#include "migration/migration.h"
#include <uuid/uuid.h>
+#include <glib.h>
+
+/* Options for VHDX creation */
+
+#define VHDX_BLOCK_OPT_LOG_SIZE "log_size"
+#define VHDX_BLOCK_OPT_BLOCK_SIZE "block_size"
+#define VHDX_BLOCK_OPT_ZERO "block_state_zero"
+
+typedef enum VHDXImageType {
+ VHDX_TYPE_DYNAMIC = 0,
+ VHDX_TYPE_FIXED,
+ VHDX_TYPE_DIFFERENCING, /* Currently unsupported */
+} VHDXImageType;
/* Several metadata and region table data entries are identified by
* guids in a MS-specific GUID format. */
}
+
+/*
+ * Create VHDX Headers
+ *
+ * There are 2 headers, and the highest sequence number will represent
+ * the active header
+ */
+static int vhdx_create_new_headers(BlockDriverState *bs, uint64_t image_size,
+ uint32_t log_size)
+{
+ int ret = 0;
+ VHDXHeader *hdr = NULL;
+
+ hdr = g_malloc0(sizeof(VHDXHeader));
+
+ hdr->signature = VHDX_HEADER_SIGNATURE;
+ hdr->sequence_number = g_random_int();
+ hdr->log_version = 0;
+ hdr->version = 1;
+ hdr->log_length = log_size;
+ hdr->log_offset = VHDX_HEADER_SECTION_END;
+ vhdx_guid_generate(&hdr->file_write_guid);
+ vhdx_guid_generate(&hdr->data_write_guid);
+
+ ret = vhdx_write_header(bs, hdr, VHDX_HEADER1_OFFSET, false);
+ if (ret < 0) {
+ goto exit;
+ }
+ hdr->sequence_number++;
+ ret = vhdx_write_header(bs, hdr, VHDX_HEADER2_OFFSET, false);
+ if (ret < 0) {
+ goto exit;
+ }
+
+exit:
+ g_free(hdr);
+ return ret;
+}
+
+
+/*
+ * Create the Metadata entries.
+ *
+ * For more details on the entries, see section 3.5 (pg 29) in the
+ * VHDX 1.00 specification.
+ *
+ * We support 5 metadata entries (all required by spec):
+ * File Parameters,
+ * Virtual Disk Size,
+ * Page 83 Data,
+ * Logical Sector Size,
+ * Physical Sector Size
+ *
+ * The first 64KB of the Metadata section is reserved for the metadata
+ * header and entries; beyond that, the metadata items themselves reside.
+ */
+static int vhdx_create_new_metadata(BlockDriverState *bs,
+ uint64_t image_size,
+ uint32_t block_size,
+ uint32_t sector_size,
+ uint64_t metadata_offset,
+ VHDXImageType type)
+{
+ int ret = 0;
+ uint32_t offset = 0;
+ void *buffer = NULL;
+ void *entry_buffer;
+ VHDXMetadataTableHeader *md_table;;
+ VHDXMetadataTableEntry *md_table_entry;
+
+ /* Metadata entries */
+ VHDXFileParameters *mt_file_params;
+ VHDXVirtualDiskSize *mt_virtual_size;
+ VHDXPage83Data *mt_page83;
+ VHDXVirtualDiskLogicalSectorSize *mt_log_sector_size;
+ VHDXVirtualDiskPhysicalSectorSize *mt_phys_sector_size;
+
+ entry_buffer = g_malloc0(sizeof(VHDXFileParameters) +
+ sizeof(VHDXVirtualDiskSize) +
+ sizeof(VHDXPage83Data) +
+ sizeof(VHDXVirtualDiskLogicalSectorSize) +
+ sizeof(VHDXVirtualDiskPhysicalSectorSize));
+
+ mt_file_params = entry_buffer;
+ offset += sizeof(VHDXFileParameters);
+ mt_virtual_size = entry_buffer + offset;
+ offset += sizeof(VHDXVirtualDiskSize);
+ mt_page83 = entry_buffer + offset;
+ offset += sizeof(VHDXPage83Data);
+ mt_log_sector_size = entry_buffer + offset;
+ offset += sizeof(VHDXVirtualDiskLogicalSectorSize);
+ mt_phys_sector_size = entry_buffer + offset;
+
+ mt_file_params->block_size = cpu_to_le32(block_size);
+ if (type == VHDX_TYPE_FIXED) {
+ mt_file_params->data_bits |= VHDX_PARAMS_LEAVE_BLOCKS_ALLOCED;
+ cpu_to_le32s(&mt_file_params->data_bits);
+ }
+
+ vhdx_guid_generate(&mt_page83->page_83_data);
+ cpu_to_leguids(&mt_page83->page_83_data);
+ mt_virtual_size->virtual_disk_size = cpu_to_le64(image_size);
+ mt_log_sector_size->logical_sector_size = cpu_to_le32(sector_size);
+ mt_phys_sector_size->physical_sector_size = cpu_to_le32(sector_size);
+
+ buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
+ md_table = buffer;
+
+ md_table->signature = VHDX_METADATA_SIGNATURE;
+ md_table->entry_count = 5;
+ vhdx_metadata_header_le_export(md_table);
+
+
+ /* This will reference beyond the reserved table portion */
+ offset = 64 * KiB;
+
+ md_table_entry = buffer + sizeof(VHDXMetadataTableHeader);
+
+ md_table_entry[0].item_id = file_param_guid;
+ md_table_entry[0].offset = offset;
+ md_table_entry[0].length = sizeof(VHDXFileParameters);
+ md_table_entry[0].data_bits |= VHDX_META_FLAGS_IS_REQUIRED;
+ offset += md_table_entry[0].length;
+ vhdx_metadata_entry_le_export(&md_table_entry[0]);
+
+ md_table_entry[1].item_id = virtual_size_guid;
+ md_table_entry[1].offset = offset;
+ md_table_entry[1].length = sizeof(VHDXVirtualDiskSize);
+ md_table_entry[1].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
+ VHDX_META_FLAGS_IS_VIRTUAL_DISK;
+ offset += md_table_entry[1].length;
+ vhdx_metadata_entry_le_export(&md_table_entry[1]);
+
+ md_table_entry[2].item_id = page83_guid;
+ md_table_entry[2].offset = offset;
+ md_table_entry[2].length = sizeof(VHDXPage83Data);
+ md_table_entry[2].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
+ VHDX_META_FLAGS_IS_VIRTUAL_DISK;
+ offset += md_table_entry[2].length;
+ vhdx_metadata_entry_le_export(&md_table_entry[2]);
+
+ md_table_entry[3].item_id = logical_sector_guid;
+ md_table_entry[3].offset = offset;
+ md_table_entry[3].length = sizeof(VHDXVirtualDiskLogicalSectorSize);
+ md_table_entry[3].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
+ VHDX_META_FLAGS_IS_VIRTUAL_DISK;
+ offset += md_table_entry[3].length;
+ vhdx_metadata_entry_le_export(&md_table_entry[3]);
+
+ md_table_entry[4].item_id = phys_sector_guid;
+ md_table_entry[4].offset = offset;
+ md_table_entry[4].length = sizeof(VHDXVirtualDiskPhysicalSectorSize);
+ md_table_entry[4].data_bits |= VHDX_META_FLAGS_IS_REQUIRED |
+ VHDX_META_FLAGS_IS_VIRTUAL_DISK;
+ vhdx_metadata_entry_le_export(&md_table_entry[4]);
+
+ ret = bdrv_pwrite(bs, metadata_offset, buffer, VHDX_HEADER_BLOCK_SIZE);
+ if (ret < 0) {
+ goto exit;
+ }
+
+ ret = bdrv_pwrite(bs, metadata_offset + (64 * KiB), entry_buffer,
+ VHDX_HEADER_BLOCK_SIZE);
+ if (ret < 0) {
+ goto exit;
+ }
+
+
+exit:
+ g_free(buffer);
+ g_free(entry_buffer);
+ return ret;
+}
+
+/* This create the actual BAT itself. We currently only support
+ * 'Dynamic' and 'Fixed' image types.
+ *
+ * Dynamic images: default state of the BAT is all zeroes.
+ *
+ * Fixed images: default state of the BAT is fully populated, with
+ * file offsets and state PAYLOAD_BLOCK_FULLY_PRESENT.
+ */
+static int vhdx_create_bat(BlockDriverState *bs, BDRVVHDXState *s,
+ uint64_t image_size, VHDXImageType type,
+ bool use_zero_blocks, VHDXRegionTableEntry *rt_bat)
+{
+ int ret = 0;
+ uint64_t data_file_offset;
+ uint64_t total_sectors = 0;
+ uint64_t sector_num = 0;
+ uint64_t unused;
+ int block_state;
+ VHDXSectorInfo sinfo;
+
+ assert(s->bat == NULL);
+
+ /* this gives a data start after BAT/bitmap entries, and well
+ * past any metadata entries (with a 4 MB buffer for future
+ * expansion */
+ data_file_offset = rt_bat->file_offset + rt_bat->length + 5 * MiB;
+ total_sectors = image_size >> s->logical_sector_size_bits;
+
+ if (type == VHDX_TYPE_DYNAMIC) {
+ /* All zeroes, so we can just extend the file - the end of the BAT
+ * is the furthest thing we have written yet */
+ ret = bdrv_truncate(bs, data_file_offset);
+ if (ret < 0) {
+ goto exit;
+ }
+ } else if (type == VHDX_TYPE_FIXED) {
+ ret = bdrv_truncate(bs, data_file_offset + image_size);
+ if (ret < 0) {
+ goto exit;
+ }
+ } else {
+ ret = -ENOTSUP;
+ goto exit;
+ }
+
+ if (type == VHDX_TYPE_FIXED ||
+ use_zero_blocks ||
+ bdrv_has_zero_init(bs) == 0) {
+ /* for a fixed file, the default BAT entry is not zero */
+ s->bat = g_malloc0(rt_bat->length);
+ block_state = type == VHDX_TYPE_FIXED ? PAYLOAD_BLOCK_FULLY_PRESENT :
+ PAYLOAD_BLOCK_NOT_PRESENT;
+ block_state = use_zero_blocks ? PAYLOAD_BLOCK_ZERO : block_state;
+ /* fill the BAT by emulating sector writes of sectors_per_block size */
+ while (sector_num < total_sectors) {
+ vhdx_block_translate(s, sector_num, s->sectors_per_block, &sinfo);
+ sinfo.file_offset = data_file_offset +
+ (sector_num << s->logical_sector_size_bits);
+ sinfo.file_offset = ROUND_UP(sinfo.file_offset, MiB);
+ vhdx_update_bat_table_entry(bs, s, &sinfo, &unused, &unused,
+ block_state);
+ cpu_to_le64s(&s->bat[sinfo.bat_idx]);
+ sector_num += s->sectors_per_block;
+ }
+ ret = bdrv_pwrite(bs, rt_bat->file_offset, s->bat, rt_bat->length);
+ if (ret < 0) {
+ goto exit;
+ }
+ }
+
+
+
+exit:
+ g_free(s->bat);
+ return ret;
+}
+
+/* Creates the region table header, and region table entries.
+ * There are 2 supported region table entries: BAT, and Metadata/
+ *
+ * As the calculations for the BAT region table are also needed
+ * to create the BAT itself, we will also cause the BAT to be
+ * created.
+ */
+static int vhdx_create_new_region_table(BlockDriverState *bs,
+ uint64_t image_size,
+ uint32_t block_size,
+ uint32_t sector_size,
+ uint32_t log_size,
+ bool use_zero_blocks,
+ VHDXImageType type,
+ uint64_t *metadata_offset)
+{
+ int ret = 0;
+ uint32_t offset = 0;
+ void *buffer = NULL;
+ BDRVVHDXState *s = NULL;
+ VHDXRegionTableHeader *region_table;
+ VHDXRegionTableEntry *rt_bat;
+ VHDXRegionTableEntry *rt_metadata;
+
+ assert(metadata_offset != NULL);
+
+ /* Populate enough of the BDRVVHDXState to be able to use the
+ * pre-existing BAT calculation, translation, and update functions */
+ s = g_malloc0(sizeof(BDRVVHDXState));
+
+ s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) *
+ (uint64_t) sector_size / (uint64_t) block_size;
+
+ s->sectors_per_block = block_size / sector_size;
+ s->virtual_disk_size = image_size;
+ s->block_size = block_size;
+ s->logical_sector_size = sector_size;
+
+ vhdx_set_shift_bits(s);
+
+ vhdx_calc_bat_entries(s);
+
+ /* At this point the VHDX state is populated enough for creation */
+
+ /* a single buffer is used so we can calculate the checksum over the
+ * entire 64KB block */
+ buffer = g_malloc0(VHDX_HEADER_BLOCK_SIZE);
+ region_table = buffer;
+ offset += sizeof(VHDXRegionTableHeader);
+ rt_bat = buffer + offset;
+ offset += sizeof(VHDXRegionTableEntry);
+ rt_metadata = buffer + offset;
+
+ region_table->signature = VHDX_REGION_SIGNATURE;
+ region_table->entry_count = 2; /* BAT and Metadata */
+
+ rt_bat->guid = bat_guid;
+ rt_bat->length = ROUND_UP(s->bat_entries * sizeof(VHDXBatEntry), MiB);
+ rt_bat->file_offset = ROUND_UP(VHDX_HEADER_SECTION_END + log_size, MiB);
+ s->bat_offset = rt_bat->file_offset;
+
+ rt_metadata->guid = metadata_guid;
+ rt_metadata->file_offset = ROUND_UP(rt_bat->file_offset + rt_bat->length,
+ MiB);
+ rt_metadata->length = 1 * MiB; /* min size, and more than enough */
+ *metadata_offset = rt_metadata->file_offset;
+
+ vhdx_update_checksum(buffer, VHDX_HEADER_BLOCK_SIZE,
+ offsetof(VHDXRegionTableHeader, checksum));
+
+
+ /* The region table gives us the data we need to create the BAT,
+ * so do that now */
+ ret = vhdx_create_bat(bs, s, image_size, type, use_zero_blocks, rt_bat);
+
+ /* Now write out the region headers to disk */
+ vhdx_region_header_le_export(region_table);
+ vhdx_region_entry_le_export(rt_bat);
+ vhdx_region_entry_le_export(rt_metadata);
+
+ ret = bdrv_pwrite(bs, VHDX_REGION_TABLE_OFFSET, buffer,
+ VHDX_HEADER_BLOCK_SIZE);
+ if (ret < 0) {
+ goto exit;
+ }
+
+ ret = bdrv_pwrite(bs, VHDX_REGION_TABLE2_OFFSET, buffer,
+ VHDX_HEADER_BLOCK_SIZE);
+ if (ret < 0) {
+ goto exit;
+ }
+
+
+exit:
+ g_free(s);
+ g_free(buffer);
+ return ret;
+}
+
+/* We need to create the following elements:
+ *
+ * .-----------------------------------------------------------------.
+ * | (A) | (B) | (C) | (D) | (E) |
+ * | File ID | Header1 | Header 2 | Region Tbl 1 | Region Tbl 2 |
+ * | | | | | |
+ * .-----------------------------------------------------------------.
+ * 0 64KB 128KB 192KB 256KB 320KB
+ *
+ *
+ * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
+ * | (F) | (G) | (H) | |
+ * | Journal Log | BAT / Bitmap | Metadata | .... data ...... |
+ * | | | | |
+ * .---- ~ ----------- ~ ------------ ~ ---------------- ~ -----------.
+ * 1MB
+ */
+static int vhdx_create(const char *filename, QEMUOptionParameter *options,
+ Error **errp)
+{
+ int ret = 0;
+ uint64_t image_size = (uint64_t) 2 * GiB;
+ uint32_t log_size = 1 * MiB;
+ uint32_t block_size = 0;
+ uint64_t signature;
+ uint64_t metadata_offset;
+ bool use_zero_blocks = false;
+
+ gunichar2 *creator = NULL;
+ glong creator_items;
+ BlockDriverState *bs;
+ const char *type = NULL;
+ VHDXImageType image_type;
+ Error *local_err = NULL;
+
+ while (options && options->name) {
+ if (!strcmp(options->name, BLOCK_OPT_SIZE)) {
+ image_size = options->value.n;
+ } else if (!strcmp(options->name, VHDX_BLOCK_OPT_LOG_SIZE)) {
+ log_size = options->value.n;
+ } else if (!strcmp(options->name, VHDX_BLOCK_OPT_BLOCK_SIZE)) {
+ block_size = options->value.n;
+ } else if (!strcmp(options->name, BLOCK_OPT_SUBFMT)) {
+ type = options->value.s;
+ } else if (!strcmp(options->name, VHDX_BLOCK_OPT_ZERO)) {
+ use_zero_blocks = options->value.n != 0;
+ }
+ options++;
+ }
+
+ if (image_size > VHDX_MAX_IMAGE_SIZE) {
+ error_setg_errno(errp, EINVAL, "Image size too large; max of 64TB");
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ if (type == NULL) {
+ type = "dynamic";
+ }
+
+ if (!strcmp(type, "dynamic")) {
+ image_type = VHDX_TYPE_DYNAMIC;
+ } else if (!strcmp(type, "fixed")) {
+ image_type = VHDX_TYPE_FIXED;
+ } else if (!strcmp(type, "differencing")) {
+ error_setg_errno(errp, ENOTSUP,
+ "Differencing files not yet supported");
+ ret = -ENOTSUP;
+ goto exit;
+ } else {
+ ret = -EINVAL;
+ goto exit;
+ }
+
+ /* These are pretty arbitrary, and mainly designed to keep the BAT
+ * size reasonable to load into RAM */
+ if (block_size == 0) {
+ if (image_size > 32 * TiB) {
+ block_size = 64 * MiB;
+ } else if (image_size > (uint64_t) 100 * GiB) {
+ block_size = 32 * MiB;
+ } else if (image_size > 1 * GiB) {
+ block_size = 16 * MiB;
+ } else {
+ block_size = 8 * MiB;
+ }
+ }
+
+
+ /* make the log size close to what was specified, but must be
+ * min 1MB, and multiple of 1MB */
+ log_size = ROUND_UP(log_size, MiB);
+
+ block_size = ROUND_UP(block_size, MiB);
+ block_size = block_size > VHDX_BLOCK_SIZE_MAX ? VHDX_BLOCK_SIZE_MAX :
+ block_size;
+
+ ret = bdrv_create_file(filename, options, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ goto exit;
+ }
+
+ ret = bdrv_file_open(&bs, filename, NULL, BDRV_O_RDWR, &local_err);
+ if (ret < 0) {
+ error_propagate(errp, local_err);
+ goto exit;
+ }
+
+ /* Create (A) */
+
+ /* The creator field is optional, but may be useful for
+ * debugging / diagnostics */
+ creator = g_utf8_to_utf16("QEMU v" QEMU_VERSION, -1, NULL,
+ &creator_items, NULL);
+ signature = cpu_to_le64(VHDX_FILE_SIGNATURE);
+ bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature));
+ if (ret < 0) {
+ goto delete_and_exit;
+ }
+ if (creator) {
+ bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET + sizeof(signature), creator,
+ creator_items * sizeof(gunichar2));
+ if (ret < 0) {
+ goto delete_and_exit;
+ }
+ }
+
+
+ /* Creates (B),(C) */
+ ret = vhdx_create_new_headers(bs, image_size, log_size);
+ if (ret < 0) {
+ goto delete_and_exit;
+ }
+
+ /* Creates (D),(E),(G) explicitly. (F) created as by-product */
+ ret = vhdx_create_new_region_table(bs, image_size, block_size, 512,
+ log_size, use_zero_blocks, image_type,
+ &metadata_offset);
+ if (ret < 0) {
+ goto delete_and_exit;
+ }
+
+ /* Creates (H) */
+ ret = vhdx_create_new_metadata(bs, image_size, block_size, 512,
+ metadata_offset, image_type);
+ if (ret < 0) {
+ goto delete_and_exit;
+ }
+
+
+
+delete_and_exit:
+ bdrv_unref(bs);
+exit:
+ g_free(creator);
+ return ret;
+}
+
+static QEMUOptionParameter vhdx_create_options[] = {
+ {
+ .name = BLOCK_OPT_SIZE,
+ .type = OPT_SIZE,
+ .help = "Virtual disk size; max of 64TB."
+ },
+ {
+ .name = VHDX_BLOCK_OPT_LOG_SIZE,
+ .type = OPT_SIZE,
+ .value.n = 1 * MiB,
+ .help = "Log size; min 1MB."
+ },
+ {
+ .name = VHDX_BLOCK_OPT_BLOCK_SIZE,
+ .type = OPT_SIZE,
+ .value.n = 0,
+ .help = "Block Size; min 1MB, max 256MB. " \
+ "0 means auto-calculate based on image size."
+ },
+ {
+ .name = BLOCK_OPT_SUBFMT,
+ .type = OPT_STRING,
+ .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\
+ "Default is 'dynamic'."
+ },
+ {
+ .name = VHDX_BLOCK_OPT_ZERO,
+ .type = OPT_FLAG,
+ .help = "Force use of payload blocks of type 'ZERO'. Non-standard."
+ },
+ { NULL }
+};
+
static BlockDriver bdrv_vhdx = {
.format_name = "vhdx",
.instance_size = sizeof(BDRVVHDXState),
.bdrv_reopen_prepare = vhdx_reopen_prepare,
.bdrv_co_readv = vhdx_co_readv,
.bdrv_co_writev = vhdx_co_writev,
+ .bdrv_create = vhdx_create,
+
+ .create_options = vhdx_create_options,
};
static void bdrv_vhdx_init(void)
projects / qemu.git / blobdiff