/* * 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/osdep.h" #include "qemu/units.h" #include "qapi/error.h" #include "qapi/qobject-input-visitor.h" #include "qapi/qapi-visit-block-core.h" #include "block/block_int.h" #include "block/qdict.h" #include "sysemu/block-backend.h" #include "qemu/module.h" #include "qemu/option.h" #include "qemu/bswap.h" #include "migration/blocker.h" #include "qemu/coroutine.h" #include "qemu/cutils.h" #include "qemu/uuid.h" /* 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 SECTOR_SIZE 512 #define DEFAULT_CLUSTER_SIZE 1048576 /* Note: can't use 1 * MiB, because it's passed to stringify() */ #if defined(CONFIG_VDI_DEBUG) #define VDI_DEBUG 1 #else #define VDI_DEBUG 0 #endif #define logout(fmt, ...) \ do { \ if (VDI_DEBUG) { \ fprintf(stderr, "vdi\t%-24s" fmt, __func__, ##__VA_ARGS__); \ } \ } while (0) /* 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) static QemuOptsList vdi_create_opts; 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; QemuUUID uuid_image; QemuUUID uuid_last_snap; QemuUUID uuid_link; QemuUUID uuid_parent; uint64_t unused2[7]; } QEMU_PACKED VdiHeader; QEMU_BUILD_BUG_ON(sizeof(VdiHeader) != 512); typedef struct { /* The block map entries are little endian (even in memory). */ uint32_t *bmap; /* Size of block (bytes). */ uint32_t block_size; /* First sector of block map. */ uint32_t bmap_sector; /* VDI header (converted to host endianness). */ VdiHeader header; CoRwlock bmap_lock; Error *migration_blocker; } BDRVVdiState; static void vdi_header_to_cpu(VdiHeader *header) { header->signature = le32_to_cpu(header->signature); header->version = le32_to_cpu(header->version); header->header_size = le32_to_cpu(header->header_size); header->image_type = le32_to_cpu(header->image_type); header->image_flags = le32_to_cpu(header->image_flags); header->offset_bmap = le32_to_cpu(header->offset_bmap); header->offset_data = le32_to_cpu(header->offset_data); header->cylinders = le32_to_cpu(header->cylinders); header->heads = le32_to_cpu(header->heads); header->sectors = le32_to_cpu(header->sectors); header->sector_size = le32_to_cpu(header->sector_size); header->disk_size = le64_to_cpu(header->disk_size); header->block_size = le32_to_cpu(header->block_size); header->block_extra = le32_to_cpu(header->block_extra); header->blocks_in_image = le32_to_cpu(header->blocks_in_image); header->blocks_allocated = le32_to_cpu(header->blocks_allocated); header->uuid_image = qemu_uuid_bswap(header->uuid_image); header->uuid_last_snap = qemu_uuid_bswap(header->uuid_last_snap); header->uuid_link = qemu_uuid_bswap(header->uuid_link); header->uuid_parent = qemu_uuid_bswap(header->uuid_parent); } static void vdi_header_to_le(VdiHeader *header) { header->signature = cpu_to_le32(header->signature); header->version = cpu_to_le32(header->version); header->header_size = cpu_to_le32(header->header_size); header->image_type = cpu_to_le32(header->image_type); header->image_flags = cpu_to_le32(header->image_flags); header->offset_bmap = cpu_to_le32(header->offset_bmap); header->offset_data = cpu_to_le32(header->offset_data); header->cylinders = cpu_to_le32(header->cylinders); header->heads = cpu_to_le32(header->heads); header->sectors = cpu_to_le32(header->sectors); header->sector_size = cpu_to_le32(header->sector_size); header->disk_size = cpu_to_le64(header->disk_size); header->block_size = cpu_to_le32(header->block_size); header->block_extra = cpu_to_le32(header->block_extra); header->blocks_in_image = cpu_to_le32(header->blocks_in_image); header->blocks_allocated = cpu_to_le32(header->blocks_allocated); header->uuid_image = qemu_uuid_bswap(header->uuid_image); header->uuid_last_snap = qemu_uuid_bswap(header->uuid_last_snap); header->uuid_link = qemu_uuid_bswap(header->uuid_link); header->uuid_parent = qemu_uuid_bswap(header->uuid_parent); } static void vdi_header_print(VdiHeader *header) { char uuidstr[37]; QemuUUID uuid; 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 = header->uuid_image; qemu_uuid_unparse(&uuid, uuidstr); logout("uuid image %s\n", uuidstr); uuid = header->uuid_last_snap; qemu_uuid_unparse(&uuid, uuidstr); logout("uuid snap %s\n", uuidstr); uuid = header->uuid_link; qemu_uuid_unparse(&uuid, uuidstr); logout("uuid link %s\n", uuidstr); uuid = header->uuid_parent; qemu_uuid_unparse(&uuid, uuidstr); logout("uuid parent %s\n", uuidstr); } static int coroutine_fn vdi_co_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; Error *local_err = NULL; QemuUUID uuid_link, uuid_parent; bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, false, errp); if (!bs->file) { return -EINVAL; } logout("\n"); ret = bdrv_pread(bs->file, 0, &header, sizeof(header)); if (ret < 0) { goto fail; } vdi_header_to_cpu(&header); if (VDI_DEBUG) { vdi_header_print(&header); } 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; } uuid_link = header.uuid_link; uuid_parent = header.uuid_parent; 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 %" PRIu32 ")", 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 (!qemu_uuid_is_null(&uuid_link)) { error_setg(errp, "unsupported VDI image (non-NULL link UUID)"); ret = -ENOTSUP; goto fail; } else if (!qemu_uuid_is_null(&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->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->bs, bmap_size * SECTOR_SIZE); if (s->bmap == NULL) { ret = -ENOMEM; goto fail; } ret = bdrv_pread(bs->file, header.offset_bmap, s->bmap, bmap_size * SECTOR_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)); ret = migrate_add_blocker(s->migration_blocker, &local_err); if (local_err) { error_propagate(errp, local_err); error_free(s->migration_blocker); goto fail_free_bmap; } qemu_co_rwlock_init(&s->bmap_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 int coroutine_fn vdi_co_block_status(BlockDriverState *bs, bool want_zero, int64_t offset, int64_t bytes, int64_t *pnum, int64_t *map, BlockDriverState **file) { BDRVVdiState *s = (BDRVVdiState *)bs->opaque; size_t bmap_index = offset / s->block_size; size_t index_in_block = offset % s->block_size; uint32_t bmap_entry = le32_to_cpu(s->bmap[bmap_index]); int result; logout("%p, %" PRId64 ", %" PRId64 ", %p\n", bs, offset, bytes, pnum); *pnum = MIN(s->block_size - index_in_block, bytes); result = VDI_IS_ALLOCATED(bmap_entry); if (!result) { return 0; } *map = s->header.offset_data + (uint64_t)bmap_entry * s->block_size + index_in_block; *file = bs->file->bs; return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | (s->header.image_type == VDI_TYPE_STATIC ? BDRV_BLOCK_RECURSE : 0); } static int coroutine_fn vdi_co_preadv(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { BDRVVdiState *s = bs->opaque; QEMUIOVector local_qiov; uint32_t bmap_entry; uint32_t block_index; uint32_t offset_in_block; uint32_t n_bytes; uint64_t bytes_done = 0; int ret = 0; logout("\n"); qemu_iovec_init(&local_qiov, qiov->niov); while (ret >= 0 && bytes > 0) { block_index = offset / s->block_size; offset_in_block = offset % s->block_size; n_bytes = MIN(bytes, s->block_size - offset_in_block); logout("will read %u bytes starting at offset %" PRIu64 "\n", n_bytes, offset); /* prepare next AIO request */ qemu_co_rwlock_rdlock(&s->bmap_lock); bmap_entry = le32_to_cpu(s->bmap[block_index]); qemu_co_rwlock_unlock(&s->bmap_lock); if (!VDI_IS_ALLOCATED(bmap_entry)) { /* Block not allocated, return zeros, no need to wait. */ qemu_iovec_memset(qiov, bytes_done, 0, n_bytes); ret = 0; } else { uint64_t data_offset = s->header.offset_data + (uint64_t)bmap_entry * s->block_size + offset_in_block; qemu_iovec_reset(&local_qiov); qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); ret = bdrv_co_preadv(bs->file, data_offset, n_bytes, &local_qiov, 0); } logout("%u bytes read\n", n_bytes); bytes -= n_bytes; offset += n_bytes; bytes_done += n_bytes; } qemu_iovec_destroy(&local_qiov); return ret; } static int coroutine_fn vdi_co_pwritev(BlockDriverState *bs, uint64_t offset, uint64_t bytes, QEMUIOVector *qiov, int flags) { BDRVVdiState *s = bs->opaque; QEMUIOVector local_qiov; uint32_t bmap_entry; uint32_t block_index; uint32_t offset_in_block; uint32_t n_bytes; uint64_t data_offset; uint32_t bmap_first = VDI_UNALLOCATED; uint32_t bmap_last = VDI_UNALLOCATED; uint8_t *block = NULL; uint64_t bytes_done = 0; int ret = 0; logout("\n"); qemu_iovec_init(&local_qiov, qiov->niov); while (ret >= 0 && bytes > 0) { block_index = offset / s->block_size; offset_in_block = offset % s->block_size; n_bytes = MIN(bytes, s->block_size - offset_in_block); logout("will write %u bytes starting at offset %" PRIu64 "\n", n_bytes, offset); /* prepare next AIO request */ qemu_co_rwlock_rdlock(&s->bmap_lock); bmap_entry = le32_to_cpu(s->bmap[block_index]); if (!VDI_IS_ALLOCATED(bmap_entry)) { /* Allocate new block and write to it. */ uint64_t data_offset; qemu_co_rwlock_upgrade(&s->bmap_lock); bmap_entry = le32_to_cpu(s->bmap[block_index]); if (VDI_IS_ALLOCATED(bmap_entry)) { /* A concurrent allocation did the work for us. */ qemu_co_rwlock_downgrade(&s->bmap_lock); goto nonallocating_write; } bmap_entry = s->header.blocks_allocated; s->bmap[block_index] = cpu_to_le32(bmap_entry); s->header.blocks_allocated++; data_offset = s->header.offset_data + (uint64_t)bmap_entry * s->block_size; if (block == NULL) { block = g_malloc(s->block_size); bmap_first = block_index; } bmap_last = block_index; /* Copy data to be written to new block and zero unused parts. */ memset(block, 0, offset_in_block); qemu_iovec_to_buf(qiov, bytes_done, block + offset_in_block, n_bytes); memset(block + offset_in_block + n_bytes, 0, s->block_size - n_bytes - offset_in_block); /* Write the new block under CoRwLock write-side protection, * so this full-cluster write does not overlap a partial write * of the same cluster, issued from the "else" branch. */ ret = bdrv_pwrite(bs->file, data_offset, block, s->block_size); qemu_co_rwlock_unlock(&s->bmap_lock); } else { nonallocating_write: data_offset = s->header.offset_data + (uint64_t)bmap_entry * s->block_size + offset_in_block; qemu_co_rwlock_unlock(&s->bmap_lock); qemu_iovec_reset(&local_qiov); qemu_iovec_concat(&local_qiov, qiov, bytes_done, n_bytes); ret = bdrv_co_pwritev(bs->file, data_offset, n_bytes, &local_qiov, 0); } bytes -= n_bytes; offset += n_bytes; bytes_done += n_bytes; logout("%u bytes written\n", n_bytes); } qemu_iovec_destroy(&local_qiov); 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; uint32_t n_sectors; logout("now writing modified header\n"); assert(VDI_IS_ALLOCATED(bmap_first)); *header = s->header; vdi_header_to_le(header); ret = bdrv_pwrite(bs->file, 0, block, sizeof(VdiHeader)); 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_pwrite(bs->file, offset * SECTOR_SIZE, base, n_sectors * SECTOR_SIZE); } return ret < 0 ? ret : 0; } static int coroutine_fn vdi_co_do_create(BlockdevCreateOptions *create_options, size_t block_size, Error **errp) { BlockdevCreateOptionsVdi *vdi_opts; int ret = 0; uint64_t bytes = 0; uint32_t blocks; uint32_t image_type; VdiHeader header; size_t i; size_t bmap_size; int64_t offset = 0; BlockDriverState *bs_file = NULL; BlockBackend *blk = NULL; uint32_t *bmap = NULL; QemuUUID uuid; assert(create_options->driver == BLOCKDEV_DRIVER_VDI); vdi_opts = &create_options->u.vdi; logout("\n"); /* Validate options and set default values */ bytes = vdi_opts->size; if (!vdi_opts->has_preallocation) { vdi_opts->preallocation = PREALLOC_MODE_OFF; } switch (vdi_opts->preallocation) { case PREALLOC_MODE_OFF: image_type = VDI_TYPE_DYNAMIC; break; case PREALLOC_MODE_METADATA: image_type = VDI_TYPE_STATIC; break; default: error_setg(errp, "Preallocation mode not supported for vdi"); return -EINVAL; } #ifndef CONFIG_VDI_STATIC_IMAGE if (image_type == VDI_TYPE_STATIC) { ret = -ENOTSUP; error_setg(errp, "Statically allocated images cannot be created in " "this build"); goto exit; } #endif #ifndef CONFIG_VDI_BLOCK_SIZE if (block_size != DEFAULT_CLUSTER_SIZE) { ret = -ENOTSUP; error_setg(errp, "A non-default cluster size is not supported in this build"); goto exit; } #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; } /* Create BlockBackend to write to the image */ bs_file = bdrv_open_blockdev_ref(vdi_opts->file, errp); if (!bs_file) { ret = -EIO; goto exit; } blk = blk_new(bdrv_get_aio_context(bs_file), BLK_PERM_WRITE | BLK_PERM_RESIZE, BLK_PERM_ALL); ret = blk_insert_bs(blk, bs_file, errp); if (ret < 0) { goto exit; } blk_set_allow_write_beyond_eof(blk, true); /* 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; } qemu_uuid_generate(&uuid); header.uuid_image = uuid; qemu_uuid_generate(&uuid); header.uuid_last_snap = uuid; /* There is no need to set header.uuid_link or header.uuid_parent here. */ if (VDI_DEBUG) { vdi_header_print(&header); } vdi_header_to_le(&header); ret = blk_pwrite(blk, offset, &header, sizeof(header), 0); if (ret < 0) { error_setg(errp, "Error writing header"); 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 = blk_pwrite(blk, offset, bmap, bmap_size, 0); if (ret < 0) { error_setg(errp, "Error writing bmap"); goto exit; } offset += bmap_size; } if (image_type == VDI_TYPE_STATIC) { ret = blk_truncate(blk, offset + blocks * block_size, false, PREALLOC_MODE_OFF, 0, errp); if (ret < 0) { error_prepend(errp, "Failed to statically allocate file"); goto exit; } } ret = 0; exit: blk_unref(blk); bdrv_unref(bs_file); g_free(bmap); return ret; } static int coroutine_fn vdi_co_create(BlockdevCreateOptions *create_options, Error **errp) { return vdi_co_do_create(create_options, DEFAULT_CLUSTER_SIZE, errp); } static int coroutine_fn vdi_co_create_opts(BlockDriver *drv, const char *filename, QemuOpts *opts, Error **errp) { QDict *qdict = NULL; BlockdevCreateOptions *create_options = NULL; BlockDriverState *bs_file = NULL; uint64_t block_size = DEFAULT_CLUSTER_SIZE; bool is_static = false; Visitor *v; Error *local_err = NULL; int ret; /* Parse options and convert legacy syntax. * * Since CONFIG_VDI_BLOCK_SIZE is disabled by default, * cluster-size is not part of the QAPI schema; therefore we have * to parse it before creating the QAPI object. */ #if defined(CONFIG_VDI_BLOCK_SIZE) block_size = qemu_opt_get_size_del(opts, BLOCK_OPT_CLUSTER_SIZE, DEFAULT_CLUSTER_SIZE); if (block_size < BDRV_SECTOR_SIZE || block_size > UINT32_MAX || !is_power_of_2(block_size)) { error_setg(errp, "Invalid cluster size"); ret = -EINVAL; goto done; } #endif if (qemu_opt_get_bool_del(opts, BLOCK_OPT_STATIC, false)) { is_static = true; } qdict = qemu_opts_to_qdict_filtered(opts, NULL, &vdi_create_opts, true); /* Create and open the file (protocol layer) */ ret = bdrv_create_file(filename, opts, errp); if (ret < 0) { goto done; } bs_file = bdrv_open(filename, NULL, NULL, BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, errp); if (!bs_file) { ret = -EIO; goto done; } qdict_put_str(qdict, "driver", "vdi"); qdict_put_str(qdict, "file", bs_file->node_name); if (is_static) { qdict_put_str(qdict, "preallocation", "metadata"); } /* Get the QAPI object */ v = qobject_input_visitor_new_flat_confused(qdict, errp); if (!v) { ret = -EINVAL; goto done; } visit_type_BlockdevCreateOptions(v, NULL, &create_options, &local_err); visit_free(v); if (local_err) { error_propagate(errp, local_err); ret = -EINVAL; goto done; } /* Silently round up size */ assert(create_options->driver == BLOCKDEV_DRIVER_VDI); create_options->u.vdi.size = ROUND_UP(create_options->u.vdi.size, BDRV_SECTOR_SIZE); /* Create the vdi image (format layer) */ ret = vdi_co_do_create(create_options, block_size, errp); done: qobject_unref(qdict); qapi_free_BlockdevCreateOptions(create_options); bdrv_unref(bs_file); 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 int vdi_has_zero_init(BlockDriverState *bs) { BDRVVdiState *s = bs->opaque; if (s->header.image_type == VDI_TYPE_STATIC) { return bdrv_has_zero_init(bs->file->bs); } else { return 1; } } 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_child_perm = bdrv_format_default_perms, .bdrv_co_create = vdi_co_create, .bdrv_co_create_opts = vdi_co_create_opts, .bdrv_has_zero_init = vdi_has_zero_init, .bdrv_co_block_status = vdi_co_block_status, .bdrv_make_empty = vdi_make_empty, .bdrv_co_preadv = vdi_co_preadv, #if defined(CONFIG_VDI_WRITE) .bdrv_co_pwritev = vdi_co_pwritev, #endif .bdrv_get_info = vdi_get_info, .create_opts = &vdi_create_opts, .bdrv_co_check = vdi_co_check, }; static void bdrv_vdi_init(void) { logout("\n"); bdrv_register(&bdrv_vdi); } block_init(bdrv_vdi_init);