iommu/vt-d: Use pci_real_dma_dev() for mapping

The PCI device may have a DMA requester on another bus, such as VMD
subdevices needing to use the VMD endpoint.  This case requires the real
DMA device for the IOMMU mapping, so use pci_real_dma_dev() to find that
device.

Link: https://lore.kernel.org/r/1579613871-301529-5-git-send-email-jonathan.derrick@intel.com
Signed-off-by: Jon Derrick <jonathan.derrick@intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>

diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 0c8d81f..72f26e8 100644 (file)
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -782,6 +782,8 @@ static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devf
                        return NULL;
 #endif
 
+               pdev = pci_real_dma_dev(pdev);
+
                /* VFs aren't listed in scope tables; we need to look up
                 * the PF instead to find the IOMMU. */
                pf_pdev = pci_physfn(pdev);
@@ -2428,6 +2430,9 @@ static struct dmar_domain *find_domain(struct device *dev)
                     dev->archdata.iommu == DUMMY_DEVICE_DOMAIN_INFO))
                return NULL;
 
+       if (dev_is_pci(dev))
+               dev = &pci_real_dma_dev(to_pci_dev(dev))->dev;
+
        /* No lock here, assumes no domain exit in normal case */
        info = dev->archdata.iommu;
        if (likely(info))