ia64/xen-unstable

view tools/ioemu/block-vmdk.c @ 8740:3d7ea7972b39

Update patches for linux 2.6.15.

Signed-off-by: Christian Limpach <Christian.Limpach@cl.cam.ac.uk>
author cl349@firebug.cl.cam.ac.uk
date Thu Feb 02 17:16:00 2006 +0000 (2006-02-02)
parents 8e5fc5fe636c
children f7b43e5c42b9
line source
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"
27 /* XXX: this code is untested */
28 /* XXX: add write support */
30 #define VMDK3_MAGIC (('C' << 24) | ('O' << 16) | ('W' << 8) | 'D')
31 #define VMDK4_MAGIC (('K' << 24) | ('D' << 16) | ('M' << 8) | 'V')
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;
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;
61 #define L2_CACHE_SIZE 16
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;
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];
75 unsigned int cluster_sectors;
76 } BDRVVmdkState;
78 static int vmdk_probe(const uint8_t *buf, int buf_size, const char *filename)
79 {
80 uint32_t magic;
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 }
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;
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 = be32_to_cpu(magic);
105 if (magic == VMDK3_MAGIC) {
106 VMDK3Header header;
107 if (read(fd, &header, sizeof(header)) !=
108 sizeof(header))
109 goto fail;
110 s->cluster_sectors = le32_to_cpu(header.granularity);
111 s->l2_size = 1 << 9;
112 s->l1_size = 1 << 6;
113 bs->total_sectors = le32_to_cpu(header.disk_sectors);
114 s->l1_table_offset = le32_to_cpu(header.l1dir_offset) * 512;
115 s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
116 } else if (magic == VMDK4_MAGIC) {
117 VMDK4Header header;
119 if (read(fd, &header, sizeof(header)) != sizeof(header))
120 goto fail;
121 bs->total_sectors = le32_to_cpu(header.capacity);
122 s->cluster_sectors = le32_to_cpu(header.granularity);
123 s->l2_size = le32_to_cpu(header.num_gtes_per_gte);
124 s->l1_entry_sectors = s->l2_size * s->cluster_sectors;
125 if (s->l1_entry_sectors <= 0)
126 goto fail;
127 s->l1_size = (bs->total_sectors + s->l1_entry_sectors - 1)
128 / s->l1_entry_sectors;
129 s->l1_table_offset = le64_to_cpu(header.rgd_offset) * 512;
130 } else {
131 goto fail;
132 }
133 /* read the L1 table */
134 l1_size = s->l1_size * sizeof(uint32_t);
135 s->l1_table = qemu_malloc(l1_size);
136 if (!s->l1_table)
137 goto fail;
138 if (lseek(fd, s->l1_table_offset, SEEK_SET) == -1)
139 goto fail;
140 if (read(fd, s->l1_table, l1_size) != l1_size)
141 goto fail;
142 for(i = 0; i < s->l1_size; i++) {
143 le32_to_cpus(&s->l1_table[i]);
144 }
146 s->l2_cache = qemu_malloc(s->l2_size * L2_CACHE_SIZE * sizeof(uint32_t));
147 if (!s->l2_cache)
148 goto fail;
149 s->fd = fd;
150 /* XXX: currently only read only */
151 bs->read_only = 1;
152 return 0;
153 fail:
154 qemu_free(s->l1_table);
155 qemu_free(s->l2_cache);
156 close(fd);
157 return -1;
158 }
160 static uint64_t get_cluster_offset(BlockDriverState *bs,
161 uint64_t offset)
162 {
163 BDRVVmdkState *s = bs->opaque;
164 unsigned int l1_index, l2_offset, l2_index;
165 int min_index, i, j;
166 uint32_t min_count, *l2_table;
167 uint64_t cluster_offset;
169 l1_index = (offset >> 9) / s->l1_entry_sectors;
170 if (l1_index >= s->l1_size)
171 return 0;
172 l2_offset = s->l1_table[l1_index];
173 if (!l2_offset)
174 return 0;
176 for(i = 0; i < L2_CACHE_SIZE; i++) {
177 if (l2_offset == s->l2_cache_offsets[i]) {
178 /* increment the hit count */
179 if (++s->l2_cache_counts[i] == 0xffffffff) {
180 for(j = 0; j < L2_CACHE_SIZE; j++) {
181 s->l2_cache_counts[j] >>= 1;
182 }
183 }
184 l2_table = s->l2_cache + (i * s->l2_size);
185 goto found;
186 }
187 }
188 /* not found: load a new entry in the least used one */
189 min_index = 0;
190 min_count = 0xffffffff;
191 for(i = 0; i < L2_CACHE_SIZE; i++) {
192 if (s->l2_cache_counts[i] < min_count) {
193 min_count = s->l2_cache_counts[i];
194 min_index = i;
195 }
196 }
197 l2_table = s->l2_cache + (min_index * s->l2_size);
198 lseek(s->fd, (int64_t)l2_offset * 512, SEEK_SET);
199 if (read(s->fd, l2_table, s->l2_size * sizeof(uint32_t)) !=
200 s->l2_size * sizeof(uint32_t))
201 return 0;
202 s->l2_cache_offsets[min_index] = l2_offset;
203 s->l2_cache_counts[min_index] = 1;
204 found:
205 l2_index = ((offset >> 9) / s->cluster_sectors) % s->l2_size;
206 cluster_offset = le32_to_cpu(l2_table[l2_index]);
207 cluster_offset <<= 9;
208 return cluster_offset;
209 }
211 static int vmdk_is_allocated(BlockDriverState *bs, int64_t sector_num,
212 int nb_sectors, int *pnum)
213 {
214 BDRVVmdkState *s = bs->opaque;
215 int index_in_cluster, n;
216 uint64_t cluster_offset;
218 cluster_offset = get_cluster_offset(bs, sector_num << 9);
219 index_in_cluster = sector_num % s->cluster_sectors;
220 n = s->cluster_sectors - index_in_cluster;
221 if (n > nb_sectors)
222 n = nb_sectors;
223 *pnum = n;
224 return (cluster_offset != 0);
225 }
227 static int vmdk_read(BlockDriverState *bs, int64_t sector_num,
228 uint8_t *buf, int nb_sectors)
229 {
230 BDRVVmdkState *s = bs->opaque;
231 int ret, index_in_cluster, n;
232 uint64_t cluster_offset;
234 while (nb_sectors > 0) {
235 cluster_offset = get_cluster_offset(bs, sector_num << 9);
236 index_in_cluster = sector_num % s->cluster_sectors;
237 n = s->cluster_sectors - index_in_cluster;
238 if (n > nb_sectors)
239 n = nb_sectors;
240 if (!cluster_offset) {
241 memset(buf, 0, 512 * n);
242 } else {
243 lseek(s->fd, cluster_offset + index_in_cluster * 512, SEEK_SET);
244 ret = read(s->fd, buf, n * 512);
245 if (ret != n * 512)
246 return -1;
247 }
248 nb_sectors -= n;
249 sector_num += n;
250 buf += n * 512;
251 }
252 return 0;
253 }
255 static int vmdk_write(BlockDriverState *bs, int64_t sector_num,
256 const uint8_t *buf, int nb_sectors)
257 {
258 return -1;
259 }
261 static void vmdk_close(BlockDriverState *bs)
262 {
263 BDRVVmdkState *s = bs->opaque;
264 qemu_free(s->l1_table);
265 qemu_free(s->l2_cache);
266 close(s->fd);
267 }
269 BlockDriver bdrv_vmdk = {
270 "vmdk",
271 sizeof(BDRVVmdkState),
272 vmdk_probe,
273 vmdk_open,
274 vmdk_read,
275 vmdk_write,
276 vmdk_close,
277 NULL, /* no create yet */
278 vmdk_is_allocated,
279 };