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balloon.c 3.4 KB

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  1. /*
  2. * Generic Balloon handlers and management
  3. *
  4. * Copyright (c) 2003-2008 Fabrice Bellard
  5. * Copyright (C) 2011 Red Hat, Inc.
  6. * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
  7. *
  8. * Permission is hereby granted, free of charge, to any person obtaining a copy
  9. * of this software and associated documentation files (the "Software"), to deal
  10. * in the Software without restriction, including without limitation the rights
  11. * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12. * copies of the Software, and to permit persons to whom the Software is
  13. * furnished to do so, subject to the following conditions:
  14. *
  15. * The above copyright notice and this permission notice shall be included in
  16. * all copies or substantial portions of the Software.
  17. *
  18. * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19. * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20. * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  21. * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22. * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23. * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  24. * THE SOFTWARE.
  25. */
  26. #include "monitor.h"
  27. #include "cpu-common.h"
  28. #include "kvm.h"
  29. #include "balloon.h"
  30. #include "trace.h"
  31. #include "qmp-commands.h"
  32. static QEMUBalloonEvent *balloon_event_fn;
  33. static QEMUBalloonStatus *balloon_stat_fn;
  34. static void *balloon_opaque;
  35. int qemu_add_balloon_handler(QEMUBalloonEvent *event_func,
  36. QEMUBalloonStatus *stat_func, void *opaque)
  37. {
  38. if (balloon_event_fn || balloon_stat_fn || balloon_opaque) {
  39. /* We're already registered one balloon handler. How many can
  40. * a guest really have?
  41. */
  42. error_report("Another balloon device already registered");
  43. return -1;
  44. }
  45. balloon_event_fn = event_func;
  46. balloon_stat_fn = stat_func;
  47. balloon_opaque = opaque;
  48. return 0;
  49. }
  50. void qemu_remove_balloon_handler(void *opaque)
  51. {
  52. if (balloon_opaque != opaque) {
  53. return;
  54. }
  55. balloon_event_fn = NULL;
  56. balloon_stat_fn = NULL;
  57. balloon_opaque = NULL;
  58. }
  59. static int qemu_balloon(ram_addr_t target)
  60. {
  61. if (!balloon_event_fn) {
  62. return 0;
  63. }
  64. trace_balloon_event(balloon_opaque, target);
  65. balloon_event_fn(balloon_opaque, target);
  66. return 1;
  67. }
  68. static int qemu_balloon_status(BalloonInfo *info)
  69. {
  70. if (!balloon_stat_fn) {
  71. return 0;
  72. }
  73. balloon_stat_fn(balloon_opaque, info);
  74. return 1;
  75. }
  76. BalloonInfo *qmp_query_balloon(Error **errp)
  77. {
  78. BalloonInfo *info;
  79. if (kvm_enabled() && !kvm_has_sync_mmu()) {
  80. error_set(errp, QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
  81. return NULL;
  82. }
  83. info = g_malloc0(sizeof(*info));
  84. if (qemu_balloon_status(info) == 0) {
  85. error_set(errp, QERR_DEVICE_NOT_ACTIVE, "balloon");
  86. qapi_free_BalloonInfo(info);
  87. return NULL;
  88. }
  89. return info;
  90. }
  91. void qmp_balloon(int64_t value, Error **errp)
  92. {
  93. if (kvm_enabled() && !kvm_has_sync_mmu()) {
  94. error_set(errp, QERR_KVM_MISSING_CAP, "synchronous MMU", "balloon");
  95. return;
  96. }
  97. if (value <= 0) {
  98. error_set(errp, QERR_INVALID_PARAMETER_VALUE, "target", "a size");
  99. return;
  100. }
  101. if (qemu_balloon(value) == 0) {
  102. error_set(errp, QERR_DEVICE_NOT_ACTIVE, "balloon");
  103. }
  104. }