iommu/vt-d: Avoid caching stale domain_device_info and fix memory leak

Function device_notifier() in intel-iommu.c fails to remove
device_domain_info data structures for PCI devices if they are
associated with si_domain because iommu_no_mapping() returns true
for those PCI devices. This will cause memory leak and caching of
stale information in domain->devices list.

So fix the issue by not calling iommu_no_mapping() and skipping check
of iommu_pass_through.

Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com>
Signed-off-by: Joerg Roedel <joro@8bytes.org>

drivers/iommu/intel-iommu.c

@@ -3600,14 +3600,14 @@ static int device_notifier(struct notifier_block *nb,
 	struct pci_dev *pdev = to_pci_dev(dev);
 	struct dmar_domain *domain;
 
-	if (iommu_no_mapping(dev))
+	if (iommu_dummy(pdev))
 		return 0;
 
 	domain = find_domain(pdev);
 	if (!domain)
 		return 0;
 
-	if (action == BUS_NOTIFY_UNBOUND_DRIVER && !iommu_pass_through) {
+	if (action == BUS_NOTIFY_UNBOUND_DRIVER) {
 		domain_remove_one_dev_info(domain, pdev);
 
 		if (!(domain->flags & DOMAIN_FLAG_VIRTUAL_MACHINE) &&