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1 | bd322087 | aliguori | /*
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2 | d4443cb6 | Amit Shah | * Virtio Balloon Device
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3 | bd322087 | aliguori | *
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4 | bd322087 | aliguori | * Copyright IBM, Corp. 2008
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5 | d4443cb6 | Amit Shah | * Copyright (C) 2011 Red Hat, Inc.
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6 | d4443cb6 | Amit Shah | * Copyright (C) 2011 Amit Shah <amit.shah@redhat.com>
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7 | bd322087 | aliguori | *
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8 | bd322087 | aliguori | * Authors:
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9 | bd322087 | aliguori | * Anthony Liguori <aliguori@us.ibm.com>
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10 | bd322087 | aliguori | *
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11 | bd322087 | aliguori | * This work is licensed under the terms of the GNU GPL, version 2. See
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12 | bd322087 | aliguori | * the COPYING file in the top-level directory.
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13 | bd322087 | aliguori | *
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14 | bd322087 | aliguori | */
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15 | bd322087 | aliguori | |
16 | fa6111f2 | Amit Shah | #include "iov.h" |
17 | bd322087 | aliguori | #include "qemu-common.h" |
18 | bd322087 | aliguori | #include "virtio.h" |
19 | bd322087 | aliguori | #include "pc.h" |
20 | bd322087 | aliguori | #include "cpu.h" |
21 | bd322087 | aliguori | #include "balloon.h" |
22 | bd322087 | aliguori | #include "virtio-balloon.h" |
23 | bd322087 | aliguori | #include "kvm.h" |
24 | bd322087 | aliguori | |
25 | bd322087 | aliguori | #if defined(__linux__)
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26 | bd322087 | aliguori | #include <sys/mman.h> |
27 | bd322087 | aliguori | #endif
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28 | bd322087 | aliguori | |
29 | bd322087 | aliguori | typedef struct VirtIOBalloon |
30 | bd322087 | aliguori | { |
31 | bd322087 | aliguori | VirtIODevice vdev; |
32 | 625a5bef | Adam Litke | VirtQueue *ivq, *dvq, *svq; |
33 | bd322087 | aliguori | uint32_t num_pages; |
34 | bd322087 | aliguori | uint32_t actual; |
35 | 625a5bef | Adam Litke | uint64_t stats[VIRTIO_BALLOON_S_NR]; |
36 | 625a5bef | Adam Litke | VirtQueueElement stats_vq_elem; |
37 | 625a5bef | Adam Litke | size_t stats_vq_offset; |
38 | ac720400 | Amit Shah | DeviceState *qdev; |
39 | bd322087 | aliguori | } VirtIOBalloon; |
40 | bd322087 | aliguori | |
41 | bd322087 | aliguori | static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
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42 | bd322087 | aliguori | { |
43 | bd322087 | aliguori | return (VirtIOBalloon *)vdev;
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44 | bd322087 | aliguori | } |
45 | bd322087 | aliguori | |
46 | bd322087 | aliguori | static void balloon_page(void *addr, int deflate) |
47 | bd322087 | aliguori | { |
48 | bd322087 | aliguori | #if defined(__linux__)
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49 | bd322087 | aliguori | if (!kvm_enabled() || kvm_has_sync_mmu())
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50 | e78815a5 | Andreas Färber | qemu_madvise(addr, TARGET_PAGE_SIZE, |
51 | e78815a5 | Andreas Färber | deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED); |
52 | bd322087 | aliguori | #endif
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53 | bd322087 | aliguori | } |
54 | bd322087 | aliguori | |
55 | 625a5bef | Adam Litke | /*
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56 | 625a5bef | Adam Litke | * reset_stats - Mark all items in the stats array as unset
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57 | 625a5bef | Adam Litke | *
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58 | 625a5bef | Adam Litke | * This function needs to be called at device intialization and before
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59 | 625a5bef | Adam Litke | * before updating to a set of newly-generated stats. This will ensure that no
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60 | 625a5bef | Adam Litke | * stale values stick around in case the guest reports a subset of the supported
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61 | 625a5bef | Adam Litke | * statistics.
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62 | 625a5bef | Adam Litke | */
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63 | 625a5bef | Adam Litke | static inline void reset_stats(VirtIOBalloon *dev) |
64 | 625a5bef | Adam Litke | { |
65 | 625a5bef | Adam Litke | int i;
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66 | 625a5bef | Adam Litke | for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); |
67 | 625a5bef | Adam Litke | } |
68 | 625a5bef | Adam Litke | |
69 | bd322087 | aliguori | static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
70 | bd322087 | aliguori | { |
71 | bd322087 | aliguori | VirtIOBalloon *s = to_virtio_balloon(vdev); |
72 | bd322087 | aliguori | VirtQueueElement elem; |
73 | bd322087 | aliguori | |
74 | bd322087 | aliguori | while (virtqueue_pop(vq, &elem)) {
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75 | bd322087 | aliguori | size_t offset = 0;
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76 | bd322087 | aliguori | uint32_t pfn; |
77 | bd322087 | aliguori | |
78 | fa6111f2 | Amit Shah | while (iov_to_buf(elem.out_sg, elem.out_num, &pfn, offset, 4) == 4) { |
79 | c227f099 | Anthony Liguori | ram_addr_t pa; |
80 | c227f099 | Anthony Liguori | ram_addr_t addr; |
81 | bd322087 | aliguori | |
82 | c227f099 | Anthony Liguori | pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT; |
83 | bd322087 | aliguori | offset += 4;
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84 | bd322087 | aliguori | |
85 | bd322087 | aliguori | addr = cpu_get_physical_page_desc(pa); |
86 | bd322087 | aliguori | if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM)
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87 | bd322087 | aliguori | continue;
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88 | bd322087 | aliguori | |
89 | 5c130f65 | pbrook | /* Using qemu_get_ram_ptr is bending the rules a bit, but
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90 | 5c130f65 | pbrook | should be OK because we only want a single page. */
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91 | 5c130f65 | pbrook | balloon_page(qemu_get_ram_ptr(addr), !!(vq == s->dvq)); |
92 | bd322087 | aliguori | } |
93 | bd322087 | aliguori | |
94 | bd322087 | aliguori | virtqueue_push(vq, &elem, offset); |
95 | bd322087 | aliguori | virtio_notify(vdev, vq); |
96 | bd322087 | aliguori | } |
97 | bd322087 | aliguori | } |
98 | bd322087 | aliguori | |
99 | 625a5bef | Adam Litke | static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) |
100 | 625a5bef | Adam Litke | { |
101 | 625a5bef | Adam Litke | VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); |
102 | 625a5bef | Adam Litke | VirtQueueElement *elem = &s->stats_vq_elem; |
103 | 625a5bef | Adam Litke | VirtIOBalloonStat stat; |
104 | 625a5bef | Adam Litke | size_t offset = 0;
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105 | 625a5bef | Adam Litke | |
106 | 625a5bef | Adam Litke | if (!virtqueue_pop(vq, elem)) {
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107 | 625a5bef | Adam Litke | return;
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108 | 625a5bef | Adam Litke | } |
109 | 625a5bef | Adam Litke | |
110 | 625a5bef | Adam Litke | /* Initialize the stats to get rid of any stale values. This is only
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111 | 625a5bef | Adam Litke | * needed to handle the case where a guest supports fewer stats than it
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112 | 625a5bef | Adam Litke | * used to (ie. it has booted into an old kernel).
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113 | 625a5bef | Adam Litke | */
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114 | 625a5bef | Adam Litke | reset_stats(s); |
115 | 625a5bef | Adam Litke | |
116 | fa6111f2 | Amit Shah | while (iov_to_buf(elem->out_sg, elem->out_num, &stat, offset, sizeof(stat)) |
117 | fa6111f2 | Amit Shah | == sizeof(stat)) {
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118 | 625a5bef | Adam Litke | uint16_t tag = tswap16(stat.tag); |
119 | 625a5bef | Adam Litke | uint64_t val = tswap64(stat.val); |
120 | 625a5bef | Adam Litke | |
121 | 625a5bef | Adam Litke | offset += sizeof(stat);
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122 | 625a5bef | Adam Litke | if (tag < VIRTIO_BALLOON_S_NR)
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123 | 625a5bef | Adam Litke | s->stats[tag] = val; |
124 | 625a5bef | Adam Litke | } |
125 | 625a5bef | Adam Litke | s->stats_vq_offset = offset; |
126 | 625a5bef | Adam Litke | } |
127 | 625a5bef | Adam Litke | |
128 | bd322087 | aliguori | static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) |
129 | bd322087 | aliguori | { |
130 | bd322087 | aliguori | VirtIOBalloon *dev = to_virtio_balloon(vdev); |
131 | bd322087 | aliguori | struct virtio_balloon_config config;
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132 | bd322087 | aliguori | |
133 | bd322087 | aliguori | config.num_pages = cpu_to_le32(dev->num_pages); |
134 | bd322087 | aliguori | config.actual = cpu_to_le32(dev->actual); |
135 | bd322087 | aliguori | |
136 | bd322087 | aliguori | memcpy(config_data, &config, 8);
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137 | bd322087 | aliguori | } |
138 | bd322087 | aliguori | |
139 | bd322087 | aliguori | static void virtio_balloon_set_config(VirtIODevice *vdev, |
140 | bd322087 | aliguori | const uint8_t *config_data)
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141 | bd322087 | aliguori | { |
142 | bd322087 | aliguori | VirtIOBalloon *dev = to_virtio_balloon(vdev); |
143 | bd322087 | aliguori | struct virtio_balloon_config config;
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144 | bd322087 | aliguori | memcpy(&config, config_data, 8);
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145 | e54f1771 | Alexey Kardashevskiy | dev->actual = le32_to_cpu(config.actual); |
146 | bd322087 | aliguori | } |
147 | bd322087 | aliguori | |
148 | 8172539d | Michael S. Tsirkin | static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
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149 | bd322087 | aliguori | { |
150 | 625a5bef | Adam Litke | f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
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151 | 8172539d | Michael S. Tsirkin | return f;
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152 | bd322087 | aliguori | } |
153 | bd322087 | aliguori | |
154 | 96637bcd | Luiz Capitulino | static void virtio_balloon_stat(void *opaque, BalloonInfo *info) |
155 | dce911c7 | Amit Shah | { |
156 | dce911c7 | Amit Shah | VirtIOBalloon *dev = opaque; |
157 | dce911c7 | Amit Shah | |
158 | 96637bcd | Luiz Capitulino | #if 0
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159 | 96637bcd | Luiz Capitulino | /* Disable guest-provided stats for now. For more details please check:
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160 | 96637bcd | Luiz Capitulino | * https://bugzilla.redhat.com/show_bug.cgi?id=623903
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161 | 96637bcd | Luiz Capitulino | *
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162 | 96637bcd | Luiz Capitulino | * If you do enable it (which is probably not going to happen as we
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163 | 96637bcd | Luiz Capitulino | * need a new command for it), remember that you also need to fill the
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164 | 96637bcd | Luiz Capitulino | * appropriate members of the BalloonInfo structure so that the stats
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165 | 96637bcd | Luiz Capitulino | * are returned to the client.
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166 | dce911c7 | Amit Shah | */
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167 | 96637bcd | Luiz Capitulino | if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) {
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168 | dce911c7 | Amit Shah | virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset);
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169 | dce911c7 | Amit Shah | virtio_notify(&dev->vdev, dev->svq);
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170 | dce911c7 | Amit Shah | return;
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171 | dce911c7 | Amit Shah | }
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172 | 96637bcd | Luiz Capitulino | #endif
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173 | dce911c7 | Amit Shah | |
174 | dce911c7 | Amit Shah | /* Stats are not supported. Clear out any stale values that might
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175 | dce911c7 | Amit Shah | * have been set by a more featureful guest kernel.
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176 | dce911c7 | Amit Shah | */
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177 | dce911c7 | Amit Shah | reset_stats(dev); |
178 | 96637bcd | Luiz Capitulino | |
179 | 96637bcd | Luiz Capitulino | info->actual = ram_size - ((uint64_t) dev->actual << |
180 | 96637bcd | Luiz Capitulino | VIRTIO_BALLOON_PFN_SHIFT); |
181 | dce911c7 | Amit Shah | } |
182 | dce911c7 | Amit Shah | |
183 | 30fb2ca6 | Amit Shah | static void virtio_balloon_to_target(void *opaque, ram_addr_t target) |
184 | bd322087 | aliguori | { |
185 | bd322087 | aliguori | VirtIOBalloon *dev = opaque; |
186 | bd322087 | aliguori | |
187 | dce911c7 | Amit Shah | if (target > ram_size) {
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188 | bd322087 | aliguori | target = ram_size; |
189 | dce911c7 | Amit Shah | } |
190 | bd322087 | aliguori | if (target) {
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191 | bd322087 | aliguori | dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; |
192 | bd322087 | aliguori | virtio_notify_config(&dev->vdev); |
193 | bd322087 | aliguori | } |
194 | bd322087 | aliguori | } |
195 | bd322087 | aliguori | |
196 | bd322087 | aliguori | static void virtio_balloon_save(QEMUFile *f, void *opaque) |
197 | bd322087 | aliguori | { |
198 | bd322087 | aliguori | VirtIOBalloon *s = opaque; |
199 | bd322087 | aliguori | |
200 | bd322087 | aliguori | virtio_save(&s->vdev, f); |
201 | bd322087 | aliguori | |
202 | bd322087 | aliguori | qemu_put_be32(f, s->num_pages); |
203 | bd322087 | aliguori | qemu_put_be32(f, s->actual); |
204 | bd322087 | aliguori | } |
205 | bd322087 | aliguori | |
206 | bd322087 | aliguori | static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) |
207 | bd322087 | aliguori | { |
208 | bd322087 | aliguori | VirtIOBalloon *s = opaque; |
209 | bd322087 | aliguori | |
210 | bd322087 | aliguori | if (version_id != 1) |
211 | bd322087 | aliguori | return -EINVAL;
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212 | bd322087 | aliguori | |
213 | bd322087 | aliguori | virtio_load(&s->vdev, f); |
214 | bd322087 | aliguori | |
215 | bd322087 | aliguori | s->num_pages = qemu_get_be32(f); |
216 | bd322087 | aliguori | s->actual = qemu_get_be32(f); |
217 | bd322087 | aliguori | return 0; |
218 | bd322087 | aliguori | } |
219 | bd322087 | aliguori | |
220 | 53c25cea | Paul Brook | VirtIODevice *virtio_balloon_init(DeviceState *dev) |
221 | bd322087 | aliguori | { |
222 | bd322087 | aliguori | VirtIOBalloon *s; |
223 | f76f6655 | Amit Shah | int ret;
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224 | bd322087 | aliguori | |
225 | 53c25cea | Paul Brook | s = (VirtIOBalloon *)virtio_common_init("virtio-balloon",
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226 | 53c25cea | Paul Brook | VIRTIO_ID_BALLOON, |
227 | 53c25cea | Paul Brook | 8, sizeof(VirtIOBalloon)); |
228 | bd322087 | aliguori | |
229 | bd322087 | aliguori | s->vdev.get_config = virtio_balloon_get_config; |
230 | bd322087 | aliguori | s->vdev.set_config = virtio_balloon_set_config; |
231 | bd322087 | aliguori | s->vdev.get_features = virtio_balloon_get_features; |
232 | bd322087 | aliguori | |
233 | f76f6655 | Amit Shah | ret = qemu_add_balloon_handler(virtio_balloon_to_target, |
234 | f76f6655 | Amit Shah | virtio_balloon_stat, s); |
235 | f76f6655 | Amit Shah | if (ret < 0) { |
236 | f76f6655 | Amit Shah | virtio_cleanup(&s->vdev); |
237 | f76f6655 | Amit Shah | return NULL; |
238 | f76f6655 | Amit Shah | } |
239 | f76f6655 | Amit Shah | |
240 | bd322087 | aliguori | s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
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241 | bd322087 | aliguori | s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
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242 | 625a5bef | Adam Litke | s->svq = virtio_add_queue(&s->vdev, 128, virtio_balloon_receive_stats);
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243 | bd322087 | aliguori | |
244 | 625a5bef | Adam Litke | reset_stats(s); |
245 | bd322087 | aliguori | |
246 | ac720400 | Amit Shah | s->qdev = dev; |
247 | 0be71e32 | Alex Williamson | register_savevm(dev, "virtio-balloon", -1, 1, |
248 | 0be71e32 | Alex Williamson | virtio_balloon_save, virtio_balloon_load, s); |
249 | bd322087 | aliguori | |
250 | 53c25cea | Paul Brook | return &s->vdev;
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251 | bd322087 | aliguori | } |
252 | 855d7e25 | Amit Shah | |
253 | 855d7e25 | Amit Shah | void virtio_balloon_exit(VirtIODevice *vdev)
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254 | 855d7e25 | Amit Shah | { |
255 | ac720400 | Amit Shah | VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); |
256 | 3b86b13a | Amit Shah | |
257 | 3b86b13a | Amit Shah | qemu_remove_balloon_handler(s); |
258 | ac720400 | Amit Shah | unregister_savevm(s->qdev, "virtio-balloon", s);
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259 | 855d7e25 | Amit Shah | virtio_cleanup(vdev); |
260 | 855d7e25 | Amit Shah | } |