PPC: e500mc: add missing IVORs to bitmap
[qemu.git] / block / bochs.c
1 /*
2 * Block driver for the various disk image formats used by Bochs
3 * Currently only for "growing" type in read-only mode
4 *
5 * Copyright (c) 2005 Alex Beregszaszi
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25 #include "qemu-common.h"
26 #include "block_int.h"
27 #include "module.h"
28
29 /**************************************************************/
30
31 #define HEADER_MAGIC "Bochs Virtual HD Image"
32 #define HEADER_VERSION 0x00020000
33 #define HEADER_V1 0x00010000
34 #define HEADER_SIZE 512
35
36 #define REDOLOG_TYPE "Redolog"
37 #define GROWING_TYPE "Growing"
38
39 // not allocated: 0xffffffff
40
41 // always little-endian
42 struct bochs_header_v1 {
43 char magic[32]; // "Bochs Virtual HD Image"
44 char type[16]; // "Redolog"
45 char subtype[16]; // "Undoable" / "Volatile" / "Growing"
46 uint32_t version;
47 uint32_t header; // size of header
48
49 union {
50 struct {
51 uint32_t catalog; // num of entries
52 uint32_t bitmap; // bitmap size
53 uint32_t extent; // extent size
54 uint64_t disk; // disk size
55 char padding[HEADER_SIZE - 64 - 8 - 20];
56 } redolog;
57 char padding[HEADER_SIZE - 64 - 8];
58 } extra;
59 };
60
61 // always little-endian
62 struct bochs_header {
63 char magic[32]; // "Bochs Virtual HD Image"
64 char type[16]; // "Redolog"
65 char subtype[16]; // "Undoable" / "Volatile" / "Growing"
66 uint32_t version;
67 uint32_t header; // size of header
68
69 union {
70 struct {
71 uint32_t catalog; // num of entries
72 uint32_t bitmap; // bitmap size
73 uint32_t extent; // extent size
74 uint32_t reserved; // for ???
75 uint64_t disk; // disk size
76 char padding[HEADER_SIZE - 64 - 8 - 24];
77 } redolog;
78 char padding[HEADER_SIZE - 64 - 8];
79 } extra;
80 };
81
82 typedef struct BDRVBochsState {
83 CoMutex lock;
84 uint32_t *catalog_bitmap;
85 int catalog_size;
86
87 int data_offset;
88
89 int bitmap_blocks;
90 int extent_blocks;
91 int extent_size;
92 } BDRVBochsState;
93
94 static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
95 {
96 const struct bochs_header *bochs = (const void *)buf;
97
98 if (buf_size < HEADER_SIZE)
99 return 0;
100
101 if (!strcmp(bochs->magic, HEADER_MAGIC) &&
102 !strcmp(bochs->type, REDOLOG_TYPE) &&
103 !strcmp(bochs->subtype, GROWING_TYPE) &&
104 ((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
105 (le32_to_cpu(bochs->version) == HEADER_V1)))
106 return 100;
107
108 return 0;
109 }
110
111 static int bochs_open(BlockDriverState *bs, int flags)
112 {
113 BDRVBochsState *s = bs->opaque;
114 int i;
115 struct bochs_header bochs;
116 struct bochs_header_v1 header_v1;
117
118 bs->read_only = 1; // no write support yet
119
120 if (bdrv_pread(bs->file, 0, &bochs, sizeof(bochs)) != sizeof(bochs)) {
121 goto fail;
122 }
123
124 if (strcmp(bochs.magic, HEADER_MAGIC) ||
125 strcmp(bochs.type, REDOLOG_TYPE) ||
126 strcmp(bochs.subtype, GROWING_TYPE) ||
127 ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
128 (le32_to_cpu(bochs.version) != HEADER_V1))) {
129 goto fail;
130 }
131
132 if (le32_to_cpu(bochs.version) == HEADER_V1) {
133 memcpy(&header_v1, &bochs, sizeof(bochs));
134 bs->total_sectors = le64_to_cpu(header_v1.extra.redolog.disk) / 512;
135 } else {
136 bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
137 }
138
139 s->catalog_size = le32_to_cpu(bochs.extra.redolog.catalog);
140 s->catalog_bitmap = g_malloc(s->catalog_size * 4);
141 if (bdrv_pread(bs->file, le32_to_cpu(bochs.header), s->catalog_bitmap,
142 s->catalog_size * 4) != s->catalog_size * 4)
143 goto fail;
144 for (i = 0; i < s->catalog_size; i++)
145 le32_to_cpus(&s->catalog_bitmap[i]);
146
147 s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
148
149 s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512;
150 s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512;
151
152 s->extent_size = le32_to_cpu(bochs.extra.redolog.extent);
153
154 qemu_co_mutex_init(&s->lock);
155 return 0;
156 fail:
157 return -1;
158 }
159
160 static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
161 {
162 BDRVBochsState *s = bs->opaque;
163 int64_t offset = sector_num * 512;
164 int64_t extent_index, extent_offset, bitmap_offset;
165 char bitmap_entry;
166
167 // seek to sector
168 extent_index = offset / s->extent_size;
169 extent_offset = (offset % s->extent_size) / 512;
170
171 if (s->catalog_bitmap[extent_index] == 0xffffffff) {
172 return -1; /* not allocated */
173 }
174
175 bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] *
176 (s->extent_blocks + s->bitmap_blocks));
177
178 /* read in bitmap for current extent */
179 if (bdrv_pread(bs->file, bitmap_offset + (extent_offset / 8),
180 &bitmap_entry, 1) != 1) {
181 return -1;
182 }
183
184 if (!((bitmap_entry >> (extent_offset % 8)) & 1)) {
185 return -1; /* not allocated */
186 }
187
188 return bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
189 }
190
191 static int bochs_read(BlockDriverState *bs, int64_t sector_num,
192 uint8_t *buf, int nb_sectors)
193 {
194 int ret;
195
196 while (nb_sectors > 0) {
197 int64_t block_offset = seek_to_sector(bs, sector_num);
198 if (block_offset >= 0) {
199 ret = bdrv_pread(bs->file, block_offset, buf, 512);
200 if (ret != 512) {
201 return -1;
202 }
203 } else
204 memset(buf, 0, 512);
205 nb_sectors--;
206 sector_num++;
207 buf += 512;
208 }
209 return 0;
210 }
211
212 static coroutine_fn int bochs_co_read(BlockDriverState *bs, int64_t sector_num,
213 uint8_t *buf, int nb_sectors)
214 {
215 int ret;
216 BDRVBochsState *s = bs->opaque;
217 qemu_co_mutex_lock(&s->lock);
218 ret = bochs_read(bs, sector_num, buf, nb_sectors);
219 qemu_co_mutex_unlock(&s->lock);
220 return ret;
221 }
222
223 static void bochs_close(BlockDriverState *bs)
224 {
225 BDRVBochsState *s = bs->opaque;
226 g_free(s->catalog_bitmap);
227 }
228
229 static BlockDriver bdrv_bochs = {
230 .format_name = "bochs",
231 .instance_size = sizeof(BDRVBochsState),
232 .bdrv_probe = bochs_probe,
233 .bdrv_open = bochs_open,
234 .bdrv_read = bochs_co_read,
235 .bdrv_close = bochs_close,
236 };
237
238 static void bdrv_bochs_init(void)
239 {
240 bdrv_register(&bdrv_bochs);
241 }
242
243 block_init(bdrv_bochs_init);