+++ /dev/null
-/*
- * Block driver for the various disk image formats used by Bochs
- * Currently only for "growing" type in read-only mode
- *
- * Copyright (c) 2005 Alex Beregszaszi
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-#include "qemu-common.h"
-#include "block_int.h"
-
-/**************************************************************/
-
-#define HEADER_MAGIC "Bochs Virtual HD Image"
-#define HEADER_VERSION 0x00020000
-#define HEADER_V1 0x00010000
-#define HEADER_SIZE 512
-
-#define REDOLOG_TYPE "Redolog"
-#define GROWING_TYPE "Growing"
-
-// not allocated: 0xffffffff
-
-// always little-endian
-struct bochs_header_v1 {
- char magic[32]; // "Bochs Virtual HD Image"
- char type[16]; // "Redolog"
- char subtype[16]; // "Undoable" / "Volatile" / "Growing"
- uint32_t version;
- uint32_t header; // size of header
-
- union {
- struct {
- uint32_t catalog; // num of entries
- uint32_t bitmap; // bitmap size
- uint32_t extent; // extent size
- uint64_t disk; // disk size
- char padding[HEADER_SIZE - 64 - 8 - 20];
- } redolog;
- char padding[HEADER_SIZE - 64 - 8];
- } extra;
-};
-
-// always little-endian
-struct bochs_header {
- char magic[32]; // "Bochs Virtual HD Image"
- char type[16]; // "Redolog"
- char subtype[16]; // "Undoable" / "Volatile" / "Growing"
- uint32_t version;
- uint32_t header; // size of header
-
- union {
- struct {
- uint32_t catalog; // num of entries
- uint32_t bitmap; // bitmap size
- uint32_t extent; // extent size
- uint32_t reserved; // for ???
- uint64_t disk; // disk size
- char padding[HEADER_SIZE - 64 - 8 - 24];
- } redolog;
- char padding[HEADER_SIZE - 64 - 8];
- } extra;
-};
-
-typedef struct BDRVBochsState {
- int fd;
-
- uint32_t *catalog_bitmap;
- int catalog_size;
-
- int data_offset;
-
- int bitmap_blocks;
- int extent_blocks;
- int extent_size;
-} BDRVBochsState;
-
-static int bochs_probe(const uint8_t *buf, int buf_size, const char *filename)
-{
- const struct bochs_header *bochs = (const void *)buf;
-
- if (buf_size < HEADER_SIZE)
- return 0;
-
- if (!strcmp(bochs->magic, HEADER_MAGIC) &&
- !strcmp(bochs->type, REDOLOG_TYPE) &&
- !strcmp(bochs->subtype, GROWING_TYPE) &&
- ((le32_to_cpu(bochs->version) == HEADER_VERSION) ||
- (le32_to_cpu(bochs->version) == HEADER_V1)))
- return 100;
-
- return 0;
-}
-
-static int bochs_open(BlockDriverState *bs, const char *filename, int flags)
-{
- BDRVBochsState *s = bs->opaque;
- int fd, i;
- struct bochs_header bochs;
- struct bochs_header_v1 header_v1;
-
- fd = open(filename, O_RDWR | O_BINARY);
- if (fd < 0) {
- fd = open(filename, O_RDONLY | O_BINARY);
- if (fd < 0)
- return -1;
- }
-
- bs->read_only = 1; // no write support yet
-
- s->fd = fd;
-
- if (read(fd, &bochs, sizeof(bochs)) != sizeof(bochs)) {
- goto fail;
- }
-
- if (strcmp(bochs.magic, HEADER_MAGIC) ||
- strcmp(bochs.type, REDOLOG_TYPE) ||
- strcmp(bochs.subtype, GROWING_TYPE) ||
- ((le32_to_cpu(bochs.version) != HEADER_VERSION) &&
- (le32_to_cpu(bochs.version) != HEADER_V1))) {
- goto fail;
- }
-
- if (le32_to_cpu(bochs.version) == HEADER_V1) {
- memcpy(&header_v1, &bochs, sizeof(bochs));
- bs->total_sectors = le64_to_cpu(header_v1.extra.redolog.disk) / 512;
- } else {
- bs->total_sectors = le64_to_cpu(bochs.extra.redolog.disk) / 512;
- }
-
- lseek(s->fd, le32_to_cpu(bochs.header), SEEK_SET);
-
- s->catalog_size = le32_to_cpu(bochs.extra.redolog.catalog);
- s->catalog_bitmap = qemu_malloc(s->catalog_size * 4);
- if (read(s->fd, s->catalog_bitmap, s->catalog_size * 4) !=
- s->catalog_size * 4)
- goto fail;
- for (i = 0; i < s->catalog_size; i++)
- le32_to_cpus(&s->catalog_bitmap[i]);
-
- s->data_offset = le32_to_cpu(bochs.header) + (s->catalog_size * 4);
-
- s->bitmap_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.bitmap) - 1) / 512;
- s->extent_blocks = 1 + (le32_to_cpu(bochs.extra.redolog.extent) - 1) / 512;
-
- s->extent_size = le32_to_cpu(bochs.extra.redolog.extent);
-
- return 0;
- fail:
- close(fd);
- return -1;
-}
-
-static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num)
-{
- BDRVBochsState *s = bs->opaque;
- int64_t offset = sector_num * 512;
- int64_t extent_index, extent_offset, bitmap_offset, block_offset;
- char bitmap_entry;
-
- // seek to sector
- extent_index = offset / s->extent_size;
- extent_offset = (offset % s->extent_size) / 512;
-
- if (s->catalog_bitmap[extent_index] == 0xffffffff)
- {
-// fprintf(stderr, "page not allocated [%x - %x:%x]\n",
-// sector_num, extent_index, extent_offset);
- return -1; // not allocated
- }
-
- bitmap_offset = s->data_offset + (512 * s->catalog_bitmap[extent_index] *
- (s->extent_blocks + s->bitmap_blocks));
- block_offset = bitmap_offset + (512 * (s->bitmap_blocks + extent_offset));
-
-// fprintf(stderr, "sect: %x [ext i: %x o: %x] -> %x bitmap: %x block: %x\n",
-// sector_num, extent_index, extent_offset,
-// le32_to_cpu(s->catalog_bitmap[extent_index]),
-// bitmap_offset, block_offset);
-
- // read in bitmap for current extent
- lseek(s->fd, bitmap_offset + (extent_offset / 8), SEEK_SET);
-
- read(s->fd, &bitmap_entry, 1);
-
- if (!((bitmap_entry >> (extent_offset % 8)) & 1))
- {
-// fprintf(stderr, "sector (%x) in bitmap not allocated\n",
-// sector_num);
- return -1; // not allocated
- }
-
- lseek(s->fd, block_offset, SEEK_SET);
-
- return 0;
-}
-
-static int bochs_read(BlockDriverState *bs, int64_t sector_num,
- uint8_t *buf, int nb_sectors)
-{
- BDRVBochsState *s = bs->opaque;
- int ret;
-
- while (nb_sectors > 0) {
- if (!seek_to_sector(bs, sector_num))
- {
- ret = read(s->fd, buf, 512);
- if (ret != 512)
- return -1;
- }
- else
- memset(buf, 0, 512);
- nb_sectors--;
- sector_num++;
- buf += 512;
- }
- return 0;
-}
-
-static void bochs_close(BlockDriverState *bs)
-{
- BDRVBochsState *s = bs->opaque;
- qemu_free(s->catalog_bitmap);
- close(s->fd);
-}
-
-BlockDriver bdrv_bochs = {
- .format_name = "bochs",
- .instance_size = sizeof(BDRVBochsState),
- .bdrv_probe = bochs_probe,
- .bdrv_open = bochs_open,
- .bdrv_read = bochs_read,
- .bdrv_close = bochs_close,
-};
projects / qemu / blobdiff