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authorJon Derrick <jonathan.derrick@intel.com>2017-08-31 00:05:59 +0300
committerBjorn Helgaas <bhelgaas@google.com>2017-08-31 00:43:58 +0300
commit5823e330b58c52d74bcf4588626863994a53f6d9 (patch)
tree5effe977542a89c5ab0d0d1172459027ae350ee3 /drivers
parentc37f23d44e866d079d30399cb358dd19617562a1 (diff)
downloadlinux-5823e330b58c52d74bcf4588626863994a53f6d9.tar.xz
iommu/vt-d: Prevent VMD child devices from being remapping targets
VMD child devices must use the VMD endpoint's ID as the requester. Because of this, there needs to be a way to link the parent VMD endpoint's IOMMU group and associated mappings to the VMD child devices such that attaching and detaching child devices modify the endpoint's mappings, while preventing early detaching on a singular device removal or unbinding. The reassignment of individual VMD child devices devices to VMs is outside the scope of VMD, but may be implemented in the future. For now it is best to prevent any such attempts. Prevent VMD child devices from returning an IOMMU, which prevents it from exposing an iommu_group sysfs directory and allowing subsequent binding by userspace-access drivers such as VFIO. Signed-off-by: Jon Derrick <jonathan.derrick@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/intel-iommu.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 687f18f65cea..2800a6ee8cc9 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -901,6 +901,13 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf
struct pci_dev *pf_pdev;
pdev = to_pci_dev(dev);
+
+#ifdef CONFIG_X86
+ /* VMD child devices currently cannot be handled individually */
+ if (is_vmd(pdev->bus))
+ return NULL;
+#endif
+
/* VFs aren't listed in scope tables; we need to look up
* the PF instead to find the IOMMU. */
pf_pdev = pci_physfn(pdev);