diff options
Diffstat (limited to 'softmmu/balloon.c')
-rw-r--r-- | softmmu/balloon.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/softmmu/balloon.c b/softmmu/balloon.c new file mode 100644 index 0000000..354408c --- /dev/null +++ b/softmmu/balloon.c @@ -0,0 +1,106 @@ +/* + * 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/atomic.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 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); +} |