blob: 199ac2b9af7ba4b61a64b4171c2700fadf0f71cc [file] [log] [blame]
bellarda8753c32005-04-26 21:34:00 +00001/*
2 * Block driver for the various disk image formats used by Bochs
3 * Currently only for "growing" type in read-only mode
ths5fafdf22007-09-16 21:08:06 +00004 *
bellarda8753c32005-04-26 21:34:00 +00005 * Copyright (c) 2005 Alex Beregszaszi
ths5fafdf22007-09-16 21:08:06 +00006 *
bellarda8753c32005-04-26 21:34:00 +00007 * 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 */
pbrookfaf07962007-11-11 02:51:17 +000025#include "qemu-common.h"
Paolo Bonzini737e1502012-12-17 18:19:44 +010026#include "block/block_int.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010027#include "qemu/module.h"
bellarda8753c32005-04-26 21:34:00 +000028
29/**************************************************************/
30
31#define HEADER_MAGIC "Bochs Virtual HD Image"
ths6850dd92007-01-05 18:56:04 +000032#define HEADER_VERSION 0x00020000
33#define HEADER_V1 0x00010000
bellarda8753c32005-04-26 21:34:00 +000034#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
42struct bochs_header {
Kevin Wolf3dd8a672014-03-26 13:05:31 +010043 char magic[32]; /* "Bochs Virtual HD Image" */
44 char type[16]; /* "Redolog" */
45 char subtype[16]; /* "Undoable" / "Volatile" / "Growing" */
bellarda8753c32005-04-26 21:34:00 +000046 uint32_t version;
Kevin Wolf3dd8a672014-03-26 13:05:31 +010047 uint32_t header; /* size of header */
48
49 uint32_t catalog; /* num of entries */
50 uint32_t bitmap; /* bitmap size */
51 uint32_t extent; /* extent size */
ths3b46e622007-09-17 08:09:54 +000052
bellarda8753c32005-04-26 21:34:00 +000053 union {
Kevin Wolf3dd8a672014-03-26 13:05:31 +010054 struct {
55 uint32_t reserved; /* for ??? */
56 uint64_t disk; /* disk size */
57 char padding[HEADER_SIZE - 64 - 20 - 12];
58 } QEMU_PACKED redolog;
59 struct {
60 uint64_t disk; /* disk size */
61 char padding[HEADER_SIZE - 64 - 20 - 8];
62 } QEMU_PACKED redolog_v1;
63 char padding[HEADER_SIZE - 64 - 20];
bellarda8753c32005-04-26 21:34:00 +000064 } extra;
Kevin Wolf3dd8a672014-03-26 13:05:31 +010065} QEMU_PACKED;
bellarda8753c32005-04-26 21:34:00 +000066
67typedef struct BDRVBochsState {
Paolo Bonzini848c66e2011-10-20 13:16:21 +020068 CoMutex lock;
bellarda8753c32005-04-26 21:34:00 +000069 uint32_t *catalog_bitmap;
Kevin Wolf246f6582014-03-26 13:05:32 +010070 uint32_t catalog_size;
ths3b46e622007-09-17 08:09:54 +000071
Kevin Wolf246f6582014-03-26 13:05:32 +010072 uint32_t data_offset;
ths3b46e622007-09-17 08:09:54 +000073
Kevin Wolf246f6582014-03-26 13:05:32 +010074 uint32_t bitmap_blocks;
75 uint32_t extent_blocks;
76 uint32_t extent_size;
bellarda8753c32005-04-26 21:34:00 +000077} BDRVBochsState;
78
79static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
80{
81 const struct bochs_header *bochs = (const void *)buf;
ths3b46e622007-09-17 08:09:54 +000082
bellarda8753c32005-04-26 21:34:00 +000083 if (buf_size < HEADER_SIZE)
84 return 0;
85
86 if (!strcmp(bochs->magic, HEADER_MAGIC) &&
87 !strcmp(bochs->type, REDOLOG_TYPE) &&
88 !strcmp(bochs->subtype, GROWING_TYPE) &&
ths6850dd92007-01-05 18:56:04 +000089 ((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
90 (le32_to_cpu(bochs->version) == HEADER_V1)))
bellarda8753c32005-04-26 21:34:00 +000091 return 100;
92
93 return 0;
94}
95
Max Reitz015a1032013-09-05 14:22:29 +020096static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
97 Error **errp)
bellarda8753c32005-04-26 21:34:00 +000098{
99 BDRVBochsState *s = bs->opaque;
Kevin Wolf246f6582014-03-26 13:05:32 +0100100 uint32_t i;
bellarda8753c32005-04-26 21:34:00 +0000101 struct bochs_header bochs;
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100102 int ret;
bellarda8753c32005-04-26 21:34:00 +0000103
bellarda8753c32005-04-26 21:34:00 +0000104 bs->read_only = 1; // no write support yet
ths3b46e622007-09-17 08:09:54 +0000105
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100106 ret = bdrv_pread(bs->file, 0, &bochs, sizeof(bochs));
107 if (ret < 0) {
108 return ret;
bellarda8753c32005-04-26 21:34:00 +0000109 }
110
111 if (strcmp(bochs.magic, HEADER_MAGIC) ||
112 strcmp(bochs.type, REDOLOG_TYPE) ||
113 strcmp(bochs.subtype, GROWING_TYPE) ||
ths6850dd92007-01-05 18:56:04 +0000114 ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
115 (le32_to_cpu(bochs.version) != HEADER_V1))) {
Paolo Bonzini76abe402014-02-17 14:44:06 +0100116 error_setg(errp, "Image not in Bochs format");
117 return -EINVAL;
bellarda8753c32005-04-26 21:34:00 +0000118 }
119
ths6850dd92007-01-05 18:56:04 +0000120 if (le32_to_cpu(bochs.version) == HEADER_V1) {
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100121 bs->total_sectors = le64_to_cpu(bochs.extra.redolog_v1.disk) / 512;
ths6850dd92007-01-05 18:56:04 +0000122 } else {
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100123 bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
ths6850dd92007-01-05 18:56:04 +0000124 }
bellarda8753c32005-04-26 21:34:00 +0000125
Kevin Wolfe3737b82014-03-26 13:05:33 +0100126 /* Limit to 1M entries to avoid unbounded allocation. This is what is
127 * needed for the largest image that bximage can create (~8 TB). */
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100128 s->catalog_size = le32_to_cpu(bochs.catalog);
Kevin Wolfe3737b82014-03-26 13:05:33 +0100129 if (s->catalog_size > 0x100000) {
130 error_setg(errp, "Catalog size is too large");
131 return -EFBIG;
132 }
133
Markus Armbruster02c4f262014-08-19 10:31:09 +0200134 s->catalog_bitmap = g_try_new(uint32_t, s->catalog_size);
Kevin Wolf7bf665e2014-05-20 13:21:26 +0200135 if (s->catalog_size && s->catalog_bitmap == NULL) {
136 error_setg(errp, "Could not allocate memory for catalog");
137 return -ENOMEM;
138 }
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100139
140 ret = bdrv_pread(bs->file, le32_to_cpu(bochs.header), s->catalog_bitmap,
141 s->catalog_size * 4);
142 if (ret < 0) {
143 goto fail;
144 }
145
bellarda8753c32005-04-26 21:34:00 +0000146 for (i = 0; i < s->catalog_size; i++)
147 le32_to_cpus(&s->catalog_bitmap[i]);
148
149 s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
150
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100151 s->bitmap_blocks = 1 + (le32_to_cpu(bochs.bitmap) - 1) / 512;
152 s->extent_blocks = 1 + (le32_to_cpu(bochs.extent) - 1) / 512;
ths3b46e622007-09-17 08:09:54 +0000153
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100154 s->extent_size = le32_to_cpu(bochs.extent);
Kevin Wolf715c3f62014-04-09 12:10:34 +0200155 if (s->extent_size < BDRV_SECTOR_SIZE) {
156 /* bximage actually never creates extents smaller than 4k */
157 error_setg(errp, "Extent size must be at least 512");
158 ret = -EINVAL;
159 goto fail;
160 } else if (!is_power_of_2(s->extent_size)) {
161 error_setg(errp, "Extent size %" PRIu32 " is not a power of two",
162 s->extent_size);
Kevin Wolf28ec11b2014-04-09 11:19:04 +0200163 ret = -EINVAL;
164 goto fail;
Kevin Wolf8e53abb2014-03-26 13:05:34 +0100165 } else if (s->extent_size > 0x800000) {
166 error_setg(errp, "Extent size %" PRIu32 " is too large",
167 s->extent_size);
Kevin Wolf28ec11b2014-04-09 11:19:04 +0200168 ret = -EINVAL;
169 goto fail;
Kevin Wolf8e53abb2014-03-26 13:05:34 +0100170 }
bellarda8753c32005-04-26 21:34:00 +0000171
Kevin Wolf715c3f62014-04-09 12:10:34 +0200172 if (s->catalog_size < DIV_ROUND_UP(bs->total_sectors,
173 s->extent_size / BDRV_SECTOR_SIZE))
174 {
Kevin Wolfe3737b82014-03-26 13:05:33 +0100175 error_setg(errp, "Catalog size is too small for this disk size");
176 ret = -EINVAL;
177 goto fail;
178 }
179
Paolo Bonzini848c66e2011-10-20 13:16:21 +0200180 qemu_co_mutex_init(&s->lock);
bellarda8753c32005-04-26 21:34:00 +0000181 return 0;
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100182
183fail:
184 g_free(s->catalog_bitmap);
185 return ret;
bellarda8753c32005-04-26 21:34:00 +0000186}
187
Christoph Hellwigefbca102010-05-04 12:44:08 +0200188static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
bellarda8753c32005-04-26 21:34:00 +0000189{
190 BDRVBochsState *s = bs->opaque;
Kevin Wolf246f6582014-03-26 13:05:32 +0100191 uint64_t offset = sector_num * 512;
192 uint64_t extent_index, extent_offset, bitmap_offset;
bellarda8753c32005-04-26 21:34:00 +0000193 char bitmap_entry;
Max Reitze1b42f42014-04-29 19:03:15 +0200194 int ret;
bellarda8753c32005-04-26 21:34:00 +0000195
196 // seek to sector
197 extent_index = offset / s->extent_size;
198 extent_offset = (offset % s->extent_size) / 512;
ths3b46e622007-09-17 08:09:54 +0000199
Christoph Hellwigefbca102010-05-04 12:44:08 +0200200 if (s->catalog_bitmap[extent_index] == 0xffffffff) {
Max Reitze1b42f42014-04-29 19:03:15 +0200201 return 0; /* not allocated */
bellarda8753c32005-04-26 21:34:00 +0000202 }
203
Kevin Wolfa9ba36a2014-03-26 13:05:35 +0100204 bitmap_offset = s->data_offset +
205 (512 * (uint64_t) s->catalog_bitmap[extent_index] *
206 (s->extent_blocks + s->bitmap_blocks));
ths3b46e622007-09-17 08:09:54 +0000207
Christoph Hellwigefbca102010-05-04 12:44:08 +0200208 /* read in bitmap for current extent */
Max Reitze1b42f42014-04-29 19:03:15 +0200209 ret = bdrv_pread(bs->file, bitmap_offset + (extent_offset / 8),
210 &bitmap_entry, 1);
211 if (ret < 0) {
212 return ret;
Blue Swirlecbe1572009-12-25 19:27:18 +0000213 }
ths3b46e622007-09-17 08:09:54 +0000214
Christoph Hellwigefbca102010-05-04 12:44:08 +0200215 if (!((bitmap_entry >> (extent_offset % 8)) & 1)) {
Max Reitze1b42f42014-04-29 19:03:15 +0200216 return 0; /* not allocated */
bellarda8753c32005-04-26 21:34:00 +0000217 }
218
Christoph Hellwigefbca102010-05-04 12:44:08 +0200219 return bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
bellarda8753c32005-04-26 21:34:00 +0000220}
221
ths5fafdf22007-09-16 21:08:06 +0000222static int bochs_read(BlockDriverState *bs, int64_t sector_num,
bellarda8753c32005-04-26 21:34:00 +0000223 uint8_t *buf, int nb_sectors)
224{
bellarda8753c32005-04-26 21:34:00 +0000225 int ret;
226
227 while (nb_sectors > 0) {
Christoph Hellwigefbca102010-05-04 12:44:08 +0200228 int64_t block_offset = seek_to_sector(bs, sector_num);
Max Reitze1b42f42014-04-29 19:03:15 +0200229 if (block_offset < 0) {
230 return block_offset;
231 } else if (block_offset > 0) {
Christoph Hellwig7a6f3912010-05-04 12:44:21 +0200232 ret = bdrv_pread(bs->file, block_offset, buf, 512);
Max Reitze1b42f42014-04-29 19:03:15 +0200233 if (ret < 0) {
234 return ret;
Christoph Hellwigefbca102010-05-04 12:44:08 +0200235 }
Max Reitze1b42f42014-04-29 19:03:15 +0200236 } else {
bellarda8753c32005-04-26 21:34:00 +0000237 memset(buf, 0, 512);
Max Reitze1b42f42014-04-29 19:03:15 +0200238 }
bellarda8753c32005-04-26 21:34:00 +0000239 nb_sectors--;
240 sector_num++;
241 buf += 512;
242 }
243 return 0;
244}
245
Paolo Bonzini2914caa2011-10-20 13:16:22 +0200246static coroutine_fn int bochs_co_read(BlockDriverState *bs, int64_t sector_num,
247 uint8_t *buf, int nb_sectors)
248{
249 int ret;
250 BDRVBochsState *s = bs->opaque;
251 qemu_co_mutex_lock(&s->lock);
252 ret = bochs_read(bs, sector_num, buf, nb_sectors);
253 qemu_co_mutex_unlock(&s->lock);
254 return ret;
255}
256
bellarda8753c32005-04-26 21:34:00 +0000257static void bochs_close(BlockDriverState *bs)
258{
259 BDRVBochsState *s = bs->opaque;
Anthony Liguori7267c092011-08-20 22:09:37 -0500260 g_free(s->catalog_bitmap);
bellarda8753c32005-04-26 21:34:00 +0000261}
262
Anthony Liguori5efa9d52009-05-09 17:03:42 -0500263static BlockDriver bdrv_bochs = {
aurel32e60f4692009-03-07 22:00:29 +0000264 .format_name = "bochs",
265 .instance_size = sizeof(BDRVBochsState),
266 .bdrv_probe = bochs_probe,
Christoph Hellwig7a6f3912010-05-04 12:44:21 +0200267 .bdrv_open = bochs_open,
Paolo Bonzini2914caa2011-10-20 13:16:22 +0200268 .bdrv_read = bochs_co_read,
aurel32e60f4692009-03-07 22:00:29 +0000269 .bdrv_close = bochs_close,
bellarda8753c32005-04-26 21:34:00 +0000270};
Anthony Liguori5efa9d52009-05-09 17:03:42 -0500271
272static void bdrv_bochs_init(void)
273{
274 bdrv_register(&bdrv_bochs);
275}
276
277block_init(bdrv_bochs_init);