root / block-vmdk.c @ ea2384d3
History | View | Annotate | Download (8.1 kB)
1 |
/*
|
---|---|
2 |
* Block driver for the VMDK format
|
3 |
*
|
4 |
* Copyright (c) 2004 Fabrice Bellard
|
5 |
*
|
6 |
* Permission is hereby granted, free of charge, to any person obtaining a copy
|
7 |
* of this software and associated documentation files (the "Software"), to deal
|
8 |
* in the Software without restriction, including without limitation the rights
|
9 |
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
|
10 |
* copies of the Software, and to permit persons to whom the Software is
|
11 |
* furnished to do so, subject to the following conditions:
|
12 |
*
|
13 |
* The above copyright notice and this permission notice shall be included in
|
14 |
* all copies or substantial portions of the Software.
|
15 |
*
|
16 |
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
|
17 |
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
|
18 |
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
|
19 |
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
|
20 |
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
|
21 |
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
|
22 |
* THE SOFTWARE.
|
23 |
*/
|
24 |
#include "vl.h" |
25 |
#include "block_int.h" |
26 |
|
27 |
/* XXX: this code is untested */
|
28 |
/* XXX: add write support */
|
29 |
|
30 |
#define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D') |
31 |
#define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V') |
32 |
|
33 |
typedef struct { |
34 |
uint32_t version; |
35 |
uint32_t flags; |
36 |
uint32_t disk_sectors; |
37 |
uint32_t granularity; |
38 |
uint32_t l1dir_offset; |
39 |
uint32_t l1dir_size; |
40 |
uint32_t file_sectors; |
41 |
uint32_t cylinders; |
42 |
uint32_t heads; |
43 |
uint32_t sectors_per_track; |
44 |
} VMDK3Header; |
45 |
|
46 |
typedef struct { |
47 |
uint32_t version; |
48 |
uint32_t flags; |
49 |
int64_t capacity; |
50 |
int64_t granularity; |
51 |
int64_t desc_offset; |
52 |
int64_t desc_size; |
53 |
int32_t num_gtes_per_gte; |
54 |
int64_t rgd_offset; |
55 |
int64_t gd_offset; |
56 |
int64_t grain_offset; |
57 |
char filler[1]; |
58 |
char check_bytes[4]; |
59 |
} VMDK4Header; |
60 |
|
61 |
#define L2_CACHE_SIZE 16 |
62 |
|
63 |
typedef struct BDRVVmdkState { |
64 |
int fd;
|
65 |
int64_t l1_table_offset; |
66 |
uint32_t *l1_table; |
67 |
unsigned int l1_size; |
68 |
uint32_t l1_entry_sectors; |
69 |
|
70 |
unsigned int l2_size; |
71 |
uint32_t *l2_cache; |
72 |
uint32_t l2_cache_offsets[L2_CACHE_SIZE]; |
73 |
uint32_t l2_cache_counts[L2_CACHE_SIZE]; |
74 |
|
75 |
unsigned int cluster_sectors; |
76 |
} BDRVVmdkState; |
77 |
|
78 |
static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename) |
79 |
{ |
80 |
uint32_t magic; |
81 |
|
82 |
if (buf_size < 4) |
83 |
return 0; |
84 |
magic = be32_to_cpu(*(uint32_t *)buf); |
85 |
if (magic == VMDK3_MAGIC ||
|
86 |
magic == VMDK4_MAGIC) |
87 |
return 100; |
88 |
else
|
89 |
return 0; |
90 |
} |
91 |
|
92 |
static int vmdk_open(BlockDriverState *bs, const char *filename) |
93 |
{ |
94 |
BDRVVmdkState *s = bs->opaque; |
95 |
int fd, i;
|
96 |
uint32_t magic; |
97 |
int l1_size;
|
98 |
|
99 |
fd = open(filename, O_RDONLY | O_BINARY | O_LARGEFILE); |
100 |
if (fd < 0) |
101 |
return -1; |
102 |
if (read(fd, &magic, sizeof(magic)) != sizeof(magic)) |
103 |
goto fail;
|
104 |
magic = le32_to_cpu(magic); |
105 |
|
106 |
if (magic == VMDK3_MAGIC) {
|
107 |
VMDK3Header header; |
108 |
if (read(fd, &header, sizeof(header)) != |
109 |
sizeof(header))
|
110 |
goto fail;
|
111 |
s->cluster_sectors = le32_to_cpu(header.granularity); |
112 |
s->l2_size = 1 << 9; |
113 |
s->l1_size = 1 << 6; |
114 |
bs->total_sectors = le32_to_cpu(header.disk_sectors); |
115 |
s->l1_table_offset = le32_to_cpu(header.l1dir_offset) * 512;
|
116 |
s->l1_entry_sectors = s->l2_size * s->cluster_sectors; |
117 |
} else if (magic == VMDK4_MAGIC) { |
118 |
VMDK4Header header; |
119 |
|
120 |
if (read(fd, &header, sizeof(header)) != sizeof(header)) |
121 |
goto fail;
|
122 |
bs->total_sectors = le32_to_cpu(header.capacity); |
123 |
s->cluster_sectors = le32_to_cpu(header.granularity); |
124 |
s->l2_size = le32_to_cpu(header.num_gtes_per_gte); |
125 |
s->l1_entry_sectors = s->l2_size * s->cluster_sectors; |
126 |
if (s->l1_entry_sectors <= 0) |
127 |
goto fail;
|
128 |
s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
|
129 |
/ s->l1_entry_sectors; |
130 |
s->l1_table_offset = le64_to_cpu(header.rgd_offset) * 512;
|
131 |
} else {
|
132 |
goto fail;
|
133 |
} |
134 |
/* read the L1 table */
|
135 |
l1_size = s->l1_size * sizeof(uint32_t);
|
136 |
s->l1_table = qemu_malloc(l1_size); |
137 |
if (!s->l1_table)
|
138 |
goto fail;
|
139 |
if (read(s->fd, s->l1_table, l1_size) != l1_size)
|
140 |
goto fail;
|
141 |
for(i = 0; i < s->l1_size; i++) { |
142 |
le32_to_cpus(&s->l1_table[i]); |
143 |
} |
144 |
|
145 |
s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
|
146 |
if (!s->l2_cache)
|
147 |
goto fail;
|
148 |
s->fd = fd; |
149 |
/* XXX: currently only read only */
|
150 |
bs->read_only = 1;
|
151 |
return 0; |
152 |
fail:
|
153 |
qemu_free(s->l1_table); |
154 |
qemu_free(s->l2_cache); |
155 |
close(fd); |
156 |
return -1; |
157 |
} |
158 |
|
159 |
static uint64_t get_cluster_offset(BlockDriverState *bs,
|
160 |
uint64_t offset) |
161 |
{ |
162 |
BDRVVmdkState *s = bs->opaque; |
163 |
unsigned int l1_index, l2_offset, l2_index; |
164 |
int min_index, i, j;
|
165 |
uint32_t min_count, *l2_table; |
166 |
uint64_t cluster_offset; |
167 |
|
168 |
l1_index = (offset >> 9) / s->l1_entry_sectors;
|
169 |
if (l1_index >= s->l1_size)
|
170 |
return 0; |
171 |
l2_offset = s->l1_table[l1_index]; |
172 |
if (!l2_offset)
|
173 |
return 0; |
174 |
|
175 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
176 |
if (l2_offset == s->l2_cache_offsets[i]) {
|
177 |
/* increment the hit count */
|
178 |
if (++s->l2_cache_counts[i] == 0xffffffff) { |
179 |
for(j = 0; j < L2_CACHE_SIZE; j++) { |
180 |
s->l2_cache_counts[j] >>= 1;
|
181 |
} |
182 |
} |
183 |
l2_table = s->l2_cache + (i * s->l2_size); |
184 |
goto found;
|
185 |
} |
186 |
} |
187 |
/* not found: load a new entry in the least used one */
|
188 |
min_index = 0;
|
189 |
min_count = 0xffffffff;
|
190 |
for(i = 0; i < L2_CACHE_SIZE; i++) { |
191 |
if (s->l2_cache_counts[i] < min_count) {
|
192 |
min_count = s->l2_cache_counts[i]; |
193 |
min_index = i; |
194 |
} |
195 |
} |
196 |
l2_table = s->l2_cache + (min_index * s->l2_size); |
197 |
lseek(s->fd, (int64_t)l2_offset * 512, SEEK_SET);
|
198 |
if (read(s->fd, l2_table, s->l2_size * sizeof(uint32_t)) != |
199 |
s->l2_size * sizeof(uint32_t))
|
200 |
return 0; |
201 |
s->l2_cache_offsets[min_index] = l2_offset; |
202 |
s->l2_cache_counts[min_index] = 1;
|
203 |
found:
|
204 |
l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
|
205 |
cluster_offset = le32_to_cpu(l2_table[l2_index]); |
206 |
cluster_offset <<= 9;
|
207 |
return cluster_offset;
|
208 |
} |
209 |
|
210 |
static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num, |
211 |
int nb_sectors, int *pnum) |
212 |
{ |
213 |
BDRVVmdkState *s = bs->opaque; |
214 |
int index_in_cluster, n;
|
215 |
uint64_t cluster_offset; |
216 |
|
217 |
cluster_offset = get_cluster_offset(bs, sector_num << 9);
|
218 |
index_in_cluster = sector_num % s->cluster_sectors; |
219 |
n = s->cluster_sectors - index_in_cluster; |
220 |
if (n > nb_sectors)
|
221 |
n = nb_sectors; |
222 |
*pnum = n; |
223 |
return (cluster_offset != 0); |
224 |
} |
225 |
|
226 |
static int vmdk_read(BlockDriverState *bs, int64_t sector_num, |
227 |
uint8_t *buf, int nb_sectors)
|
228 |
{ |
229 |
BDRVVmdkState *s = bs->opaque; |
230 |
int ret, index_in_cluster, n;
|
231 |
uint64_t cluster_offset; |
232 |
|
233 |
while (nb_sectors > 0) { |
234 |
cluster_offset = get_cluster_offset(bs, sector_num << 9);
|
235 |
index_in_cluster = sector_num % s->cluster_sectors; |
236 |
n = s->cluster_sectors - index_in_cluster; |
237 |
if (n > nb_sectors)
|
238 |
n = nb_sectors; |
239 |
if (!cluster_offset) {
|
240 |
memset(buf, 0, 512 * n); |
241 |
} else {
|
242 |
lseek64(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
|
243 |
ret = read(s->fd, buf, n * 512);
|
244 |
if (ret != n * 512) |
245 |
return -1; |
246 |
} |
247 |
nb_sectors -= n; |
248 |
sector_num += n; |
249 |
buf += n * 512;
|
250 |
} |
251 |
return 0; |
252 |
} |
253 |
|
254 |
static int vmdk_write(BlockDriverState *bs, int64_t sector_num, |
255 |
const uint8_t *buf, int nb_sectors) |
256 |
{ |
257 |
return -1; |
258 |
} |
259 |
|
260 |
static int vmdk_close(BlockDriverState *bs) |
261 |
{ |
262 |
BDRVVmdkState *s = bs->opaque; |
263 |
qemu_free(s->l1_table); |
264 |
qemu_free(s->l2_cache); |
265 |
close(s->fd); |
266 |
} |
267 |
|
268 |
BlockDriver bdrv_vmdk = { |
269 |
"vmdk",
|
270 |
sizeof(BDRVVmdkState),
|
271 |
vmdk_probe, |
272 |
vmdk_open, |
273 |
vmdk_read, |
274 |
vmdk_write, |
275 |
vmdk_close, |
276 |
NULL, /* no create yet */ |
277 |
vmdk_is_allocated, |
278 |
}; |