diff options
Diffstat (limited to 'qemu/block/vdi.c')
| -rw-r--r-- | qemu/block/vdi.c | 914 |
1 files changed, 914 insertions, 0 deletions
diff --git a/qemu/block/vdi.c b/qemu/block/vdi.c new file mode 100644 index 000000000..7642ef359 --- /dev/null +++ b/qemu/block/vdi.c @@ -0,0 +1,914 @@ +/* + * 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-common.h" +#include "block/block_int.h" +#include "qemu/module.h" +#include "migration/migration.h" +#include "block/coroutine.h" + +#if defined(CONFIG_UUID) +#include <uuid/uuid.h> +#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; + uint32_t n_sectors; + uint32_t bmap_first = VDI_UNALLOCATED; + uint32_t bmap_last = VDI_UNALLOCATED; + uint8_t *block = NULL; + 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 write %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)) { + /* Allocate new block and write to it. */ + uint64_t offset; + bmap_entry = s->header.blocks_allocated; + s->bmap[block_index] = cpu_to_le32(bmap_entry); + s->header.blocks_allocated++; + offset = s->header.offset_data / SECTOR_SIZE + + (uint64_t)bmap_entry * s->block_sectors; + 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, 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); |