iommu/iova: Don't try to copy anchor nodes

Anchor nodes are not reserved IOVAs in the way that copy_reserved_iova()
cares about - while the failure from reserve_iova() is benign since the
target domain will already have its own anchor, we still don't want to
be triggering spurious warnings.

Reported-by: kernel test robot <fengguang.wu@intel.com>
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Fixes: bb68b2fbfb ('iommu/iova: Add rbtree anchor node')
Signed-off-by: Joerg Roedel <jroedel@suse.de>

drivers/iommu/iova.c

@@ -704,6 +704,9 @@ copy_reserved_iova(struct iova_domain *from, struct iova_domain *to)
 		struct iova *iova = rb_entry(node, struct iova, node);
 		struct iova *new_iova;
 
+		if (iova->pfn_lo == IOVA_ANCHOR)
+			continue;
+
 		new_iova = reserve_iova(to, iova->pfn_lo, iova->pfn_hi);
 		if (!new_iova)
 			printk(KERN_ERR "Reserve iova range %lx@%lx failed\n",