X-Git-Url: http://git.maemo.org/git/?p=qemu;a=blobdiff_plain;f=block-vpc.c;fp=block-vpc.c;h=0000000000000000000000000000000000000000;hp=71a171d0ebff5607dbdca3afd6e599986fbfd8fa;hb=759b334a9739814df2883aa4c41b1c0f5670e90a;hpb=7e2198fc87e878b8ce5df965477e21713ebf7834 diff --git a/block-vpc.c b/block-vpc.c deleted file mode 100644 index 71a171d..0000000 --- a/block-vpc.c +++ /dev/null @@ -1,598 +0,0 @@ -/* - * Block driver for Conectix/Microsoft Virtual PC images - * - * Copyright (c) 2005 Alex Beregszaszi - * Copyright (c) 2009 Kevin Wolf - * - * 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 - -enum vhd_type { - VHD_FIXED = 2, - VHD_DYNAMIC = 3, - VHD_DIFFERENCING = 4, -}; - -// Seconds since Jan 1, 2000 0:00:00 (UTC) -#define VHD_TIMESTAMP_BASE 946684800 - -// always big-endian -struct vhd_footer { - char creator[8]; // "conectix" - uint32_t features; - uint32_t version; - - // Offset of next header structure, 0xFFFFFFFF if none - uint64_t data_offset; - - // Seconds since Jan 1, 2000 0:00:00 (UTC) - uint32_t timestamp; - - char creator_app[4]; // "vpc " - uint16_t major; - uint16_t minor; - char creator_os[4]; // "Wi2k" - - uint64_t orig_size; - uint64_t size; - - uint16_t cyls; - uint8_t heads; - uint8_t secs_per_cyl; - - uint32_t type; - - // Checksum of the Hard Disk Footer ("one's complement of the sum of all - // the bytes in the footer without the checksum field") - uint32_t checksum; - - // UUID used to identify a parent hard disk (backing file) - uint8_t uuid[16]; - - uint8_t in_saved_state; -}; - -struct vhd_dyndisk_header { - char magic[8]; // "cxsparse" - - // Offset of next header structure, 0xFFFFFFFF if none - uint64_t data_offset; - - // Offset of the Block Allocation Table (BAT) - uint64_t table_offset; - - uint32_t version; - uint32_t max_table_entries; // 32bit/entry - - // 2 MB by default, must be a power of two - uint32_t block_size; - - uint32_t checksum; - uint8_t parent_uuid[16]; - uint32_t parent_timestamp; - uint32_t reserved; - - // Backing file name (in UTF-16) - uint8_t parent_name[512]; - - struct { - uint32_t platform; - uint32_t data_space; - uint32_t data_length; - uint32_t reserved; - uint64_t data_offset; - } parent_locator[8]; -}; - -typedef struct BDRVVPCState { - BlockDriverState *hd; - - uint8_t footer_buf[HEADER_SIZE]; - uint64_t free_data_block_offset; - int max_table_entries; - uint32_t *pagetable; - uint64_t bat_offset; - uint64_t last_bitmap_offset; - - uint32_t block_size; - uint32_t bitmap_size; - -#ifdef CACHE - uint8_t *pageentry_u8; - uint32_t *pageentry_u32; - uint16_t *pageentry_u16; - - uint64_t last_bitmap; -#endif -} BDRVVPCState; - -static uint32_t vpc_checksum(uint8_t* buf, size_t size) -{ - uint32_t res = 0; - int i; - - for (i = 0; i < size; i++) - res += buf[i]; - - return ~res; -} - - -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 ret, i; - struct vhd_footer* footer; - struct vhd_dyndisk_header* dyndisk_header; - uint8_t buf[HEADER_SIZE]; - uint32_t checksum; - - ret = bdrv_file_open(&s->hd, filename, flags); - if (ret < 0) - return ret; - - if (bdrv_pread(s->hd, 0, s->footer_buf, HEADER_SIZE) != HEADER_SIZE) - goto fail; - - footer = (struct vhd_footer*) s->footer_buf; - if (strncmp(footer->creator, "conectix", 8)) - goto fail; - - checksum = be32_to_cpu(footer->checksum); - footer->checksum = 0; - if (vpc_checksum(s->footer_buf, HEADER_SIZE) != checksum) - fprintf(stderr, "block-vpc: The header checksum of '%s' is " - "incorrect.\n", filename); - - // The visible size of a image in Virtual PC depends on the geometry - // rather than on the size stored in the footer (the size in the footer - // is too large usually) - bs->total_sectors = (int64_t) - be16_to_cpu(footer->cyls) * footer->heads * footer->secs_per_cyl; - - if (bdrv_pread(s->hd, be64_to_cpu(footer->data_offset), buf, HEADER_SIZE) - != HEADER_SIZE) - goto fail; - - dyndisk_header = (struct vhd_dyndisk_header*) buf; - - if (strncmp(dyndisk_header->magic, "cxsparse", 8)) - goto fail; - - - s->block_size = be32_to_cpu(dyndisk_header->block_size); - s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511; - - s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries); - s->pagetable = qemu_malloc(s->max_table_entries * 4); - - s->bat_offset = be64_to_cpu(dyndisk_header->table_offset); - if (bdrv_pread(s->hd, s->bat_offset, s->pagetable, - s->max_table_entries * 4) != s->max_table_entries * 4) - goto fail; - - s->free_data_block_offset = - (s->bat_offset + (s->max_table_entries * 4) + 511) & ~511; - - for (i = 0; i < s->max_table_entries; i++) { - be32_to_cpus(&s->pagetable[i]); - if (s->pagetable[i] != 0xFFFFFFFF) { - int64_t next = (512 * (int64_t) s->pagetable[i]) + - s->bitmap_size + s->block_size; - - if (next> s->free_data_block_offset) - s->free_data_block_offset = next; - } - } - - s->last_bitmap_offset = (int64_t) -1; - -#ifdef CACHE - s->pageentry_u8 = qemu_malloc(512); - s->pageentry_u32 = s->pageentry_u8; - s->pageentry_u16 = s->pageentry_u8; - s->last_pagetable = -1; -#endif - - return 0; - fail: - bdrv_delete(s->hd); - return -1; -} - -/* - * Returns the absolute byte offset of the given sector in the image file. - * If the sector is not allocated, -1 is returned instead. - * - * The parameter write must be 1 if the offset will be used for a write - * operation (the block bitmaps is updated then), 0 otherwise. - */ -static inline int64_t get_sector_offset(BlockDriverState *bs, - int64_t sector_num, int write) -{ - 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->block_size; - pageentry_index = (offset % s->block_size) / 512; - - if (pagetable_index >= s->max_table_entries || s->pagetable[pagetable_index] == 0xffffffff) - return -1; // not allocated - - bitmap_offset = 512 * (uint64_t) s->pagetable[pagetable_index]; - block_offset = bitmap_offset + s->bitmap_size + (512 * pageentry_index); - - // We must ensure that we don't write to any sectors which are marked as - // unused in the bitmap. We get away with setting all bits in the block - // bitmap each time we write to a new block. This might cause Virtual PC to - // miss sparse read optimization, but it's not a problem in terms of - // correctness. - if (write && (s->last_bitmap_offset != bitmap_offset)) { - uint8_t bitmap[s->bitmap_size]; - - s->last_bitmap_offset = bitmap_offset; - memset(bitmap, 0xff, s->bitmap_size); - bdrv_pwrite(s->hd, bitmap_offset, bitmap, s->bitmap_size); - } - -// 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 - - return block_offset; -} - -/* - * Writes the footer to the end of the image file. This is needed when the - * file grows as it overwrites the old footer - * - * Returns 0 on success and < 0 on error - */ -static int rewrite_footer(BlockDriverState* bs) -{ - int ret; - BDRVVPCState *s = bs->opaque; - int64_t offset = s->free_data_block_offset; - - ret = bdrv_pwrite(s->hd, offset, s->footer_buf, HEADER_SIZE); - if (ret < 0) - return ret; - - return 0; -} - -/* - * Allocates a new block. This involves writing a new footer and updating - * the Block Allocation Table to use the space at the old end of the image - * file (overwriting the old footer) - * - * Returns the sectors' offset in the image file on success and < 0 on error - */ -static int64_t alloc_block(BlockDriverState* bs, int64_t sector_num) -{ - BDRVVPCState *s = bs->opaque; - int64_t bat_offset; - uint32_t index, bat_value; - int ret; - uint8_t bitmap[s->bitmap_size]; - - // Check if sector_num is valid - if ((sector_num < 0) || (sector_num > bs->total_sectors)) - return -1; - - // Write entry into in-memory BAT - index = (sector_num * 512) / s->block_size; - if (s->pagetable[index] != 0xFFFFFFFF) - return -1; - - s->pagetable[index] = s->free_data_block_offset / 512; - - // Initialize the block's bitmap - memset(bitmap, 0xff, s->bitmap_size); - bdrv_pwrite(s->hd, s->free_data_block_offset, bitmap, s->bitmap_size); - - // Write new footer (the old one will be overwritten) - s->free_data_block_offset += s->block_size + s->bitmap_size; - ret = rewrite_footer(bs); - if (ret < 0) - goto fail; - - // Write BAT entry to disk - bat_offset = s->bat_offset + (4 * index); - bat_value = be32_to_cpu(s->pagetable[index]); - ret = bdrv_pwrite(s->hd, bat_offset, &bat_value, 4); - if (ret < 0) - goto fail; - - return get_sector_offset(bs, sector_num, 0); - -fail: - s->free_data_block_offset -= (s->block_size + s->bitmap_size); - return -1; -} - -static int vpc_read(BlockDriverState *bs, int64_t sector_num, - uint8_t *buf, int nb_sectors) -{ - BDRVVPCState *s = bs->opaque; - int ret; - int64_t offset; - - while (nb_sectors > 0) { - offset = get_sector_offset(bs, sector_num, 0); - - if (offset == -1) { - memset(buf, 0, 512); - } else { - ret = bdrv_pread(s->hd, offset, buf, 512); - if (ret != 512) - return -1; - } - - nb_sectors--; - sector_num++; - buf += 512; - } - return 0; -} - -static int vpc_write(BlockDriverState *bs, int64_t sector_num, - const uint8_t *buf, int nb_sectors) -{ - BDRVVPCState *s = bs->opaque; - int64_t offset; - int ret; - - while (nb_sectors > 0) { - offset = get_sector_offset(bs, sector_num, 1); - - if (offset == -1) { - offset = alloc_block(bs, sector_num); - if (offset < 0) - return -1; - } - - ret = bdrv_pwrite(s->hd, offset, buf, 512); - if (ret != 512) - return -1; - - nb_sectors--; - sector_num++; - buf += 512; - } - - return 0; -} - - -/* - * Calculates the number of cylinders, heads and sectors per cylinder - * based on a given number of sectors. This is the algorithm described - * in the VHD specification. - * - * Note that the geometry doesn't always exactly match total_sectors but - * may round it down. - * - * Returns 0 on success, -EFBIG if the size is larger than 127 GB - */ -static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, - uint8_t* heads, uint8_t* secs_per_cyl) -{ - uint32_t cyls_times_heads; - - if (total_sectors > 65535 * 16 * 255) - return -EFBIG; - - if (total_sectors > 65535 * 16 * 63) { - *secs_per_cyl = 255; - *heads = 16; - cyls_times_heads = total_sectors / *secs_per_cyl; - } else { - *secs_per_cyl = 17; - cyls_times_heads = total_sectors / *secs_per_cyl; - *heads = (cyls_times_heads + 1023) / 1024; - - if (*heads < 4) - *heads = 4; - - if (cyls_times_heads >= (*heads * 1024) || *heads > 16) { - *secs_per_cyl = 31; - *heads = 16; - cyls_times_heads = total_sectors / *secs_per_cyl; - } - - if (cyls_times_heads >= (*heads * 1024)) { - *secs_per_cyl = 63; - *heads = 16; - cyls_times_heads = total_sectors / *secs_per_cyl; - } - } - - // Note: Rounding up deviates from the Virtual PC behaviour - // However, we need this to avoid truncating images in qemu-img convert - *cyls = (cyls_times_heads + *heads - 1) / *heads; - - return 0; -} - -static int vpc_create(const char *filename, int64_t total_sectors, - const char *backing_file, int flags) -{ - uint8_t buf[1024]; - struct vhd_footer* footer = (struct vhd_footer*) buf; - struct vhd_dyndisk_header* dyndisk_header = - (struct vhd_dyndisk_header*) buf; - int fd, i; - uint16_t cyls; - uint8_t heads; - uint8_t secs_per_cyl; - size_t block_size, num_bat_entries; - - if (backing_file != NULL) - return -ENOTSUP; - - fd = open(filename, O_WRONLY | O_CREAT | O_TRUNC | O_BINARY, 0644); - if (fd < 0) - return -EIO; - - // Calculate matching total_size and geometry - if (calculate_geometry(total_sectors, &cyls, &heads, &secs_per_cyl)) - return -EFBIG; - total_sectors = (int64_t) cyls * heads * secs_per_cyl; - - // Prepare the Hard Disk Footer - memset(buf, 0, 1024); - - strncpy(footer->creator, "conectix", 8); - // TODO Check if "qemu" creator_app is ok for VPC - strncpy(footer->creator_app, "qemu", 4); - strncpy(footer->creator_os, "Wi2k", 4); - - footer->features = be32_to_cpu(0x02); - footer->version = be32_to_cpu(0x00010000); - footer->data_offset = be64_to_cpu(HEADER_SIZE); - footer->timestamp = be32_to_cpu(time(NULL) - VHD_TIMESTAMP_BASE); - - // Version of Virtual PC 2007 - footer->major = be16_to_cpu(0x0005); - footer->minor =be16_to_cpu(0x0003); - - footer->orig_size = be64_to_cpu(total_sectors * 512); - footer->size = be64_to_cpu(total_sectors * 512); - - footer->cyls = be16_to_cpu(cyls); - footer->heads = heads; - footer->secs_per_cyl = secs_per_cyl; - - footer->type = be32_to_cpu(VHD_DYNAMIC); - - // TODO uuid is missing - - footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE)); - - // Write the footer (twice: at the beginning and at the end) - block_size = 0x200000; - num_bat_entries = (total_sectors + block_size / 512) / (block_size / 512); - - if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) - return -EIO; - - if (lseek(fd, 1536 + ((num_bat_entries * 4 + 511) & ~511), SEEK_SET) < 0) - return -EIO; - if (write(fd, buf, HEADER_SIZE) != HEADER_SIZE) - return -EIO; - - // Write the initial BAT - if (lseek(fd, 3 * 512, SEEK_SET) < 0) - return -EIO; - - memset(buf, 0xFF, 512); - for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) - if (write(fd, buf, 512) != 512) - return -EIO; - - - // Prepare the Dynamic Disk Header - memset(buf, 0, 1024); - - strncpy(dyndisk_header->magic, "cxsparse", 8); - - dyndisk_header->data_offset = be64_to_cpu(0xFFFFFFFF); - dyndisk_header->table_offset = be64_to_cpu(3 * 512); - dyndisk_header->version = be32_to_cpu(0x00010000); - dyndisk_header->block_size = be32_to_cpu(block_size); - dyndisk_header->max_table_entries = be32_to_cpu(num_bat_entries); - - dyndisk_header->checksum = be32_to_cpu(vpc_checksum(buf, 1024)); - - // Write the header - if (lseek(fd, 512, SEEK_SET) < 0) - return -EIO; - if (write(fd, buf, 1024) != 1024) - return -EIO; - - close(fd); - return 0; -} - -static void vpc_close(BlockDriverState *bs) -{ - BDRVVPCState *s = bs->opaque; - qemu_free(s->pagetable); -#ifdef CACHE - qemu_free(s->pageentry_u8); -#endif - bdrv_delete(s->hd); -} - -BlockDriver bdrv_vpc = { - .format_name = "vpc", - .instance_size = sizeof(BDRVVPCState), - .bdrv_probe = vpc_probe, - .bdrv_open = vpc_open, - .bdrv_read = vpc_read, - .bdrv_write = vpc_write, - .bdrv_close = vpc_close, - .bdrv_create = vpc_create, -};