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bd322087 AL |
1 | /* |
2 | * Virtio Block Device | |
3 | * | |
4 | * Copyright IBM, Corp. 2008 | |
5 | * | |
6 | * Authors: | |
7 | * Anthony Liguori <[email protected]> | |
8 | * | |
9 | * This work is licensed under the terms of the GNU GPL, version 2. See | |
10 | * the COPYING file in the top-level directory. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include "qemu-common.h" | |
15 | #include "virtio.h" | |
16 | #include "pc.h" | |
17 | #include "sysemu.h" | |
18 | #include "cpu.h" | |
625a5bef | 19 | #include "monitor.h" |
bd322087 AL |
20 | #include "balloon.h" |
21 | #include "virtio-balloon.h" | |
22 | #include "kvm.h" | |
625a5bef AL |
23 | #include "qlist.h" |
24 | #include "qint.h" | |
25 | #include "qstring.h" | |
bd322087 AL |
26 | |
27 | #if defined(__linux__) | |
28 | #include <sys/mman.h> | |
29 | #endif | |
30 | ||
31 | typedef struct VirtIOBalloon | |
32 | { | |
33 | VirtIODevice vdev; | |
625a5bef | 34 | VirtQueue *ivq, *dvq, *svq; |
bd322087 AL |
35 | uint32_t num_pages; |
36 | uint32_t actual; | |
625a5bef AL |
37 | uint64_t stats[VIRTIO_BALLOON_S_NR]; |
38 | VirtQueueElement stats_vq_elem; | |
39 | size_t stats_vq_offset; | |
40 | MonitorCompletion *stats_callback; | |
41 | void *stats_opaque_callback_data; | |
bd322087 AL |
42 | } VirtIOBalloon; |
43 | ||
44 | static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev) | |
45 | { | |
46 | return (VirtIOBalloon *)vdev; | |
47 | } | |
48 | ||
49 | static void balloon_page(void *addr, int deflate) | |
50 | { | |
51 | #if defined(__linux__) | |
52 | if (!kvm_enabled() || kvm_has_sync_mmu()) | |
53 | madvise(addr, TARGET_PAGE_SIZE, | |
54 | deflate ? MADV_WILLNEED : MADV_DONTNEED); | |
55 | #endif | |
56 | } | |
57 | ||
625a5bef AL |
58 | /* |
59 | * reset_stats - Mark all items in the stats array as unset | |
60 | * | |
61 | * This function needs to be called at device intialization and before | |
62 | * before updating to a set of newly-generated stats. This will ensure that no | |
63 | * stale values stick around in case the guest reports a subset of the supported | |
64 | * statistics. | |
65 | */ | |
66 | static inline void reset_stats(VirtIOBalloon *dev) | |
67 | { | |
68 | int i; | |
69 | for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); | |
70 | } | |
71 | ||
72 | static void stat_put(QDict *dict, const char *label, uint64_t val) | |
73 | { | |
74 | if (val != -1) | |
75 | qdict_put(dict, label, qint_from_int(val)); | |
76 | } | |
77 | ||
78 | static QObject *get_stats_qobject(VirtIOBalloon *dev) | |
79 | { | |
80 | QDict *dict = qdict_new(); | |
bd12ff9d AL |
81 | uint64_t actual = ram_size - ((uint64_t) dev->actual << |
82 | VIRTIO_BALLOON_PFN_SHIFT); | |
625a5bef AL |
83 | |
84 | stat_put(dict, "actual", actual); | |
85 | stat_put(dict, "mem_swapped_in", dev->stats[VIRTIO_BALLOON_S_SWAP_IN]); | |
86 | stat_put(dict, "mem_swapped_out", dev->stats[VIRTIO_BALLOON_S_SWAP_OUT]); | |
87 | stat_put(dict, "major_page_faults", dev->stats[VIRTIO_BALLOON_S_MAJFLT]); | |
88 | stat_put(dict, "minor_page_faults", dev->stats[VIRTIO_BALLOON_S_MINFLT]); | |
89 | stat_put(dict, "free_mem", dev->stats[VIRTIO_BALLOON_S_MEMFREE]); | |
90 | stat_put(dict, "total_mem", dev->stats[VIRTIO_BALLOON_S_MEMTOT]); | |
91 | ||
92 | return QOBJECT(dict); | |
93 | } | |
94 | ||
bd322087 AL |
95 | /* FIXME: once we do a virtio refactoring, this will get subsumed into common |
96 | * code */ | |
97 | static size_t memcpy_from_iovector(void *data, size_t offset, size_t size, | |
98 | struct iovec *iov, int iovlen) | |
99 | { | |
100 | int i; | |
101 | uint8_t *ptr = data; | |
102 | size_t iov_off = 0; | |
103 | size_t data_off = 0; | |
104 | ||
105 | for (i = 0; i < iovlen && size; i++) { | |
106 | if (offset < (iov_off + iov[i].iov_len)) { | |
107 | size_t len = MIN((iov_off + iov[i].iov_len) - offset , size); | |
108 | ||
109 | memcpy(ptr + data_off, iov[i].iov_base + (offset - iov_off), len); | |
110 | ||
111 | data_off += len; | |
112 | offset += len; | |
113 | size -= len; | |
114 | } | |
115 | ||
116 | iov_off += iov[i].iov_len; | |
117 | } | |
118 | ||
119 | return data_off; | |
120 | } | |
121 | ||
122 | static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) | |
123 | { | |
124 | VirtIOBalloon *s = to_virtio_balloon(vdev); | |
125 | VirtQueueElement elem; | |
126 | ||
127 | while (virtqueue_pop(vq, &elem)) { | |
128 | size_t offset = 0; | |
129 | uint32_t pfn; | |
130 | ||
131 | while (memcpy_from_iovector(&pfn, offset, 4, | |
132 | elem.out_sg, elem.out_num) == 4) { | |
c227f099 AL |
133 | ram_addr_t pa; |
134 | ram_addr_t addr; | |
bd322087 | 135 | |
c227f099 | 136 | pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT; |
bd322087 AL |
137 | offset += 4; |
138 | ||
139 | addr = cpu_get_physical_page_desc(pa); | |
140 | if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM) | |
141 | continue; | |
142 | ||
5c130f65 PB |
143 | /* Using qemu_get_ram_ptr is bending the rules a bit, but |
144 | should be OK because we only want a single page. */ | |
145 | balloon_page(qemu_get_ram_ptr(addr), !!(vq == s->dvq)); | |
bd322087 AL |
146 | } |
147 | ||
148 | virtqueue_push(vq, &elem, offset); | |
149 | virtio_notify(vdev, vq); | |
150 | } | |
151 | } | |
152 | ||
625a5bef AL |
153 | static void complete_stats_request(VirtIOBalloon *vb) |
154 | { | |
155 | QObject *stats; | |
156 | ||
157 | if (!vb->stats_opaque_callback_data) | |
158 | return; | |
159 | ||
160 | stats = get_stats_qobject(vb); | |
161 | vb->stats_callback(vb->stats_opaque_callback_data, stats); | |
162 | qobject_decref(stats); | |
163 | vb->stats_opaque_callback_data = NULL; | |
164 | vb->stats_callback = NULL; | |
165 | } | |
166 | ||
167 | static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) | |
168 | { | |
169 | VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); | |
170 | VirtQueueElement *elem = &s->stats_vq_elem; | |
171 | VirtIOBalloonStat stat; | |
172 | size_t offset = 0; | |
173 | ||
174 | if (!virtqueue_pop(vq, elem)) { | |
175 | return; | |
176 | } | |
177 | ||
178 | /* Initialize the stats to get rid of any stale values. This is only | |
179 | * needed to handle the case where a guest supports fewer stats than it | |
180 | * used to (ie. it has booted into an old kernel). | |
181 | */ | |
182 | reset_stats(s); | |
183 | ||
184 | while (memcpy_from_iovector(&stat, offset, sizeof(stat), elem->out_sg, | |
185 | elem->out_num) == sizeof(stat)) { | |
186 | uint16_t tag = tswap16(stat.tag); | |
187 | uint64_t val = tswap64(stat.val); | |
188 | ||
189 | offset += sizeof(stat); | |
190 | if (tag < VIRTIO_BALLOON_S_NR) | |
191 | s->stats[tag] = val; | |
192 | } | |
193 | s->stats_vq_offset = offset; | |
194 | ||
195 | complete_stats_request(s); | |
196 | } | |
197 | ||
bd322087 AL |
198 | static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) |
199 | { | |
200 | VirtIOBalloon *dev = to_virtio_balloon(vdev); | |
201 | struct virtio_balloon_config config; | |
202 | ||
203 | config.num_pages = cpu_to_le32(dev->num_pages); | |
204 | config.actual = cpu_to_le32(dev->actual); | |
205 | ||
206 | memcpy(config_data, &config, 8); | |
207 | } | |
208 | ||
209 | static void virtio_balloon_set_config(VirtIODevice *vdev, | |
210 | const uint8_t *config_data) | |
211 | { | |
212 | VirtIOBalloon *dev = to_virtio_balloon(vdev); | |
213 | struct virtio_balloon_config config; | |
214 | memcpy(&config, config_data, 8); | |
215 | dev->actual = config.actual; | |
216 | } | |
217 | ||
8172539d | 218 | static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f) |
bd322087 | 219 | { |
625a5bef | 220 | f |= (1 << VIRTIO_BALLOON_F_STATS_VQ); |
8172539d | 221 | return f; |
bd322087 AL |
222 | } |
223 | ||
625a5bef AL |
224 | static void virtio_balloon_to_target(void *opaque, ram_addr_t target, |
225 | MonitorCompletion cb, void *cb_data) | |
bd322087 AL |
226 | { |
227 | VirtIOBalloon *dev = opaque; | |
228 | ||
229 | if (target > ram_size) | |
230 | target = ram_size; | |
231 | ||
232 | if (target) { | |
233 | dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; | |
234 | virtio_notify_config(&dev->vdev); | |
625a5bef AL |
235 | } else { |
236 | /* For now, only allow one request at a time. This restriction can be | |
237 | * removed later by queueing callback and data pairs. | |
238 | */ | |
239 | if (dev->stats_callback != NULL) { | |
240 | return; | |
241 | } | |
242 | dev->stats_callback = cb; | |
243 | dev->stats_opaque_callback_data = cb_data; | |
244 | if (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ)) { | |
245 | virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset); | |
246 | virtio_notify(&dev->vdev, dev->svq); | |
247 | } else { | |
248 | /* Stats are not supported. Clear out any stale values that might | |
249 | * have been set by a more featureful guest kernel. | |
250 | */ | |
251 | reset_stats(dev); | |
252 | complete_stats_request(dev); | |
253 | } | |
bd322087 | 254 | } |
bd322087 AL |
255 | } |
256 | ||
257 | static void virtio_balloon_save(QEMUFile *f, void *opaque) | |
258 | { | |
259 | VirtIOBalloon *s = opaque; | |
260 | ||
261 | virtio_save(&s->vdev, f); | |
262 | ||
263 | qemu_put_be32(f, s->num_pages); | |
264 | qemu_put_be32(f, s->actual); | |
265 | } | |
266 | ||
267 | static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) | |
268 | { | |
269 | VirtIOBalloon *s = opaque; | |
270 | ||
271 | if (version_id != 1) | |
272 | return -EINVAL; | |
273 | ||
274 | virtio_load(&s->vdev, f); | |
275 | ||
276 | s->num_pages = qemu_get_be32(f); | |
277 | s->actual = qemu_get_be32(f); | |
bd322087 AL |
278 | return 0; |
279 | } | |
280 | ||
53c25cea | 281 | VirtIODevice *virtio_balloon_init(DeviceState *dev) |
bd322087 AL |
282 | { |
283 | VirtIOBalloon *s; | |
284 | ||
53c25cea PB |
285 | s = (VirtIOBalloon *)virtio_common_init("virtio-balloon", |
286 | VIRTIO_ID_BALLOON, | |
287 | 8, sizeof(VirtIOBalloon)); | |
bd322087 AL |
288 | |
289 | s->vdev.get_config = virtio_balloon_get_config; | |
290 | s->vdev.set_config = virtio_balloon_set_config; | |
291 | s->vdev.get_features = virtio_balloon_get_features; | |
292 | ||
293 | s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output); | |
294 | s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output); | |
625a5bef | 295 | s->svq = virtio_add_queue(&s->vdev, 128, virtio_balloon_receive_stats); |
bd322087 | 296 | |
625a5bef | 297 | reset_stats(s); |
bd322087 AL |
298 | qemu_add_balloon_handler(virtio_balloon_to_target, s); |
299 | ||
300 | register_savevm("virtio-balloon", -1, 1, virtio_balloon_save, virtio_balloon_load, s); | |
301 | ||
53c25cea | 302 | return &s->vdev; |
bd322087 | 303 | } |