balloon: Don't allow multiple balloon handler registrations

Multiple balloon devices don't make sense; disallow more than one
registration attempt to register handlers.

Signed-off-by: Amit Shah <amit.shah@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Amit Shah 2011-07-27 12:28:19 +05:30 committed by Anthony Liguori
parent d4443cb616
commit 6c6ec1821a
2 changed files with 12 additions and 4 deletions

View File

@ -36,12 +36,20 @@ static QEMUBalloonEvent *balloon_event_fn;
static QEMUBalloonStatus *balloon_stat_fn;
static void *balloon_opaque;
void qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
QEMUBalloonStatus *stat_func, void *opaque)
{
if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
/* We're already registered one balloon handler. How many can
* a guest really have?
*/
error_report("Another balloon device already registered");
return -1;
}
balloon_event_fn = event_func;
balloon_stat_fn = stat_func;
balloon_opaque = opaque;
return 0;
}
static int qemu_balloon(ram_addr_t target)

View File

@ -20,7 +20,7 @@ typedef void (QEMUBalloonEvent)(void *opaque, ram_addr_t target);
typedef void (QEMUBalloonStatus)(void *opaque, MonitorCompletion cb,
void *cb_data);
void qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
QEMUBalloonStatus *stat_func, void *opaque);
void monitor_print_balloon(Monitor *mon, const QObject *data);