xemu/backends/rng.c
Igor Mammedov 269e09f3fc add optional 2nd stage initialization to -object/object-add commands
Introduces USER_CREATABLE interface that must be implemented by
objects which are designed to created with -object CLI option or
object-add QMP command.

Interface provides an ability to do an optional second stage
initialization of the object created with -object/object-add
commands. By providing complete() callback, which is called
after the object properties were set.

It allows to:
 * prevents misusing of -object/object-add by filtering out
   objects that are not designed for it.
 * generalize second stage backend initialization instead of
   adding custom APIs to perform it
 * early error detection of backend initialization at -object/
   object-add time rather than through a proxy DEVICE object
   that tries to use backend.

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
2014-01-28 12:47:02 -05:00

99 lines
2.2 KiB
C

/*
* QEMU Random Number Generator Backend
*
* Copyright IBM, Corp. 2012
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.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/rng.h"
#include "qapi/qmp/qerror.h"
#include "qom/object_interfaces.h"
void rng_backend_request_entropy(RngBackend *s, size_t size,
EntropyReceiveFunc *receive_entropy,
void *opaque)
{
RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
if (k->request_entropy) {
k->request_entropy(s, size, receive_entropy, opaque);
}
}
void rng_backend_cancel_requests(RngBackend *s)
{
RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
if (k->cancel_requests) {
k->cancel_requests(s);
}
}
static bool rng_backend_prop_get_opened(Object *obj, Error **errp)
{
RngBackend *s = RNG_BACKEND(obj);
return s->opened;
}
void rng_backend_open(RngBackend *s, Error **errp)
{
object_property_set_bool(OBJECT(s), true, "opened", errp);
}
static void rng_backend_prop_set_opened(Object *obj, bool value, Error **errp)
{
RngBackend *s = RNG_BACKEND(obj);
RngBackendClass *k = RNG_BACKEND_GET_CLASS(s);
if (value == s->opened) {
return;
}
if (!value && s->opened) {
error_set(errp, QERR_PERMISSION_DENIED);
return;
}
if (k->opened) {
k->opened(s, errp);
}
if (!error_is_set(errp)) {
s->opened = value;
}
}
static void rng_backend_init(Object *obj)
{
object_property_add_bool(obj, "opened",
rng_backend_prop_get_opened,
rng_backend_prop_set_opened,
NULL);
}
static const TypeInfo rng_backend_info = {
.name = TYPE_RNG_BACKEND,
.parent = TYPE_OBJECT,
.instance_size = sizeof(RngBackend),
.instance_init = rng_backend_init,
.class_size = sizeof(RngBackendClass),
.abstract = true,
.interfaces = (InterfaceInfo[]) {
{ TYPE_USER_CREATABLE },
{ }
}
};
static void register_types(void)
{
type_register_static(&rng_backend_info);
}
type_init(register_types);