intel-iommu: Fix device-to-iommu mapping for PCI-PCI bridges.

When the DMAR table identifies that a PCI-PCI bridge belongs to a given
IOMMU, that means that the bridge and all devices behind it should be
associated with the IOMMU. Not just the bridge itself.

This fixes the device_to_iommu() function accordingly.

(It's broken if you have the same PCI bus numbers in multiple domains,
but this function was always broken in that way; I'll be dealing with
that later).

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>

1 files changed, 6 insertions, 1 deletions

diff --git a/drivers/pci/intel-iommu.c b/drivers/pci/intel-iommu.c
index f3eebd2b2d72..6262c198e56e 100644
--- a/drivers/pci/intel-iommu.c
+++ b/drivers/pci/intel-iommu.c
@@ -477,11 +477,16 @@ static struct intel_iommu *device_to_iommu(u8 bus, u8 devfn)
                 if (drhd->ignored)
                         continue;
 
-                for (i = 0; i < drhd->devices_cnt; i++)
+                for (i = 0; i < drhd->devices_cnt; i++) {
                         if (drhd->devices[i] &&
                             drhd->devices[i]->bus->number == bus &&
                             drhd->devices[i]->devfn == devfn)
                                 return drhd->iommu;
+                        if (drhd->devices[i]->subordinate &&
+                            drhd->devices[i]->subordinate->number <= bus &&
+                            drhd->devices[i]->subordinate->subordinate >= bus)
+                                return drhd->iommu;
+                }
 
                 if (drhd->include_all)
                         return drhd->iommu;