backends/hostmem.c

   1 /*
   2  * QEMU Host Memory Backend
   3  *
   4  * Copyright (C) 2013-2014 Red Hat Inc
   5  *
   6  * Authors:
   7  *   Igor Mammedov <imammedo@redhat.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12 #include "sysemu/hostmem.h"
  13 #include "sysemu/sysemu.h"
  14 #include "qapi/visitor.h"
  15 #include "qapi/qmp/qerror.h"
  16 #include "qemu/config-file.h"
  17 #include "qom/object_interfaces.h"
  18
  19 static void
  20 hostmemory_backend_get_size(Object *obj, Visitor *v, void *opaque,
  21                             const char *name, Error **errp)
  22 {
  23     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
  24     uint64_t value = backend->size;
  25
  26     visit_type_size(v, &value, name, errp);
  27 }
  28
  29 static void
  30 hostmemory_backend_set_size(Object *obj, Visitor *v, void *opaque,
  31                             const char *name, Error **errp)
  32 {
  33     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
  34     Error *local_err = NULL;
  35     uint64_t value;
  36
  37     if (memory_region_size(&backend->mr)) {
  38         error_setg(&local_err, "cannot change property value");
  39         goto out;
  40     }
  41
  42     visit_type_size(v, &value, name, &local_err);
  43     if (local_err) {
  44         goto out;
  45     }
  46     if (!value) {
  47         error_setg(&local_err, "Property '%s.%s' doesn't take value '%"
  48                    PRIu64 "'", object_get_typename(obj), name, value);
  49         goto out;
  50     }
  51     backend->size = value;
  52 out:
  53     error_propagate(errp, local_err);
  54 }
  55
  56 static void hostmemory_backend_init(Object *obj)
  57 {
  58     object_property_add(obj, "size", "int",
  59                         hostmemory_backend_get_size,
  60                         hostmemory_backend_set_size, NULL, NULL, NULL);
  61 }
  62
  63 static void hostmemory_backend_finalize(Object *obj)
  64 {
  65     HostMemoryBackend *backend = MEMORY_BACKEND(obj);
  66
  67     if (memory_region_size(&backend->mr)) {
  68         memory_region_destroy(&backend->mr);
  69     }
  70 }
  71
  72 MemoryRegion *
  73 host_memory_backend_get_memory(HostMemoryBackend *backend, Error **errp)
  74 {
  75     return memory_region_size(&backend->mr) ? &backend->mr : NULL;
  76 }
  77
  78 static const TypeInfo hostmemory_backend_info = {
  79     .name = TYPE_MEMORY_BACKEND,
  80     .parent = TYPE_OBJECT,
  81     .abstract = true,
  82     .class_size = sizeof(HostMemoryBackendClass),
  83     .instance_size = sizeof(HostMemoryBackend),
  84     .instance_init = hostmemory_backend_init,
  85     .instance_finalize = hostmemory_backend_finalize,
  86     .interfaces = (InterfaceInfo[]) {
  87         { TYPE_USER_CREATABLE },
  88         { }
  89     }
  90 };
  91
  92 static void register_types(void)
  93 {
  94     type_register_static(&hostmemory_backend_info);
  95 }
  96
  97 type_init(register_types);