root / hw / virtio-balloon.c @ b651fc6f
History | View | Annotate | Download (8 kB)
1 |
/*
|
---|---|
2 |
* Virtio Block Device
|
3 |
*
|
4 |
* Copyright IBM, Corp. 2008
|
5 |
*
|
6 |
* Authors:
|
7 |
* Anthony Liguori <aliguori@us.ibm.com>
|
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 "iov.h" |
15 |
#include "qemu-common.h" |
16 |
#include "virtio.h" |
17 |
#include "pc.h" |
18 |
#include "sysemu.h" |
19 |
#include "cpu.h" |
20 |
#include "monitor.h" |
21 |
#include "balloon.h" |
22 |
#include "virtio-balloon.h" |
23 |
#include "kvm.h" |
24 |
#include "qlist.h" |
25 |
#include "qint.h" |
26 |
#include "qstring.h" |
27 |
|
28 |
#if defined(__linux__)
|
29 |
#include <sys/mman.h> |
30 |
#endif
|
31 |
|
32 |
/* Disable guest-provided stats by now (https://bugzilla.redhat.com/show_bug.cgi?id=623903) */
|
33 |
#define ENABLE_GUEST_STATS 0 |
34 |
|
35 |
|
36 |
typedef struct VirtIOBalloon |
37 |
{ |
38 |
VirtIODevice vdev; |
39 |
VirtQueue *ivq, *dvq, *svq; |
40 |
uint32_t num_pages; |
41 |
uint32_t actual; |
42 |
uint64_t stats[VIRTIO_BALLOON_S_NR]; |
43 |
VirtQueueElement stats_vq_elem; |
44 |
size_t stats_vq_offset; |
45 |
MonitorCompletion *stats_callback; |
46 |
void *stats_opaque_callback_data;
|
47 |
} VirtIOBalloon; |
48 |
|
49 |
static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
|
50 |
{ |
51 |
return (VirtIOBalloon *)vdev;
|
52 |
} |
53 |
|
54 |
static void balloon_page(void *addr, int deflate) |
55 |
{ |
56 |
#if defined(__linux__)
|
57 |
if (!kvm_enabled() || kvm_has_sync_mmu())
|
58 |
qemu_madvise(addr, TARGET_PAGE_SIZE, |
59 |
deflate ? QEMU_MADV_WILLNEED : QEMU_MADV_DONTNEED); |
60 |
#endif
|
61 |
} |
62 |
|
63 |
/*
|
64 |
* reset_stats - Mark all items in the stats array as unset
|
65 |
*
|
66 |
* This function needs to be called at device intialization and before
|
67 |
* before updating to a set of newly-generated stats. This will ensure that no
|
68 |
* stale values stick around in case the guest reports a subset of the supported
|
69 |
* statistics.
|
70 |
*/
|
71 |
static inline void reset_stats(VirtIOBalloon *dev) |
72 |
{ |
73 |
int i;
|
74 |
for (i = 0; i < VIRTIO_BALLOON_S_NR; dev->stats[i++] = -1); |
75 |
} |
76 |
|
77 |
static void stat_put(QDict *dict, const char *label, uint64_t val) |
78 |
{ |
79 |
if (val != -1) |
80 |
qdict_put(dict, label, qint_from_int(val)); |
81 |
} |
82 |
|
83 |
static QObject *get_stats_qobject(VirtIOBalloon *dev)
|
84 |
{ |
85 |
QDict *dict = qdict_new(); |
86 |
uint64_t actual = ram_size - ((uint64_t) dev->actual << |
87 |
VIRTIO_BALLOON_PFN_SHIFT); |
88 |
|
89 |
stat_put(dict, "actual", actual);
|
90 |
#if ENABLE_GUEST_STATS
|
91 |
stat_put(dict, "mem_swapped_in", dev->stats[VIRTIO_BALLOON_S_SWAP_IN]);
|
92 |
stat_put(dict, "mem_swapped_out", dev->stats[VIRTIO_BALLOON_S_SWAP_OUT]);
|
93 |
stat_put(dict, "major_page_faults", dev->stats[VIRTIO_BALLOON_S_MAJFLT]);
|
94 |
stat_put(dict, "minor_page_faults", dev->stats[VIRTIO_BALLOON_S_MINFLT]);
|
95 |
stat_put(dict, "free_mem", dev->stats[VIRTIO_BALLOON_S_MEMFREE]);
|
96 |
stat_put(dict, "total_mem", dev->stats[VIRTIO_BALLOON_S_MEMTOT]);
|
97 |
#endif
|
98 |
|
99 |
return QOBJECT(dict);
|
100 |
} |
101 |
|
102 |
static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq) |
103 |
{ |
104 |
VirtIOBalloon *s = to_virtio_balloon(vdev); |
105 |
VirtQueueElement elem; |
106 |
|
107 |
while (virtqueue_pop(vq, &elem)) {
|
108 |
size_t offset = 0;
|
109 |
uint32_t pfn; |
110 |
|
111 |
while (iov_to_buf(elem.out_sg, elem.out_num, &pfn, offset, 4) == 4) { |
112 |
ram_addr_t pa; |
113 |
ram_addr_t addr; |
114 |
|
115 |
pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT; |
116 |
offset += 4;
|
117 |
|
118 |
addr = cpu_get_physical_page_desc(pa); |
119 |
if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM)
|
120 |
continue;
|
121 |
|
122 |
/* Using qemu_get_ram_ptr is bending the rules a bit, but
|
123 |
should be OK because we only want a single page. */
|
124 |
balloon_page(qemu_get_ram_ptr(addr), !!(vq == s->dvq)); |
125 |
} |
126 |
|
127 |
virtqueue_push(vq, &elem, offset); |
128 |
virtio_notify(vdev, vq); |
129 |
} |
130 |
} |
131 |
|
132 |
static void complete_stats_request(VirtIOBalloon *vb) |
133 |
{ |
134 |
QObject *stats; |
135 |
|
136 |
if (!vb->stats_opaque_callback_data)
|
137 |
return;
|
138 |
|
139 |
stats = get_stats_qobject(vb); |
140 |
vb->stats_callback(vb->stats_opaque_callback_data, stats); |
141 |
qobject_decref(stats); |
142 |
vb->stats_opaque_callback_data = NULL;
|
143 |
vb->stats_callback = NULL;
|
144 |
} |
145 |
|
146 |
static void virtio_balloon_receive_stats(VirtIODevice *vdev, VirtQueue *vq) |
147 |
{ |
148 |
VirtIOBalloon *s = DO_UPCAST(VirtIOBalloon, vdev, vdev); |
149 |
VirtQueueElement *elem = &s->stats_vq_elem; |
150 |
VirtIOBalloonStat stat; |
151 |
size_t offset = 0;
|
152 |
|
153 |
if (!virtqueue_pop(vq, elem)) {
|
154 |
return;
|
155 |
} |
156 |
|
157 |
/* Initialize the stats to get rid of any stale values. This is only
|
158 |
* needed to handle the case where a guest supports fewer stats than it
|
159 |
* used to (ie. it has booted into an old kernel).
|
160 |
*/
|
161 |
reset_stats(s); |
162 |
|
163 |
while (iov_to_buf(elem->out_sg, elem->out_num, &stat, offset, sizeof(stat)) |
164 |
== sizeof(stat)) {
|
165 |
uint16_t tag = tswap16(stat.tag); |
166 |
uint64_t val = tswap64(stat.val); |
167 |
|
168 |
offset += sizeof(stat);
|
169 |
if (tag < VIRTIO_BALLOON_S_NR)
|
170 |
s->stats[tag] = val; |
171 |
} |
172 |
s->stats_vq_offset = offset; |
173 |
|
174 |
complete_stats_request(s); |
175 |
} |
176 |
|
177 |
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data) |
178 |
{ |
179 |
VirtIOBalloon *dev = to_virtio_balloon(vdev); |
180 |
struct virtio_balloon_config config;
|
181 |
|
182 |
config.num_pages = cpu_to_le32(dev->num_pages); |
183 |
config.actual = cpu_to_le32(dev->actual); |
184 |
|
185 |
memcpy(config_data, &config, 8);
|
186 |
} |
187 |
|
188 |
static void virtio_balloon_set_config(VirtIODevice *vdev, |
189 |
const uint8_t *config_data)
|
190 |
{ |
191 |
VirtIOBalloon *dev = to_virtio_balloon(vdev); |
192 |
struct virtio_balloon_config config;
|
193 |
memcpy(&config, config_data, 8);
|
194 |
dev->actual = config.actual; |
195 |
} |
196 |
|
197 |
static uint32_t virtio_balloon_get_features(VirtIODevice *vdev, uint32_t f)
|
198 |
{ |
199 |
f |= (1 << VIRTIO_BALLOON_F_STATS_VQ);
|
200 |
return f;
|
201 |
} |
202 |
|
203 |
static void virtio_balloon_to_target(void *opaque, ram_addr_t target, |
204 |
MonitorCompletion cb, void *cb_data)
|
205 |
{ |
206 |
VirtIOBalloon *dev = opaque; |
207 |
|
208 |
if (target > ram_size)
|
209 |
target = ram_size; |
210 |
|
211 |
if (target) {
|
212 |
dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT; |
213 |
virtio_notify_config(&dev->vdev); |
214 |
} else {
|
215 |
/* For now, only allow one request at a time. This restriction can be
|
216 |
* removed later by queueing callback and data pairs.
|
217 |
*/
|
218 |
if (dev->stats_callback != NULL) { |
219 |
return;
|
220 |
} |
221 |
dev->stats_callback = cb; |
222 |
dev->stats_opaque_callback_data = cb_data; |
223 |
if (ENABLE_GUEST_STATS && (dev->vdev.guest_features & (1 << VIRTIO_BALLOON_F_STATS_VQ))) { |
224 |
virtqueue_push(dev->svq, &dev->stats_vq_elem, dev->stats_vq_offset); |
225 |
virtio_notify(&dev->vdev, dev->svq); |
226 |
} else {
|
227 |
/* Stats are not supported. Clear out any stale values that might
|
228 |
* have been set by a more featureful guest kernel.
|
229 |
*/
|
230 |
reset_stats(dev); |
231 |
complete_stats_request(dev); |
232 |
} |
233 |
} |
234 |
} |
235 |
|
236 |
static void virtio_balloon_save(QEMUFile *f, void *opaque) |
237 |
{ |
238 |
VirtIOBalloon *s = opaque; |
239 |
|
240 |
virtio_save(&s->vdev, f); |
241 |
|
242 |
qemu_put_be32(f, s->num_pages); |
243 |
qemu_put_be32(f, s->actual); |
244 |
} |
245 |
|
246 |
static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id) |
247 |
{ |
248 |
VirtIOBalloon *s = opaque; |
249 |
|
250 |
if (version_id != 1) |
251 |
return -EINVAL;
|
252 |
|
253 |
virtio_load(&s->vdev, f); |
254 |
|
255 |
s->num_pages = qemu_get_be32(f); |
256 |
s->actual = qemu_get_be32(f); |
257 |
return 0; |
258 |
} |
259 |
|
260 |
VirtIODevice *virtio_balloon_init(DeviceState *dev) |
261 |
{ |
262 |
VirtIOBalloon *s; |
263 |
|
264 |
s = (VirtIOBalloon *)virtio_common_init("virtio-balloon",
|
265 |
VIRTIO_ID_BALLOON, |
266 |
8, sizeof(VirtIOBalloon)); |
267 |
|
268 |
s->vdev.get_config = virtio_balloon_get_config; |
269 |
s->vdev.set_config = virtio_balloon_set_config; |
270 |
s->vdev.get_features = virtio_balloon_get_features; |
271 |
|
272 |
s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
|
273 |
s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
|
274 |
s->svq = virtio_add_queue(&s->vdev, 128, virtio_balloon_receive_stats);
|
275 |
|
276 |
reset_stats(s); |
277 |
qemu_add_balloon_handler(virtio_balloon_to_target, s); |
278 |
|
279 |
register_savevm(dev, "virtio-balloon", -1, 1, |
280 |
virtio_balloon_save, virtio_balloon_load, s); |
281 |
|
282 |
return &s->vdev;
|
283 |
} |