mirror of
https://github.com/qemu/qemu.git
synced 2024-12-22 11:43:48 +08:00
01ccbec7bd
A simple true/false internal state does not allow multiple users. Fix this within the existing interface by converting to a counter, so long as the counter is elevated, ballooning is inhibited. Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
126 lines
3.6 KiB
C
126 lines
3.6 KiB
C
/*
|
|
* Generic Balloon handlers and management
|
|
*
|
|
* Copyright (c) 2003-2008 Fabrice Bellard
|
|
* Copyright (C) 2011 Red Hat, Inc.
|
|
* Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
|
|
*
|
|
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
|
* of this software and associated documentation files (the "Software"), to deal
|
|
* in the Software without restriction, including without limitation the rights
|
|
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
|
* copies of the Software, and to permit persons to whom the Software is
|
|
* furnished to do so, subject to the following conditions:
|
|
*
|
|
* The above copyright notice and this permission notice shall be included in
|
|
* all copies or substantial portions of the Software.
|
|
*
|
|
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
|
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
|
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
|
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
|
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
|
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
|
* THE SOFTWARE.
|
|
*/
|
|
|
|
#include "qemu/osdep.h"
|
|
#include "qemu-common.h"
|
|
#include "qemu/atomic.h"
|
|
#include "exec/cpu-common.h"
|
|
#include "sysemu/kvm.h"
|
|
#include "sysemu/balloon.h"
|
|
#include "trace-root.h"
|
|
#include "qapi/error.h"
|
|
#include "qapi/qapi-commands-misc.h"
|
|
#include "qapi/qmp/qerror.h"
|
|
|
|
static QEMUBalloonEvent *balloon_event_fn;
|
|
static QEMUBalloonStatus *balloon_stat_fn;
|
|
static void *balloon_opaque;
|
|
static int balloon_inhibit_count;
|
|
|
|
bool qemu_balloon_is_inhibited(void)
|
|
{
|
|
return atomic_read(&balloon_inhibit_count) > 0;
|
|
}
|
|
|
|
void qemu_balloon_inhibit(bool state)
|
|
{
|
|
if (state) {
|
|
atomic_inc(&balloon_inhibit_count);
|
|
} else {
|
|
atomic_dec(&balloon_inhibit_count);
|
|
}
|
|
|
|
assert(atomic_read(&balloon_inhibit_count) >= 0);
|
|
}
|
|
|
|
static bool have_balloon(Error **errp)
|
|
{
|
|
if (kvm_enabled() && !kvm_has_sync_mmu()) {
|
|
error_set(errp, ERROR_CLASS_KVM_MISSING_CAP,
|
|
"Using KVM without synchronous MMU, balloon unavailable");
|
|
return false;
|
|
}
|
|
if (!balloon_event_fn) {
|
|
error_set(errp, ERROR_CLASS_DEVICE_NOT_ACTIVE,
|
|
"No balloon device has been activated");
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
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?
|
|
*/
|
|
return -1;
|
|
}
|
|
balloon_event_fn = event_func;
|
|
balloon_stat_fn = stat_func;
|
|
balloon_opaque = opaque;
|
|
return 0;
|
|
}
|
|
|
|
void qemu_remove_balloon_handler(void *opaque)
|
|
{
|
|
if (balloon_opaque != opaque) {
|
|
return;
|
|
}
|
|
balloon_event_fn = NULL;
|
|
balloon_stat_fn = NULL;
|
|
balloon_opaque = NULL;
|
|
}
|
|
|
|
BalloonInfo *qmp_query_balloon(Error **errp)
|
|
{
|
|
BalloonInfo *info;
|
|
|
|
if (!have_balloon(errp)) {
|
|
return NULL;
|
|
}
|
|
|
|
info = g_malloc0(sizeof(*info));
|
|
balloon_stat_fn(balloon_opaque, info);
|
|
return info;
|
|
}
|
|
|
|
void qmp_balloon(int64_t target, Error **errp)
|
|
{
|
|
if (!have_balloon(errp)) {
|
|
return;
|
|
}
|
|
|
|
if (target <= 0) {
|
|
error_setg(errp, QERR_INVALID_PARAMETER_VALUE, "target", "a size");
|
|
return;
|
|
}
|
|
|
|
trace_balloon_event(balloon_opaque, target);
|
|
balloon_event_fn(balloon_opaque, target);
|
|
}
|