4 files changed, 46 insertions, 14 deletions

diff --git a/exec.c b/exec.c
index bad16e0..11e0328 100644
--- a/exec.c
+++ b/exec.c
@@ -1090,14 +1090,6 @@ error:
     }
     return NULL;
 }
-#else
-static void *file_ram_alloc(RAMBlock *block,
-                            ram_addr_t memory,
-                            const char *path)
-{
-    fprintf(stderr, "-mem-path not supported on this host\n");
-    exit(1);
-}
 #endif
 
 static ram_addr_t find_ram_offset(ram_addr_t size)
@@ -1287,6 +1279,7 @@ static ram_addr_t ram_block_add(RAMBlock *new_block)
     return new_block->offset;
 }
 
+#ifdef __linux__
 ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
                                     const char *mem_path)
 {
@@ -1315,6 +1308,7 @@ ram_addr_t qemu_ram_alloc_from_file(ram_addr_t size, MemoryRegion *mr,
     new_block->host = file_ram_alloc(new_block, size, mem_path);
     return ram_block_add(new_block);
 }
+#endif
 
 ram_addr_t qemu_ram_alloc_from_ptr(ram_addr_t size, void *host,
                                    MemoryRegion *mr)
diff --git a/include/exec/memory.h b/include/exec/memory.h
index f4c8d49..65ddb7a 100644
--- a/include/exec/memory.h
+++ b/include/exec/memory.h
@@ -311,6 +311,24 @@ void memory_region_init_ram(MemoryRegion *mr,
                             const char *name,
                             uint64_t size);
 
+#ifdef __linux__
+/**
+ * memory_region_init_ram_from_file:  Initialize RAM memory region with a
+ *                                    mmap-ed backend.
+ *
+ * @mr: the #MemoryRegion to be initialized.
+ * @owner: the object that tracks the region's reference count
+ * @name: the name of the region.
+ * @size: size of the region.
+ * @path: the path in which to allocate the RAM.
+ */
+void memory_region_init_ram_from_file(MemoryRegion *mr,
+                                      struct Object *owner,
+                                      const char *name,
+                                      uint64_t size,
+                                      const char *path);
+#endif
+
 /**
  * memory_region_init_ram_ptr:  Initialize RAM memory region from a
  *                              user-provided pointer.  Accesses into the
diff --git a/memory.c b/memory.c
index 063effe..09f98fc 100644
--- a/memory.c
+++ b/memory.c
@@ -1030,13 +1030,24 @@ void memory_region_init_ram(MemoryRegion *mr,
     mr->ram = true;
     mr->terminates = true;
     mr->destructor = memory_region_destructor_ram;
-    if (mem_path) {
-        mr->ram_addr = qemu_ram_alloc_from_file(size, mr, mem_path);
-    } else {
-        mr->ram_addr = qemu_ram_alloc(size, mr);
-    }
+    mr->ram_addr = qemu_ram_alloc(size, mr);
 }
 
+#ifdef __linux__
+void memory_region_init_ram_from_file(MemoryRegion *mr,
+                                      struct Object *owner,
+                                      const char *name,
+                                      uint64_t size,
+                                      const char *path)
+{
+    memory_region_init(mr, owner, name, size);
+    mr->ram = true;
+    mr->terminates = true;
+    mr->destructor = memory_region_destructor_ram;
+    mr->ram_addr = qemu_ram_alloc_from_file(size, mr, path);
+}
+#endif
+
 void memory_region_init_ram_ptr(MemoryRegion *mr,
                                 Object *owner,
                                 const char *name,
diff --git a/numa.c b/numa.c
index b24bb9d..7c36bb5 100644
--- a/numa.c
+++ b/numa.c
@@ -228,7 +228,16 @@ static void allocate_system_memory_nonnuma(MemoryRegion *mr, Object *owner,
                                            const char *name,
                                            uint64_t ram_size)
 {
-    memory_region_init_ram(mr, owner, name, ram_size);
+    if (mem_path) {
+#ifdef __linux__
+        memory_region_init_ram_from_file(mr, owner, name, ram_size, mem_path);
+#else
+        fprintf(stderr, "-mem-path not supported on this host\n");
+        exit(1);
+#endif
+    } else {
+        memory_region_init_ram(mr, owner, name, ram_size);
+    }
     vmstate_register_ram_global(mr);
 }