbitrary memory.
*/
unsigned int untrusted:1;
+ /*
+ * Devices are marked as external-facing using info from platform
+ * (ACPI / devicetree). An external-facing device is still an internal
+ * trusted device, but it faces external untrusted devices. Thus any
+ * devices enumerated downstream an external-facing device is marked
+ * as untrusted.
+ */
+ unsigned int external_facing:1;
unsigned int broken_intx_masking:1; /* INTx masking can't be used */
unsigned int io_window_1k:1; /* Intel bridge 1K I/O windows */
unsigned int irq_managed:1;
The "ExternalFacing" devices (root ports) are still internal devices that sit on the internal system fabric and thus trusted. Currently they were being marked untrusted - likely as an unintended border case. This patch uses the platform flag to identify the external facing devices and then use it to mark any downstream devices as "untrusted". The external-facing devices themselves are left as "trusted". This was discussed here: https://lkml.org/lkml/2020/6/10/1049 Signed-off-by: Rajat Jain <rajatja@google.com> --- drivers/iommu/intel/iommu.c | 2 +- drivers/pci/of.c | 2 +- drivers/pci/pci-acpi.c | 13 +++++++------ drivers/pci/probe.c | 2 +- include/linux/pci.h | 8 ++++++++ 5 files changed, 18 insertions(+), 9 deletions(-)