1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
|
/*
* Virtio Block Device
*
* Copyright IBM, Corp. 2008
*
* Authors:
* Anthony Liguori <aliguori@us.ibm.com>
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include "qemu-common.h"
#include "virtio.h"
#include "pc.h"
#include "sysemu.h"
#include "cpu.h"
#include "balloon.h"
#include "virtio-balloon.h"
#include "kvm.h"
#if defined(__linux__)
#include <sys/mman.h>
#endif
typedef struct VirtIOBalloon
{
VirtIODevice vdev;
VirtQueue *ivq, *dvq;
uint32_t num_pages;
uint32_t actual;
} VirtIOBalloon;
static VirtIOBalloon *to_virtio_balloon(VirtIODevice *vdev)
{
return (VirtIOBalloon *)vdev;
}
static void balloon_page(void *addr, int deflate)
{
#if defined(__linux__)
if (!kvm_enabled() || kvm_has_sync_mmu())
madvise(addr, TARGET_PAGE_SIZE,
deflate ? MADV_WILLNEED : MADV_DONTNEED);
#endif
}
/* FIXME: once we do a virtio refactoring, this will get subsumed into common
* code */
static size_t memcpy_from_iovector(void *data, size_t offset, size_t size,
struct iovec *iov, int iovlen)
{
int i;
uint8_t *ptr = data;
size_t iov_off = 0;
size_t data_off = 0;
for (i = 0; i < iovlen && size; i++) {
if (offset < (iov_off + iov[i].iov_len)) {
size_t len = MIN((iov_off + iov[i].iov_len) - offset , size);
memcpy(ptr + data_off, iov[i].iov_base + (offset - iov_off), len);
data_off += len;
offset += len;
size -= len;
}
iov_off += iov[i].iov_len;
}
return data_off;
}
static void virtio_balloon_handle_output(VirtIODevice *vdev, VirtQueue *vq)
{
VirtIOBalloon *s = to_virtio_balloon(vdev);
VirtQueueElement elem;
while (virtqueue_pop(vq, &elem)) {
size_t offset = 0;
uint32_t pfn;
while (memcpy_from_iovector(&pfn, offset, 4,
elem.out_sg, elem.out_num) == 4) {
ram_addr_t pa;
ram_addr_t addr;
pa = (ram_addr_t)ldl_p(&pfn) << VIRTIO_BALLOON_PFN_SHIFT;
offset += 4;
addr = cpu_get_physical_page_desc(pa);
if ((addr & ~TARGET_PAGE_MASK) != IO_MEM_RAM)
continue;
balloon_page(phys_ram_base + addr, !!(vq == s->dvq));
}
virtqueue_push(vq, &elem, offset);
virtio_notify(vdev, vq);
}
}
static void virtio_balloon_get_config(VirtIODevice *vdev, uint8_t *config_data)
{
VirtIOBalloon *dev = to_virtio_balloon(vdev);
struct virtio_balloon_config config;
config.num_pages = cpu_to_le32(dev->num_pages);
config.actual = cpu_to_le32(dev->actual);
memcpy(config_data, &config, 8);
}
static void virtio_balloon_set_config(VirtIODevice *vdev,
const uint8_t *config_data)
{
VirtIOBalloon *dev = to_virtio_balloon(vdev);
struct virtio_balloon_config config;
memcpy(&config, config_data, 8);
dev->actual = config.actual;
}
static uint32_t virtio_balloon_get_features(VirtIODevice *vdev)
{
return 0;
}
static ram_addr_t virtio_balloon_to_target(void *opaque, ram_addr_t target)
{
VirtIOBalloon *dev = opaque;
if (target > ram_size)
target = ram_size;
if (target) {
dev->num_pages = (ram_size - target) >> VIRTIO_BALLOON_PFN_SHIFT;
virtio_notify_config(&dev->vdev);
}
return ram_size - (dev->actual << VIRTIO_BALLOON_PFN_SHIFT);
}
static void virtio_balloon_save(QEMUFile *f, void *opaque)
{
VirtIOBalloon *s = opaque;
virtio_save(&s->vdev, f);
qemu_put_be32(f, s->num_pages);
qemu_put_be32(f, s->actual);
}
static int virtio_balloon_load(QEMUFile *f, void *opaque, int version_id)
{
VirtIOBalloon *s = opaque;
if (version_id != 1)
return -EINVAL;
virtio_load(&s->vdev, f);
s->num_pages = qemu_get_be32(f);
s->actual = qemu_get_be32(f);
return 0;
}
void *virtio_balloon_init(PCIBus *bus)
{
VirtIOBalloon *s;
s = (VirtIOBalloon *)virtio_init_pci(bus, "virtio-balloon",
6900, 0x1002,
0, VIRTIO_ID_BALLOON,
0x05, 0x00, 0x00,
8, sizeof(VirtIOBalloon));
if (s == NULL)
return NULL;
s->vdev.get_config = virtio_balloon_get_config;
s->vdev.set_config = virtio_balloon_set_config;
s->vdev.get_features = virtio_balloon_get_features;
s->ivq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
s->dvq = virtio_add_queue(&s->vdev, 128, virtio_balloon_handle_output);
qemu_add_balloon_handler(virtio_balloon_to_target, s);
register_savevm("virtio-balloon", -1, 1, virtio_balloon_save, virtio_balloon_load, s);
return &s->vdev;
}
|
