iommu/vt-d: Avoid duplicate device_domain_info structures

When a 'struct device_domain_info' is created as an alias
for another device, this struct will not be re-used when the
real device is encountered. Fix that to avoid duplicate
device_domain_info structures being added.

Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/intel-iommu.c

@@ -2270,12 +2270,16 @@ static struct dmar_domain *dmar_insert_one_dev_info(struct intel_iommu *iommu,
 	spin_lock_irqsave(&device_domain_lock, flags);
 	if (dev)
 		found = find_domain(dev);
-	else {
+
+	if (!found) {
 		struct device_domain_info *info2;
 		info2 = dmar_search_domain_by_dev_info(iommu->segment, bus, devfn);
-		if (info2)
-			found = info2->domain;
+		if (info2) {
+			found      = info2->domain;
+			info2->dev = dev;
+		}
 	}
+
 	if (found) {
 		spin_unlock_irqrestore(&device_domain_lock, flags);
 		free_devinfo_mem(info);