Work around broken devices and adhere to ACS support when determining
IOMMU grouping.
Signed-off-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
---
drivers/iommu/intel-iommu.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index d42ce10..c26d21b 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -4090,6 +4090,8 @@ static int intel_iommu_domain_has_cap(struct iommu_domain *domain,
return 0;
}
+#define PCI_ACS_ENABLED (PCI_ACS_SV | PCI_ACS_RR | PCI_ACS_CR | PCI_ACS_UF)
+
static int intel_iommu_add_device(struct device *dev)
{
struct pci_dev *pdev = to_pci_dev(dev);
@@ -4116,6 +4118,22 @@ static int intel_iommu_add_device(struct device *dev)
dma_pdev = pci_get_slot(pdev->bus,
PCI_DEVFN(PCI_SLOT(pdev->devfn), 0));
+ dma_pdev = pci_dma_source(dma_pdev);
+
+ if (dma_pdev->multifunction &&
+ !pci_acs_enabled(dma_pdev, PCI_ACS_ENABLED))
+ dma_pdev = pci_get_slot(dma_pdev->bus,
+ PCI_DEVFN(PCI_SLOT(dma_pdev->devfn),
+ 0));
+
+ while (!pci_is_root_bus(dma_pdev->bus)) {
+ if (pci_acs_path_enabled(dma_pdev->bus->self,
+ NULL, PCI_ACS_ENABLED))
+ break;
+
+ dma_pdev = dma_pdev->bus->self;
+ }
+
group = iommu_group_get(&dma_pdev->dev);
if (!group) {
group = iommu_group_alloc();
--
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