diff options
author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/block/vhdx.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/block/vhdx.c')
-rw-r--r-- | qemu/block/vhdx.c | 1980 |
1 files changed, 1980 insertions, 0 deletions
diff --git a/qemu/block/vhdx.c b/qemu/block/vhdx.c new file mode 100644 index 000000000..0776de717 --- /dev/null +++ b/qemu/block/vhdx.c @@ -0,0 +1,1980 @@ +/* + * Block driver for Hyper-V VHDX Images + * + * Copyright (c) 2013 Red Hat, Inc., + * + * Authors: + * Jeff Cody <jcody@redhat.com> + * + * This is based on the "VHDX Format Specification v1.00", published 8/25/2012 + * by Microsoft: + * https://www.microsoft.com/en-us/download/details.aspx?id=34750 + * + * This work is licensed under the terms of the GNU LGPL, version 2 or later. + * See the COPYING.LIB file in the top-level directory. + * + */ + +#include "qemu-common.h" +#include "block/block_int.h" +#include "qemu/module.h" +#include "qemu/crc32c.h" +#include "block/vhdx.h" +#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. */ + + +/* ------- Known Region Table GUIDs ---------------------- */ +static const MSGUID bat_guid = { .data1 = 0x2dc27766, + .data2 = 0xf623, + .data3 = 0x4200, + .data4 = { 0x9d, 0x64, 0x11, 0x5e, + 0x9b, 0xfd, 0x4a, 0x08} }; + +static const MSGUID metadata_guid = { .data1 = 0x8b7ca206, + .data2 = 0x4790, + .data3 = 0x4b9a, + .data4 = { 0xb8, 0xfe, 0x57, 0x5f, + 0x05, 0x0f, 0x88, 0x6e} }; + + + +/* ------- Known Metadata Entry GUIDs ---------------------- */ +static const MSGUID file_param_guid = { .data1 = 0xcaa16737, + .data2 = 0xfa36, + .data3 = 0x4d43, + .data4 = { 0xb3, 0xb6, 0x33, 0xf0, + 0xaa, 0x44, 0xe7, 0x6b} }; + +static const MSGUID virtual_size_guid = { .data1 = 0x2FA54224, + .data2 = 0xcd1b, + .data3 = 0x4876, + .data4 = { 0xb2, 0x11, 0x5d, 0xbe, + 0xd8, 0x3b, 0xf4, 0xb8} }; + +static const MSGUID page83_guid = { .data1 = 0xbeca12ab, + .data2 = 0xb2e6, + .data3 = 0x4523, + .data4 = { 0x93, 0xef, 0xc3, 0x09, + 0xe0, 0x00, 0xc7, 0x46} }; + + +static const MSGUID phys_sector_guid = { .data1 = 0xcda348c7, + .data2 = 0x445d, + .data3 = 0x4471, + .data4 = { 0x9c, 0xc9, 0xe9, 0x88, + 0x52, 0x51, 0xc5, 0x56} }; + +static const MSGUID parent_locator_guid = { .data1 = 0xa8d35f2d, + .data2 = 0xb30b, + .data3 = 0x454d, + .data4 = { 0xab, 0xf7, 0xd3, + 0xd8, 0x48, 0x34, + 0xab, 0x0c} }; + +static const MSGUID logical_sector_guid = { .data1 = 0x8141bf1d, + .data2 = 0xa96f, + .data3 = 0x4709, + .data4 = { 0xba, 0x47, 0xf2, + 0x33, 0xa8, 0xfa, + 0xab, 0x5f} }; + +/* Each parent type must have a valid GUID; this is for parent images + * of type 'VHDX'. If we were to allow e.g. a QCOW2 parent, we would + * need to make up our own QCOW2 GUID type */ +static const MSGUID parent_vhdx_guid __attribute__((unused)) + = { .data1 = 0xb04aefb7, + .data2 = 0xd19e, + .data3 = 0x4a81, + .data4 = { 0xb7, 0x89, 0x25, 0xb8, + 0xe9, 0x44, 0x59, 0x13} }; + + +#define META_FILE_PARAMETER_PRESENT 0x01 +#define META_VIRTUAL_DISK_SIZE_PRESENT 0x02 +#define META_PAGE_83_PRESENT 0x04 +#define META_LOGICAL_SECTOR_SIZE_PRESENT 0x08 +#define META_PHYS_SECTOR_SIZE_PRESENT 0x10 +#define META_PARENT_LOCATOR_PRESENT 0x20 + +#define META_ALL_PRESENT \ + (META_FILE_PARAMETER_PRESENT | META_VIRTUAL_DISK_SIZE_PRESENT | \ + META_PAGE_83_PRESENT | META_LOGICAL_SECTOR_SIZE_PRESENT | \ + META_PHYS_SECTOR_SIZE_PRESENT) + + +typedef struct VHDXSectorInfo { + uint32_t bat_idx; /* BAT entry index */ + uint32_t sectors_avail; /* sectors available in payload block */ + uint32_t bytes_left; /* bytes left in the block after data to r/w */ + uint32_t bytes_avail; /* bytes available in payload block */ + uint64_t file_offset; /* absolute offset in bytes, in file */ + uint64_t block_offset; /* block offset, in bytes */ +} VHDXSectorInfo; + +/* Calculates new checksum. + * + * Zero is substituted during crc calculation for the original crc field + * crc_offset: byte offset in buf of the buffer crc + * buf: buffer pointer + * size: size of buffer (must be > crc_offset+4) + * + * Note: The buffer should have all multi-byte data in little-endian format, + * and the resulting checksum is in little endian format. + */ +uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset) +{ + uint32_t crc; + + assert(buf != NULL); + assert(size > (crc_offset + sizeof(crc))); + + memset(buf + crc_offset, 0, sizeof(crc)); + crc = crc32c(0xffffffff, buf, size); + cpu_to_le32s(&crc); + memcpy(buf + crc_offset, &crc, sizeof(crc)); + + return crc; +} + +uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size, + int crc_offset) +{ + uint32_t crc_new; + uint32_t crc_orig; + assert(buf != NULL); + + if (crc_offset > 0) { + memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); + memset(buf + crc_offset, 0, sizeof(crc_orig)); + } + + crc_new = crc32c(crc, buf, size); + if (crc_offset > 0) { + memcpy(buf + crc_offset, &crc_orig, sizeof(crc_orig)); + } + + return crc_new; +} + +/* Validates the checksum of the buffer, with an in-place CRC. + * + * Zero is substituted during crc calculation for the original crc field, + * and the crc field is restored afterwards. But the buffer will be modifed + * during the calculation, so this may not be not suitable for multi-threaded + * use. + * + * crc_offset: byte offset in buf of the buffer crc + * buf: buffer pointer + * size: size of buffer (must be > crc_offset+4) + * + * returns true if checksum is valid, false otherwise + */ +bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset) +{ + uint32_t crc_orig; + uint32_t crc; + + assert(buf != NULL); + assert(size > (crc_offset + 4)); + + memcpy(&crc_orig, buf + crc_offset, sizeof(crc_orig)); + crc_orig = le32_to_cpu(crc_orig); + + crc = vhdx_checksum_calc(0xffffffff, buf, size, crc_offset); + + return crc == crc_orig; +} + + +/* + * This generates a UUID that is compliant with the MS GUIDs used + * in the VHDX spec (and elsewhere). + */ +void vhdx_guid_generate(MSGUID *guid) +{ + uuid_t uuid; + assert(guid != NULL); + + uuid_generate(uuid); + memcpy(guid, uuid, sizeof(MSGUID)); +} + +/* Check for region overlaps inside the VHDX image */ +static int vhdx_region_check(BDRVVHDXState *s, uint64_t start, uint64_t length) +{ + int ret = 0; + uint64_t end; + VHDXRegionEntry *r; + + end = start + length; + QLIST_FOREACH(r, &s->regions, entries) { + if (!((start >= r->end) || (end <= r->start))) { + ret = -EINVAL; + goto exit; + } + } + +exit: + return ret; +} + +/* Register a region for future checks */ +static void vhdx_region_register(BDRVVHDXState *s, + uint64_t start, uint64_t length) +{ + VHDXRegionEntry *r; + + r = g_malloc0(sizeof(*r)); + + r->start = start; + r->end = start + length; + + QLIST_INSERT_HEAD(&s->regions, r, entries); +} + +/* Free all registered regions */ +static void vhdx_region_unregister_all(BDRVVHDXState *s) +{ + VHDXRegionEntry *r, *r_next; + + QLIST_FOREACH_SAFE(r, &s->regions, entries, r_next) { + QLIST_REMOVE(r, entries); + g_free(r); + } +} + +static void vhdx_set_shift_bits(BDRVVHDXState *s) +{ + s->logical_sector_size_bits = 31 - clz32(s->logical_sector_size); + s->sectors_per_block_bits = 31 - clz32(s->sectors_per_block); + s->chunk_ratio_bits = 63 - clz64(s->chunk_ratio); + s->block_size_bits = 31 - clz32(s->block_size); +} + +/* + * Per the MS VHDX Specification, for every VHDX file: + * - The header section is fixed size - 1 MB + * - The header section is always the first "object" + * - The first 64KB of the header is the File Identifier + * - The first uint64 (8 bytes) is the VHDX Signature ("vhdxfile") + * - The following 512 bytes constitute a UTF-16 string identifiying the + * software that created the file, and is optional and diagnostic only. + * + * Therefore, we probe by looking for the vhdxfile signature "vhdxfile" + */ +static int vhdx_probe(const uint8_t *buf, int buf_size, const char *filename) +{ + if (buf_size >= 8 && !memcmp(buf, "vhdxfile", 8)) { + return 100; + } + return 0; +} + +/* + * Writes the header to the specified offset. + * + * This will optionally read in buffer data from disk (otherwise zero-fill), + * and then update the header checksum. Header is converted to proper + * endianness before being written to the specified file offset + */ +static int vhdx_write_header(BlockDriverState *bs_file, VHDXHeader *hdr, + uint64_t offset, bool read) +{ + uint8_t *buffer = NULL; + int ret; + VHDXHeader *header_le; + + assert(bs_file != NULL); + assert(hdr != NULL); + + /* the header checksum is not over just the packed size of VHDXHeader, + * but rather over the entire 'reserved' range for the header, which is + * 4KB (VHDX_HEADER_SIZE). */ + + buffer = qemu_blockalign(bs_file, VHDX_HEADER_SIZE); + if (read) { + /* if true, we can't assume the extra reserved bytes are 0 */ + ret = bdrv_pread(bs_file, offset, buffer, VHDX_HEADER_SIZE); + if (ret < 0) { + goto exit; + } + } else { + memset(buffer, 0, VHDX_HEADER_SIZE); + } + + /* overwrite the actual VHDXHeader portion */ + header_le = (VHDXHeader *)buffer; + memcpy(header_le, hdr, sizeof(VHDXHeader)); + vhdx_header_le_export(hdr, header_le); + vhdx_update_checksum(buffer, VHDX_HEADER_SIZE, + offsetof(VHDXHeader, checksum)); + ret = bdrv_pwrite_sync(bs_file, offset, header_le, sizeof(VHDXHeader)); + +exit: + qemu_vfree(buffer); + return ret; +} + +/* Update the VHDX headers + * + * This follows the VHDX spec procedures for header updates. + * + * - non-current header is updated with largest sequence number + */ +static int vhdx_update_header(BlockDriverState *bs, BDRVVHDXState *s, + bool generate_data_write_guid, MSGUID *log_guid) +{ + int ret = 0; + int hdr_idx = 0; + uint64_t header_offset = VHDX_HEADER1_OFFSET; + + VHDXHeader *active_header; + VHDXHeader *inactive_header; + + /* operate on the non-current header */ + if (s->curr_header == 0) { + hdr_idx = 1; + header_offset = VHDX_HEADER2_OFFSET; + } + + active_header = s->headers[s->curr_header]; + inactive_header = s->headers[hdr_idx]; + + inactive_header->sequence_number = active_header->sequence_number + 1; + + /* a new file guid must be generated before any file write, including + * headers */ + inactive_header->file_write_guid = s->session_guid; + + /* a new data guid only needs to be generated before any guest-visible + * writes (i.e. something observable via virtual disk read) */ + if (generate_data_write_guid) { + vhdx_guid_generate(&inactive_header->data_write_guid); + } + + /* update the log guid if present */ + if (log_guid) { + inactive_header->log_guid = *log_guid; + } + + ret = vhdx_write_header(bs->file, inactive_header, header_offset, true); + if (ret < 0) { + goto exit; + } + s->curr_header = hdr_idx; + +exit: + return ret; +} + +/* + * The VHDX spec calls for header updates to be performed twice, so that both + * the current and non-current header have valid info + */ +int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, + bool generate_data_write_guid, MSGUID *log_guid) +{ + int ret; + + ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); + if (ret < 0) { + return ret; + } + ret = vhdx_update_header(bs, s, generate_data_write_guid, log_guid); + return ret; +} + +/* opens the specified header block from the VHDX file header section */ +static void vhdx_parse_header(BlockDriverState *bs, BDRVVHDXState *s, + Error **errp) +{ + int ret; + VHDXHeader *header1; + VHDXHeader *header2; + bool h1_valid = false; + bool h2_valid = false; + uint64_t h1_seq = 0; + uint64_t h2_seq = 0; + uint8_t *buffer; + + /* header1 & header2 are freed in vhdx_close() */ + header1 = qemu_blockalign(bs, sizeof(VHDXHeader)); + header2 = qemu_blockalign(bs, sizeof(VHDXHeader)); + + buffer = qemu_blockalign(bs, VHDX_HEADER_SIZE); + + s->headers[0] = header1; + s->headers[1] = header2; + + /* We have to read the whole VHDX_HEADER_SIZE instead of + * sizeof(VHDXHeader), because the checksum is over the whole + * region */ + ret = bdrv_pread(bs->file, VHDX_HEADER1_OFFSET, buffer, VHDX_HEADER_SIZE); + if (ret < 0) { + goto fail; + } + /* copy over just the relevant portion that we need */ + memcpy(header1, buffer, sizeof(VHDXHeader)); + + if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { + vhdx_header_le_import(header1); + if (header1->signature == VHDX_HEADER_SIGNATURE && + header1->version == 1) { + h1_seq = header1->sequence_number; + h1_valid = true; + } + } + + ret = bdrv_pread(bs->file, VHDX_HEADER2_OFFSET, buffer, VHDX_HEADER_SIZE); + if (ret < 0) { + goto fail; + } + /* copy over just the relevant portion that we need */ + memcpy(header2, buffer, sizeof(VHDXHeader)); + + if (vhdx_checksum_is_valid(buffer, VHDX_HEADER_SIZE, 4)) { + vhdx_header_le_import(header2); + if (header2->signature == VHDX_HEADER_SIGNATURE && + header2->version == 1) { + h2_seq = header2->sequence_number; + h2_valid = true; + } + } + + /* If there is only 1 valid header (or no valid headers), we + * don't care what the sequence numbers are */ + if (h1_valid && !h2_valid) { + s->curr_header = 0; + } else if (!h1_valid && h2_valid) { + s->curr_header = 1; + } else if (!h1_valid && !h2_valid) { + goto fail; + } else { + /* If both headers are valid, then we choose the active one by the + * highest sequence number. If the sequence numbers are equal, that is + * invalid */ + if (h1_seq > h2_seq) { + s->curr_header = 0; + } else if (h2_seq > h1_seq) { + s->curr_header = 1; + } else { + /* The Microsoft Disk2VHD tool will create 2 identical + * headers, with identical sequence numbers. If the headers are + * identical, don't consider the file corrupt */ + if (!memcmp(header1, header2, sizeof(VHDXHeader))) { + s->curr_header = 0; + } else { + goto fail; + } + } + } + + vhdx_region_register(s, s->headers[s->curr_header]->log_offset, + s->headers[s->curr_header]->log_length); + goto exit; + +fail: + error_setg_errno(errp, -ret, "No valid VHDX header found"); + qemu_vfree(header1); + qemu_vfree(header2); + s->headers[0] = NULL; + s->headers[1] = NULL; +exit: + qemu_vfree(buffer); +} + + +static int vhdx_open_region_tables(BlockDriverState *bs, BDRVVHDXState *s) +{ + int ret = 0; + uint8_t *buffer; + int offset = 0; + VHDXRegionTableEntry rt_entry; + uint32_t i; + bool bat_rt_found = false; + bool metadata_rt_found = false; + + /* We have to read the whole 64KB block, because the crc32 is over the + * whole block */ + buffer = qemu_blockalign(bs, VHDX_HEADER_BLOCK_SIZE); + + ret = bdrv_pread(bs->file, VHDX_REGION_TABLE_OFFSET, buffer, + VHDX_HEADER_BLOCK_SIZE); + if (ret < 0) { + goto fail; + } + memcpy(&s->rt, buffer, sizeof(s->rt)); + offset += sizeof(s->rt); + + if (!vhdx_checksum_is_valid(buffer, VHDX_HEADER_BLOCK_SIZE, 4)) { + ret = -EINVAL; + goto fail; + } + + vhdx_region_header_le_import(&s->rt); + + if (s->rt.signature != VHDX_REGION_SIGNATURE) { + ret = -EINVAL; + goto fail; + } + + + /* Per spec, maximum region table entry count is 2047 */ + if (s->rt.entry_count > 2047) { + ret = -EINVAL; + goto fail; + } + + for (i = 0; i < s->rt.entry_count; i++) { + memcpy(&rt_entry, buffer + offset, sizeof(rt_entry)); + offset += sizeof(rt_entry); + + vhdx_region_entry_le_import(&rt_entry); + + /* check for region overlap between these entries, and any + * other memory regions in the file */ + ret = vhdx_region_check(s, rt_entry.file_offset, rt_entry.length); + if (ret < 0) { + goto fail; + } + + vhdx_region_register(s, rt_entry.file_offset, rt_entry.length); + + /* see if we recognize the entry */ + if (guid_eq(rt_entry.guid, bat_guid)) { + /* must be unique; if we have already found it this is invalid */ + if (bat_rt_found) { + ret = -EINVAL; + goto fail; + } + bat_rt_found = true; + s->bat_rt = rt_entry; + continue; + } + + if (guid_eq(rt_entry.guid, metadata_guid)) { + /* must be unique; if we have already found it this is invalid */ + if (metadata_rt_found) { + ret = -EINVAL; + goto fail; + } + metadata_rt_found = true; + s->metadata_rt = rt_entry; + continue; + } + + if (rt_entry.data_bits & VHDX_REGION_ENTRY_REQUIRED) { + /* cannot read vhdx file - required region table entry that + * we do not understand. per spec, we must fail to open */ + ret = -ENOTSUP; + goto fail; + } + } + + if (!bat_rt_found || !metadata_rt_found) { + ret = -EINVAL; + goto fail; + } + + ret = 0; + +fail: + qemu_vfree(buffer); + return ret; +} + + + +/* Metadata initial parser + * + * This loads all the metadata entry fields. This may cause additional + * fields to be processed (e.g. parent locator, etc..). + * + * There are 5 Metadata items that are always required: + * - File Parameters (block size, has a parent) + * - Virtual Disk Size (size, in bytes, of the virtual drive) + * - Page 83 Data (scsi page 83 guid) + * - Logical Sector Size (logical sector size in bytes, either 512 or + * 4096. We only support 512 currently) + * - Physical Sector Size (512 or 4096) + * + * Also, if the File Parameters indicate this is a differencing file, + * we must also look for the Parent Locator metadata item. + */ +static int vhdx_parse_metadata(BlockDriverState *bs, BDRVVHDXState *s) +{ + int ret = 0; + uint8_t *buffer; + int offset = 0; + uint32_t i = 0; + VHDXMetadataTableEntry md_entry; + + buffer = qemu_blockalign(bs, VHDX_METADATA_TABLE_MAX_SIZE); + + ret = bdrv_pread(bs->file, s->metadata_rt.file_offset, buffer, + VHDX_METADATA_TABLE_MAX_SIZE); + if (ret < 0) { + goto exit; + } + memcpy(&s->metadata_hdr, buffer, sizeof(s->metadata_hdr)); + offset += sizeof(s->metadata_hdr); + + vhdx_metadata_header_le_import(&s->metadata_hdr); + + if (s->metadata_hdr.signature != VHDX_METADATA_SIGNATURE) { + ret = -EINVAL; + goto exit; + } + + s->metadata_entries.present = 0; + + if ((s->metadata_hdr.entry_count * sizeof(md_entry)) > + (VHDX_METADATA_TABLE_MAX_SIZE - offset)) { + ret = -EINVAL; + goto exit; + } + + for (i = 0; i < s->metadata_hdr.entry_count; i++) { + memcpy(&md_entry, buffer + offset, sizeof(md_entry)); + offset += sizeof(md_entry); + + vhdx_metadata_entry_le_import(&md_entry); + + if (guid_eq(md_entry.item_id, file_param_guid)) { + if (s->metadata_entries.present & META_FILE_PARAMETER_PRESENT) { + ret = -EINVAL; + goto exit; + } + s->metadata_entries.file_parameters_entry = md_entry; + s->metadata_entries.present |= META_FILE_PARAMETER_PRESENT; + continue; + } + + if (guid_eq(md_entry.item_id, virtual_size_guid)) { + if (s->metadata_entries.present & META_VIRTUAL_DISK_SIZE_PRESENT) { + ret = -EINVAL; + goto exit; + } + s->metadata_entries.virtual_disk_size_entry = md_entry; + s->metadata_entries.present |= META_VIRTUAL_DISK_SIZE_PRESENT; + continue; + } + + if (guid_eq(md_entry.item_id, page83_guid)) { + if (s->metadata_entries.present & META_PAGE_83_PRESENT) { + ret = -EINVAL; + goto exit; + } + s->metadata_entries.page83_data_entry = md_entry; + s->metadata_entries.present |= META_PAGE_83_PRESENT; + continue; + } + + if (guid_eq(md_entry.item_id, logical_sector_guid)) { + if (s->metadata_entries.present & + META_LOGICAL_SECTOR_SIZE_PRESENT) { + ret = -EINVAL; + goto exit; + } + s->metadata_entries.logical_sector_size_entry = md_entry; + s->metadata_entries.present |= META_LOGICAL_SECTOR_SIZE_PRESENT; + continue; + } + + if (guid_eq(md_entry.item_id, phys_sector_guid)) { + if (s->metadata_entries.present & META_PHYS_SECTOR_SIZE_PRESENT) { + ret = -EINVAL; + goto exit; + } + s->metadata_entries.phys_sector_size_entry = md_entry; + s->metadata_entries.present |= META_PHYS_SECTOR_SIZE_PRESENT; + continue; + } + + if (guid_eq(md_entry.item_id, parent_locator_guid)) { + if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { + ret = -EINVAL; + goto exit; + } + s->metadata_entries.parent_locator_entry = md_entry; + s->metadata_entries.present |= META_PARENT_LOCATOR_PRESENT; + continue; + } + + if (md_entry.data_bits & VHDX_META_FLAGS_IS_REQUIRED) { + /* cannot read vhdx file - required region table entry that + * we do not understand. per spec, we must fail to open */ + ret = -ENOTSUP; + goto exit; + } + } + + if (s->metadata_entries.present != META_ALL_PRESENT) { + ret = -ENOTSUP; + goto exit; + } + + ret = bdrv_pread(bs->file, + s->metadata_entries.file_parameters_entry.offset + + s->metadata_rt.file_offset, + &s->params, + sizeof(s->params)); + + if (ret < 0) { + goto exit; + } + + le32_to_cpus(&s->params.block_size); + le32_to_cpus(&s->params.data_bits); + + + /* We now have the file parameters, so we can tell if this is a + * differencing file (i.e.. has_parent), is dynamic or fixed + * sized (leave_blocks_allocated), and the block size */ + + /* The parent locator required iff the file parameters has_parent set */ + if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { + if (s->metadata_entries.present & META_PARENT_LOCATOR_PRESENT) { + /* TODO: parse parent locator fields */ + ret = -ENOTSUP; /* temp, until differencing files are supported */ + goto exit; + } else { + /* if has_parent is set, but there is not parent locator present, + * then that is an invalid combination */ + ret = -EINVAL; + goto exit; + } + } + + /* determine virtual disk size, logical sector size, + * and phys sector size */ + + ret = bdrv_pread(bs->file, + s->metadata_entries.virtual_disk_size_entry.offset + + s->metadata_rt.file_offset, + &s->virtual_disk_size, + sizeof(uint64_t)); + if (ret < 0) { + goto exit; + } + ret = bdrv_pread(bs->file, + s->metadata_entries.logical_sector_size_entry.offset + + s->metadata_rt.file_offset, + &s->logical_sector_size, + sizeof(uint32_t)); + if (ret < 0) { + goto exit; + } + ret = bdrv_pread(bs->file, + s->metadata_entries.phys_sector_size_entry.offset + + s->metadata_rt.file_offset, + &s->physical_sector_size, + sizeof(uint32_t)); + if (ret < 0) { + goto exit; + } + + le64_to_cpus(&s->virtual_disk_size); + le32_to_cpus(&s->logical_sector_size); + le32_to_cpus(&s->physical_sector_size); + + if (s->params.block_size < VHDX_BLOCK_SIZE_MIN || + s->params.block_size > VHDX_BLOCK_SIZE_MAX) { + ret = -EINVAL; + goto exit; + } + + /* only 2 supported sector sizes */ + if (s->logical_sector_size != 512 && s->logical_sector_size != 4096) { + ret = -EINVAL; + goto exit; + } + + /* Both block_size and sector_size are guaranteed powers of 2, below. + Due to range checks above, s->sectors_per_block can never be < 256 */ + s->sectors_per_block = s->params.block_size / s->logical_sector_size; + s->chunk_ratio = (VHDX_MAX_SECTORS_PER_BLOCK) * + (uint64_t)s->logical_sector_size / + (uint64_t)s->params.block_size; + + /* These values are ones we will want to use for division / multiplication + * later on, and they are all guaranteed (per the spec) to be powers of 2, + * so we can take advantage of that for shift operations during + * reads/writes */ + if (s->logical_sector_size & (s->logical_sector_size - 1)) { + ret = -EINVAL; + goto exit; + } + if (s->sectors_per_block & (s->sectors_per_block - 1)) { + ret = -EINVAL; + goto exit; + } + if (s->chunk_ratio & (s->chunk_ratio - 1)) { + ret = -EINVAL; + goto exit; + } + s->block_size = s->params.block_size; + if (s->block_size & (s->block_size - 1)) { + ret = -EINVAL; + goto exit; + } + + vhdx_set_shift_bits(s); + + ret = 0; + +exit: + qemu_vfree(buffer); + return ret; +} + +/* + * Calculate the number of BAT entries, including sector + * bitmap entries. + */ +static void vhdx_calc_bat_entries(BDRVVHDXState *s) +{ + uint32_t data_blocks_cnt, bitmap_blocks_cnt; + + data_blocks_cnt = s->virtual_disk_size >> s->block_size_bits; + if (s->virtual_disk_size - (data_blocks_cnt << s->block_size_bits)) { + data_blocks_cnt++; + } + bitmap_blocks_cnt = data_blocks_cnt >> s->chunk_ratio_bits; + if (data_blocks_cnt - (bitmap_blocks_cnt << s->chunk_ratio_bits)) { + bitmap_blocks_cnt++; + } + + if (s->parent_entries) { + s->bat_entries = bitmap_blocks_cnt * (s->chunk_ratio + 1); + } else { + s->bat_entries = data_blocks_cnt + + ((data_blocks_cnt - 1) >> s->chunk_ratio_bits); + } + +} + +static void vhdx_close(BlockDriverState *bs) +{ + BDRVVHDXState *s = bs->opaque; + qemu_vfree(s->headers[0]); + s->headers[0] = NULL; + qemu_vfree(s->headers[1]); + s->headers[1] = NULL; + qemu_vfree(s->bat); + s->bat = NULL; + qemu_vfree(s->parent_entries); + s->parent_entries = NULL; + migrate_del_blocker(s->migration_blocker); + error_free(s->migration_blocker); + qemu_vfree(s->log.hdr); + s->log.hdr = NULL; + vhdx_region_unregister_all(s); +} + +static int vhdx_open(BlockDriverState *bs, QDict *options, int flags, + Error **errp) +{ + BDRVVHDXState *s = bs->opaque; + int ret = 0; + uint32_t i; + uint64_t signature; + Error *local_err = NULL; + + s->bat = NULL; + s->first_visible_write = true; + + qemu_co_mutex_init(&s->lock); + QLIST_INIT(&s->regions); + + /* validate the file signature */ + ret = bdrv_pread(bs->file, 0, &signature, sizeof(uint64_t)); + if (ret < 0) { + goto fail; + } + if (memcmp(&signature, "vhdxfile", 8)) { + ret = -EINVAL; + goto fail; + } + + /* This is used for any header updates, for the file_write_guid. + * The spec dictates that a new value should be used for the first + * header update */ + vhdx_guid_generate(&s->session_guid); + + vhdx_parse_header(bs, s, &local_err); + if (local_err != NULL) { + error_propagate(errp, local_err); + ret = -EINVAL; + goto fail; + } + + ret = vhdx_parse_log(bs, s, &s->log_replayed_on_open, errp); + if (ret < 0) { + goto fail; + } + + ret = vhdx_open_region_tables(bs, s); + if (ret < 0) { + goto fail; + } + + ret = vhdx_parse_metadata(bs, s); + if (ret < 0) { + goto fail; + } + + s->block_size = s->params.block_size; + + /* the VHDX spec dictates that virtual_disk_size is always a multiple of + * logical_sector_size */ + bs->total_sectors = s->virtual_disk_size >> s->logical_sector_size_bits; + + vhdx_calc_bat_entries(s); + + s->bat_offset = s->bat_rt.file_offset; + + if (s->bat_entries > s->bat_rt.length / sizeof(VHDXBatEntry)) { + /* BAT allocation is not large enough for all entries */ + ret = -EINVAL; + goto fail; + } + + /* s->bat is freed in vhdx_close() */ + s->bat = qemu_try_blockalign(bs->file, s->bat_rt.length); + if (s->bat == NULL) { + ret = -ENOMEM; + goto fail; + } + + ret = bdrv_pread(bs->file, s->bat_offset, s->bat, s->bat_rt.length); + if (ret < 0) { + goto fail; + } + + uint64_t payblocks = s->chunk_ratio; + /* endian convert, and verify populated BAT field file offsets against + * region table and log entries */ + for (i = 0; i < s->bat_entries; i++) { + le64_to_cpus(&s->bat[i]); + if (payblocks--) { + /* payload bat entries */ + if ((s->bat[i] & VHDX_BAT_STATE_BIT_MASK) == + PAYLOAD_BLOCK_FULLY_PRESENT) { + ret = vhdx_region_check(s, s->bat[i] & VHDX_BAT_FILE_OFF_MASK, + s->block_size); + if (ret < 0) { + goto fail; + } + } + } else { + payblocks = s->chunk_ratio; + /* Once differencing files are supported, verify sector bitmap + * blocks here */ + } + } + + if (flags & BDRV_O_RDWR) { + ret = vhdx_update_headers(bs, s, false, NULL); + if (ret < 0) { + goto fail; + } + } + + /* TODO: differencing files */ + + /* Disable migration when VHDX images are used */ + error_setg(&s->migration_blocker, "The vhdx format used by node '%s' " + "does not support live migration", + bdrv_get_device_or_node_name(bs)); + migrate_add_blocker(s->migration_blocker); + + return 0; +fail: + vhdx_close(bs); + return ret; +} + +static int vhdx_reopen_prepare(BDRVReopenState *state, + BlockReopenQueue *queue, Error **errp) +{ + return 0; +} + + +/* + * Perform sector to block offset translations, to get various + * sector and file offsets into the image. See VHDXSectorInfo + */ +static void vhdx_block_translate(BDRVVHDXState *s, int64_t sector_num, + int nb_sectors, VHDXSectorInfo *sinfo) +{ + uint32_t block_offset; + + sinfo->bat_idx = sector_num >> s->sectors_per_block_bits; + /* effectively a modulo - this gives us the offset into the block + * (in sector sizes) for our sector number */ + block_offset = sector_num - (sinfo->bat_idx << s->sectors_per_block_bits); + /* the chunk ratio gives us the interleaving of the sector + * bitmaps, so we need to advance our page block index by the + * sector bitmaps entry number */ + sinfo->bat_idx += sinfo->bat_idx >> s->chunk_ratio_bits; + + /* the number of sectors we can read/write in this cycle */ + sinfo->sectors_avail = s->sectors_per_block - block_offset; + + sinfo->bytes_left = sinfo->sectors_avail << s->logical_sector_size_bits; + + if (sinfo->sectors_avail > nb_sectors) { + sinfo->sectors_avail = nb_sectors; + } + + sinfo->bytes_avail = sinfo->sectors_avail << s->logical_sector_size_bits; + + sinfo->file_offset = s->bat[sinfo->bat_idx] & VHDX_BAT_FILE_OFF_MASK; + + sinfo->block_offset = block_offset << s->logical_sector_size_bits; + + /* The file offset must be past the header section, so must be > 0 */ + if (sinfo->file_offset == 0) { + return; + } + + /* block offset is the offset in vhdx logical sectors, in + * the payload data block. Convert that to a byte offset + * in the block, and add in the payload data block offset + * in the file, in bytes, to get the final read address */ + + sinfo->file_offset += sinfo->block_offset; +} + + +static int vhdx_get_info(BlockDriverState *bs, BlockDriverInfo *bdi) +{ + BDRVVHDXState *s = bs->opaque; + + bdi->cluster_size = s->block_size; + + bdi->unallocated_blocks_are_zero = + (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) == 0; + + return 0; +} + + +static coroutine_fn int vhdx_co_readv(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) +{ + BDRVVHDXState *s = bs->opaque; + int ret = 0; + VHDXSectorInfo sinfo; + uint64_t bytes_done = 0; + QEMUIOVector hd_qiov; + + qemu_iovec_init(&hd_qiov, qiov->niov); + + qemu_co_mutex_lock(&s->lock); + + while (nb_sectors > 0) { + /* We are a differencing file, so we need to inspect the sector bitmap + * to see if we have the data or not */ + if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { + /* not supported yet */ + ret = -ENOTSUP; + goto exit; + } else { + vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); + + qemu_iovec_reset(&hd_qiov); + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, sinfo.bytes_avail); + + /* check the payload block state */ + switch (s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK) { + case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ + case PAYLOAD_BLOCK_UNDEFINED: + case PAYLOAD_BLOCK_UNMAPPED: + case PAYLOAD_BLOCK_UNMAPPED_v095: + case PAYLOAD_BLOCK_ZERO: + /* return zero */ + qemu_iovec_memset(&hd_qiov, 0, 0, sinfo.bytes_avail); + break; + case PAYLOAD_BLOCK_FULLY_PRESENT: + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_readv(bs->file, + sinfo.file_offset >> BDRV_SECTOR_BITS, + sinfo.sectors_avail, &hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + goto exit; + } + break; + case PAYLOAD_BLOCK_PARTIALLY_PRESENT: + /* we don't yet support difference files, fall through + * to error */ + default: + ret = -EIO; + goto exit; + break; + } + nb_sectors -= sinfo.sectors_avail; + sector_num += sinfo.sectors_avail; + bytes_done += sinfo.bytes_avail; + } + } + ret = 0; +exit: + qemu_co_mutex_unlock(&s->lock); + qemu_iovec_destroy(&hd_qiov); + return ret; +} + +/* + * Allocate a new payload block at the end of the file. + * + * Allocation will happen at 1MB alignment inside the file + * + * Returns the file offset start of the new payload block + */ +static int vhdx_allocate_block(BlockDriverState *bs, BDRVVHDXState *s, + uint64_t *new_offset) +{ + *new_offset = bdrv_getlength(bs->file); + + /* per the spec, the address for a block is in units of 1MB */ + *new_offset = ROUND_UP(*new_offset, 1024 * 1024); + + return bdrv_truncate(bs->file, *new_offset + s->block_size); +} + +/* + * Update the BAT table entry with the new file offset, and the new entry + * state */ +static void vhdx_update_bat_table_entry(BlockDriverState *bs, BDRVVHDXState *s, + VHDXSectorInfo *sinfo, + uint64_t *bat_entry_le, + uint64_t *bat_offset, int state) +{ + /* The BAT entry is a uint64, with 44 bits for the file offset in units of + * 1MB, and 3 bits for the block state. */ + if ((state == PAYLOAD_BLOCK_ZERO) || + (state == PAYLOAD_BLOCK_UNDEFINED) || + (state == PAYLOAD_BLOCK_NOT_PRESENT) || + (state == PAYLOAD_BLOCK_UNMAPPED)) { + s->bat[sinfo->bat_idx] = 0; /* For PAYLOAD_BLOCK_ZERO, the + FileOffsetMB field is denoted as + 'reserved' in the v1.0 spec. If it is + non-zero, MS Hyper-V will fail to read + the disk image */ + } else { + s->bat[sinfo->bat_idx] = sinfo->file_offset; + } + + s->bat[sinfo->bat_idx] |= state & VHDX_BAT_STATE_BIT_MASK; + + *bat_entry_le = cpu_to_le64(s->bat[sinfo->bat_idx]); + *bat_offset = s->bat_offset + sinfo->bat_idx * sizeof(VHDXBatEntry); + +} + +/* Per the spec, on the first write of guest-visible data to the file the + * data write guid must be updated in the header */ +int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s) +{ + int ret = 0; + if (s->first_visible_write) { + s->first_visible_write = false; + ret = vhdx_update_headers(bs, s, true, NULL); + } + return ret; +} + +static coroutine_fn int vhdx_co_writev(BlockDriverState *bs, int64_t sector_num, + int nb_sectors, QEMUIOVector *qiov) +{ + int ret = -ENOTSUP; + BDRVVHDXState *s = bs->opaque; + VHDXSectorInfo sinfo; + uint64_t bytes_done = 0; + uint64_t bat_entry = 0; + uint64_t bat_entry_offset = 0; + QEMUIOVector hd_qiov; + struct iovec iov1 = { 0 }; + struct iovec iov2 = { 0 }; + int sectors_to_write; + int bat_state; + uint64_t bat_prior_offset = 0; + bool bat_update = false; + + qemu_iovec_init(&hd_qiov, qiov->niov); + + qemu_co_mutex_lock(&s->lock); + + ret = vhdx_user_visible_write(bs, s); + if (ret < 0) { + goto exit; + } + + while (nb_sectors > 0) { + bool use_zero_buffers = false; + bat_update = false; + if (s->params.data_bits & VHDX_PARAMS_HAS_PARENT) { + /* not supported yet */ + ret = -ENOTSUP; + goto exit; + } else { + vhdx_block_translate(s, sector_num, nb_sectors, &sinfo); + sectors_to_write = sinfo.sectors_avail; + + qemu_iovec_reset(&hd_qiov); + /* check the payload block state */ + bat_state = s->bat[sinfo.bat_idx] & VHDX_BAT_STATE_BIT_MASK; + switch (bat_state) { + case PAYLOAD_BLOCK_ZERO: + /* in this case, we need to preserve zero writes for + * data that is not part of this write, so we must pad + * the rest of the buffer to zeroes */ + + /* if we are on a posix system with ftruncate() that extends + * a file, then it is zero-filled for us. On Win32, the raw + * layer uses SetFilePointer and SetFileEnd, which does not + * zero fill AFAIK */ + + /* Queue another write of zero buffers if the underlying file + * does not zero-fill on file extension */ + + if (bdrv_has_zero_init(bs->file) == 0) { + use_zero_buffers = true; + + /* zero fill the front, if any */ + if (sinfo.block_offset) { + iov1.iov_len = sinfo.block_offset; + iov1.iov_base = qemu_blockalign(bs, iov1.iov_len); + memset(iov1.iov_base, 0, iov1.iov_len); + qemu_iovec_concat_iov(&hd_qiov, &iov1, 1, 0, + iov1.iov_len); + sectors_to_write += iov1.iov_len >> BDRV_SECTOR_BITS; + } + + /* our actual data */ + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, + sinfo.bytes_avail); + + /* zero fill the back, if any */ + if ((sinfo.bytes_avail - sinfo.block_offset) < + s->block_size) { + iov2.iov_len = s->block_size - + (sinfo.bytes_avail + sinfo.block_offset); + iov2.iov_base = qemu_blockalign(bs, iov2.iov_len); + memset(iov2.iov_base, 0, iov2.iov_len); + qemu_iovec_concat_iov(&hd_qiov, &iov2, 1, 0, + iov2.iov_len); + sectors_to_write += iov2.iov_len >> BDRV_SECTOR_BITS; + } + } + /* fall through */ + case PAYLOAD_BLOCK_NOT_PRESENT: /* fall through */ + case PAYLOAD_BLOCK_UNMAPPED: + case PAYLOAD_BLOCK_UNMAPPED_v095: + case PAYLOAD_BLOCK_UNDEFINED: + bat_prior_offset = sinfo.file_offset; + ret = vhdx_allocate_block(bs, s, &sinfo.file_offset); + if (ret < 0) { + goto exit; + } + /* once we support differencing files, this may also be + * partially present */ + /* update block state to the newly specified state */ + vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, + &bat_entry_offset, + PAYLOAD_BLOCK_FULLY_PRESENT); + bat_update = true; + /* since we just allocated a block, file_offset is the + * beginning of the payload block. It needs to be the + * write address, which includes the offset into the block */ + if (!use_zero_buffers) { + sinfo.file_offset += sinfo.block_offset; + } + /* fall through */ + case PAYLOAD_BLOCK_FULLY_PRESENT: + /* if the file offset address is in the header zone, + * there is a problem */ + if (sinfo.file_offset < (1024 * 1024)) { + ret = -EFAULT; + goto error_bat_restore; + } + + if (!use_zero_buffers) { + qemu_iovec_concat(&hd_qiov, qiov, bytes_done, + sinfo.bytes_avail); + } + /* block exists, so we can just overwrite it */ + qemu_co_mutex_unlock(&s->lock); + ret = bdrv_co_writev(bs->file, + sinfo.file_offset >> BDRV_SECTOR_BITS, + sectors_to_write, &hd_qiov); + qemu_co_mutex_lock(&s->lock); + if (ret < 0) { + goto error_bat_restore; + } + break; + case PAYLOAD_BLOCK_PARTIALLY_PRESENT: + /* we don't yet support difference files, fall through + * to error */ + default: + ret = -EIO; + goto exit; + break; + } + + if (bat_update) { + /* this will update the BAT entry into the log journal, and + * then flush the log journal out to disk */ + ret = vhdx_log_write_and_flush(bs, s, &bat_entry, + sizeof(VHDXBatEntry), + bat_entry_offset); + if (ret < 0) { + goto exit; + } + } + + nb_sectors -= sinfo.sectors_avail; + sector_num += sinfo.sectors_avail; + bytes_done += sinfo.bytes_avail; + + } + } + + goto exit; + +error_bat_restore: + if (bat_update) { + /* keep metadata in sync, and restore the bat entry state + * if error. */ + sinfo.file_offset = bat_prior_offset; + vhdx_update_bat_table_entry(bs, s, &sinfo, &bat_entry, + &bat_entry_offset, bat_state); + } +exit: + qemu_vfree(iov1.iov_base); + qemu_vfree(iov2.iov_base); + qemu_co_mutex_unlock(&s->lock); + qemu_iovec_destroy(&hd_qiov); + return ret; +} + + + +/* + * 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_new0(VHDXHeader, 1); + + 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; +} + +#define VHDX_METADATA_ENTRY_BUFFER_SIZE \ + (sizeof(VHDXFileParameters) +\ + sizeof(VHDXVirtualDiskSize) +\ + sizeof(VHDXPage83Data) +\ + sizeof(VHDXVirtualDiskLogicalSectorSize) +\ + sizeof(VHDXVirtualDiskPhysicalSectorSize)) + +/* + * 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(VHDX_METADATA_ENTRY_BUFFER_SIZE); + + 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_METADATA_ENTRY_BUFFER_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, uint64_t file_offset, + uint32_t length) +{ + 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 = file_offset + 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_try_malloc0(length); + if (length && s->bat == NULL) { + ret = -ENOMEM; + goto exit; + } + 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, file_offset, s->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; + uint64_t bat_file_offset; + uint32_t bat_length; + 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_new0(BDRVVHDXState, 1); + + 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; + + bat_file_offset = rt_bat->file_offset; + bat_length = rt_bat->length; + + vhdx_region_header_le_export(region_table); + vhdx_region_entry_le_export(rt_bat); + vhdx_region_entry_le_export(rt_metadata); + + 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, + bat_file_offset, bat_length); + if (ret < 0) { + goto exit; + } + + /* Now write out the region headers to disk */ + 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, QemuOpts *opts, 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; + char *type = NULL; + VHDXImageType image_type; + Error *local_err = NULL; + + image_size = ROUND_UP(qemu_opt_get_size_del(opts, BLOCK_OPT_SIZE, 0), + BDRV_SECTOR_SIZE); + log_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_LOG_SIZE, 0); + block_size = qemu_opt_get_size_del(opts, VHDX_BLOCK_OPT_BLOCK_SIZE, 0); + type = qemu_opt_get_del(opts, BLOCK_OPT_SUBFMT); + use_zero_blocks = qemu_opt_get_bool_del(opts, VHDX_BLOCK_OPT_ZERO, true); + + 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 = g_strdup("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, opts, &local_err); + if (ret < 0) { + error_propagate(errp, local_err); + goto exit; + } + + bs = NULL; + 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; + } + + /* 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); + ret = bdrv_pwrite(bs, VHDX_FILE_ID_OFFSET, &signature, sizeof(signature)); + if (ret < 0) { + goto delete_and_exit; + } + if (creator) { + ret = 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(type); + g_free(creator); + return ret; +} + +/* If opened r/w, the VHDX driver will automatically replay the log, + * if one is present, inside the vhdx_open() call. + * + * If qemu-img check -r all is called, the image is automatically opened + * r/w and any log has already been replayed, so there is nothing (currently) + * for us to do here + */ +static int vhdx_check(BlockDriverState *bs, BdrvCheckResult *result, + BdrvCheckMode fix) +{ + BDRVVHDXState *s = bs->opaque; + + if (s->log_replayed_on_open) { + result->corruptions_fixed++; + } + return 0; +} + +static QemuOptsList vhdx_create_opts = { + .name = "vhdx-create-opts", + .head = QTAILQ_HEAD_INITIALIZER(vhdx_create_opts.head), + .desc = { + { + .name = BLOCK_OPT_SIZE, + .type = QEMU_OPT_SIZE, + .help = "Virtual disk size; max of 64TB." + }, + { + .name = VHDX_BLOCK_OPT_LOG_SIZE, + .type = QEMU_OPT_SIZE, + .def_value_str = stringify(DEFAULT_LOG_SIZE), + .help = "Log size; min 1MB." + }, + { + .name = VHDX_BLOCK_OPT_BLOCK_SIZE, + .type = QEMU_OPT_SIZE, + .def_value_str = stringify(0), + .help = "Block Size; min 1MB, max 256MB. " \ + "0 means auto-calculate based on image size." + }, + { + .name = BLOCK_OPT_SUBFMT, + .type = QEMU_OPT_STRING, + .help = "VHDX format type, can be either 'dynamic' or 'fixed'. "\ + "Default is 'dynamic'." + }, + { + .name = VHDX_BLOCK_OPT_ZERO, + .type = QEMU_OPT_BOOL, + .help = "Force use of payload blocks of type 'ZERO'. "\ + "Non-standard, but default. Do not set to 'off' when "\ + "using 'qemu-img convert' with subformat=dynamic." + }, + { NULL } + } +}; + +static BlockDriver bdrv_vhdx = { + .format_name = "vhdx", + .instance_size = sizeof(BDRVVHDXState), + .bdrv_probe = vhdx_probe, + .bdrv_open = vhdx_open, + .bdrv_close = vhdx_close, + .bdrv_reopen_prepare = vhdx_reopen_prepare, + .bdrv_co_readv = vhdx_co_readv, + .bdrv_co_writev = vhdx_co_writev, + .bdrv_create = vhdx_create, + .bdrv_get_info = vhdx_get_info, + .bdrv_check = vhdx_check, + .bdrv_has_zero_init = bdrv_has_zero_init_1, + + .create_opts = &vhdx_create_opts, +}; + +static void bdrv_vhdx_init(void) +{ + bdrv_register(&bdrv_vhdx); +} + +block_init(bdrv_vhdx_init); |