]> git.proxmox.com Git - qemu.git/blame - block-bochs.c
CRIS: Use $eda to instead of debug1 (removed) for fault addr.
[qemu.git] / block-bochs.c
CommitLineData
a8753c34
FB
1/*
2 * Block driver for the various disk image formats used by Bochs
3 * Currently only for "growing" type in read-only mode
5fafdf24 4 *
a8753c34 5 * Copyright (c) 2005 Alex Beregszaszi
5fafdf24 6 *
a8753c34
FB
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 */
faf07963 25#include "qemu-common.h"
a8753c34
FB
26#include "block_int.h"
27
28/**************************************************************/
29
30#define HEADER_MAGIC "Bochs Virtual HD Image"
6850dd94
TS
31#define HEADER_VERSION 0x00020000
32#define HEADER_V1 0x00010000
a8753c34
FB
33#define HEADER_SIZE 512
34
35#define REDOLOG_TYPE "Redolog"
36#define GROWING_TYPE "Growing"
37
38// not allocated: 0xffffffff
39
40// always little-endian
6850dd94 41struct bochs_header_v1 {
a8753c34
FB
42 char magic[32]; // "Bochs Virtual HD Image"
43 char type[16]; // "Redolog"
44 char subtype[16]; // "Undoable" / "Volatile" / "Growing"
45 uint32_t version;
46 uint32_t header; // size of header
3b46e624 47
a8753c34
FB
48 union {
49 struct {
50 uint32_t catalog; // num of entries
51 uint32_t bitmap; // bitmap size
52 uint32_t extent; // extent size
53 uint64_t disk; // disk size
54 char padding[HEADER_SIZE - 64 - 8 - 20];
55 } redolog;
56 char padding[HEADER_SIZE - 64 - 8];
57 } extra;
58};
59
6850dd94
TS
60// always little-endian
61struct bochs_header {
62 char magic[32]; // "Bochs Virtual HD Image"
63 char type[16]; // "Redolog"
64 char subtype[16]; // "Undoable" / "Volatile" / "Growing"
65 uint32_t version;
66 uint32_t header; // size of header
3b46e624 67
6850dd94
TS
68 union {
69 struct {
70 uint32_t catalog; // num of entries
71 uint32_t bitmap; // bitmap size
72 uint32_t extent; // extent size
73 uint32_t reserved; // for ???
74 uint64_t disk; // disk size
75 char padding[HEADER_SIZE - 64 - 8 - 24];
76 } redolog;
77 char padding[HEADER_SIZE - 64 - 8];
78 } extra;
79};
80
a8753c34
FB
81typedef struct BDRVBochsState {
82 int fd;
83
84 uint32_t *catalog_bitmap;
85 int catalog_size;
3b46e624 86
a8753c34 87 int data_offset;
3b46e624 88
a8753c34
FB
89 int bitmap_blocks;
90 int extent_blocks;
91 int extent_size;
92} BDRVBochsState;
93
94static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
95{
96 const struct bochs_header *bochs = (const void *)buf;
3b46e624 97
a8753c34
FB
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) &&
6850dd94
TS
104 ((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
105 (le32_to_cpu(bochs->version) == HEADER_V1)))
a8753c34
FB
106 return 100;
107
108 return 0;
109}
110
83f64091 111static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
a8753c34
FB
112{
113 BDRVBochsState *s = bs->opaque;
114 int fd, i;
115 struct bochs_header bochs;
6850dd94 116 struct bochs_header_v1 header_v1;
a8753c34 117
83f64091 118 fd = open(filename, O_RDWR | O_BINARY);
a8753c34 119 if (fd < 0) {
83f64091 120 fd = open(filename, O_RDONLY | O_BINARY);
a8753c34
FB
121 if (fd < 0)
122 return -1;
123 }
3b46e624 124
a8753c34 125 bs->read_only = 1; // no write support yet
3b46e624 126
a8753c34
FB
127 s->fd = fd;
128
129 if (read(fd, &bochs, sizeof(bochs)) != sizeof(bochs)) {
130 goto fail;
131 }
132
133 if (strcmp(bochs.magic, HEADER_MAGIC) ||
134 strcmp(bochs.type, REDOLOG_TYPE) ||
135 strcmp(bochs.subtype, GROWING_TYPE) ||
6850dd94
TS
136 ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
137 (le32_to_cpu(bochs.version) != HEADER_V1))) {
a8753c34
FB
138 goto fail;
139 }
140
6850dd94
TS
141 if (le32_to_cpu(bochs.version) == HEADER_V1) {
142 memcpy(&header_v1, &bochs, sizeof(bochs));
143 bs->total_sectors = le64_to_cpu(header_v1.extra.redolog.disk) / 512;
144 } else {
145 bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
146 }
a8753c34
FB
147
148 lseek(s->fd, le32_to_cpu(bochs.header), SEEK_SET);
149
150 s->catalog_size = le32_to_cpu(bochs.extra.redolog.catalog);
151 s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);
152 if (!s->catalog_bitmap)
153 goto fail;
154 if (read(s->fd, s->catalog_bitmap, s->catalog_size * 4) !=
155 s->catalog_size * 4)
156 goto fail;
157 for (i = 0; i < s->catalog_size; i++)
158 le32_to_cpus(&s->catalog_bitmap[i]);
159
160 s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
161
162 s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512;
163 s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512;
3b46e624 164
a8753c34
FB
165 s->extent_size = le32_to_cpu(bochs.extra.redolog.extent);
166
167 return 0;
168 fail:
169 close(fd);
170 return -1;
171}
172
173static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
174{
175 BDRVBochsState *s = bs->opaque;
176 int64_t offset = sector_num * 512;
177 int64_t extent_index, extent_offset, bitmap_offset, block_offset;
178 char bitmap_entry;
179
180 // seek to sector
181 extent_index = offset / s->extent_size;
182 extent_offset = (offset % s->extent_size) / 512;
3b46e624 183
a8753c34
FB
184 if (s->catalog_bitmap[extent_index] == 0xffffffff)
185 {
186// fprintf(stderr, "page not allocated [%x - %x:%x]\n",
187// sector_num, extent_index, extent_offset);
188 return -1; // not allocated
189 }
190
191 bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] *
192 (s->extent_blocks + s->bitmap_blocks));
193 block_offset = bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
3b46e624 194
a8753c34
FB
195// fprintf(stderr, "sect: %x [ext i: %x o: %x] -> %x bitmap: %x block: %x\n",
196// sector_num, extent_index, extent_offset,
197// le32_to_cpu(s->catalog_bitmap[extent_index]),
198// bitmap_offset, block_offset);
3b46e624 199
a8753c34
FB
200 // read in bitmap for current extent
201 lseek(s->fd, bitmap_offset + (extent_offset / 8), SEEK_SET);
3b46e624 202
a8753c34 203 read(s->fd, &bitmap_entry, 1);
3b46e624 204
a8753c34
FB
205 if (!((bitmap_entry >> (extent_offset % 8)) & 1))
206 {
207// fprintf(stderr, "sector (%x) in bitmap not allocated\n",
208// sector_num);
209 return -1; // not allocated
210 }
211
212 lseek(s->fd, block_offset, SEEK_SET);
3b46e624 213
a8753c34
FB
214 return 0;
215}
216
5fafdf24 217static int bochs_read(BlockDriverState *bs, int64_t sector_num,
a8753c34
FB
218 uint8_t *buf, int nb_sectors)
219{
220 BDRVBochsState *s = bs->opaque;
221 int ret;
222
223 while (nb_sectors > 0) {
224 if (!seek_to_sector(bs, sector_num))
225 {
226 ret = read(s->fd, buf, 512);
227 if (ret != 512)
228 return -1;
229 }
230 else
231 memset(buf, 0, 512);
232 nb_sectors--;
233 sector_num++;
234 buf += 512;
235 }
236 return 0;
237}
238
239static void bochs_close(BlockDriverState *bs)
240{
241 BDRVBochsState *s = bs->opaque;
242 qemu_free(s->catalog_bitmap);
243 close(s->fd);
244}
245
246BlockDriver bdrv_bochs = {
247 "bochs",
248 sizeof(BDRVBochsState),
249 bochs_probe,
250 bochs_open,
251 bochs_read,
252 NULL,
253 bochs_close,
254};