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authorJean-Philippe Brucker <jean-philippe@linaro.org>2020-05-20 17:22:01 +0200
committerJoerg Roedel <jroedel@suse.de>2020-05-27 14:35:41 +0200
commit7a441b2110527851f630144ec76ab8409e1d6c61 (patch)
tree31988a75f053d89f24a343d2ca8925786e459ec4 /drivers/iommu
parent521376741b2c26fe53a1ec24d02da24d477eb739 (diff)
iommu/amd: Use pci_ats_supported()
The pci_ats_supported() function checks if a device supports ATS and is allowed to use it. In addition to checking that the device has an ATS capability and that the global pci=noats is not set (pci_ats_disabled()), it also checks if a device is untrusted. A device is untrusted if it is plugged into an external-facing port such as Thunderbolt and could be spoofing an existing device to exploit weaknesses in the IOMMU configuration. By calling pci_ats_supported() we keep DTE[I]=0 for untrusted devices and abort transactions with Pretranslated Addresses. Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Reviewed-by: Joerg Roedel <jroedel@suse.de> Link: https://lore.kernel.org/r/20200520152201.3309416-3-jean-philippe@linaro.org Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/amd_iommu.c12
1 files changed, 4 insertions, 8 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index 1880811cec33..254f028cd18e 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -291,16 +291,15 @@ static struct iommu_group *acpihid_device_group(struct device *dev)
static bool pci_iommuv2_capable(struct pci_dev *pdev)
{
static const int caps[] = {
- PCI_EXT_CAP_ID_ATS,
PCI_EXT_CAP_ID_PRI,
PCI_EXT_CAP_ID_PASID,
};
int i, pos;
- if (pci_ats_disabled())
+ if (!pci_ats_supported(pdev))
return false;
- for (i = 0; i < 3; ++i) {
+ for (i = 0; i < 2; ++i) {
pos = pci_find_ext_capability(pdev, caps[i]);
if (pos == 0)
return false;
@@ -3028,11 +3027,8 @@ int amd_iommu_device_info(struct pci_dev *pdev,
memset(info, 0, sizeof(*info));
- if (!pci_ats_disabled()) {
- pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_ATS);
- if (pos)
- info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;
- }
+ if (pci_ats_supported(pdev))
+ info->flags |= AMD_IOMMU_DEVICE_FLAG_ATS_SUP;
pos = pci_find_ext_capability(pdev, PCI_EXT_CAP_ID_PRI);
if (pos)