1 files changed, 40 insertions, 1 deletions

diff --git a/backends/hostmem-file.c b/backends/hostmem-file.c
index e44c319915..e319ec1ad8 100644
--- a/backends/hostmem-file.c
+++ b/backends/hostmem-file.c
@@ -34,6 +34,7 @@ struct HostMemoryBackendFile {
     bool share;
     bool discard_data;
     char *mem_path;
+    uint64_t align;
 };
 
 static void
@@ -58,7 +59,7 @@ file_backend_memory_alloc(HostMemoryBackend *backend, Error **errp)
         path = object_get_canonical_path(OBJECT(backend));
         memory_region_init_ram_from_file(&backend->mr, OBJECT(backend),
                                  path,
-                                 backend->size, fb->share,
+                                 backend->size, fb->align, fb->share,
                                  fb->mem_path, errp);
         g_free(path);
     }
@@ -115,6 +116,40 @@ static void file_memory_backend_set_discard_data(Object *o, bool value,
     MEMORY_BACKEND_FILE(o)->discard_data = value;
 }
 
+static void file_memory_backend_get_align(Object *o, Visitor *v,
+                                          const char *name, void *opaque,
+                                          Error **errp)
+{
+    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
+    uint64_t val = fb->align;
+
+    visit_type_size(v, name, &val, errp);
+}
+
+static void file_memory_backend_set_align(Object *o, Visitor *v,
+                                          const char *name, void *opaque,
+                                          Error **errp)
+{
+    HostMemoryBackend *backend = MEMORY_BACKEND(o);
+    HostMemoryBackendFile *fb = MEMORY_BACKEND_FILE(o);
+    Error *local_err = NULL;
+    uint64_t val;
+
+    if (host_memory_backend_mr_inited(backend)) {
+        error_setg(&local_err, "cannot change property value");
+        goto out;
+    }
+
+    visit_type_size(v, name, &val, &local_err);
+    if (local_err) {
+        goto out;
+    }
+    fb->align = val;
+
+ out:
+    error_propagate(errp, local_err);
+}
+
 static void file_backend_unparent(Object *obj)
 {
     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
@@ -145,6 +180,10 @@ file_backend_class_init(ObjectClass *oc, void *data)
     object_class_property_add_str(oc, "mem-path",
         get_mem_path, set_mem_path,
         &error_abort);
+    object_class_property_add(oc, "align", "int",
+        file_memory_backend_get_align,
+        file_memory_backend_set_align,
+        NULL, NULL, &error_abort);
 }
 
 static void file_backend_instance_finalize(Object *o)