| /* |
| * Block driver for Connectix / Microsoft Virtual PC images |
| * |
| * Copyright (c) 2005 Alex Beregszaszi |
| * Copyright (c) 2009 Kevin Wolf <kwolf@suse.de> |
| * |
| * 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/osdep.h" |
| #include "qapi/error.h" |
| #include "qemu-common.h" |
| #include "block/block_int.h" |
| #include "sysemu/block-backend.h" |
| #include "qemu/module.h" |
| #include "migration/migration.h" |
| #include "qemu/bswap.h" |
| #if defined(CONFIG_UUID) |
| #include <uuid/uuid.h> |
| #endif |
| |
| /**************************************************************/ |
| |
| #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 |
| |
| #define VHD_CHS_MAX_C 65535LL |
| #define VHD_CHS_MAX_H 16 |
| #define VHD_CHS_MAX_S 255 |
| |
| #define VHD_MAX_SECTORS 0xff000000 /* 2040 GiB max image size */ |
| #define VHD_MAX_GEOMETRY (VHD_CHS_MAX_C * VHD_CHS_MAX_H * VHD_CHS_MAX_S) |
| |
| #define VPC_OPT_FORCE_SIZE "force_size" |
| |
| /* always big-endian */ |
| typedef 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]; /* e.g., "vpc " */ |
| uint16_t major; |
| uint16_t minor; |
| char creator_os[4]; /* "Wi2k" */ |
| |
| uint64_t orig_size; |
| uint64_t current_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; |
| } QEMU_PACKED VHDFooter; |
| |
| typedef 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]; |
| } QEMU_PACKED VHDDynDiskHeader; |
| |
| typedef struct BDRVVPCState { |
| CoMutex lock; |
| 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; |
| bool force_use_chs; |
| bool force_use_sz; |
| |
| #ifdef CACHE |
| uint8_t *pageentry_u8; |
| uint32_t *pageentry_u32; |
| uint16_t *pageentry_u16; |
| |
| uint64_t last_bitmap; |
| #endif |
| |
| Error *migration_blocker; |
| } BDRVVPCState; |
| |
| #define VPC_OPT_SIZE_CALC "force_size_calc" |
| static QemuOptsList vpc_runtime_opts = { |
| .name = "vpc-runtime-opts", |
| .head = QTAILQ_HEAD_INITIALIZER(vpc_runtime_opts.head), |
| .desc = { |
| { |
| .name = VPC_OPT_SIZE_CALC, |
| .type = QEMU_OPT_STRING, |
| .help = "Force disk size calculation to use either CHS geometry, " |
| "or use the disk current_size specified in the VHD footer. " |
| "{chs, current_size}" |
| }, |
| { /* end of list */ } |
| } |
| }; |
| |
| 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 void vpc_parse_options(BlockDriverState *bs, QemuOpts *opts, |
| Error **errp) |
| { |
| BDRVVPCState *s = bs->opaque; |
| const char *size_calc; |
| |
| size_calc = qemu_opt_get(opts, VPC_OPT_SIZE_CALC); |
| |
| if (!size_calc) { |
| /* no override, use autodetect only */ |
| } else if (!strcmp(size_calc, "current_size")) { |
| s->force_use_sz = true; |
| } else if (!strcmp(size_calc, "chs")) { |
| s->force_use_chs = true; |
| } else { |
| error_setg(errp, "Invalid size calculation mode: '%s'", size_calc); |
| } |
| } |
| |
| static int vpc_open(BlockDriverState *bs, QDict *options, int flags, |
| Error **errp) |
| { |
| BDRVVPCState *s = bs->opaque; |
| int i; |
| VHDFooter *footer; |
| VHDDynDiskHeader *dyndisk_header; |
| QemuOpts *opts = NULL; |
| Error *local_err = NULL; |
| bool use_chs; |
| uint8_t buf[HEADER_SIZE]; |
| uint32_t checksum; |
| uint64_t computed_size; |
| uint64_t pagetable_size; |
| int disk_type = VHD_DYNAMIC; |
| int ret; |
| |
| opts = qemu_opts_create(&vpc_runtime_opts, NULL, 0, &error_abort); |
| qemu_opts_absorb_qdict(opts, options, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| vpc_parse_options(bs, opts, &local_err); |
| if (local_err) { |
| error_propagate(errp, local_err); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE); |
| if (ret < 0) { |
| error_setg(errp, "Unable to read VHD header"); |
| goto fail; |
| } |
| |
| footer = (VHDFooter *) s->footer_buf; |
| if (strncmp(footer->creator, "conectix", 8)) { |
| int64_t offset = bdrv_getlength(bs->file->bs); |
| if (offset < 0) { |
| ret = offset; |
| error_setg(errp, "Invalid file size"); |
| goto fail; |
| } else if (offset < HEADER_SIZE) { |
| ret = -EINVAL; |
| error_setg(errp, "File too small for a VHD header"); |
| goto fail; |
| } |
| |
| /* If a fixed disk, the footer is found only at the end of the file */ |
| ret = bdrv_pread(bs->file, offset-HEADER_SIZE, s->footer_buf, |
| HEADER_SIZE); |
| if (ret < 0) { |
| goto fail; |
| } |
| if (strncmp(footer->creator, "conectix", 8)) { |
| error_setg(errp, "invalid VPC image"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| disk_type = VHD_FIXED; |
| } |
| |
| 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", bs->filename); |
| |
| /* Write 'checksum' back to footer, or else will leave it with zero. */ |
| footer->checksum = cpu_to_be32(checksum); |
| |
| /* 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; |
| |
| /* Microsoft Virtual PC and Microsoft Hyper-V produce and read |
| * VHD image sizes differently. VPC will rely on CHS geometry, |
| * while Hyper-V and disk2vhd use the size specified in the footer. |
| * |
| * We use a couple of approaches to try and determine the correct method: |
| * look at the Creator App field, and look for images that have CHS |
| * geometry that is the maximum value. |
| * |
| * If the CHS geometry is the maximum CHS geometry, then we assume that |
| * the size is the footer->current_size to avoid truncation. Otherwise, |
| * we follow the table based on footer->creator_app: |
| * |
| * Known creator apps: |
| * 'vpc ' : CHS Virtual PC (uses disk geometry) |
| * 'qemu' : CHS QEMU (uses disk geometry) |
| * 'qem2' : current_size QEMU (uses current_size) |
| * 'win ' : current_size Hyper-V |
| * 'd2v ' : current_size Disk2vhd |
| * 'tap\0' : current_size XenServer |
| * 'CTXS' : current_size XenConverter |
| * |
| * The user can override the table values via drive options, however |
| * even with an override we will still use current_size for images |
| * that have CHS geometry of the maximum size. |
| */ |
| use_chs = (!!strncmp(footer->creator_app, "win ", 4) && |
| !!strncmp(footer->creator_app, "qem2", 4) && |
| !!strncmp(footer->creator_app, "d2v ", 4) && |
| !!strncmp(footer->creator_app, "CTXS", 4) && |
| !!memcmp(footer->creator_app, "tap", 4)) || s->force_use_chs; |
| |
| if (!use_chs || bs->total_sectors == VHD_MAX_GEOMETRY || s->force_use_sz) { |
| bs->total_sectors = be64_to_cpu(footer->current_size) / |
| BDRV_SECTOR_SIZE; |
| } |
| |
| /* Allow a maximum disk size of 2040 GiB */ |
| if (bs->total_sectors > VHD_MAX_SECTORS) { |
| ret = -EFBIG; |
| goto fail; |
| } |
| |
| if (disk_type == VHD_DYNAMIC) { |
| ret = bdrv_pread(bs->file, be64_to_cpu(footer->data_offset), buf, |
| HEADER_SIZE); |
| if (ret < 0) { |
| error_setg(errp, "Error reading dynamic VHD header"); |
| goto fail; |
| } |
| |
| dyndisk_header = (VHDDynDiskHeader *) buf; |
| |
| if (strncmp(dyndisk_header->magic, "cxsparse", 8)) { |
| error_setg(errp, "Invalid header magic"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| s->block_size = be32_to_cpu(dyndisk_header->block_size); |
| if (!is_power_of_2(s->block_size) || s->block_size < BDRV_SECTOR_SIZE) { |
| error_setg(errp, "Invalid block size %" PRIu32, s->block_size); |
| ret = -EINVAL; |
| goto fail; |
| } |
| s->bitmap_size = ((s->block_size / (8 * 512)) + 511) & ~511; |
| |
| s->max_table_entries = be32_to_cpu(dyndisk_header->max_table_entries); |
| |
| if ((bs->total_sectors * 512) / s->block_size > 0xffffffffU) { |
| error_setg(errp, "Too many blocks"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| computed_size = (uint64_t) s->max_table_entries * s->block_size; |
| if (computed_size < bs->total_sectors * 512) { |
| error_setg(errp, "Page table too small"); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| if (s->max_table_entries > SIZE_MAX / 4 || |
| s->max_table_entries > (int) INT_MAX / 4) { |
| error_setg(errp, "Max Table Entries too large (%" PRId32 ")", |
| s->max_table_entries); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| pagetable_size = (uint64_t) s->max_table_entries * 4; |
| |
| s->pagetable = qemu_try_blockalign(bs->file->bs, pagetable_size); |
| if (s->pagetable == NULL) { |
| error_setg(errp, "Unable to allocate memory for page table"); |
| ret = -ENOMEM; |
| goto fail; |
| } |
| |
| s->bat_offset = be64_to_cpu(dyndisk_header->table_offset); |
| |
| ret = bdrv_pread(bs->file, s->bat_offset, s->pagetable, |
| pagetable_size); |
| if (ret < 0) { |
| error_setg(errp, "Error reading pagetable"); |
| goto fail; |
| } |
| |
| s->free_data_block_offset = |
| ROUND_UP(s->bat_offset + pagetable_size, 512); |
| |
| 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; |
| } |
| } |
| } |
| |
| if (s->free_data_block_offset > bdrv_getlength(bs->file->bs)) { |
| error_setg(errp, "block-vpc: free_data_block_offset points after " |
| "the end of file. The image has been truncated."); |
| ret = -EINVAL; |
| goto fail; |
| } |
| |
| s->last_bitmap_offset = (int64_t) -1; |
| |
| #ifdef CACHE |
| s->pageentry_u8 = g_malloc(512); |
| s->pageentry_u32 = s->pageentry_u8; |
| s->pageentry_u16 = s->pageentry_u8; |
| s->last_pagetable = -1; |
| #endif |
| } |
| |
| qemu_co_mutex_init(&s->lock); |
| |
| /* Disable migration when VHD images are used */ |
| error_setg(&s->migration_blocker, "The vpc format used by node '%s' " |
| "does not support live migration", |
| bdrv_get_device_or_node_name(bs)); |
| migrate_add_blocker(s->migration_blocker); |
| |
| return 0; |
| |
| fail: |
| qemu_vfree(s->pagetable); |
| #ifdef CACHE |
| g_free(s->pageentry_u8); |
| #endif |
| return ret; |
| } |
| |
| static int vpc_reopen_prepare(BDRVReopenState *state, |
| BlockReopenQueue *queue, Error **errp) |
| { |
| return 0; |
| } |
| |
| /* |
| * 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_image_offset(BlockDriverState *bs, uint64_t offset, |
| bool write) |
| { |
| BDRVVPCState *s = bs->opaque; |
| uint64_t bitmap_offset, block_offset; |
| uint32_t pagetable_index, offset_in_block; |
| |
| pagetable_index = offset / s->block_size; |
| offset_in_block = offset % s->block_size; |
| |
| 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 + offset_in_block; |
| |
| /* 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_sync(bs->file, bitmap_offset, bitmap, s->bitmap_size); |
| } |
| |
| return block_offset; |
| } |
| |
| static inline int64_t get_sector_offset(BlockDriverState *bs, |
| int64_t sector_num, bool write) |
| { |
| return get_image_offset(bs, sector_num * BDRV_SECTOR_SIZE, write); |
| } |
| |
| /* |
| * 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_sync(bs->file, 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 offset) |
| { |
| 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 ((offset < 0) || (offset > bs->total_sectors * BDRV_SECTOR_SIZE)) { |
| return -EINVAL; |
| } |
| |
| /* Write entry into in-memory BAT */ |
| index = offset / s->block_size; |
| assert(s->pagetable[index] == 0xFFFFFFFF); |
| s->pagetable[index] = s->free_data_block_offset / 512; |
| |
| /* Initialize the block's bitmap */ |
| memset(bitmap, 0xff, s->bitmap_size); |
| ret = bdrv_pwrite_sync(bs->file, s->free_data_block_offset, bitmap, |
| s->bitmap_size); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| /* 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 = cpu_to_be32(s->pagetable[index]); |
| ret = bdrv_pwrite_sync(bs->file, bat_offset, &bat_value, 4); |
| if (ret < 0) |
| goto fail; |
| |
| return get_image_offset(bs, offset, false); |
| |
| fail: |
| s->free_data_block_offset -= (s->block_size + s->bitmap_size); |
| return ret; |
| } |
| |
| static int vpc_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) |
| { |
| BDRVVPCState *s = (BDRVVPCState *)bs->opaque; |
| VHDFooter *footer = (VHDFooter *) s->footer_buf; |
| |
| if (be32_to_cpu(footer->type) != VHD_FIXED) { |
| bdi->cluster_size = s->block_size; |
| } |
| |
| bdi->unallocated_blocks_are_zero = true; |
| return 0; |
| } |
| |
| static int coroutine_fn |
| vpc_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, int flags) |
| { |
| BDRVVPCState *s = bs->opaque; |
| int ret; |
| int64_t image_offset; |
| int64_t n_bytes; |
| int64_t bytes_done = 0; |
| VHDFooter *footer = (VHDFooter *) s->footer_buf; |
| QEMUIOVector local_qiov; |
| |
| if (be32_to_cpu(footer->type) == VHD_FIXED) { |
| return bdrv_co_preadv(bs->file, offset, bytes, qiov, 0); |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| qemu_iovec_init(&local_qiov, qiov->niov); |
| |
| while (bytes > 0) { |
| image_offset = get_image_offset(bs, offset, false); |
| n_bytes = MIN(bytes, s->block_size - (offset % s->block_size)); |
| |
| if (image_offset == -1) { |
| qemu_iovec_memset(qiov, bytes_done, 0, n_bytes); |
| } else { |
| qemu_iovec_reset(&local_qiov); |
| qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); |
| |
| ret = bdrv_co_preadv(bs->file, image_offset, n_bytes, |
| &local_qiov, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| } |
| |
| bytes -= n_bytes; |
| offset += n_bytes; |
| bytes_done += n_bytes; |
| } |
| |
| ret = 0; |
| fail: |
| qemu_iovec_destroy(&local_qiov); |
| qemu_co_mutex_unlock(&s->lock); |
| |
| return ret; |
| } |
| |
| static int coroutine_fn |
| vpc_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, |
| QEMUIOVector *qiov, int flags) |
| { |
| BDRVVPCState *s = bs->opaque; |
| int64_t image_offset; |
| int64_t n_bytes; |
| int64_t bytes_done = 0; |
| int ret; |
| VHDFooter *footer = (VHDFooter *) s->footer_buf; |
| QEMUIOVector local_qiov; |
| |
| if (be32_to_cpu(footer->type) == VHD_FIXED) { |
| return bdrv_co_pwritev(bs->file, offset, bytes, qiov, 0); |
| } |
| |
| qemu_co_mutex_lock(&s->lock); |
| qemu_iovec_init(&local_qiov, qiov->niov); |
| |
| while (bytes > 0) { |
| image_offset = get_image_offset(bs, offset, true); |
| n_bytes = MIN(bytes, s->block_size - (offset % s->block_size)); |
| |
| if (image_offset == -1) { |
| image_offset = alloc_block(bs, offset); |
| if (image_offset < 0) { |
| ret = image_offset; |
| goto fail; |
| } |
| } |
| |
| qemu_iovec_reset(&local_qiov); |
| qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); |
| |
| ret = bdrv_co_pwritev(bs->file, image_offset, n_bytes, |
| &local_qiov, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| bytes -= n_bytes; |
| offset += n_bytes; |
| bytes_done += n_bytes; |
| } |
| |
| ret = 0; |
| fail: |
| qemu_iovec_destroy(&local_qiov); |
| qemu_co_mutex_unlock(&s->lock); |
| |
| return ret; |
| } |
| |
| static int64_t coroutine_fn vpc_co_get_block_status(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file) |
| { |
| BDRVVPCState *s = bs->opaque; |
| VHDFooter *footer = (VHDFooter*) s->footer_buf; |
| int64_t start, offset; |
| bool allocated; |
| int n; |
| |
| if (be32_to_cpu(footer->type) == VHD_FIXED) { |
| *pnum = nb_sectors; |
| *file = bs->file->bs; |
| return BDRV_BLOCK_RAW | BDRV_BLOCK_OFFSET_VALID | BDRV_BLOCK_DATA | |
| (sector_num << BDRV_SECTOR_BITS); |
| } |
| |
| offset = get_sector_offset(bs, sector_num, 0); |
| start = offset; |
| allocated = (offset != -1); |
| *pnum = 0; |
| |
| do { |
| /* All sectors in a block are contiguous (without using the bitmap) */ |
| n = ROUND_UP(sector_num + 1, s->block_size / BDRV_SECTOR_SIZE) |
| - sector_num; |
| n = MIN(n, nb_sectors); |
| |
| *pnum += n; |
| sector_num += n; |
| nb_sectors -= n; |
| /* *pnum can't be greater than one block for allocated |
| * sectors since there is always a bitmap in between. */ |
| if (allocated) { |
| *file = bs->file->bs; |
| return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | start; |
| } |
| if (nb_sectors == 0) { |
| break; |
| } |
| offset = get_sector_offset(bs, sector_num, 0); |
| } while (offset == -1); |
| |
| 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 2040 GiB. Override |
| * the hardware EIDE and ATA-2 limit of 16 heads (max disk size of 127 GB) |
| * and instead allow up to 255 heads. |
| */ |
| static int calculate_geometry(int64_t total_sectors, uint16_t* cyls, |
| uint8_t* heads, uint8_t* secs_per_cyl) |
| { |
| uint32_t cyls_times_heads; |
| |
| total_sectors = MIN(total_sectors, VHD_MAX_GEOMETRY); |
| |
| if (total_sectors >= 65535LL * 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; |
| } |
| } |
| |
| *cyls = cyls_times_heads / *heads; |
| |
| return 0; |
| } |
| |
| static int create_dynamic_disk(BlockBackend *blk, uint8_t *buf, |
| int64_t total_sectors) |
| { |
| VHDDynDiskHeader *dyndisk_header = |
| (VHDDynDiskHeader *) buf; |
| size_t block_size, num_bat_entries; |
| int i; |
| int ret; |
| int64_t offset = 0; |
| |
| /* 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); |
| |
| ret = blk_pwrite(blk, offset, buf, HEADER_SIZE, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| offset = 1536 + ((num_bat_entries * 4 + 511) & ~511); |
| ret = blk_pwrite(blk, offset, buf, HEADER_SIZE, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| /* Write the initial BAT */ |
| offset = 3 * 512; |
| |
| memset(buf, 0xFF, 512); |
| for (i = 0; i < (num_bat_entries * 4 + 511) / 512; i++) { |
| ret = blk_pwrite(blk, offset, buf, 512, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| offset += 512; |
| } |
| |
| /* Prepare the Dynamic Disk Header */ |
| memset(buf, 0, 1024); |
| |
| memcpy(dyndisk_header->magic, "cxsparse", 8); |
| |
| /* |
| * Note: The spec is actually wrong here for data_offset, it says |
| * 0xFFFFFFFF, but MS tools expect all 64 bits to be set. |
| */ |
| dyndisk_header->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL); |
| dyndisk_header->table_offset = cpu_to_be64(3 * 512); |
| dyndisk_header->version = cpu_to_be32(0x00010000); |
| dyndisk_header->block_size = cpu_to_be32(block_size); |
| dyndisk_header->max_table_entries = cpu_to_be32(num_bat_entries); |
| |
| dyndisk_header->checksum = cpu_to_be32(vpc_checksum(buf, 1024)); |
| |
| /* Write the header */ |
| offset = 512; |
| |
| ret = blk_pwrite(blk, offset, buf, 1024, 0); |
| if (ret < 0) { |
| goto fail; |
| } |
| |
| fail: |
| return ret; |
| } |
| |
| static int create_fixed_disk(BlockBackend *blk, uint8_t *buf, |
| int64_t total_size) |
| { |
| int ret; |
| |
| /* Add footer to total size */ |
| total_size += HEADER_SIZE; |
| |
| ret = blk_truncate(blk, total_size); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| ret = blk_pwrite(blk, total_size - HEADER_SIZE, buf, HEADER_SIZE, 0); |
| if (ret < 0) { |
| return ret; |
| } |
| |
| return ret; |
| } |
| |
| static int vpc_create(const char *filename, QemuOpts *opts, Error **errp) |
| { |
| uint8_t buf[1024]; |
| VHDFooter *footer = (VHDFooter *) buf; |
| char *disk_type_param; |
| int i; |
| uint16_t cyls = 0; |
| uint8_t heads = 0; |
| uint8_t secs_per_cyl = 0; |
| int64_t total_sectors; |
| int64_t total_size; |
| int disk_type; |
| int ret = -EIO; |
| bool force_size; |
| Error *local_err = NULL; |
| BlockBackend *blk = NULL; |
| |
| /* Read out options */ |
| total_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), |
| BDRV_SECTOR_SIZE); |
| disk_type_param = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT); |
| if (disk_type_param) { |
| if (!strcmp(disk_type_param, "dynamic")) { |
| disk_type = VHD_DYNAMIC; |
| } else if (!strcmp(disk_type_param, "fixed")) { |
| disk_type = VHD_FIXED; |
| } else { |
| error_setg(errp, "Invalid disk type, %s", disk_type_param); |
| ret = -EINVAL; |
| goto out; |
| } |
| } else { |
| disk_type = VHD_DYNAMIC; |
| } |
| |
| force_size = qemu_opt_get_bool_del(opts, VPC_OPT_FORCE_SIZE, false); |
| |
| ret = bdrv_create_file(filename, opts, &local_err); |
| if (ret < 0) { |
| error_propagate(errp, local_err); |
| goto out; |
| } |
| |
| blk = blk_new_open(filename, NULL, NULL, |
| BDRV_O_RDWR | BDRV_O_PROTOCOL, &local_err); |
| if (blk == NULL) { |
| error_propagate(errp, local_err); |
| ret = -EIO; |
| goto out; |
| } |
| |
| blk_set_allow_write_beyond_eof(blk, true); |
| |
| /* |
| * Calculate matching total_size and geometry. Increase the number of |
| * sectors requested until we get enough (or fail). This ensures that |
| * qemu-img convert doesn't truncate images, but rather rounds up. |
| * |
| * If the image size can't be represented by a spec conformant CHS geometry, |
| * we set the geometry to 65535 x 16 x 255 (CxHxS) sectors and use |
| * the image size from the VHD footer to calculate total_sectors. |
| */ |
| if (force_size) { |
| /* This will force the use of total_size for sector count, below */ |
| cyls = VHD_CHS_MAX_C; |
| heads = VHD_CHS_MAX_H; |
| secs_per_cyl = VHD_CHS_MAX_S; |
| } else { |
| total_sectors = MIN(VHD_MAX_GEOMETRY, total_size / BDRV_SECTOR_SIZE); |
| for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) { |
| calculate_geometry(total_sectors + i, &cyls, &heads, &secs_per_cyl); |
| } |
| } |
| |
| if ((int64_t)cyls * heads * secs_per_cyl == VHD_MAX_GEOMETRY) { |
| total_sectors = total_size / BDRV_SECTOR_SIZE; |
| /* Allow a maximum disk size of 2040 GiB */ |
| if (total_sectors > VHD_MAX_SECTORS) { |
| error_setg(errp, "Disk size is too large, max size is 2040 GiB"); |
| ret = -EFBIG; |
| goto out; |
| } |
| } else { |
| total_sectors = (int64_t)cyls * heads * secs_per_cyl; |
| total_size = total_sectors * BDRV_SECTOR_SIZE; |
| } |
| |
| /* Prepare the Hard Disk Footer */ |
| memset(buf, 0, 1024); |
| |
| memcpy(footer->creator, "conectix", 8); |
| if (force_size) { |
| memcpy(footer->creator_app, "qem2", 4); |
| } else { |
| memcpy(footer->creator_app, "qemu", 4); |
| } |
| memcpy(footer->creator_os, "Wi2k", 4); |
| |
| footer->features = cpu_to_be32(0x02); |
| footer->version = cpu_to_be32(0x00010000); |
| if (disk_type == VHD_DYNAMIC) { |
| footer->data_offset = cpu_to_be64(HEADER_SIZE); |
| } else { |
| footer->data_offset = cpu_to_be64(0xFFFFFFFFFFFFFFFFULL); |
| } |
| footer->timestamp = cpu_to_be32(time(NULL) - VHD_TIMESTAMP_BASE); |
| |
| /* Version of Virtual PC 2007 */ |
| footer->major = cpu_to_be16(0x0005); |
| footer->minor = cpu_to_be16(0x0003); |
| footer->orig_size = cpu_to_be64(total_size); |
| footer->current_size = cpu_to_be64(total_size); |
| footer->cyls = cpu_to_be16(cyls); |
| footer->heads = heads; |
| footer->secs_per_cyl = secs_per_cyl; |
| |
| footer->type = cpu_to_be32(disk_type); |
| |
| #if defined(CONFIG_UUID) |
| uuid_generate(footer->uuid); |
| #endif |
| |
| footer->checksum = cpu_to_be32(vpc_checksum(buf, HEADER_SIZE)); |
| |
| if (disk_type == VHD_DYNAMIC) { |
| ret = create_dynamic_disk(blk, buf, total_sectors); |
| } else { |
| ret = create_fixed_disk(blk, buf, total_size); |
| } |
| if (ret < 0) { |
| error_setg(errp, "Unable to create or write VHD header"); |
| } |
| |
| out: |
| blk_unref(blk); |
| g_free(disk_type_param); |
| return ret; |
| } |
| |
| static int vpc_has_zero_init(BlockDriverState *bs) |
| { |
| BDRVVPCState *s = bs->opaque; |
| VHDFooter *footer = (VHDFooter *) s->footer_buf; |
| |
| if (be32_to_cpu(footer->type) == VHD_FIXED) { |
| return bdrv_has_zero_init(bs->file->bs); |
| } else { |
| return 1; |
| } |
| } |
| |
| static void vpc_close(BlockDriverState *bs) |
| { |
| BDRVVPCState *s = bs->opaque; |
| qemu_vfree(s->pagetable); |
| #ifdef CACHE |
| g_free(s->pageentry_u8); |
| #endif |
| |
| migrate_del_blocker(s->migration_blocker); |
| error_free(s->migration_blocker); |
| } |
| |
| static QemuOptsList vpc_create_opts = { |
| .name = "vpc-create-opts", |
| .head = QTAILQ_HEAD_INITIALIZER(vpc_create_opts.head), |
| .desc = { |
| { |
| .name = BLOCK_OPT_SIZE, |
| .type = QEMU_OPT_SIZE, |
| .help = "Virtual disk size" |
| }, |
| { |
| .name = BLOCK_OPT_SUBFMT, |
| .type = QEMU_OPT_STRING, |
| .help = |
| "Type of virtual hard disk format. Supported formats are " |
| "{dynamic (default) | fixed} " |
| }, |
| { |
| .name = VPC_OPT_FORCE_SIZE, |
| .type = QEMU_OPT_BOOL, |
| .help = "Force disk size calculation to use the actual size " |
| "specified, rather than using the nearest CHS-based " |
| "calculation" |
| }, |
| { /* end of list */ } |
| } |
| }; |
| |
| static BlockDriver bdrv_vpc = { |
| .format_name = "vpc", |
| .instance_size = sizeof(BDRVVPCState), |
| |
| .bdrv_probe = vpc_probe, |
| .bdrv_open = vpc_open, |
| .bdrv_close = vpc_close, |
| .bdrv_reopen_prepare = vpc_reopen_prepare, |
| .bdrv_create = vpc_create, |
| |
| .bdrv_co_preadv = vpc_co_preadv, |
| .bdrv_co_pwritev = vpc_co_pwritev, |
| .bdrv_co_get_block_status = vpc_co_get_block_status, |
| |
| .bdrv_get_info = vpc_get_info, |
| |
| .create_opts = &vpc_create_opts, |
| .bdrv_has_zero_init = vpc_has_zero_init, |
| }; |
| |
| static void bdrv_vpc_init(void) |
| { |
| bdrv_register(&bdrv_vpc); |
| } |
| |
| block_init(bdrv_vpc_init); |