* Authors:
* Jeff Cody <jcody@redhat.com>
*
- * This is based on the "VHDX Format Specification v0.95", published 4/12/2012
+ * 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=29681
+ * 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.
#ifndef BLOCK_VHDX_H
#define BLOCK_VHDX_H
+#include "qemu/units.h"
+
+#define DEFAULT_LOG_SIZE 1048576 /* 1MiB */
+/* Note: can't use 1 * MiB, because it's passed to stringify() */
/* Structures and fields present in the VHDX file */
* 0.........64KB...........128KB........192KB..........256KB................1MB
*/
-#define VHDX_HEADER_BLOCK_SIZE (64*1024)
+#define VHDX_HEADER_BLOCK_SIZE (64 * KiB)
#define VHDX_FILE_ID_OFFSET 0
-#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_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.
/* These structures are ones that are defined in the VHDX specification
* document */
+#define VHDX_FILE_SIGNATURE 0x656C696678646876ULL /* "vhdxfile" in ASCII */
typedef struct VHDXFileIdentifier {
uint64_t signature; /* "vhdxfile" in ASCII */
uint16_t creator[256]; /* optional; utf-16 string to identify
- the vhdx file creator. Diagnotistic
+ the vhdx file creator. Diagnostic
only */
} VHDXFileIdentifier;
* Microsoft is not just 16 bytes though - it is a structure that is defined,
* so we need to follow it here so that endianness does not trip us up */
-typedef struct MSGUID {
+typedef struct QEMU_PACKED MSGUID {
uint32_t data1;
uint16_t data2;
uint16_t data3;
#define guid_eq(a, b) \
(memcmp(&(a), &(b), sizeof(MSGUID)) == 0)
-#define VHDX_HEADER_SIZE (4*1024) /* although the vhdx_header struct in disk
- is only 582 bytes, for purposes of crc
- the header is the first 4KB of the 64KB
- block */
+#define VHDX_HEADER_SIZE (4 * KiB) /* although the vhdx_header struct in disk
+ is only 582 bytes, for purposes of crc
+ the header is the first 4KB of the 64KB
+ block */
/* 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 */
VHDX file has 2 of these headers,
and only the header with the highest
sequence number is valid */
- MSGUID file_write_guid; /* 128 bit unique identifier. Must be
+ MSGUID file_write_guid; /* 128 bit unique identifier. Must be
updated to new, unique value before
the first modification is made to
file */
there is no valid log. If non-zero,
log entries with this guid are
valid. */
- uint16_t log_version; /* version of the log format. Mustn't be
- zero, unless log_guid is also zero */
- uint16_t version; /* version of th evhdx file. Currently,
+ uint16_t log_version; /* version of the log format. Must be
+ set to zero */
+ uint16_t version; /* version of the vhdx file. Currently,
only supported version is "1" */
uint32_t log_length; /* length of the log. Must be multiple
of 1MB */
} 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 */
/* ---- LOG ENTRY STRUCTURES ---- */
+#define VHDX_LOG_MIN_SIZE (1 * MiB)
+#define VHDX_LOG_SECTOR_SIZE (4 * KiB)
#define VHDX_LOG_HDR_SIZE 64
+#define VHDX_LOG_SIGNATURE 0x65676f6c
typedef struct QEMU_PACKED VHDXLogEntryHeader {
uint32_t signature; /* "loge" in ASCII */
uint32_t checksum; /* CRC-32C hash of the 64KB table */
vhdx_header. If not found in
vhdx_header, it is invalid */
uint64_t flushed_file_offset; /* see spec for full details - this
- sould be vhdx file size in bytes */
+ should be vhdx file size in bytes */
uint64_t last_file_offset; /* size in bytes that all allocated
file structures fit into */
} VHDXLogEntryHeader;
#define VHDX_LOG_DESC_SIZE 32
-
+#define VHDX_LOG_DESC_SIGNATURE 0x63736564
+#define VHDX_LOG_ZERO_SIGNATURE 0x6f72657a
typedef struct QEMU_PACKED VHDXLogDescriptor {
uint32_t signature; /* "zero" or "desc" in ASCII */
union {
vhdx_log_entry_header */
} VHDXLogDescriptor;
+#define VHDX_LOG_DATA_SIGNATURE 0x61746164
typedef struct QEMU_PACKED VHDXLogDataSector {
uint32_t data_signature; /* "data" in ASCII */
uint32_t sequence_high; /* 4 MSB of 8 byte sequence_number */
#define PAYLOAD_BLOCK_NOT_PRESENT 0
#define PAYLOAD_BLOCK_UNDEFINED 1
#define PAYLOAD_BLOCK_ZERO 2
-#define PAYLOAD_BLOCK_UNMAPPED 5
-#define PAYLOAD_BLOCK_FULL_PRESENT 6
+#define PAYLOAD_BLOCK_UNMAPPED 3
+#define PAYLOAD_BLOCK_UNMAPPED_v095 5
+#define PAYLOAD_BLOCK_FULLY_PRESENT 6
#define PAYLOAD_BLOCK_PARTIALLY_PRESENT 7
#define SB_BLOCK_NOT_PRESENT 0
#define SB_BLOCK_PRESENT 6
/* per the spec */
-#define VHDX_MAX_SECTORS_PER_BLOCK (1<<23)
+#define VHDX_MAX_SECTORS_PER_BLOCK (1 << 23)
/* upper 44 bits are the file offset in 1MB units lower 3 bits are the state
other bits are reserved */
#define VHDX_BAT_STATE_BIT_MASK 0x07
-#define VHDX_BAT_FILE_OFF_BITS (64-44)
+#define VHDX_BAT_FILE_OFF_MASK 0xFFFFFFFFFFF00000ULL /* upper 44 bits */
typedef uint64_t VHDXBatEntry;
/* ---- METADATA REGION STRUCTURES ---- */
#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 0x617461646174656DULL /* "metadata" in ASCII */
typedef struct QEMU_PACKED VHDXMetadataTableHeader {
uint64_t signature; /* "metadata" in ASCII */
uint16_t reserved;
metadata region */
/* note: if length = 0, so is offset */
uint32_t length; /* length of metadata. <= 1MB. */
- uint32_t data_bits; /* least-significant 3 bits are flags, the
- rest are reserved (see above) */
+ uint32_t data_bits; /* least-significant 3 bits are flags,
+ the rest are reserved (see above) */
uint32_t reserved2;
} 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. */
- uint32_t data_bits; /* least-significant 2 bits are flags, the rest
- are reserved (see above) */
+ uint32_t data_bits; /* least-significant 2 bits are flags,
+ 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,
} VHDXVirtualDiskSize;
typedef struct QEMU_PACKED VHDXPage83Data {
- MSGUID page_83_data[16]; /* unique id for scsi devices that
+ MSGUID page_83_data; /* unique id for scsi devices that
support page 0x83 */
} VHDXPage83Data;
} VHDXVirtualDiskPhysicalSectorSize;
typedef struct QEMU_PACKED VHDXParentLocatorHeader {
- MSGUID locator_type[16]; /* type of the parent virtual disk. */
+ MSGUID locator_type; /* type of the parent virtual disk. */
uint16_t reserved;
uint16_t key_value_count; /* number of key/value pairs for this
locator */
/* ----- END VHDX SPECIFICATION STRUCTURES ---- */
+typedef struct VHDXMetadataEntries {
+ VHDXMetadataTableEntry file_parameters_entry;
+ VHDXMetadataTableEntry virtual_disk_size_entry;
+ VHDXMetadataTableEntry page83_data_entry;
+ VHDXMetadataTableEntry logical_sector_size_entry;
+ VHDXMetadataTableEntry phys_sector_size_entry;
+ VHDXMetadataTableEntry parent_locator_entry;
+ uint16_t present;
+} VHDXMetadataEntries;
+
+typedef struct VHDXLogEntries {
+ uint64_t offset;
+ uint64_t length;
+ uint32_t write;
+ uint32_t read;
+ VHDXLogEntryHeader *hdr;
+ void *desc_buffer;
+ uint64_t sequence;
+ uint32_t tail;
+} VHDXLogEntries;
+
+typedef struct VHDXRegionEntry {
+ uint64_t start;
+ uint64_t end;
+ QLIST_ENTRY(VHDXRegionEntry) entries;
+} VHDXRegionEntry;
+
+typedef struct BDRVVHDXState {
+ CoMutex lock;
+
+ int curr_header;
+ VHDXHeader *headers[2];
+
+ VHDXRegionTableHeader rt;
+ VHDXRegionTableEntry bat_rt; /* region table for the BAT */
+ VHDXRegionTableEntry metadata_rt; /* region table for the metadata */
+
+ VHDXMetadataTableHeader metadata_hdr;
+ VHDXMetadataEntries metadata_entries;
+
+ VHDXFileParameters params;
+ uint32_t block_size;
+ uint32_t block_size_bits;
+ uint32_t sectors_per_block;
+ uint32_t sectors_per_block_bits;
+
+ uint64_t virtual_disk_size;
+ uint32_t logical_sector_size;
+ uint32_t physical_sector_size;
+
+ uint64_t chunk_ratio;
+ uint32_t chunk_ratio_bits;
+ uint32_t logical_sector_size_bits;
+
+ uint32_t bat_entries;
+ VHDXBatEntry *bat;
+ uint64_t bat_offset;
+ bool first_visible_write;
+ MSGUID session_guid;
+
+ VHDXLogEntries log;
+
+ VHDXParentLocatorHeader parent_header;
+ VHDXParentLocatorEntry *parent_entries;
+
+ Error *migration_blocker;
+
+ bool log_replayed_on_open;
+
+ QLIST_HEAD(, VHDXRegionEntry) regions;
+} BDRVVHDXState;
+
+void vhdx_guid_generate(MSGUID *guid);
+
+int vhdx_update_headers(BlockDriverState *bs, BDRVVHDXState *s, bool rw,
+ MSGUID *log_guid);
+
+uint32_t vhdx_update_checksum(uint8_t *buf, size_t size, int crc_offset);
uint32_t vhdx_checksum_calc(uint32_t crc, uint8_t *buf, size_t size,
int crc_offset);
bool vhdx_checksum_is_valid(uint8_t *buf, size_t size, int crc_offset);
+int vhdx_parse_log(BlockDriverState *bs, BDRVVHDXState *s, bool *flushed,
+ Error **errp);
+
+int vhdx_log_write_and_flush(BlockDriverState *bs, BDRVVHDXState *s,
+ void *data, uint32_t length, uint64_t offset);
+
+static inline void leguid_to_cpus(MSGUID *guid)
+{
+ guid->data1 = le32_to_cpu(guid->data1);
+ guid->data2 = le16_to_cpu(guid->data2);
+ guid->data3 = le16_to_cpu(guid->data3);
+}
-static void leguid_to_cpus(MSGUID *guid)
+static inline void cpu_to_leguids(MSGUID *guid)
{
- le32_to_cpus(&guid->data1);
- le16_to_cpus(&guid->data2);
- le16_to_cpus(&guid->data3);
+ guid->data1 = cpu_to_le32(guid->data1);
+ guid->data2 = cpu_to_le16(guid->data2);
+ guid->data3 = cpu_to_le16(guid->data3);
}
+void vhdx_header_le_import(VHDXHeader *h);
+void vhdx_header_le_export(VHDXHeader *orig_h, VHDXHeader *new_h);
+void vhdx_log_desc_le_import(VHDXLogDescriptor *d);
+void vhdx_log_desc_le_export(VHDXLogDescriptor *d);
+void vhdx_log_data_le_import(VHDXLogDataSector *d);
+void vhdx_log_data_le_export(VHDXLogDataSector *d);
+void vhdx_log_entry_hdr_le_import(VHDXLogEntryHeader *hdr);
+void vhdx_log_entry_hdr_le_export(VHDXLogEntryHeader *hdr);
+void vhdx_region_header_le_import(VHDXRegionTableHeader *hdr);
+void vhdx_region_header_le_export(VHDXRegionTableHeader *hdr);
+void vhdx_region_entry_le_import(VHDXRegionTableEntry *e);
+void vhdx_region_entry_le_export(VHDXRegionTableEntry *e);
+void vhdx_metadata_header_le_import(VHDXMetadataTableHeader *hdr);
+void vhdx_metadata_header_le_export(VHDXMetadataTableHeader *hdr);
+void vhdx_metadata_entry_le_import(VHDXMetadataTableEntry *e);
+void vhdx_metadata_entry_le_export(VHDXMetadataTableEntry *e);
+int vhdx_user_visible_write(BlockDriverState *bs, BDRVVHDXState *s);
+
#endif
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