iommu/vt-d: Create RMRR mappings in newly allocated domains

Currently the RMRR entries are created only at boot time.
This means they will vanish when the domain allocated at
boot time is destroyed.
This patch makes sure that also newly allocated domains will
get RMRR mappings.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 24d3109..6ac6e74 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -3241,7 +3241,10 @@
 
 static struct dmar_domain *__get_valid_domain_for_dev(struct device *dev)
 {
+	struct dmar_rmrr_unit *rmrr;
 	struct dmar_domain *domain;
+	struct device *i_dev;
+	int i, ret;
 
 	domain = get_domain_for_dev(dev, DEFAULT_DOMAIN_ADDRESS_WIDTH);
 	if (!domain) {
@@ -3250,6 +3253,23 @@
 		return NULL;
 	}
 
+	/* We have a new domain - setup possible RMRRs for the device */
+	rcu_read_lock();
+	for_each_rmrr_units(rmrr) {
+		for_each_active_dev_scope(rmrr->devices, rmrr->devices_cnt,
+					  i, i_dev) {
+			if (i_dev != dev)
+				continue;
+
+			ret = domain_prepare_identity_map(dev, domain,
+							  rmrr->base_address,
+							  rmrr->end_address);
+			if (ret)
+				dev_err(dev, "Mapping reserved region failed\n");
+		}
+	}
+	rcu_read_unlock();
+
 	return domain;
 }