--- /dev/null
+/*
+ * 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);
Code Review / kvmfornfv.git / blobdiff