memory: add getter for owner

Whenever memory regions are accessed outside the BQL, they need to be
preserved against hot-unplug.  MemoryRegions actually do not have their
own reference count; they piggyback on a QOM object, their "owner".
The owner is set at creation time, and there is a function to retrieve
the owner.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/include/exec/memory.h b/include/exec/memory.h
index 3f48f076396a5ad450f306734abc79080a545b77..2f3e8e426d32245bba572111a60d2fbee68d508f 100644 (file)
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -381,6 +381,13 @@ void memory_region_init_iommu(MemoryRegion *mr,
  */
 void memory_region_destroy(MemoryRegion *mr);
 
+/**
+ * memory_region_owner: get a memory region's owner.
+ *
+ * @mr: the memory region being queried.
+ */
+struct Object *memory_region_owner(MemoryRegion *mr);
+
 /**
  * memory_region_size: get a memory region's size.
  *

diff --git a/memory.c b/memory.c
index 56ef4bae4e46a0679049f6b20575dc78755ff61d..f85774a11ffb214f4264cdb547d515dac22151c3 100644 (file)
--- a/memory.c
+++ b/memory.c
@@ -738,6 +738,7 @@ void memory_region_init(MemoryRegion *mr,
     mr->owner = owner;
     mr->iommu_ops = NULL;
     mr->parent = NULL;
+    mr->owner = NULL;
     mr->size = int128_make64(size);
     if (size == UINT64_MAX) {
         mr->size = int128_2_64();
@@ -1013,6 +1014,11 @@ void memory_region_destroy(MemoryRegion *mr)
     g_free(mr->ioeventfds);
 }
 
+Object *memory_region_owner(MemoryRegion *mr)
+{
+    return mr->owner;
+}
+
 uint64_t memory_region_size(MemoryRegion *mr)
 {
     if (int128_eq(mr->size, int128_2_64())) {