blob: 50c630047ba158c034ae854095e8613e768f975d [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 */
Peter Maydell80c71a22016-01-18 18:01:42 +000025#include "qemu/osdep.h"
Markus Armbrusterda34e652016-03-14 09:01:28 +010026#include "qapi/error.h"
pbrookfaf07962007-11-11 02:51:17 +000027#include "qemu-common.h"
Paolo Bonzini737e1502012-12-17 18:19:44 +010028#include "block/block_int.h"
Paolo Bonzini1de7afc2012-12-17 18:20:00 +010029#include "qemu/module.h"
Paolo Bonzini58369e22016-03-15 17:22:36 +010030#include "qemu/bswap.h"
Kevin Wolf398e6ad2017-11-07 18:21:41 +010031#include "qemu/error-report.h"
bellarda8753c32005-04-26 21:34:00 +000032
33/**************************************************************/
34
35#define HEADER_MAGIC "Bochs Virtual HD Image"
ths6850dd92007-01-05 18:56:04 +000036#define HEADER_VERSION 0x00020000
37#define HEADER_V1 0x00010000
bellarda8753c32005-04-26 21:34:00 +000038#define HEADER_SIZE 512
39
40#define REDOLOG_TYPE "Redolog"
41#define GROWING_TYPE "Growing"
42
43// not allocated: 0xffffffff
44
45// always little-endian
46struct bochs_header {
Kevin Wolf3dd8a672014-03-26 13:05:31 +010047 char magic[32]; /* "Bochs Virtual HD Image" */
48 char type[16]; /* "Redolog" */
49 char subtype[16]; /* "Undoable" / "Volatile" / "Growing" */
bellarda8753c32005-04-26 21:34:00 +000050 uint32_t version;
Kevin Wolf3dd8a672014-03-26 13:05:31 +010051 uint32_t header; /* size of header */
52
53 uint32_t catalog; /* num of entries */
54 uint32_t bitmap; /* bitmap size */
55 uint32_t extent; /* extent size */
ths3b46e622007-09-17 08:09:54 +000056
bellarda8753c32005-04-26 21:34:00 +000057 union {
Kevin Wolf3dd8a672014-03-26 13:05:31 +010058 struct {
59 uint32_t reserved; /* for ??? */
60 uint64_t disk; /* disk size */
61 char padding[HEADER_SIZE - 64 - 20 - 12];
62 } QEMU_PACKED redolog;
63 struct {
64 uint64_t disk; /* disk size */
65 char padding[HEADER_SIZE - 64 - 20 - 8];
66 } QEMU_PACKED redolog_v1;
67 char padding[HEADER_SIZE - 64 - 20];
bellarda8753c32005-04-26 21:34:00 +000068 } extra;
Kevin Wolf3dd8a672014-03-26 13:05:31 +010069} QEMU_PACKED;
bellarda8753c32005-04-26 21:34:00 +000070
71typedef struct BDRVBochsState {
Paolo Bonzini848c66e2011-10-20 13:16:21 +020072 CoMutex lock;
bellarda8753c32005-04-26 21:34:00 +000073 uint32_t *catalog_bitmap;
Kevin Wolf246f6582014-03-26 13:05:32 +010074 uint32_t catalog_size;
ths3b46e622007-09-17 08:09:54 +000075
Kevin Wolf246f6582014-03-26 13:05:32 +010076 uint32_t data_offset;
ths3b46e622007-09-17 08:09:54 +000077
Kevin Wolf246f6582014-03-26 13:05:32 +010078 uint32_t bitmap_blocks;
79 uint32_t extent_blocks;
80 uint32_t extent_size;
bellarda8753c32005-04-26 21:34:00 +000081} BDRVBochsState;
82
83static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
84{
85 const struct bochs_header *bochs = (const void *)buf;
ths3b46e622007-09-17 08:09:54 +000086
bellarda8753c32005-04-26 21:34:00 +000087 if (buf_size < HEADER_SIZE)
88 return 0;
89
90 if (!strcmp(bochs->magic, HEADER_MAGIC) &&
91 !strcmp(bochs->type, REDOLOG_TYPE) &&
92 !strcmp(bochs->subtype, GROWING_TYPE) &&
ths6850dd92007-01-05 18:56:04 +000093 ((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
94 (le32_to_cpu(bochs->version) == HEADER_V1)))
bellarda8753c32005-04-26 21:34:00 +000095 return 100;
96
97 return 0;
98}
99
Max Reitz015a1032013-09-05 14:22:29 +0200100static int bochs_open(BlockDriverState *bs, QDict *options, int flags,
101 Error **errp)
bellarda8753c32005-04-26 21:34:00 +0000102{
103 BDRVBochsState *s = bs->opaque;
Kevin Wolf246f6582014-03-26 13:05:32 +0100104 uint32_t i;
bellarda8753c32005-04-26 21:34:00 +0000105 struct bochs_header bochs;
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100106 int ret;
bellarda8753c32005-04-26 21:34:00 +0000107
Kevin Wolf4e4bf5c2016-12-16 18:52:37 +0100108 bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file,
109 false, errp);
110 if (!bs->file) {
111 return -EINVAL;
112 }
113
Kevin Wolf398e6ad2017-11-07 18:21:41 +0100114 if (!bdrv_is_read_only(bs)) {
115 error_report("Opening bochs images without an explicit read-only=on "
116 "option is deprecated. Future versions will refuse to "
117 "open the image instead of automatically marking the "
118 "image read-only.");
119 ret = bdrv_set_read_only(bs, true, errp); /* no write support yet */
120 if (ret < 0) {
121 return ret;
122 }
Jeff Codye2b82472017-04-07 16:55:26 -0400123 }
ths3b46e622007-09-17 08:09:54 +0000124
Kevin Wolfcf2ab8f2016-06-20 18:24:02 +0200125 ret = bdrv_pread(bs->file, 0, &bochs, sizeof(bochs));
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100126 if (ret < 0) {
127 return ret;
bellarda8753c32005-04-26 21:34:00 +0000128 }
129
130 if (strcmp(bochs.magic, HEADER_MAGIC) ||
131 strcmp(bochs.type, REDOLOG_TYPE) ||
132 strcmp(bochs.subtype, GROWING_TYPE) ||
ths6850dd92007-01-05 18:56:04 +0000133 ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
134 (le32_to_cpu(bochs.version) != HEADER_V1))) {
Paolo Bonzini76abe402014-02-17 14:44:06 +0100135 error_setg(errp, "Image not in Bochs format");
136 return -EINVAL;
bellarda8753c32005-04-26 21:34:00 +0000137 }
138
ths6850dd92007-01-05 18:56:04 +0000139 if (le32_to_cpu(bochs.version) == HEADER_V1) {
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100140 bs->total_sectors = le64_to_cpu(bochs.extra.redolog_v1.disk) / 512;
ths6850dd92007-01-05 18:56:04 +0000141 } else {
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100142 bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
ths6850dd92007-01-05 18:56:04 +0000143 }
bellarda8753c32005-04-26 21:34:00 +0000144
Kevin Wolfe3737b82014-03-26 13:05:33 +0100145 /* Limit to 1M entries to avoid unbounded allocation. This is what is
146 * needed for the largest image that bximage can create (~8 TB). */
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100147 s->catalog_size = le32_to_cpu(bochs.catalog);
Kevin Wolfe3737b82014-03-26 13:05:33 +0100148 if (s->catalog_size > 0x100000) {
149 error_setg(errp, "Catalog size is too large");
150 return -EFBIG;
151 }
152
Markus Armbruster02c4f262014-08-19 10:31:09 +0200153 s->catalog_bitmap = g_try_new(uint32_t, s->catalog_size);
Kevin Wolf7bf665e2014-05-20 13:21:26 +0200154 if (s->catalog_size && s->catalog_bitmap == NULL) {
155 error_setg(errp, "Could not allocate memory for catalog");
156 return -ENOMEM;
157 }
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100158
Kevin Wolfcf2ab8f2016-06-20 18:24:02 +0200159 ret = bdrv_pread(bs->file, le32_to_cpu(bochs.header), s->catalog_bitmap,
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100160 s->catalog_size * 4);
161 if (ret < 0) {
162 goto fail;
163 }
164
bellarda8753c32005-04-26 21:34:00 +0000165 for (i = 0; i < s->catalog_size; i++)
166 le32_to_cpus(&s->catalog_bitmap[i]);
167
168 s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
169
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100170 s->bitmap_blocks = 1 + (le32_to_cpu(bochs.bitmap) - 1) / 512;
171 s->extent_blocks = 1 + (le32_to_cpu(bochs.extent) - 1) / 512;
ths3b46e622007-09-17 08:09:54 +0000172
Kevin Wolf3dd8a672014-03-26 13:05:31 +0100173 s->extent_size = le32_to_cpu(bochs.extent);
Kevin Wolf715c3f62014-04-09 12:10:34 +0200174 if (s->extent_size < BDRV_SECTOR_SIZE) {
175 /* bximage actually never creates extents smaller than 4k */
176 error_setg(errp, "Extent size must be at least 512");
177 ret = -EINVAL;
178 goto fail;
179 } else if (!is_power_of_2(s->extent_size)) {
180 error_setg(errp, "Extent size %" PRIu32 " is not a power of two",
181 s->extent_size);
Kevin Wolf28ec11b2014-04-09 11:19:04 +0200182 ret = -EINVAL;
183 goto fail;
Kevin Wolf8e53abb2014-03-26 13:05:34 +0100184 } else if (s->extent_size > 0x800000) {
185 error_setg(errp, "Extent size %" PRIu32 " is too large",
186 s->extent_size);
Kevin Wolf28ec11b2014-04-09 11:19:04 +0200187 ret = -EINVAL;
188 goto fail;
Kevin Wolf8e53abb2014-03-26 13:05:34 +0100189 }
bellarda8753c32005-04-26 21:34:00 +0000190
Kevin Wolf715c3f62014-04-09 12:10:34 +0200191 if (s->catalog_size < DIV_ROUND_UP(bs->total_sectors,
192 s->extent_size / BDRV_SECTOR_SIZE))
193 {
Kevin Wolfe3737b82014-03-26 13:05:33 +0100194 error_setg(errp, "Catalog size is too small for this disk size");
195 ret = -EINVAL;
196 goto fail;
197 }
198
Paolo Bonzini848c66e2011-10-20 13:16:21 +0200199 qemu_co_mutex_init(&s->lock);
bellarda8753c32005-04-26 21:34:00 +0000200 return 0;
Kevin Wolf5b7d7df2013-01-25 17:07:27 +0100201
202fail:
203 g_free(s->catalog_bitmap);
204 return ret;
bellarda8753c32005-04-26 21:34:00 +0000205}
206
Eric Blakea6506482016-06-23 16:37:17 -0600207static void bochs_refresh_limits(BlockDriverState *bs, Error **errp)
208{
Eric Blakea5b8dd22016-06-23 16:37:24 -0600209 bs->bl.request_alignment = BDRV_SECTOR_SIZE; /* No sub-sector I/O */
Eric Blakea6506482016-06-23 16:37:17 -0600210}
211
Christoph Hellwigefbca102010-05-04 12:44:08 +0200212static int64_t seek_to_sector(BlockDriverState *bs, int64_t sector_num)
bellarda8753c32005-04-26 21:34:00 +0000213{
214 BDRVBochsState *s = bs->opaque;
Kevin Wolf246f6582014-03-26 13:05:32 +0100215 uint64_t offset = sector_num * 512;
216 uint64_t extent_index, extent_offset, bitmap_offset;
bellarda8753c32005-04-26 21:34:00 +0000217 char bitmap_entry;
Max Reitze1b42f42014-04-29 19:03:15 +0200218 int ret;
bellarda8753c32005-04-26 21:34:00 +0000219
220 // seek to sector
221 extent_index = offset / s->extent_size;
222 extent_offset = (offset % s->extent_size) / 512;
ths3b46e622007-09-17 08:09:54 +0000223
Christoph Hellwigefbca102010-05-04 12:44:08 +0200224 if (s->catalog_bitmap[extent_index] == 0xffffffff) {
Max Reitze1b42f42014-04-29 19:03:15 +0200225 return 0; /* not allocated */
bellarda8753c32005-04-26 21:34:00 +0000226 }
227
Kevin Wolfa9ba36a2014-03-26 13:05:35 +0100228 bitmap_offset = s->data_offset +
229 (512 * (uint64_t) s->catalog_bitmap[extent_index] *
230 (s->extent_blocks + s->bitmap_blocks));
ths3b46e622007-09-17 08:09:54 +0000231
Christoph Hellwigefbca102010-05-04 12:44:08 +0200232 /* read in bitmap for current extent */
Kevin Wolfcf2ab8f2016-06-20 18:24:02 +0200233 ret = bdrv_pread(bs->file, bitmap_offset + (extent_offset / 8),
Max Reitze1b42f42014-04-29 19:03:15 +0200234 &bitmap_entry, 1);
235 if (ret < 0) {
236 return ret;
Blue Swirlecbe1572009-12-25 19:27:18 +0000237 }
ths3b46e622007-09-17 08:09:54 +0000238
Christoph Hellwigefbca102010-05-04 12:44:08 +0200239 if (!((bitmap_entry >> (extent_offset % 8)) & 1)) {
Max Reitze1b42f42014-04-29 19:03:15 +0200240 return 0; /* not allocated */
bellarda8753c32005-04-26 21:34:00 +0000241 }
242
Christoph Hellwigefbca102010-05-04 12:44:08 +0200243 return bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
bellarda8753c32005-04-26 21:34:00 +0000244}
245
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200246static int coroutine_fn
247bochs_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes,
248 QEMUIOVector *qiov, int flags)
bellarda8753c32005-04-26 21:34:00 +0000249{
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200250 BDRVBochsState *s = bs->opaque;
251 uint64_t sector_num = offset >> BDRV_SECTOR_BITS;
252 int nb_sectors = bytes >> BDRV_SECTOR_BITS;
253 uint64_t bytes_done = 0;
254 QEMUIOVector local_qiov;
bellarda8753c32005-04-26 21:34:00 +0000255 int ret;
256
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200257 assert((offset & (BDRV_SECTOR_SIZE - 1)) == 0);
258 assert((bytes & (BDRV_SECTOR_SIZE - 1)) == 0);
259
260 qemu_iovec_init(&local_qiov, qiov->niov);
261 qemu_co_mutex_lock(&s->lock);
262
bellarda8753c32005-04-26 21:34:00 +0000263 while (nb_sectors > 0) {
Christoph Hellwigefbca102010-05-04 12:44:08 +0200264 int64_t block_offset = seek_to_sector(bs, sector_num);
Max Reitze1b42f42014-04-29 19:03:15 +0200265 if (block_offset < 0) {
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200266 ret = block_offset;
267 goto fail;
268 }
269
270 qemu_iovec_reset(&local_qiov);
271 qemu_iovec_concat(&local_qiov, qiov, bytes_done, 512);
272
273 if (block_offset > 0) {
Kevin Wolfa03ef882016-06-20 21:31:46 +0200274 ret = bdrv_co_preadv(bs->file, block_offset, 512,
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200275 &local_qiov, 0);
Max Reitze1b42f42014-04-29 19:03:15 +0200276 if (ret < 0) {
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200277 goto fail;
Christoph Hellwigefbca102010-05-04 12:44:08 +0200278 }
Max Reitze1b42f42014-04-29 19:03:15 +0200279 } else {
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200280 qemu_iovec_memset(&local_qiov, 0, 0, 512);
Max Reitze1b42f42014-04-29 19:03:15 +0200281 }
bellarda8753c32005-04-26 21:34:00 +0000282 nb_sectors--;
283 sector_num++;
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200284 bytes_done += 512;
bellarda8753c32005-04-26 21:34:00 +0000285 }
bellarda8753c32005-04-26 21:34:00 +0000286
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200287 ret = 0;
288fail:
Paolo Bonzini2914caa2011-10-20 13:16:22 +0200289 qemu_co_mutex_unlock(&s->lock);
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200290 qemu_iovec_destroy(&local_qiov);
291
Paolo Bonzini2914caa2011-10-20 13:16:22 +0200292 return ret;
293}
294
bellarda8753c32005-04-26 21:34:00 +0000295static void bochs_close(BlockDriverState *bs)
296{
297 BDRVBochsState *s = bs->opaque;
Anthony Liguori7267c092011-08-20 22:09:37 -0500298 g_free(s->catalog_bitmap);
bellarda8753c32005-04-26 21:34:00 +0000299}
300
Anthony Liguori5efa9d52009-05-09 17:03:42 -0500301static BlockDriver bdrv_bochs = {
aurel32e60f4692009-03-07 22:00:29 +0000302 .format_name = "bochs",
303 .instance_size = sizeof(BDRVBochsState),
304 .bdrv_probe = bochs_probe,
Christoph Hellwig7a6f3912010-05-04 12:44:21 +0200305 .bdrv_open = bochs_open,
Kevin Wolf862f2152016-12-19 16:36:02 +0100306 .bdrv_child_perm = bdrv_format_default_perms,
Eric Blakea6506482016-06-23 16:37:17 -0600307 .bdrv_refresh_limits = bochs_refresh_limits,
Kevin Wolf3b8fd332016-04-25 14:53:22 +0200308 .bdrv_co_preadv = bochs_co_preadv,
aurel32e60f4692009-03-07 22:00:29 +0000309 .bdrv_close = bochs_close,
bellarda8753c32005-04-26 21:34:00 +0000310};
Anthony Liguori5efa9d52009-05-09 17:03:42 -0500311
312static void bdrv_bochs_init(void)
313{
314 bdrv_register(&bdrv_bochs);
315}
316
317block_init(bdrv_bochs_init);