[PATCH 4/8] hw/i386/intel_iommu: Use memory_region_add_subregion when priority is 0

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

It is pointless to overlap a memory subregion with priority 0.
Use the simpler memory_region_add_subregion() function.

This patch was produced with the following spatch script:

    @@
    expression region;
    expression offset;
    expression subregion;
    @@
    -memory_region_add_subregion_overlap(region, offset, subregion, 0)
    +memory_region_add_subregion(region, offset, subregion)

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 hw/i386/intel_iommu.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/hw/i386/intel_iommu.c b/hw/i386/intel_iommu.c
index 43c94b993b..afa7e07b05 100644
--- a/hw/i386/intel_iommu.c
+++ b/hw/i386/intel_iommu.c
@@ -3363,11 +3363,9 @@ VTDAddressSpace *vtd_find_add_as(IntelIOMMUState *s, PCIBus *bus, int devfn)
          * switch between DMAR & noDMAR by enable/disable
          * corresponding sub-containers
          */
-        memory_region_add_subregion_overlap(&vtd_dev_as->root, 0,
-                                            MEMORY_REGION(&vtd_dev_as->iommu),
-                                            0);
-        memory_region_add_subregion_overlap(&vtd_dev_as->root, 0,
-                                            &vtd_dev_as->nodmar, 0);
+        memory_region_add_subregion(&vtd_dev_as->root, 0,
+                                    MEMORY_REGION(&vtd_dev_as->iommu));
+        memory_region_add_subregion(&vtd_dev_as->root, 0, &vtd_dev_as->nodmar);
 
         vtd_switch_address_space(vtd_dev_as);
     }
@@ -3764,8 +3762,7 @@ static void vtd_realize(DeviceState *dev, Error **errp)
     memory_region_init_alias(&s->mr_sys_alias, OBJECT(s),
                              "vtd-sys-alias", get_system_memory(), 0,
                              memory_region_size(get_system_memory()));
-    memory_region_add_subregion_overlap(&s->mr_nodmar, 0,
-                                        &s->mr_sys_alias, 0);
+    memory_region_add_subregion(&s->mr_nodmar, 0, &s->mr_sys_alias);
     memory_region_add_subregion_overlap(&s->mr_nodmar,
                                         VTD_INTERRUPT_ADDR_FIRST,
                                         &s->mr_ir, 1);
-- 
2.21.0