| /* |
| * 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 <http://www.gnu.org/licenses/>. |
| * |
| * 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 "qapi/error.h" |
| #include "block/block_int.h" |
| #include "sysemu/block-backend.h" |
| #include "qemu/module.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 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) |
| |
| 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; |
| |
| 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; |
| |
| CoRwlock bmap_lock; |
| |
| Error *migration_blocker; |
| } BDRVVdiState; |
| |
| 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); |
| qemu_uuid_bswap(&header->uuid_image); |
| qemu_uuid_bswap(&header->uuid_last_snap); |
| qemu_uuid_bswap(&header->uuid_link); |
| qemu_uuid_bswap(&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); |
| qemu_uuid_bswap(&header->uuid_image); |
| qemu_uuid_bswap(&header->uuid_last_snap); |
| qemu_uuid_bswap(&header->uuid_link); |
| qemu_uuid_bswap(&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; |
| Error *local_err = NULL; |
| |
| bs->file = bdrv_open_child(NULL, options, "file", bs, &child_file, |
| false, errp); |
| if (!bs->file) { |
| return -EINVAL; |
| } |
| |
| 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 (!qemu_uuid_is_null(&header.uuid_link)) { |
| error_setg(errp, "unsupported VDI image (non-NULL link UUID)"); |
| ret = -ENOTSUP; |
| goto fail; |
| } else if (!qemu_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->bs, 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)); |
| 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 int64_t coroutine_fn vdi_co_get_block_status(BlockDriverState *bs, |
| int64_t sector_num, int nb_sectors, int *pnum, BlockDriverState **file) |
| { |
| /* 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; |
| *file = bs->file->bs; |
| return BDRV_BLOCK_DATA | BDRV_BLOCK_OFFSET_VALID | offset; |
| } |
| |
| 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_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; |
| BlockBackend *blk = 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; |
| } |
| |
| blk = blk_new_open(filename, NULL, NULL, |
| BDRV_O_RDWR | BDRV_O_RESIZE | BDRV_O_PROTOCOL, |
| &local_err); |
| if (blk == NULL) { |
| error_propagate(errp, local_err); |
| ret = -EIO; |
| 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(&header.uuid_image); |
| qemu_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 = blk_pwrite(blk, offset, &header, sizeof(header), 0); |
| 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 = blk_pwrite(blk, offset, bmap, bmap_size, 0); |
| if (ret < 0) { |
| error_setg(errp, "Error writing bmap to %s", filename); |
| goto exit; |
| } |
| offset += bmap_size; |
| } |
| |
| if (image_type == VDI_TYPE_STATIC) { |
| ret = blk_truncate(blk, offset + blocks * block_size, |
| PREALLOC_MODE_OFF, errp); |
| if (ret < 0) { |
| error_prepend(errp, "Failed to statically allocate %s", filename); |
| goto exit; |
| } |
| } |
| |
| exit: |
| blk_unref(blk); |
| 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_child_perm = bdrv_format_default_perms, |
| .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_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_check = vdi_check, |
| }; |
| |
| static void bdrv_vdi_init(void) |
| { |
| logout("\n"); |
| bdrv_register(&bdrv_vdi); |
| } |
| |
| block_init(bdrv_vdi_init); |
