| /* |
| * 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 "qapi/error.h" |
| #include "qapi/qapi-commands-machine.h" |
| #include "qapi/qmp/qerror.h" |
| #include "trace.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); |
| } |