iommu/amd: Implement DOMAIN_ATTR_GEOMETRY attribute

Implement the attribute itself and add the code for the
AMD IOMMU driver.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index a2e418c..259a6be 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -3069,6 +3069,10 @@
 
 	dom->priv = domain;
 
+	dom->geometry.aperture_start = 0;
+	dom->geometry.aperture_end   = ~0ULL;
+	dom->geometry.force_aperture = true;
+
 	return 0;
 
 out_free: