memory: Helpers to copy/free a MemoryRegionSection

In case one wants to create a permanent copy of a MemoryRegionSections,
one needs access to flatview_ref()/flatview_unref(). Instead of exposing
these, let's just add helpers to copy/free a MemoryRegionSection and
properly adjust references.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Alex Williamson <alex.williamson@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Igor Mammedov <imammedo@redhat.com>
Cc: Pankaj Gupta <pankaj.gupta.linux@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Auger Eric <eric.auger@redhat.com>
Cc: Wei Yang <richard.weiyang@linux.alibaba.com>
Cc: teawater <teawaterz@linux.alibaba.com>
Cc: Marek Kedzierski <mkedzier@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20210413095531.25603-3-david@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>

1 files changed, 27 insertions, 0 deletions

diff --git a/softmmu/memory.c b/softmmu/memory.c
index d20a9dec44..cea2f622c9 100644
--- a/softmmu/memory.c
+++ b/softmmu/memory.c
@@ -2701,6 +2701,33 @@ MemoryRegionSection memory_region_find(MemoryRegion *mr,
     return ret;
 }
 
+MemoryRegionSection *memory_region_section_new_copy(MemoryRegionSection *s)
+{
+    MemoryRegionSection *tmp = g_new(MemoryRegionSection, 1);
+
+    *tmp = *s;
+    if (tmp->mr) {
+        memory_region_ref(tmp->mr);
+    }
+    if (tmp->fv) {
+        bool ret  = flatview_ref(tmp->fv);
+
+        g_assert(ret);
+    }
+    return tmp;
+}
+
+void memory_region_section_free_copy(MemoryRegionSection *s)
+{
+    if (s->fv) {
+        flatview_unref(s->fv);
+    }
+    if (s->mr) {
+        memory_region_unref(s->mr);
+    }
+    g_free(s);
+}
+
 bool memory_region_present(MemoryRegion *container, hwaddr addr)
 {
     MemoryRegion *mr;