diff options
| -rw-r--r-- | block/vhdx.c | 558 | ||||
| -rw-r--r-- | block/vhdx.h | 15 |
2 files changed, 572 insertions, 1 deletions
diff --git a/block/vhdx.c b/block/vhdx.c index 7bf7cd69a1..7d1af9663b 100644 --- a/block/vhdx.c +++ b/block/vhdx.c @@ -23,6 +23,19 @@ #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. */ @@ -1320,6 +1333,548 @@ exit: } + +/* + * 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), @@ -1329,6 +1884,9 @@ static BlockDriver bdrv_vhdx = { .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) diff --git a/block/vhdx.h b/block/vhdx.h index f222d1876e..51183b243c 100644 --- a/block/vhdx.h +++ b/block/vhdx.h @@ -18,6 +18,11 @@ #ifndef BLOCK_VHDX_H #define BLOCK_VHDX_H +#define KiB (1 * 1024) +#define MiB (KiB * 1024) +#define GiB (MiB * 1024) +#define TiB ((uint64_t) GiB * 1024) + /* Structures and fields present in the VHDX file */ /* The header section has the following blocks, @@ -36,8 +41,9 @@ #define VHDX_HEADER1_OFFSET (VHDX_HEADER_BLOCK_SIZE * 1) #define VHDX_HEADER2_OFFSET (VHDX_HEADER_BLOCK_SIZE * 2) #define VHDX_REGION_TABLE_OFFSET (VHDX_HEADER_BLOCK_SIZE * 3) +#define VHDX_REGION_TABLE2_OFFSET (VHDX_HEADER_BLOCK_SIZE * 4) - +#define VHDX_HEADER_SECTION_END (1 * MiB) /* * A note on the use of MS-GUID fields. For more details on the GUID, * please see: https://en.wikipedia.org/wiki/Globally_unique_identifier. @@ -55,6 +61,7 @@ /* These structures are ones that are defined in the VHDX specification * document */ +#define VHDX_FILE_SIGNATURE 0x656C696678646876 /* "vhdxfile" in ASCII */ typedef struct VHDXFileIdentifier { uint64_t signature; /* "vhdxfile" in ASCII */ uint16_t creator[256]; /* optional; utf-16 string to identify @@ -85,6 +92,7 @@ typedef struct QEMU_PACKED MSGUID { /* The full header is 4KB, although the actual header data is much smaller. * But for the checksum calculation, it is over the entire 4KB structure, * not just the defined portion of it */ +#define VHDX_HEADER_SIGNATURE 0x64616568 typedef struct QEMU_PACKED VHDXHeader { uint32_t signature; /* "head" in ASCII */ uint32_t checksum; /* CRC-32C hash of the whole header */ @@ -125,6 +133,7 @@ typedef struct QEMU_PACKED VHDXHeader { } VHDXHeader; /* Header for the region table block */ +#define VHDX_REGION_SIGNATURE 0x69676572 /* "regi" in ASCII */ typedef struct QEMU_PACKED VHDXRegionTableHeader { uint32_t signature; /* "regi" in ASCII */ uint32_t checksum; /* CRC-32C hash of the 64KB table */ @@ -238,6 +247,7 @@ typedef uint64_t VHDXBatEntry; #define VHDX_METADATA_MAX_ENTRIES 2047 /* not including the header */ #define VHDX_METADATA_TABLE_MAX_SIZE \ (VHDX_METADATA_ENTRY_SIZE * (VHDX_METADATA_MAX_ENTRIES+1)) +#define VHDX_METADATA_SIGNATURE 0x617461646174656D /* "metadata" in ASCII */ typedef struct QEMU_PACKED VHDXMetadataTableHeader { uint64_t signature; /* "metadata" in ASCII */ uint16_t reserved; @@ -267,6 +277,8 @@ typedef struct QEMU_PACKED VHDXMetadataTableEntry { If set indicates a fixed size VHDX file */ #define VHDX_PARAMS_HAS_PARENT 0x02 /* has parent / backing file */ +#define VHDX_BLOCK_SIZE_MIN (1 * MiB) +#define VHDX_BLOCK_SIZE_MAX (256 * MiB) typedef struct QEMU_PACKED VHDXFileParameters { uint32_t block_size; /* size of each payload block, always power of 2, <= 256MB and >= 1MB. */ @@ -274,6 +286,7 @@ typedef struct QEMU_PACKED VHDXFileParameters { the rest are reserved (see above) */ } VHDXFileParameters; +#define VHDX_MAX_IMAGE_SIZE ((uint64_t) 64 * TiB) typedef struct QEMU_PACKED VHDXVirtualDiskSize { uint64_t virtual_disk_size; /* Size of the virtual disk, in bytes. Must be multiple of the sector size, |