/* * Block driver for Conectix/Microsoft Virtual PC images * * 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_SIZE 512 //#define CACHE // always big-endian struct vpc_subheader { char magic[8]; // "conectix" / "cxsparse" union { struct { uint32_t unk1[2]; uint32_t unk2; // always zero? uint32_t subheader_offset; uint32_t unk3; // some size? char creator[4]; // "vpc " uint16_t major; uint16_t minor; char guest[4]; // "Wi2k" uint32_t unk4[7]; uint8_t vnet_id[16]; // virtual network id, purpose unknown // next 16 longs are used, but dunno the purpose // next 6 longs unknown, following 7 long maybe a serial char padding[HEADER_SIZE - 84]; } main; struct { uint32_t unk1[2]; // all bits set uint32_t unk2; // always zero? uint32_t pagetable_offset; uint32_t unk3; uint32_t pagetable_entries; // 32bit/entry uint32_t pageentry_size; // 512*8*512 uint32_t nb_sectors; char padding[HEADER_SIZE - 40]; } sparse; char padding[HEADER_SIZE - 8]; } type; }; typedef struct BDRVVPCState { int fd; int pagetable_entries; uint32_t *pagetable; uint32_t pageentry_size; #ifdef CACHE uint8_t *pageentry_u8; uint32_t *pageentry_u32; uint16_t *pageentry_u16; uint64_t last_bitmap; #endif } BDRVVPCState; static int vpc_probe(const uint8_t *buf, int buf_size, const char *filename) { if (buf_size >= 8 && !strncmp((char *)buf, "conectix", 8)) return 100; return 0; } static int vpc_open(BlockDriverState *bs, const char *filename, int flags) { BDRVVPCState *s = bs->opaque; int fd, i; struct vpc_subheader header; 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, &header, HEADER_SIZE) != HEADER_SIZE) goto fail; if (strncmp(header.magic, "conectix", 8)) goto fail; lseek(s->fd, be32_to_cpu(header.type.main.subheader_offset), SEEK_SET); if (read(fd, &header, HEADER_SIZE) != HEADER_SIZE) goto fail; if (strncmp(header.magic, "cxsparse", 8)) goto fail; bs->total_sectors = ((uint64_t)be32_to_cpu(header.type.sparse.pagetable_entries) * be32_to_cpu(header.type.sparse.pageentry_size)) / 512; lseek(s->fd, be32_to_cpu(header.type.sparse.pagetable_offset), SEEK_SET); s->pagetable_entries = be32_to_cpu(header.type.sparse.pagetable_entries); s->pagetable = qemu_malloc(s->pagetable_entries * 4); if (!s->pagetable) goto fail; if (read(s->fd, s->pagetable, s->pagetable_entries * 4) != s->pagetable_entries * 4) goto fail; for (i = 0; i < s->pagetable_entries; i++) be32_to_cpus(&s->pagetable[i]); s->pageentry_size = be32_to_cpu(header.type.sparse.pageentry_size); #ifdef CACHE s->pageentry_u8 = qemu_malloc(512); if (!s->pageentry_u8) goto fail; s->pageentry_u32 = s->pageentry_u8; s->pageentry_u16 = s->pageentry_u8; s->last_pagetable = -1; #endif return 0; fail: close(fd); return -1; } static inline int seek_to_sector(BlockDriverState *bs, int64_t sector_num) { BDRVVPCState *s = bs->opaque; uint64_t offset = sector_num * 512; uint64_t bitmap_offset, block_offset; uint32_t pagetable_index, pageentry_index; pagetable_index = offset / s->pageentry_size; pageentry_index = (offset % s->pageentry_size) / 512; if (pagetable_index > s->pagetable_entries || s->pagetable[pagetable_index] == 0xffffffff) return -1; // not allocated bitmap_offset = 512 * s->pagetable[pagetable_index]; block_offset = bitmap_offset + 512 + (512 * pageentry_index); // printf("sector: %" PRIx64 ", index: %x, offset: %x, bioff: %" PRIx64 ", bloff: %" PRIx64 "\n", // sector_num, pagetable_index, pageentry_index, // bitmap_offset, block_offset); // disabled by reason #if 0 #ifdef CACHE if (bitmap_offset != s->last_bitmap) { lseek(s->fd, bitmap_offset, SEEK_SET); s->last_bitmap = bitmap_offset; // Scary! Bitmap is stored as big endian 32bit entries, // while we used to look it up byte by byte read(s->fd, s->pageentry_u8, 512); for (i = 0; i < 128; i++) be32_to_cpus(&s->pageentry_u32[i]); } if ((s->pageentry_u8[pageentry_index / 8] >> (pageentry_index % 8)) & 1) return -1; #else lseek(s->fd, bitmap_offset + (pageentry_index / 8), SEEK_SET); read(s->fd, &bitmap_entry, 1); if ((bitmap_entry >> (pageentry_index % 8)) & 1) return -1; // not allocated #endif #endif lseek(s->fd, block_offset, SEEK_SET); return 0; } static int vpc_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { BDRVVPCState *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 vpc_close(BlockDriverState *bs) { BDRVVPCState *s = bs->opaque; qemu_free(s->pagetable); #ifdef CACHE qemu_free(s->pageentry_u8); #endif close(s->fd); } BlockDriver bdrv_vpc = { "vpc", sizeof(BDRVVPCState), vpc_probe, vpc_open, vpc_read, NULL, vpc_close, };