/* * 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-endianstruct 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-endianstruct 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 (!s->catalog_bitmap)	goto fail;    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 = {    "bochs",    sizeof(BDRVBochsState),    bochs_probe,    bochs_open,    bochs_read,    NULL,    bochs_close,};