iommu/amd: Update Alias-DTE in update_device_table()

BugLink: http://bugs.launchpad.net/bugs/1615620

commit 3254de6b upstream.

Not doing so might cause IO-Page-Faults when a device uses
an alias request-id and the alias-dte is left in a lower
page-mode which does not cover the address allocated from
the iova-allocator.

Fixes: 492667da ('x86/amd-iommu: Remove amd_iommu_pd_table')
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/iommu/amd_iommu.c

@@ -2324,8 +2324,15 @@ static void update_device_table(struct protection_domain *domain)
 {
 	struct iommu_dev_data *dev_data;
 
-	list_for_each_entry(dev_data, &domain->dev_list, list)
+	list_for_each_entry(dev_data, &domain->dev_list, list) {
 		set_dte_entry(dev_data->devid, domain, dev_data->ats.enabled);
+
+		if (dev_data->devid == dev_data->alias)
+			continue;
+
+		/* There is an alias, update device table entry for it */
+		set_dte_entry(dev_data->alias, domain, dev_data->ats.enabled);
+	}
 }
 
 static void update_domain(struct protection_domain *domain)