/* * 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-common.h" #include "block/block_int.h" #include "qemu/module.h" #include "migration/migration.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_MAX_SECTORS (65535LL * 255 * 255) // 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]; // "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; } 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; #ifdef CACHE uint8_t *pageentry_u8; uint32_t *pageentry_u32; uint16_t *pageentry_u16; uint64_t last_bitmap; #endif Error *migration_blocker; } 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, QDict *options, int flags, Error **errp) { BDRVVPCState *s = bs->opaque; int i; VHDFooter *footer; VHDDynDiskHeader *dyndisk_header; uint8_t buf[HEADER_SIZE]; uint32_t checksum; uint64_t computed_size; int disk_type = VHD_DYNAMIC; int ret; ret = bdrv_pread(bs->file, 0, s->footer_buf, HEADER_SIZE); if (ret < 0) { goto fail; } footer = (VHDFooter *) s->footer_buf; if (strncmp(footer->creator, "conectix", 8)) { int64_t offset = bdrv_getlength(bs->file); if (offset < 0) { ret = offset; goto fail; } else if (offset < HEADER_SIZE) { ret = -EINVAL; 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 = be32_to_cpu(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; /* images created with disk2vhd report a far higher virtual size * than expected with the cyls * heads * sectors_per_cyl formula. * use the footer->size instead if the image was created with * disk2vhd. */ if (!strncmp(footer->creator_app, "d2v", 4)) { bs->total_sectors = be64_to_cpu(footer->size) / BDRV_SECTOR_SIZE; } /* Allow a maximum disk size of approximately 2 TB */ 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) { goto fail; } dyndisk_header = (VHDDynDiskHeader *) buf; if (strncmp(dyndisk_header->magic, "cxsparse", 8)) { 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) { ret = -EINVAL; goto fail; } if (s->max_table_entries > (VHD_MAX_SECTORS * 512) / s->block_size) { ret = -EINVAL; goto fail; } computed_size = (uint64_t) s->max_table_entries * s->block_size; if (computed_size < bs->total_sectors * 512) { ret = -EINVAL; goto fail; } s->pagetable = qemu_try_blockalign(bs->file, s->max_table_entries * 4); if (s->pagetable == NULL) { ret = -ENOMEM; goto fail; } s->bat_offset = be64_to_cpu(dyndisk_header->table_offset); ret = bdrv_pread(bs->file, s->bat_offset, s->pagetable, s->max_table_entries * 4); if (ret < 0) { 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; } } } if (s->free_data_block_offset > bdrv_getlength(bs->file)) { 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_set(&s->migration_blocker, QERR_BLOCK_FORMAT_FEATURE_NOT_SUPPORTED, "vpc", bs->device_name, "live migration"); 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_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_sync(bs->file, 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_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 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); 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 = be32_to_cpu(s->pagetable[index]); ret = bdrv_pwrite_sync(bs->file, 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_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { BDRVVPCState *s = (BDRVVPCState *)bs->opaque; VHDFooter *footer = (VHDFooter *) s->footer_buf; if (cpu_to_be32(footer->type) != VHD_FIXED) { bdi->cluster_size = s->block_size; } bdi->unallocated_blocks_are_zero = true; return 0; } 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; int64_t sectors, sectors_per_block; VHDFooter *footer = (VHDFooter *) s->footer_buf; if (cpu_to_be32(footer->type) == VHD_FIXED) { return bdrv_read(bs->file, sector_num, buf, nb_sectors); } while (nb_sectors > 0) { offset = get_sector_offset(bs, sector_num, 0); sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; sectors = sectors_per_block - (sector_num % sectors_per_block); if (sectors > nb_sectors) { sectors = nb_sectors; } if (offset == -1) { memset(buf, 0, sectors * BDRV_SECTOR_SIZE); } else { ret = bdrv_pread(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE); if (ret != sectors * BDRV_SECTOR_SIZE) { return -1; } } nb_sectors -= sectors; sector_num += sectors; buf += sectors * BDRV_SECTOR_SIZE; } return 0; } static coroutine_fn int vpc_co_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { int ret; BDRVVPCState *s = bs->opaque; qemu_co_mutex_lock(&s->lock); ret = vpc_read(bs, sector_num, buf, nb_sectors); qemu_co_mutex_unlock(&s->lock); return ret; } static int vpc_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { BDRVVPCState *s = bs->opaque; int64_t offset; int64_t sectors, sectors_per_block; int ret; VHDFooter *footer = (VHDFooter *) s->footer_buf; if (cpu_to_be32(footer->type) == VHD_FIXED) { return bdrv_write(bs->file, sector_num, buf, nb_sectors); } while (nb_sectors > 0) { offset = get_sector_offset(bs, sector_num, 1); sectors_per_block = s->block_size >> BDRV_SECTOR_BITS; sectors = sectors_per_block - (sector_num % sectors_per_block); if (sectors > nb_sectors) { sectors = nb_sectors; } if (offset == -1) { offset = alloc_block(bs, sector_num); if (offset < 0) return -1; } ret = bdrv_pwrite(bs->file, offset, buf, sectors * BDRV_SECTOR_SIZE); if (ret != sectors * BDRV_SECTOR_SIZE) { return -1; } nb_sectors -= sectors; sector_num += sectors; buf += sectors * BDRV_SECTOR_SIZE; } return 0; } static coroutine_fn int vpc_co_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { int ret; BDRVVPCState *s = bs->opaque; qemu_co_mutex_lock(&s->lock); ret = vpc_write(bs, sector_num, buf, nb_sectors); qemu_co_mutex_unlock(&s->lock); return ret; } /* * 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 ~2 TB. 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; /* Allow a maximum disk size of approximately 2 TB */ if (total_sectors > 65535LL * 255 * 255) { return -EFBIG; } if (total_sectors > 65535 * 16 * 63) { *secs_per_cyl = 255; if (total_sectors > 65535 * 16 * 255) { *heads = 255; } else { *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(BlockDriverState *bs, 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 = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE); if (ret) { goto fail; } offset = 1536 + ((num_bat_entries * 4 + 511) & ~511); ret = bdrv_pwrite_sync(bs, offset, buf, HEADER_SIZE); 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 = bdrv_pwrite_sync(bs, offset, buf, 512); 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 = be64_to_cpu(0xFFFFFFFFFFFFFFFFULL); 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 offset = 512; ret = bdrv_pwrite_sync(bs, offset, buf, 1024); if (ret < 0) { goto fail; } fail: return ret; } static int create_fixed_disk(BlockDriverState *bs, uint8_t *buf, int64_t total_size) { int ret; /* Add footer to total size */ total_size += HEADER_SIZE; ret = bdrv_truncate(bs, total_size); if (ret < 0) { return ret; } ret = bdrv_pwrite_sync(bs, total_size - HEADER_SIZE, buf, HEADER_SIZE); 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; Error *local_err = NULL; BlockDriverState *bs = NULL; /* Read out options */ total_size = qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0); 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 { ret = -EINVAL; goto out; } } else { disk_type = VHD_DYNAMIC; } ret = bdrv_create_file(filename, opts, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto out; } ret = bdrv_open(&bs, filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_PROTOCOL, NULL, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto out; } /* * 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. */ total_sectors = total_size / BDRV_SECTOR_SIZE; for (i = 0; total_sectors > (int64_t)cyls * heads * secs_per_cyl; i++) { if (calculate_geometry(total_sectors + i, &cyls, &heads, &secs_per_cyl)) { ret = -EFBIG; goto out; } } total_sectors = (int64_t) cyls * heads * secs_per_cyl; /* Prepare the Hard Disk Footer */ memset(buf, 0, 1024); memcpy(footer->creator, "conectix", 8); /* TODO Check if "qemu" creator_app is ok for VPC */ memcpy(footer->creator_app, "qemu", 4); memcpy(footer->creator_os, "Wi2k", 4); footer->features = be32_to_cpu(0x02); footer->version = be32_to_cpu(0x00010000); if (disk_type == VHD_DYNAMIC) { footer->data_offset = be64_to_cpu(HEADER_SIZE); } else { footer->data_offset = be64_to_cpu(0xFFFFFFFFFFFFFFFFULL); } 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); if (disk_type == VHD_DYNAMIC) { footer->orig_size = be64_to_cpu(total_sectors * 512); footer->size = be64_to_cpu(total_sectors * 512); } else { footer->orig_size = be64_to_cpu(total_size); footer->size = be64_to_cpu(total_size); } footer->cyls = be16_to_cpu(cyls); footer->heads = heads; footer->secs_per_cyl = secs_per_cyl; footer->type = be32_to_cpu(disk_type); #if defined(CONFIG_UUID) uuid_generate(footer->uuid); #endif footer->checksum = be32_to_cpu(vpc_checksum(buf, HEADER_SIZE)); if (disk_type == VHD_DYNAMIC) { ret = create_dynamic_disk(bs, buf, total_sectors); } else { ret = create_fixed_disk(bs, buf, total_size); } out: bdrv_unref(bs); 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 (cpu_to_be32(footer->type) == VHD_FIXED) { return bdrv_has_zero_init(bs->file); } 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 = BLOCK_OPT_NOCOW, .type = QEMU_OPT_BOOL, .help = "Turn off copy-on-write (valid only on btrfs)" }, { /* 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_read = vpc_co_read, .bdrv_write = vpc_co_write, .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);