Temporary workaround for ppc on ppc
[qemu-kvm/fedora.git] / block-bochs.c
blob593cf697c1ad550e04e67a4ee271555916ee32e1
1 /*
2 * Block driver for the various disk image formats used by Bochs
3 * Currently only for "growing" type in read-only mode
5 * Copyright (c) 2005 Alex Beregszaszi
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:
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
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.
25 #include "qemu-common.h"
26 #include "block_int.h"
28 /**************************************************************/
30 #define HEADER_MAGIC "Bochs Virtual HD Image"
31 #define HEADER_VERSION 0x00020000
32 #define HEADER_V1 0x00010000
33 #define HEADER_SIZE 512
35 #define REDOLOG_TYPE "Redolog"
36 #define GROWING_TYPE "Growing"
38 // not allocated: 0xffffffff
40 // always little-endian
41 struct bochs_header_v1 {
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
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;
60 // always little-endian
61 struct 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
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;
81 typedef struct BDRVBochsState {
82 int fd;
84 uint32_t *catalog_bitmap;
85 int catalog_size;
87 int data_offset;
89 int bitmap_blocks;
90 int extent_blocks;
91 int extent_size;
92 } BDRVBochsState;
94 static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
96 const struct bochs_header *bochs = (const void *)buf;
98 if (buf_size < HEADER_SIZE)
99 return 0;
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;
108 return 0;
111 static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
113 BDRVBochsState *s = bs->opaque;
114 int fd, i;
115 struct bochs_header bochs;
116 struct bochs_header_v1 header_v1;
118 fd = open(filename, O_RDWR | O_BINARY);
119 if (fd < 0) {
120 fd = open(filename, O_RDONLY | O_BINARY);
121 if (fd < 0)
122 return -1;
125 bs->read_only = 1; // no write support yet
127 s->fd = fd;
129 if (read(fd, &bochs, sizeof(bochs)) != sizeof(bochs)) {
130 goto fail;
133 if (strcmp(bochs.magic, HEADER_MAGIC) ||
134 strcmp(bochs.type, REDOLOG_TYPE) ||
135 strcmp(bochs.subtype, GROWING_TYPE) ||
136 ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
137 (le32_to_cpu(bochs.version) != HEADER_V1))) {
138 goto fail;
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;
148 lseek(s->fd, le32_to_cpu(bochs.header), SEEK_SET);
150 s->catalog_size = le32_to_cpu(bochs.extra.redolog.catalog);
151 s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);
152 if (read(s->fd, s->catalog_bitmap, s->catalog_size * 4) !=
153 s->catalog_size * 4)
154 goto fail;
155 for (i = 0; i < s->catalog_size; i++)
156 le32_to_cpus(&s->catalog_bitmap[i]);
158 s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
160 s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512;
161 s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512;
163 s->extent_size = le32_to_cpu(bochs.extra.redolog.extent);
165 return 0;
166 fail:
167 close(fd);
168 return -1;
171 static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
173 BDRVBochsState *s = bs->opaque;
174 int64_t offset = sector_num * 512;
175 int64_t extent_index, extent_offset, bitmap_offset, block_offset;
176 char bitmap_entry;
178 // seek to sector
179 extent_index = offset / s->extent_size;
180 extent_offset = (offset % s->extent_size) / 512;
182 if (s->catalog_bitmap[extent_index] == 0xffffffff)
184 // fprintf(stderr, "page not allocated [%x - %x:%x]\n",
185 // sector_num, extent_index, extent_offset);
186 return -1; // not allocated
189 bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] *
190 (s->extent_blocks + s->bitmap_blocks));
191 block_offset = bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
193 // fprintf(stderr, "sect: %x [ext i: %x o: %x] -> %x bitmap: %x block: %x\n",
194 // sector_num, extent_index, extent_offset,
195 // le32_to_cpu(s->catalog_bitmap[extent_index]),
196 // bitmap_offset, block_offset);
198 // read in bitmap for current extent
199 lseek(s->fd, bitmap_offset + (extent_offset / 8), SEEK_SET);
201 read(s->fd, &bitmap_entry, 1);
203 if (!((bitmap_entry >> (extent_offset % 8)) & 1))
205 // fprintf(stderr, "sector (%x) in bitmap not allocated\n",
206 // sector_num);
207 return -1; // not allocated
210 lseek(s->fd, block_offset, SEEK_SET);
212 return 0;
215 static int bochs_read(BlockDriverState *bs, int64_t sector_num,
216 uint8_t *buf, int nb_sectors)
218 BDRVBochsState *s = bs->opaque;
219 int ret;
221 while (nb_sectors > 0) {
222 if (!seek_to_sector(bs, sector_num))
224 ret = read(s->fd, buf, 512);
225 if (ret != 512)
226 return -1;
228 else
229 memset(buf, 0, 512);
230 nb_sectors--;
231 sector_num++;
232 buf += 512;
234 return 0;
237 static void bochs_close(BlockDriverState *bs)
239 BDRVBochsState *s = bs->opaque;
240 qemu_free(s->catalog_bitmap);
241 close(s->fd);
244 BlockDriver bdrv_bochs = {
245 "bochs",
246 sizeof(BDRVBochsState),
247 bochs_probe,
248 bochs_open,
249 bochs_read,
250 NULL,
251 bochs_close,