Re: [PATCH v6 2/2] PCI: Rename pci_dev->untrusted to pci_dev->untrusted_dma

From: Lu Baolu
Date: Tue Apr 26 2022 - 05:44:47 EST


On 2022/4/26 08:06, Rajat Jain wrote:
Rename the field to make it more clear, that the device can execute DMA
attacks on the system, and thus the system may need protection from
such attacks from this device.

No functional change intended.

Signed-off-by: Rajat Jain <rajatja@xxxxxxxxxx>
Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---
v6: No change in this patch, rebased on top of changes in other patch.
v5: Use "untrusted_dma" as property name, based on feedback.
Reorder the patches in the series.
v4: Initial version, created based on comments on other patch

drivers/iommu/dma-iommu.c | 6 +++---
drivers/iommu/intel/iommu.c | 2 +-
drivers/iommu/iommu.c | 2 +-
drivers/pci/ats.c | 2 +-
drivers/pci/pci-acpi.c | 2 +-
drivers/pci/pci.c | 2 +-
drivers/pci/probe.c | 8 ++++----
drivers/pci/quirks.c | 2 +-
include/linux/pci.h | 5 +++--
9 files changed, 16 insertions(+), 15 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 09f6e1c0f9c0..aeee4be7614d 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -497,14 +497,14 @@ static int iova_reserve_iommu_regions(struct device *dev,
return ret;
}
-static bool dev_is_untrusted(struct device *dev)
+static bool dev_has_untrusted_dma(struct device *dev)
{
- return dev_is_pci(dev) && to_pci_dev(dev)->untrusted;
+ return dev_is_pci(dev) && to_pci_dev(dev)->untrusted_dma;
}
static bool dev_use_swiotlb(struct device *dev)
{
- return IS_ENABLED(CONFIG_SWIOTLB) && dev_is_untrusted(dev);
+ return IS_ENABLED(CONFIG_SWIOTLB) && dev_has_untrusted_dma(dev);
}
/**
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index df5c62ecf942..b88f47391140 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4843,7 +4843,7 @@ static bool intel_iommu_is_attach_deferred(struct device *dev)
*/
static bool risky_device(struct pci_dev *pdev)
{
- if (pdev->untrusted) {
+ if (pdev->untrusted_dma) {
pci_info(pdev,
"Skipping IOMMU quirk for dev [%04X:%04X] on untrusted PCI link\n",
pdev->vendor, pdev->device);
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index f2c45b85b9fc..d8d3133e2947 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -1525,7 +1525,7 @@ static int iommu_get_def_domain_type(struct device *dev)
{
const struct iommu_ops *ops = dev_iommu_ops(dev);
- if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted)
+ if (dev_is_pci(dev) && to_pci_dev(dev)->untrusted_dma)
return IOMMU_DOMAIN_DMA;
if (ops->def_domain_type)
diff --git a/drivers/pci/ats.c b/drivers/pci/ats.c
index c967ad6e2626..477c16ba9341 100644
--- a/drivers/pci/ats.c
+++ b/drivers/pci/ats.c
@@ -42,7 +42,7 @@ bool pci_ats_supported(struct pci_dev *dev)
if (!dev->ats_cap)
return false;
- return (dev->untrusted == 0);
+ return (dev->untrusted_dma == 0);
}
EXPORT_SYMBOL_GPL(pci_ats_supported);
diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
index d7c6ba48486f..7c2784e7e954 100644
--- a/drivers/pci/pci-acpi.c
+++ b/drivers/pci/pci-acpi.c
@@ -1395,7 +1395,7 @@ 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_dev->untrusted |= pci_dev_has_dma_property(pci_dev);
+ pci_dev->untrusted_dma |= pci_dev_has_dma_property(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..1fb0eb8646c8 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -958,7 +958,7 @@ static void pci_std_enable_acs(struct pci_dev *dev)
ctrl |= (cap & PCI_ACS_UF);
/* Enable Translation Blocking for external devices and noats */
- if (pci_ats_disabled() || dev->external_facing || dev->untrusted)
+ if (pci_ats_disabled() || dev->external_facing || dev->untrusted_dma)
ctrl |= (cap & PCI_ACS_TB);
pci_write_config_word(dev, pos + PCI_ACS_CTRL, ctrl);
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 17a969942d37..d2a9b26fcede 100644
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -1587,7 +1587,7 @@ static void set_pcie_thunderbolt(struct pci_dev *dev)
dev->is_thunderbolt = 1;
}
-static void set_pcie_untrusted(struct pci_dev *dev)
+static void pci_set_untrusted_dma(struct pci_dev *dev)
{
struct pci_dev *parent;
@@ -1596,8 +1596,8 @@ static void set_pcie_untrusted(struct pci_dev *dev)
* untrusted as well.
*/
parent = pci_upstream_bridge(dev);
- if (parent && (parent->untrusted || parent->external_facing))
- dev->untrusted = true;
+ if (parent && (parent->untrusted_dma || parent->external_facing))
+ dev->untrusted_dma = true;
}
static void pci_set_removable(struct pci_dev *dev)
@@ -1862,7 +1862,7 @@ int pci_setup_device(struct pci_dev *dev)
/* Need to have dev->cfg_size ready */
set_pcie_thunderbolt(dev);
- set_pcie_untrusted(dev);
+ pci_set_untrusted_dma(dev);
/* "Unknown power state" */
dev->current_state = PCI_UNKNOWN;
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 41aeaa235132..583d35968413 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -5135,7 +5135,7 @@ static int pci_quirk_enable_intel_spt_pch_acs(struct pci_dev *dev)
ctrl |= (cap & PCI_ACS_CR);
ctrl |= (cap & PCI_ACS_UF);
- if (pci_ats_disabled() || dev->external_facing || dev->untrusted)
+ if (pci_ats_disabled() || dev->external_facing || dev->untrusted_dma)
ctrl |= (cap & PCI_ACS_TB);
pci_write_config_dword(dev, pos + INTEL_SPT_ACS_CTRL, ctrl);
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 60adf42460ab..2453a794bdb2 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -444,13 +444,14 @@ struct pci_dev {
unsigned int shpc_managed:1; /* SHPC owned by shpchp */
unsigned int is_thunderbolt:1; /* Thunderbolt controller */
/*
- * Devices marked being untrusted are the ones that can potentially
+ * Devices marked with untrusted_dma are the ones that can potentially
* execute DMA attacks and similar. They are typically connected
* through external ports such as Thunderbolt but not limited to
* that. When an IOMMU is enabled they should be getting full
* mappings to make sure they cannot access arbitrary memory.
*/
- unsigned int untrusted:1;
+ unsigned int untrusted_dma:1;
+
/*
* Info from the platform, e.g., ACPI or device tree, may mark a
* device as "external-facing". An external-facing device is

Reviewed-by: Lu Baolu <baolu.lu@xxxxxxxxxxxxxxx>

Thanks,
-baolu