/* * Block driver for the Virtual Disk Image (VDI) format * * Copyright (c) 2009, 2012 Stefan Weil * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 2 of the License, or * (at your option) version 3 or any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . * * Reference: * http://forums.virtualbox.org/viewtopic.php?t=8046 * * This driver supports create / read / write operations on VDI images. * * Todo (see also TODO in code): * * Some features like snapshots are still missing. * * Deallocation of zero-filled blocks and shrinking images are missing, too * (might be added to common block layer). * * Allocation of blocks could be optimized (less writes to block map and * header). * * Read and write of adjacent blocks could be done in one operation * (current code uses one operation per block (1 MiB). * * The code is not thread safe (missing locks for changes in header and * block table, no problem with current QEMU). * * Hints: * * Blocks (VDI documentation) correspond to clusters (QEMU). * QEMU's backing files could be implemented using VDI snapshot files (TODO). * VDI snapshot files may also contain the complete machine state. * Maybe this machine state can be converted to QEMU PC machine snapshot data. * * The driver keeps a block cache (little endian entries) in memory. * For the standard block size (1 MiB), a 1 TiB disk will use 4 MiB RAM, * so this seems to be reasonable. */ #include "qemu-common.h" #include "block/block_int.h" #include "qemu/module.h" #include "migration/migration.h" #include "block/coroutine.h" #if defined(CONFIG_UUID) #include #else /* TODO: move uuid emulation to some central place in QEMU. */ #include "sysemu/sysemu.h" /* UUID_FMT */ typedef unsigned char uuid_t[16]; #endif /* Code configuration options. */ /* Enable debug messages. */ //~ #define CONFIG_VDI_DEBUG /* Support write operations on VDI images. */ #define CONFIG_VDI_WRITE /* Support non-standard block (cluster) size. This is untested. * Maybe it will be needed for very large images. */ //~ #define CONFIG_VDI_BLOCK_SIZE /* Support static (fixed, pre-allocated) images. */ #define CONFIG_VDI_STATIC_IMAGE /* Command line option for static images. */ #define BLOCK_OPT_STATIC "static" #define KiB 1024 #define MiB (KiB * KiB) #define SECTOR_SIZE 512 #define DEFAULT_CLUSTER_SIZE (1 * MiB) #if defined(CONFIG_VDI_DEBUG) #define logout(fmt, ...) \ fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__) #else #define logout(fmt, ...) ((void)0) #endif /* Image signature. */ #define VDI_SIGNATURE 0xbeda107f /* Image version. */ #define VDI_VERSION_1_1 0x00010001 /* Image type. */ #define VDI_TYPE_DYNAMIC 1 #define VDI_TYPE_STATIC 2 /* Innotek / SUN images use these strings in header.text: * "<<< innotek VirtualBox Disk Image >>>\n" * "<<< Sun xVM VirtualBox Disk Image >>>\n" * "<<< Sun VirtualBox Disk Image >>>\n" * The value does not matter, so QEMU created images use a different text. */ #define VDI_TEXT "<<< QEMU VM Virtual Disk Image >>>\n" /* A never-allocated block; semantically arbitrary content. */ #define VDI_UNALLOCATED 0xffffffffU /* A discarded (no longer allocated) block; semantically zero-filled. */ #define VDI_DISCARDED 0xfffffffeU #define VDI_IS_ALLOCATED(X) ((X) < VDI_DISCARDED) /* The bmap will take up VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) bytes; since * the bmap is read and written in a single operation, its size needs to be * limited to INT_MAX; furthermore, when opening an image, the bmap size is * rounded up to be aligned on BDRV_SECTOR_SIZE. * Therefore this should satisfy the following: * VDI_BLOCKS_IN_IMAGE_MAX * sizeof(uint32_t) + BDRV_SECTOR_SIZE == INT_MAX + 1 * (INT_MAX + 1 is the first value not representable as an int) * This guarantees that any value below or equal to the constant will, when * multiplied by sizeof(uint32_t) and rounded up to a BDRV_SECTOR_SIZE boundary, * still be below or equal to INT_MAX. */ #define VDI_BLOCKS_IN_IMAGE_MAX \ ((unsigned)((INT_MAX + 1u - BDRV_SECTOR_SIZE) / sizeof(uint32_t))) #define VDI_DISK_SIZE_MAX ((uint64_t)VDI_BLOCKS_IN_IMAGE_MAX * \ (uint64_t)DEFAULT_CLUSTER_SIZE) #if !defined(CONFIG_UUID) static inline void uuid_generate(uuid_t out) { memset(out, 0, sizeof(uuid_t)); } static inline int uuid_is_null(const uuid_t uu) { uuid_t null_uuid = { 0 }; return memcmp(uu, null_uuid, sizeof(uuid_t)) == 0; } # if defined(CONFIG_VDI_DEBUG) static inline void uuid_unparse(const uuid_t uu, char *out) { snprintf(out, 37, UUID_FMT, uu[0], uu[1], uu[2], uu[3], uu[4], uu[5], uu[6], uu[7], uu[8], uu[9], uu[10], uu[11], uu[12], uu[13], uu[14], uu[15]); } # endif #endif typedef struct { char text[0x40]; uint32_t signature; uint32_t version; uint32_t header_size; uint32_t image_type; uint32_t image_flags; char description[256]; uint32_t offset_bmap; uint32_t offset_data; uint32_t cylinders; /* disk geometry, unused here */ uint32_t heads; /* disk geometry, unused here */ uint32_t sectors; /* disk geometry, unused here */ uint32_t sector_size; uint32_t unused1; uint64_t disk_size; uint32_t block_size; uint32_t block_extra; /* unused here */ uint32_t blocks_in_image; uint32_t blocks_allocated; uuid_t uuid_image; uuid_t uuid_last_snap; uuid_t uuid_link; uuid_t uuid_parent; uint64_t unused2[7]; } QEMU_PACKED VdiHeader; typedef struct { /* The block map entries are little endian (even in memory). */ uint32_t *bmap; /* Size of block (bytes). */ uint32_t block_size; /* Size of block (sectors). */ uint32_t block_sectors; /* First sector of block map. */ uint32_t bmap_sector; /* VDI header (converted to host endianness). */ VdiHeader header; CoMutex write_lock; Error *migration_blocker; } BDRVVdiState; /* Change UUID from little endian (IPRT = VirtualBox format) to big endian * format (network byte order, standard, see RFC 4122) and vice versa. */ static void uuid_convert(uuid_t uuid) { bswap32s((uint32_t *)&uuid[0]); bswap16s((uint16_t *)&uuid[4]); bswap16s((uint16_t *)&uuid[6]); } static void vdi_header_to_cpu(VdiHeader *header) { le32_to_cpus(&header->signature); le32_to_cpus(&header->version); le32_to_cpus(&header->header_size); le32_to_cpus(&header->image_type); le32_to_cpus(&header->image_flags); le32_to_cpus(&header->offset_bmap); le32_to_cpus(&header->offset_data); le32_to_cpus(&header->cylinders); le32_to_cpus(&header->heads); le32_to_cpus(&header->sectors); le32_to_cpus(&header->sector_size); le64_to_cpus(&header->disk_size); le32_to_cpus(&header->block_size); le32_to_cpus(&header->block_extra); le32_to_cpus(&header->blocks_in_image); le32_to_cpus(&header->blocks_allocated); uuid_convert(header->uuid_image); uuid_convert(header->uuid_last_snap); uuid_convert(header->uuid_link); uuid_convert(header->uuid_parent); } static void vdi_header_to_le(VdiHeader *header) { cpu_to_le32s(&header->signature); cpu_to_le32s(&header->version); cpu_to_le32s(&header->header_size); cpu_to_le32s(&header->image_type); cpu_to_le32s(&header->image_flags); cpu_to_le32s(&header->offset_bmap); cpu_to_le32s(&header->offset_data); cpu_to_le32s(&header->cylinders); cpu_to_le32s(&header->heads); cpu_to_le32s(&header->sectors); cpu_to_le32s(&header->sector_size); cpu_to_le64s(&header->disk_size); cpu_to_le32s(&header->block_size); cpu_to_le32s(&header->block_extra); cpu_to_le32s(&header->blocks_in_image); cpu_to_le32s(&header->blocks_allocated); uuid_convert(header->uuid_image); uuid_convert(header->uuid_last_snap); uuid_convert(header->uuid_link); uuid_convert(header->uuid_parent); } #if defined(CONFIG_VDI_DEBUG) static void vdi_header_print(VdiHeader *header) { char uuid[37]; logout("text %s", header->text); logout("signature 0x%08x\n", header->signature); logout("header size 0x%04x\n", header->header_size); logout("image type 0x%04x\n", header->image_type); logout("image flags 0x%04x\n", header->image_flags); logout("description %s\n", header->description); logout("offset bmap 0x%04x\n", header->offset_bmap); logout("offset data 0x%04x\n", header->offset_data); logout("cylinders 0x%04x\n", header->cylinders); logout("heads 0x%04x\n", header->heads); logout("sectors 0x%04x\n", header->sectors); logout("sector size 0x%04x\n", header->sector_size); logout("image size 0x%" PRIx64 " B (%" PRIu64 " MiB)\n", header->disk_size, header->disk_size / MiB); logout("block size 0x%04x\n", header->block_size); logout("block extra 0x%04x\n", header->block_extra); logout("blocks tot. 0x%04x\n", header->blocks_in_image); logout("blocks all. 0x%04x\n", header->blocks_allocated); uuid_unparse(header->uuid_image, uuid); logout("uuid image %s\n", uuid); uuid_unparse(header->uuid_last_snap, uuid); logout("uuid snap %s\n", uuid); uuid_unparse(header->uuid_link, uuid); logout("uuid link %s\n", uuid); uuid_unparse(header->uuid_parent, uuid); logout("uuid parent %s\n", uuid); } #endif static int vdi_check(BlockDriverState *bs, BdrvCheckResult *res, BdrvCheckMode fix) { /* TODO: additional checks possible. */ BDRVVdiState *s = (BDRVVdiState *)bs->opaque; uint32_t blocks_allocated = 0; uint32_t block; uint32_t *bmap; logout("\n"); if (fix) { return -ENOTSUP; } bmap = g_try_new(uint32_t, s->header.blocks_in_image); if (s->header.blocks_in_image && bmap == NULL) { res->check_errors++; return -ENOMEM; } memset(bmap, 0xff, s->header.blocks_in_image * sizeof(uint32_t)); /* Check block map and value of blocks_allocated. */ for (block = 0; block < s->header.blocks_in_image; block++) { uint32_t bmap_entry = le32_to_cpu(s->bmap[block]); if (VDI_IS_ALLOCATED(bmap_entry)) { if (bmap_entry < s->header.blocks_in_image) { blocks_allocated++; if (!VDI_IS_ALLOCATED(bmap[bmap_entry])) { bmap[bmap_entry] = bmap_entry; } else { fprintf(stderr, "ERROR: block index %" PRIu32 " also used by %" PRIu32 "\n", bmap[bmap_entry], bmap_entry); res->corruptions++; } } else { fprintf(stderr, "ERROR: block index %" PRIu32 " too large, is %" PRIu32 "\n", block, bmap_entry); res->corruptions++; } } } if (blocks_allocated != s->header.blocks_allocated) { fprintf(stderr, "ERROR: allocated blocks mismatch, is %" PRIu32 ", should be %" PRIu32 "\n", blocks_allocated, s->header.blocks_allocated); res->corruptions++; } g_free(bmap); return 0; } static int vdi_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) { /* TODO: vdi_get_info would be needed for machine snapshots. vm_state_offset is still missing. */ BDRVVdiState *s = (BDRVVdiState *)bs->opaque; logout("\n"); bdi->cluster_size = s->block_size; bdi->vm_state_offset = 0; bdi->unallocated_blocks_are_zero = true; return 0; } static int vdi_make_empty(BlockDriverState *bs) { /* TODO: missing code. */ logout("\n"); /* The return value for missing code must be 0, see block.c. */ return 0; } static int vdi_probe(const uint8_t *buf, int buf_size, const char *filename) { const VdiHeader *header = (const VdiHeader *)buf; int ret = 0; logout("\n"); if (buf_size < sizeof(*header)) { /* Header too small, no VDI. */ } else if (le32_to_cpu(header->signature) == VDI_SIGNATURE) { ret = 100; } if (ret == 0) { logout("no vdi image\n"); } else { logout("%s", header->text); } return ret; } static int vdi_open(BlockDriverState *bs, QDict *options, int flags, Error **errp) { BDRVVdiState *s = bs->opaque; VdiHeader header; size_t bmap_size; int ret; logout("\n"); ret = bdrv_read(bs->file, 0, (uint8_t *)&header, 1); if (ret < 0) { goto fail; } vdi_header_to_cpu(&header); #if defined(CONFIG_VDI_DEBUG) vdi_header_print(&header); #endif if (header.disk_size > VDI_DISK_SIZE_MAX) { error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64 ", max supported is 0x%" PRIx64 ")", header.disk_size, VDI_DISK_SIZE_MAX); ret = -ENOTSUP; goto fail; } if (header.disk_size % SECTOR_SIZE != 0) { /* 'VBoxManage convertfromraw' can create images with odd disk sizes. We accept them but round the disk size to the next multiple of SECTOR_SIZE. */ logout("odd disk size %" PRIu64 " B, round up\n", header.disk_size); header.disk_size = ROUND_UP(header.disk_size, SECTOR_SIZE); } if (header.signature != VDI_SIGNATURE) { error_setg(errp, "Image not in VDI format (bad signature %08" PRIx32 ")", header.signature); ret = -EINVAL; goto fail; } else if (header.version != VDI_VERSION_1_1) { error_setg(errp, "unsupported VDI image (version %" PRIu32 ".%" PRIu32 ")", header.version >> 16, header.version & 0xffff); ret = -ENOTSUP; goto fail; } else if (header.offset_bmap % SECTOR_SIZE != 0) { /* We only support block maps which start on a sector boundary. */ error_setg(errp, "unsupported VDI image (unaligned block map offset " "0x%" PRIx32 ")", header.offset_bmap); ret = -ENOTSUP; goto fail; } else if (header.offset_data % SECTOR_SIZE != 0) { /* We only support data blocks which start on a sector boundary. */ error_setg(errp, "unsupported VDI image (unaligned data offset 0x%" PRIx32 ")", header.offset_data); ret = -ENOTSUP; goto fail; } else if (header.sector_size != SECTOR_SIZE) { error_setg(errp, "unsupported VDI image (sector size %" PRIu32 " is not %u)", header.sector_size, SECTOR_SIZE); ret = -ENOTSUP; goto fail; } else if (header.block_size != DEFAULT_CLUSTER_SIZE) { error_setg(errp, "unsupported VDI image (block size %" PRIu32 " is not %u)", header.block_size, DEFAULT_CLUSTER_SIZE); ret = -ENOTSUP; goto fail; } else if (header.disk_size > (uint64_t)header.blocks_in_image * header.block_size) { error_setg(errp, "unsupported VDI image (disk size %" PRIu64 ", " "image bitmap has room for %" PRIu64 ")", header.disk_size, (uint64_t)header.blocks_in_image * header.block_size); ret = -ENOTSUP; goto fail; } else if (!uuid_is_null(header.uuid_link)) { error_setg(errp, "unsupported VDI image (non-NULL link UUID)"); ret = -ENOTSUP; goto fail; } else if (!uuid_is_null(header.uuid_parent)) { error_setg(errp, "unsupported VDI image (non-NULL parent UUID)"); ret = -ENOTSUP; goto fail; } else if (header.blocks_in_image > VDI_BLOCKS_IN_IMAGE_MAX) { error_setg(errp, "unsupported VDI image " "(too many blocks %u, max is %u)", header.blocks_in_image, VDI_BLOCKS_IN_IMAGE_MAX); ret = -ENOTSUP; goto fail; } bs->total_sectors = header.disk_size / SECTOR_SIZE; s->block_size = header.block_size; s->block_sectors = header.block_size / SECTOR_SIZE; s->bmap_sector = header.offset_bmap / SECTOR_SIZE; s->header = header; bmap_size = header.blocks_in_image * sizeof(uint32_t); bmap_size = DIV_ROUND_UP(bmap_size, SECTOR_SIZE); s->bmap = qemu_try_blockalign(bs->file, bmap_size * SECTOR_SIZE); if (s->bmap == NULL) { ret = -ENOMEM; goto fail; } ret = bdrv_read(bs->file, s->bmap_sector, (uint8_t *)s->bmap, bmap_size); if (ret < 0) { goto fail_free_bmap; } /* Disable migration when vdi images are used */ error_setg(&s->migration_blocker, "The vdi format used by node '%s' " "does not support live migration", bdrv_get_device_or_node_name(bs)); migrate_add_blocker(s->migration_blocker); qemu_co_mutex_init(&s->write_lock); return 0; fail_free_bmap: qemu_vfree(s->bmap); fail: return ret; } static int vdi_reopen_prepare(BDRVReopenState *state, BlockReopenQueue *queue, Error **errp) { return 0; } static int64_t coroutine_fn vdi_co_get_block_status(BlockDriverState *bs, int64_t sector_num, int nb_sectors, int *pnum) { /* TODO: Check for too large sector_num (in bdrv_is_allocated or here). */ BDRVVdiState *s = (BDRVVdiState *)bs->opaque; size_t bmap_index = sector_num / s->block_sectors; size_t sector_in_block = sector_num % s->block_sectors; int n_sectors = s->block_sectors - sector_in_block; uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]); uint64_t offset; int result; logout("%p, %" PRId64 ", %d, %p\n", bs, sector_num, nb_sectors, pnum); if (n_sectors > nb_sectors) { n_sectors = nb_sectors; } *pnum = n_sectors; result = VDI_IS_ALLOCATED(bmap_entry); if (!result) { return 0; } offset = s->header.offset_data + (uint64_t)bmap_entry * s->block_size + sector_in_block * SECTOR_SIZE; return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset; } static int vdi_co_read(BlockDriverState *bs, int64_t sector_num, uint8_t *buf, int nb_sectors) { BDRVVdiState *s = bs->opaque; uint32_t bmap_entry; uint32_t block_index; uint32_t sector_in_block; uint32_t n_sectors; int ret = 0; logout("\n"); while (ret >= 0 && nb_sectors > 0) { block_index = sector_num / s->block_sectors; sector_in_block = sector_num % s->block_sectors; n_sectors = s->block_sectors - sector_in_block; if (n_sectors > nb_sectors) { n_sectors = nb_sectors; } logout("will read %u sectors starting at sector %" PRIu64 "\n", n_sectors, sector_num); /* prepare next AIO request */ bmap_entry = le32_to_cpu(s->bmap[block_index]); if (!VDI_IS_ALLOCATED(bmap_entry)) { /* Block not allocated, return zeros, no need to wait. */ memset(buf, 0, n_sectors * SECTOR_SIZE); ret = 0; } else { uint64_t offset = s->header.offset_data / SECTOR_SIZE + (uint64_t)bmap_entry * s->block_sectors + sector_in_block; ret = bdrv_read(bs->file, offset, buf, n_sectors); } logout("%u sectors read\n", n_sectors); nb_sectors -= n_sectors; sector_num += n_sectors; buf += n_sectors * SECTOR_SIZE; } return ret; } static int vdi_co_write(BlockDriverState *bs, int64_t sector_num, const uint8_t *buf, int nb_sectors) { BDRVVdiState *s = bs->opaque; uint32_t bmap_entry; uint32_t block_index; uint32_t sector_in_block; ndex; /* Copy data to be written to new block and zero unused parts. */ memset(block, 0, sector_in_block * SECTOR_SIZE); memcpy(block + sector_in_block * SECTOR_SIZE, buf, n_sectors * SECTOR_SIZE); memset(block + (sector_in_block + n_sectors) * SECTOR_SIZE, 0, (s->block_sectors - n_sectors - sector_in_block) * SECTOR_SIZE); /* Note that this coroutine does not yield anywhere from reading the * bmap entry until here, so in regards to all the coroutines trying * to write to this cluster, the one doing the allocation will * always be the first to try to acquire the lock. * Therefore, it is also the first that will actually be able to * acquire the lock and thus the padded cluster is written before * the other coroutines can write to the affected area. */ qemu_co_mutex_lock(&s->write_lock); ret = bdrv_write(bs->file, offset, block, s->block_sectors); qemu_co_mutex_unlock(&s->write_lock); } else { uint64_t offset = s->header.offset_data / SECTOR_SIZE + (uint64_t)bmap_entry * s->block_sectors + sector_in_block; qemu_co_mutex_lock(&s->write_lock); /* This lock is only used to make sure the following write operation * is executed after the write issued by the coroutine allocating * this cluster, therefore we do not need to keep it locked. * As stated above, the allocating coroutine will always try to lock * the mutex before all the other concurrent accesses to that * cluster, therefore at this point we can be absolutely certain * that that write operation has returned (there may be other writes * in flight, but they do not concern this very operation). */ qemu_co_mutex_unlock(&s->write_lock); ret = bdrv_write(bs->file, offset, buf, n_sectors); } nb_sectors -= n_sectors; sector_num += n_sectors; buf += n_sectors * SECTOR_SIZE; logout("%u sectors written\n", n_sectors); } logout("finished data write\n"); if (ret < 0) { return ret; } if (block) { /* One or more new blocks were allocated. */ VdiHeader *header = (VdiHeader *) block; uint8_t *base; uint64_t offset; logout("now writing modified header\n"); assert(VDI_IS_ALLOCATED(bmap_first)); *header = s->header; vdi_header_to_le(header); ret = bdrv_write(bs->file, 0, block, 1); g_free(block); block = NULL; if (ret < 0) { return ret; } logout("now writing modified block map entry %u...%u\n", bmap_first, bmap_last); /* Write modified sectors from block map. */ bmap_first /= (SECTOR_SIZE / sizeof(uint32_t)); bmap_last /= (SECTOR_SIZE / sizeof(uint32_t)); n_sectors = bmap_last - bmap_first + 1; offset = s->bmap_sector + bmap_first; base = ((uint8_t *)&s->bmap[0]) + bmap_first * SECTOR_SIZE; logout("will write %u block map sectors starting from entry %u\n", n_sectors, bmap_first); ret = bdrv_write(bs->file, offset, base, n_sectors); } return ret; } static int vdi_create(const char *filename, QemuOpts *opts, Error **errp) { int ret = 0; uint64_t bytes = 0; uint32_t blocks; size_t block_size = DEFAULT_CLUSTER_SIZE; uint32_t image_type = VDI_TYPE_DYNAMIC; VdiHeader header; size_t i; size_t bmap_size; int64_t offset = 0; Error *local_err = NULL; BlockDriverState *bs = NULL; uint32_t *bmap = NULL; logout("\n"); /* Read out options. */ bytes = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), BDRV_SECTOR_SIZE); #if defined(CONFIG_VDI_BLOCK_SIZE) /* TODO: Additional checks (SECTOR_SIZE * 2^n, ...). */ block_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, DEFAULT_CLUSTER_SIZE); #endif #if defined(CONFIG_VDI_STATIC_IMAGE) if (qemu_opt_get_bool_del(opts, BLOCK_OPT_STATIC, false)) { image_type = VDI_TYPE_STATIC; } #endif if (bytes > VDI_DISK_SIZE_MAX) { ret = -ENOTSUP; error_setg(errp, "Unsupported VDI image size (size is 0x%" PRIx64 ", max supported is 0x%" PRIx64 ")", bytes, VDI_DISK_SIZE_MAX); goto exit; } ret = bdrv_create_file(filename, opts, &local_err); if (ret < 0) { error_propagate(errp, local_err); goto exit; } 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 exit; } /* We need enough blocks to store the given disk size, so always round up. */ blocks = DIV_ROUND_UP(bytes, block_size); bmap_size = blocks * sizeof(uint32_t); bmap_size = ROUND_UP(bmap_size, SECTOR_SIZE); memset(&header, 0, sizeof(header)); pstrcpy(header.text, sizeof(header.text), VDI_TEXT); header.signature = VDI_SIGNATURE; header.version = VDI_VERSION_1_1; header.header_size = 0x180; header.image_type = image_type; header.offset_bmap = 0x200; header.offset_data = 0x200 + bmap_size; header.sector_size = SECTOR_SIZE; header.disk_size = bytes; header.block_size = block_size; header.blocks_in_image = blocks; if (image_type == VDI_TYPE_STATIC) { header.blocks_allocated = blocks; } uuid_generate(header.uuid_image); uuid_generate(header.uuid_last_snap); /* There is no need to set header.uuid_link or header.uuid_parent here. */ #if defined(CONFIG_VDI_DEBUG) vdi_header_print(&header); #endif vdi_header_to_le(&header); ret = bdrv_pwrite_sync(bs, offset, &header, sizeof(header)); if (ret < 0) { error_setg(errp, "Error writing header to %s", filename); goto exit; } offset += sizeof(header); if (bmap_size > 0) { bmap = g_try_malloc0(bmap_size); if (bmap == NULL) { ret = -ENOMEM; error_setg(errp, "Could not allocate bmap"); goto exit; } for (i = 0; i < blocks; i++) { if (image_type == VDI_TYPE_STATIC) { bmap[i] = i; } else { bmap[i] = VDI_UNALLOCATED; } } ret = bdrv_pwrite_sync(bs, offset, bmap, bmap_size); if (ret < 0) { error_setg(errp, "Error writing bmap to %s", filename); goto exit; } offset += bmap_size; } if (image_type == VDI_TYPE_STATIC) { ret = bdrv_truncate(bs, offset + blocks * block_size); if (ret < 0) { error_setg(errp, "Failed to statically allocate %s", filename); goto exit; } } exit: bdrv_unref(bs); g_free(bmap); return ret; } static void vdi_close(BlockDriverState *bs) { BDRVVdiState *s = bs->opaque; qemu_vfree(s->bmap); migrate_del_blocker(s->migration_blocker); error_free(s->migration_blocker); } static QemuOptsList vdi_create_opts = { .name = "vdi-create-opts", .head = QTAILQ_HEAD_INITIALIZER(vdi_create_opts.head), .desc = { { .name = BLOCK_OPT_SIZE, .type = QEMU_OPT_SIZE, .help = "Virtual disk size" }, #if defined(CONFIG_VDI_BLOCK_SIZE) { .name = BLOCK_OPT_CLUSTER_SIZE, .type = QEMU_OPT_SIZE, .help = "VDI cluster (block) size", .def_value_str = stringify(DEFAULT_CLUSTER_SIZE) }, #endif #if defined(CONFIG_VDI_STATIC_IMAGE) { .name = BLOCK_OPT_STATIC, .type = QEMU_OPT_BOOL, .help = "VDI static (pre-allocated) image", .def_value_str = "off" }, #endif /* TODO: An additional option to set UUID values might be useful. */ { /* end of list */ } } }; static BlockDriver bdrv_vdi = { .format_name = "vdi", .instance_size = sizeof(BDRVVdiState), .bdrv_probe = vdi_probe, .bdrv_open = vdi_open, .bdrv_close = vdi_close, .bdrv_reopen_prepare = vdi_reopen_prepare, .bdrv_create = vdi_create, .bdrv_has_zero_init = bdrv_has_zero_init_1, .bdrv_co_get_block_status = vdi_co_get_block_status, .bdrv_make_empty = vdi_make_empty, .bdrv_read = vdi_co_read, #if defined(CONFIG_VDI_WRITE) .bdrv_write = vdi_co_write, #endif .bdrv_get_info = vdi_get_info, .create_opts = &vdi_create_opts, .bdrv_check = vdi_check, }; static void bdrv_vdi_init(void) { logout("\n"); bdrv_register(&bdrv_vdi); } block_init(bdrv_vdi_init);