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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 | b7c28c74 | Avi Kivity | #include "exec-memory.h" |
25 | bd322087 | aliguori | |
26 | bd322087 | aliguori | #if defined(__linux__)
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27 | bd322087 | aliguori | #include <sys/mman.h> |
28 | bd322087 | aliguori | #endif
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29 | bd322087 | aliguori | |
30 | bd322087 | aliguori | typedef struct VirtIOBalloon |
31 | bd322087 | aliguori | { |
32 | bd322087 | aliguori | VirtIODevice vdev; |
33 | 625a5bef | Adam Litke | VirtQueue *ivq, *dvq, *svq; |
34 | bd322087 | aliguori | uint32_t num_pages; |
35 | bd322087 | aliguori | uint32_t actual; |
36 | 625a5bef | Adam Litke | uint64_t stats[VIRTIO_BALLOON_S_NR]; |
37 | 625a5bef | Adam Litke | VirtQueueElement stats_vq_elem; |
38 | 625a5bef | Adam Litke | size_t stats_vq_offset; |
39 | ac720400 | Amit Shah | DeviceState *qdev; |
40 | bd322087 | aliguori | } VirtIOBalloon; |
41 | bd322087 | aliguori | |
42 | bd322087 | aliguori | static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
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43 | bd322087 | aliguori | { |
44 | bd322087 | aliguori | return (VirtIOBalloon *)vdev;
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45 | bd322087 | aliguori | } |
46 | bd322087 | aliguori | |
47 | bd322087 | aliguori | static void balloon_page(void *addr, int deflate) |
48 | bd322087 | aliguori | { |
49 | bd322087 | aliguori | #if defined(__linux__)
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50 | bd322087 | aliguori | if (!kvm_enabled() || kvm_has_sync_mmu())
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51 | e78815a5 | Andreas Färber | qemu_madvise(addr, TARGET_PAGE_SIZE, |
52 | e78815a5 | Andreas Färber | deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED); |
53 | bd322087 | aliguori | #endif
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54 | bd322087 | aliguori | } |
55 | bd322087 | aliguori | |
56 | 625a5bef | Adam Litke | /*
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57 | 625a5bef | Adam Litke | * reset_stats - Mark all items in the stats array as unset
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58 | 625a5bef | Adam Litke | *
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59 | 625a5bef | Adam Litke | * This function needs to be called at device intialization and before
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60 | 625a5bef | Adam Litke | * before updating to a set of newly-generated stats. This will ensure that no
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61 | 625a5bef | Adam Litke | * stale values stick around in case the guest reports a subset of the supported
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62 | 625a5bef | Adam Litke | * statistics.
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63 | 625a5bef | Adam Litke | */
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64 | 625a5bef | Adam Litke | static inline void reset_stats(VirtIOBalloon *dev) |
65 | 625a5bef | Adam Litke | { |
66 | 625a5bef | Adam Litke | int i;
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67 | 625a5bef | Adam Litke | for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); |
68 | 625a5bef | Adam Litke | } |
69 | 625a5bef | Adam Litke | |
70 | bd322087 | aliguori | static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
71 | bd322087 | aliguori | { |
72 | bd322087 | aliguori | VirtIOBalloon *s = to_virtio_balloon(vdev); |
73 | bd322087 | aliguori | VirtQueueElement elem; |
74 | b7c28c74 | Avi Kivity | MemoryRegionSection section; |
75 | bd322087 | aliguori | |
76 | bd322087 | aliguori | while (virtqueue_pop(vq, &elem)) {
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77 | bd322087 | aliguori | size_t offset = 0;
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78 | bd322087 | aliguori | uint32_t pfn; |
79 | bd322087 | aliguori | |
80 | dcf6f5e1 | Michael Tokarev | while (iov_to_buf(elem.out_sg, elem.out_num, offset, &pfn, 4) == 4) { |
81 | c227f099 | Anthony Liguori | ram_addr_t pa; |
82 | c227f099 | Anthony Liguori | ram_addr_t addr; |
83 | bd322087 | aliguori | |
84 | c227f099 | Anthony Liguori | pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT; |
85 | bd322087 | aliguori | offset += 4;
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86 | bd322087 | aliguori | |
87 | b7c28c74 | Avi Kivity | /* FIXME: remove get_system_memory(), but how? */
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88 | b7c28c74 | Avi Kivity | section = memory_region_find(get_system_memory(), pa, 1);
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89 | b7c28c74 | Avi Kivity | if (!section.size || !memory_region_is_ram(section.mr))
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90 | bd322087 | aliguori | continue;
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91 | bd322087 | aliguori | |
92 | b7c28c74 | Avi Kivity | /* Using memory_region_get_ram_ptr is bending the rules a bit, but
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93 | 5c130f65 | pbrook | should be OK because we only want a single page. */
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94 | b7c28c74 | Avi Kivity | addr = section.offset_within_region; |
95 | b7c28c74 | Avi Kivity | balloon_page(memory_region_get_ram_ptr(section.mr) + addr, |
96 | b7c28c74 | Avi Kivity | !!(vq == s->dvq)); |
97 | bd322087 | aliguori | } |
98 | bd322087 | aliguori | |
99 | bd322087 | aliguori | virtqueue_push(vq, &elem, offset); |
100 | bd322087 | aliguori | virtio_notify(vdev, vq); |
101 | bd322087 | aliguori | } |
102 | bd322087 | aliguori | } |
103 | bd322087 | aliguori | |
104 | 625a5bef | Adam Litke | static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) |
105 | 625a5bef | Adam Litke | { |
106 | 625a5bef | Adam Litke | VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); |
107 | 625a5bef | Adam Litke | VirtQueueElement *elem = &s->stats_vq_elem; |
108 | 625a5bef | Adam Litke | VirtIOBalloonStat stat; |
109 | 625a5bef | Adam Litke | size_t offset = 0;
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110 | 625a5bef | Adam Litke | |
111 | 625a5bef | Adam Litke | if (!virtqueue_pop(vq, elem)) {
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112 | 625a5bef | Adam Litke | return;
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113 | 625a5bef | Adam Litke | } |
114 | 625a5bef | Adam Litke | |
115 | 625a5bef | Adam Litke | /* Initialize the stats to get rid of any stale values. This is only
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116 | 625a5bef | Adam Litke | * needed to handle the case where a guest supports fewer stats than it
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117 | 625a5bef | Adam Litke | * used to (ie. it has booted into an old kernel).
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118 | 625a5bef | Adam Litke | */
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119 | 625a5bef | Adam Litke | reset_stats(s); |
120 | 625a5bef | Adam Litke | |
121 | dcf6f5e1 | Michael Tokarev | while (iov_to_buf(elem->out_sg, elem->out_num, offset, &stat, sizeof(stat)) |
122 | fa6111f2 | Amit Shah | == sizeof(stat)) {
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123 | 625a5bef | Adam Litke | uint16_t tag = tswap16(stat.tag); |
124 | 625a5bef | Adam Litke | uint64_t val = tswap64(stat.val); |
125 | 625a5bef | Adam Litke | |
126 | 625a5bef | Adam Litke | offset += sizeof(stat);
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127 | 625a5bef | Adam Litke | if (tag < VIRTIO_BALLOON_S_NR)
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128 | 625a5bef | Adam Litke | s->stats[tag] = val; |
129 | 625a5bef | Adam Litke | } |
130 | 625a5bef | Adam Litke | s->stats_vq_offset = offset; |
131 | 625a5bef | Adam Litke | } |
132 | 625a5bef | Adam Litke | |
133 | bd322087 | aliguori | static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) |
134 | bd322087 | aliguori | { |
135 | bd322087 | aliguori | VirtIOBalloon *dev = to_virtio_balloon(vdev); |
136 | bd322087 | aliguori | struct virtio_balloon_config config;
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137 | bd322087 | aliguori | |
138 | bd322087 | aliguori | config.num_pages = cpu_to_le32(dev->num_pages); |
139 | bd322087 | aliguori | config.actual = cpu_to_le32(dev->actual); |
140 | bd322087 | aliguori | |
141 | bd322087 | aliguori | memcpy(config_data, &config, 8);
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142 | bd322087 | aliguori | } |
143 | bd322087 | aliguori | |
144 | bd322087 | aliguori | static void virtio_balloon_set_config(VirtIODevice *vdev, |
145 | bd322087 | aliguori | const uint8_t *config_data)
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146 | bd322087 | aliguori | { |
147 | bd322087 | aliguori | VirtIOBalloon *dev = to_virtio_balloon(vdev); |
148 | bd322087 | aliguori | struct virtio_balloon_config config;
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149 | 973603a8 | Daniel P. Berrange | uint32_t oldactual = dev->actual; |
150 | bd322087 | aliguori | memcpy(&config, config_data, 8);
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151 | e54f1771 | Alexey Kardashevskiy | dev->actual = le32_to_cpu(config.actual); |
152 | 973603a8 | Daniel P. Berrange | if (dev->actual != oldactual) {
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153 | 973603a8 | Daniel P. Berrange | qemu_balloon_changed(ram_size - |
154 | 973603a8 | Daniel P. Berrange | (dev->actual << VIRTIO_BALLOON_PFN_SHIFT)); |
155 | 973603a8 | Daniel P. Berrange | } |
156 | bd322087 | aliguori | } |
157 | bd322087 | aliguori | |
158 | 8172539d | Michael S. Tsirkin | static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
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159 | bd322087 | aliguori | { |
160 | 625a5bef | Adam Litke | f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
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161 | 8172539d | Michael S. Tsirkin | return f;
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162 | bd322087 | aliguori | } |
163 | bd322087 | aliguori | |
164 | 96637bcd | Luiz Capitulino | static void virtio_balloon_stat(void *opaque, BalloonInfo *info) |
165 | dce911c7 | Amit Shah | { |
166 | dce911c7 | Amit Shah | VirtIOBalloon *dev = opaque; |
167 | dce911c7 | Amit Shah | |
168 | 96637bcd | Luiz Capitulino | #if 0
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169 | 96637bcd | Luiz Capitulino | /* Disable guest-provided stats for now. For more details please check:
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170 | 96637bcd | Luiz Capitulino | * https://bugzilla.redhat.com/show_bug.cgi?id=623903
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171 | 96637bcd | Luiz Capitulino | *
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172 | 96637bcd | Luiz Capitulino | * If you do enable it (which is probably not going to happen as we
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173 | 96637bcd | Luiz Capitulino | * need a new command for it), remember that you also need to fill the
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174 | 96637bcd | Luiz Capitulino | * appropriate members of the BalloonInfo structure so that the stats
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175 | 96637bcd | Luiz Capitulino | * are returned to the client.
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176 | dce911c7 | Amit Shah | */
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177 | 96637bcd | Luiz Capitulino | if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) {
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178 | dce911c7 | Amit Shah | virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset);
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179 | dce911c7 | Amit Shah | virtio_notify(&dev->vdev, dev->svq);
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180 | dce911c7 | Amit Shah | return;
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181 | dce911c7 | Amit Shah | }
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182 | 96637bcd | Luiz Capitulino | #endif
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183 | dce911c7 | Amit Shah | |
184 | dce911c7 | Amit Shah | /* Stats are not supported. Clear out any stale values that might
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185 | dce911c7 | Amit Shah | * have been set by a more featureful guest kernel.
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186 | dce911c7 | Amit Shah | */
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187 | dce911c7 | Amit Shah | reset_stats(dev); |
188 | 96637bcd | Luiz Capitulino | |
189 | 96637bcd | Luiz Capitulino | info->actual = ram_size - ((uint64_t) dev->actual << |
190 | 96637bcd | Luiz Capitulino | VIRTIO_BALLOON_PFN_SHIFT); |
191 | dce911c7 | Amit Shah | } |
192 | dce911c7 | Amit Shah | |
193 | 30fb2ca6 | Amit Shah | static void virtio_balloon_to_target(void *opaque, ram_addr_t target) |
194 | bd322087 | aliguori | { |
195 | bd322087 | aliguori | VirtIOBalloon *dev = opaque; |
196 | bd322087 | aliguori | |
197 | dce911c7 | Amit Shah | if (target > ram_size) {
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198 | bd322087 | aliguori | target = ram_size; |
199 | dce911c7 | Amit Shah | } |
200 | bd322087 | aliguori | if (target) {
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201 | bd322087 | aliguori | dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; |
202 | bd322087 | aliguori | virtio_notify_config(&dev->vdev); |
203 | bd322087 | aliguori | } |
204 | bd322087 | aliguori | } |
205 | bd322087 | aliguori | |
206 | bd322087 | aliguori | static void virtio_balloon_save(QEMUFile *f, void *opaque) |
207 | bd322087 | aliguori | { |
208 | bd322087 | aliguori | VirtIOBalloon *s = opaque; |
209 | bd322087 | aliguori | |
210 | bd322087 | aliguori | virtio_save(&s->vdev, f); |
211 | bd322087 | aliguori | |
212 | bd322087 | aliguori | qemu_put_be32(f, s->num_pages); |
213 | bd322087 | aliguori | qemu_put_be32(f, s->actual); |
214 | bd322087 | aliguori | } |
215 | bd322087 | aliguori | |
216 | bd322087 | aliguori | static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) |
217 | bd322087 | aliguori | { |
218 | bd322087 | aliguori | VirtIOBalloon *s = opaque; |
219 | 2a633c46 | Orit Wassermann | int ret;
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220 | bd322087 | aliguori | |
221 | bd322087 | aliguori | if (version_id != 1) |
222 | bd322087 | aliguori | return -EINVAL;
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223 | bd322087 | aliguori | |
224 | 2a633c46 | Orit Wassermann | ret = virtio_load(&s->vdev, f); |
225 | 2a633c46 | Orit Wassermann | if (ret) {
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226 | 2a633c46 | Orit Wassermann | return ret;
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227 | 2a633c46 | Orit Wassermann | } |
228 | bd322087 | aliguori | |
229 | bd322087 | aliguori | s->num_pages = qemu_get_be32(f); |
230 | bd322087 | aliguori | s->actual = qemu_get_be32(f); |
231 | bd322087 | aliguori | return 0; |
232 | bd322087 | aliguori | } |
233 | bd322087 | aliguori | |
234 | 53c25cea | Paul Brook | VirtIODevice *virtio_balloon_init(DeviceState *dev) |
235 | bd322087 | aliguori | { |
236 | bd322087 | aliguori | VirtIOBalloon *s; |
237 | f76f6655 | Amit Shah | int ret;
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238 | bd322087 | aliguori | |
239 | 53c25cea | Paul Brook | s = (VirtIOBalloon *)virtio_common_init("virtio-balloon",
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240 | 53c25cea | Paul Brook | VIRTIO_ID_BALLOON, |
241 | 53c25cea | Paul Brook | 8, sizeof(VirtIOBalloon)); |
242 | bd322087 | aliguori | |
243 | bd322087 | aliguori | s->vdev.get_config = virtio_balloon_get_config; |
244 | bd322087 | aliguori | s->vdev.set_config = virtio_balloon_set_config; |
245 | bd322087 | aliguori | s->vdev.get_features = virtio_balloon_get_features; |
246 | bd322087 | aliguori | |
247 | f76f6655 | Amit Shah | ret = qemu_add_balloon_handler(virtio_balloon_to_target, |
248 | f76f6655 | Amit Shah | virtio_balloon_stat, s); |
249 | f76f6655 | Amit Shah | if (ret < 0) { |
250 | f76f6655 | Amit Shah | virtio_cleanup(&s->vdev); |
251 | f76f6655 | Amit Shah | return NULL; |
252 | f76f6655 | Amit Shah | } |
253 | f76f6655 | Amit Shah | |
254 | bd322087 | aliguori | s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
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255 | bd322087 | aliguori | s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
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256 | 625a5bef | Adam Litke | s->svq = virtio_add_queue(&s->vdev, 128, virtio_balloon_receive_stats);
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257 | bd322087 | aliguori | |
258 | 625a5bef | Adam Litke | reset_stats(s); |
259 | bd322087 | aliguori | |
260 | ac720400 | Amit Shah | s->qdev = dev; |
261 | 0be71e32 | Alex Williamson | register_savevm(dev, "virtio-balloon", -1, 1, |
262 | 0be71e32 | Alex Williamson | virtio_balloon_save, virtio_balloon_load, s); |
263 | bd322087 | aliguori | |
264 | 53c25cea | Paul Brook | return &s->vdev;
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265 | bd322087 | aliguori | } |
266 | 855d7e25 | Amit Shah | |
267 | 855d7e25 | Amit Shah | void virtio_balloon_exit(VirtIODevice *vdev)
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268 | 855d7e25 | Amit Shah | { |
269 | ac720400 | Amit Shah | VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); |
270 | 3b86b13a | Amit Shah | |
271 | 3b86b13a | Amit Shah | qemu_remove_balloon_handler(s); |
272 | ac720400 | Amit Shah | unregister_savevm(s->qdev, "virtio-balloon", s);
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273 | 855d7e25 | Amit Shah | virtio_cleanup(vdev); |
274 | 855d7e25 | Amit Shah | } |