memory: provide IOMMU_NOTIFIER_FOREACH macro

A new macro is provided to iterate all the IOMMU notifiers hooked
under specific IOMMU memory region.
Reviewed-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NEric Auger <eric.auger@redhat.com>
Reviewed-by: N\"Michael S. Tsirkin\" <mst@redhat.com>
Signed-off-by: NPeter Xu <peterx@redhat.com>
Message-Id: <1491562755-23867-3-git-send-email-peterx@redhat.com>
Signed-off-by: NEduardo Habkost <ehabkost@redhat.com>

include/exec/memory.h

@@ -239,6 +239,9 @@ struct MemoryRegion {
     IOMMUNotifierFlag iommu_notify_flags;
 };
 
+#define IOMMU_NOTIFIER_FOREACH(n, mr) \
+    QLIST_FOREACH((n), &(mr)->iommu_notify, node)
+
 /**
  * MemoryListener: callbacks structure for updates to the physical memory map
  *

memory.c

@@ -1583,7 +1583,7 @@ static void memory_region_update_iommu_notify_flags(MemoryRegion *mr)
     IOMMUNotifierFlag flags = IOMMU_NOTIFIER_NONE;
     IOMMUNotifier *iommu_notifier;
 
-    QLIST_FOREACH(iommu_notifier, &mr->iommu_notify, node) {
+    IOMMU_NOTIFIER_FOREACH(iommu_notifier, mr) {
         flags |= iommu_notifier->notifier_flags;
     }
 
@@ -1667,7 +1667,7 @@ void memory_region_notify_iommu(MemoryRegion *mr,
         request_flags = IOMMU_NOTIFIER_UNMAP;
     }
 
-    QLIST_FOREACH(iommu_notifier, &mr->iommu_notify, node) {
+    IOMMU_NOTIFIER_FOREACH(iommu_notifier, mr) {
         /*
          * Skip the notification if the notification does not overlap
          * with registered range.