add memdev backend infrastructure

Provides framework for splitting host RAM allocation/
policies into a separate backend that could be used
by devices.

Initially only legacy RAM backend is provided, which
uses memory_region_init_ram() allocator and compatible
with every CLI option that affects memory_region_init_ram().

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 54 insertions, 0 deletions

diff --git a/backends/hostmem-ram.c b/backends/hostmem-ram.c
new file mode 100644
index 0000000000..bba2ebcce8
--- /dev/null
+++ b/backends/hostmem-ram.c
@@ -0,0 +1,54 @@
+/*
+ * QEMU Host Memory Backend
+ *
+ * Copyright (C) 2013-2014 Red Hat Inc
+ *
+ * Authors:
+ *   Igor Mammedov <imammedo@redhat.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+#include "sysemu/hostmem.h"
+#include "qom/object_interfaces.h"
+
+#define TYPE_MEMORY_BACKEND_RAM "memory-backend-ram"
+
+
+static void
+ram_backend_memory_init(UserCreatable *uc, Error **errp)
+{
+    HostMemoryBackend *backend = MEMORY_BACKEND(uc);
+    char *path;
+
+    if (!backend->size) {
+        error_setg(errp, "can't create backend with size 0");
+        return;
+    }
+
+    path = object_get_canonical_path_component(OBJECT(backend));
+    memory_region_init_ram(&backend->mr, OBJECT(backend), path,
+                           backend->size);
+    g_free(path);
+}
+
+static void
+ram_backend_class_init(ObjectClass *oc, void *data)
+{
+    UserCreatableClass *ucc = USER_CREATABLE_CLASS(oc);
+
+    ucc->complete = ram_backend_memory_init;
+}
+
+static const TypeInfo ram_backend_info = {
+    .name = TYPE_MEMORY_BACKEND_RAM,
+    .parent = TYPE_MEMORY_BACKEND,
+    .class_init = ram_backend_class_init,
+};
+
+static void register_types(void)
+{
+    type_register_static(&ram_backend_info);
+}
+
+type_init(register_types);