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/* Copyright (c) 2008, XenSource Inc.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of XenSource Inc. nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
* PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
* LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef __VHD_H__
#define __VHD_H__
#include <inttypes.h>
typedef uint32_t u32;
typedef uint64_t u64;
#define DEBUG 1
/* ---------------------------------------------------------------------- */
/* General definitions. */
/* ---------------------------------------------------------------------- */
#define VHD_SECTOR_SIZE 512
#define VHD_SECTOR_SHIFT 9
/* ---------------------------------------------------------------------- */
/* This is the generic disk footer, used by all disks. */
/* ---------------------------------------------------------------------- */
struct hd_ftr {
char cookie[8]; /* Identifies original creator of the disk */
u32 features; /* Feature Support -- see below */
u32 ff_version; /* (major,minor) version of disk file */
u64 data_offset; /* Abs. offset from SOF to next structure */
u32 timestamp; /* Creation time. secs since 1/1/2000GMT */
char crtr_app[4]; /* Creator application */
u32 crtr_ver; /* Creator version (major,minor) */
u32 crtr_os; /* Creator host OS */
u64 orig_size; /* Size at creation (bytes) */
u64 curr_size; /* Current size of disk (bytes) */
u32 geometry; /* Disk geometry */
u32 type; /* Disk type */
u32 checksum; /* 1's comp sum of this struct. */
blk_uuid_t uuid; /* Unique disk ID, used for naming parents */
char saved; /* one-bit -- is this disk/VM in a saved state? */
char hidden; /* tapdisk-specific field: is this vdi hidden? */
char reserved[426]; /* padding */
};
/* VHD cookie string. */
static const char HD_COOKIE[9] = "conectix";
/* Feature fields in hd_ftr */
#define HD_NO_FEATURES 0x00000000
#define HD_TEMPORARY 0x00000001 /* disk can be deleted on shutdown */
#define HD_RESERVED 0x00000002 /* NOTE: must always be set */
/* Version field in hd_ftr */
#define HD_FF_VERSION 0x00010000
/* Known creator OS type fields in hd_ftr.crtr_os */
#define HD_CR_OS_WINDOWS 0x5769326B /* (Wi2k) */
#define HD_CR_OS_MACINTOSH 0x4D616320 /* (Mac ) */
/*
* version 0.1: little endian bitmaps
* version 1.1: big endian bitmaps; batmap
* version 1.2: libvhd
* version 1.3: batmap version bump to 1.2
*/
#define VHD_VERSION(major, minor) (((major) << 16) | ((minor) & 0x0000FFFF))
#define VHD_CURRENT_VERSION VHD_VERSION(1, 3)
/* Disk geometry accessor macros. */
/* Geometry is a triple of (cylinders (2 bytes), tracks (1 byte), and
* secotrs-per-track (1 byte))
*/
#define GEOM_GET_CYLS(_g) (((_g) >> 16) & 0xffff)
#define GEOM_GET_HEADS(_g) (((_g) >> 8) & 0xff)
#define GEOM_GET_SPT(_g) ((_g) & 0xff)
#define GEOM_ENCODE(_c, _h, _s) (((_c) << 16) | ((_h) << 8) | (_s))
/* type field in hd_ftr */
#define HD_TYPE_NONE 0
#define HD_TYPE_FIXED 2 /* fixed-allocation disk */
#define HD_TYPE_DYNAMIC 3 /* dynamic disk */
#define HD_TYPE_DIFF 4 /* differencing disk */
/* String table for hd.type */
static const char *HD_TYPE_STR[7] = {
"None", /* 0 */
"Reserved (deprecated)", /* 1 */
"Fixed hard disk", /* 2 */
"Dynamic hard disk", /* 3 */
"Differencing hard disk", /* 4 */
"Reserved (deprecated)", /* 5 */
"Reserved (deprecated)" /* 6 */
};
#define HD_TYPE_MAX 6
struct prt_loc {
u32 code; /* Platform code -- see defines below. */
u32 data_space; /* Number of 512-byte sectors to store locator */
u32 data_len; /* Actual length of parent locator in bytes */
u32 res; /* Must be zero */
u64 data_offset; /* Absolute offset of locator data (bytes) */
};
/* Platform Codes */
#define PLAT_CODE_NONE 0x0
#define PLAT_CODE_WI2R 0x57693272 /* deprecated */
#define PLAT_CODE_WI2K 0x5769326B /* deprecated */
#define PLAT_CODE_W2RU 0x57327275 /* Windows relative path (UTF-16) */
#define PLAT_CODE_W2KU 0x57326B75 /* Windows absolute path (UTF-16) */
#define PLAT_CODE_MAC 0x4D616320 /* MacOS alias stored as a blob. */
#define PLAT_CODE_MACX 0x4D616358 /* File URL (UTF-8), see RFC 2396. */
/* ---------------------------------------------------------------------- */
/* This is the dynamic disk header. */
/* ---------------------------------------------------------------------- */
struct dd_hdr {
char cookie[8]; /* Should contain "cxsparse" */
u64 data_offset; /* Byte offset of next record. (Unused) 0xffs */
u64 table_offset; /* Absolute offset to the BAT. */
u32 hdr_ver; /* Version of the dd_hdr (major,minor) */
u32 max_bat_size; /* Maximum number of entries in the BAT */
u32 block_size; /* Block size in bytes. Must be power of 2. */
u32 checksum; /* Header checksum. 1's comp of all fields. */
blk_uuid_t prt_uuid; /* ID of the parent disk. */
u32 prt_ts; /* Modification time of the parent disk */
u32 res1; /* Reserved. */
char prt_name[512]; /* Parent unicode name. */
struct prt_loc loc[8]; /* Parent locator entries. */
char res2[256]; /* Reserved. */
};
/* VHD cookie string. */
static const char DD_COOKIE[9] = "cxsparse";
/* Version field in hd_ftr */
#define DD_VERSION 0x00010000
/* Default blocksize is 2 meg. */
#define DD_BLOCKSIZE_DEFAULT 0x00200000
#define DD_BLK_UNUSED 0xFFFFFFFF
struct dd_batmap_hdr {
char cookie[8]; /* should contain "tdbatmap" */
u64 batmap_offset; /* byte offset to batmap */
u32 batmap_size; /* batmap size in sectors */
u32 batmap_version; /* version of batmap */
u32 checksum; /* batmap checksum -- 1's complement of batmap */
};
static const char VHD_BATMAP_COOKIE[9] = "tdbatmap";
/*
* version 1.1: signed char checksum
*/
#define VHD_BATMAP_VERSION(major, minor) (((major) << 16) | ((minor) & 0x0000FFFF))
#define VHD_BATMAP_CURRENT_VERSION VHD_BATMAP_VERSION(1, 2)
/* Layout of a dynamic disk:
*
* +-------------------------------------------------+
* | Mirror image of HD footer (hd_ftr) (512 bytes) |
* +-------------------------------------------------+
* | Sparse drive header (dd_hdr) (1024 bytes) |
* +-------------------------------------------------+
* | BAT (Block allocation table) |
* | - Array of absolute sector offsets into the |
* | file (u32). |
* | - Rounded up to a sector boundary. |
* | - Unused entries are marked as 0xFFFFFFFF |
* | - max entries in dd_hdr->max_bat_size |
* +-------------------------------------------------+
* | Data Block 0 |
* | Bitmap (padded to 512 byte sector boundary) |
* | - each bit indicates whether the associated |
* | sector within this block is used. |
* | Data |
* | - power-of-two multiple of sectors. |
* | - default 2MB (4096 * 512) |
* | - Any entries with zero in bitmap should be |
* | zero on disk |
* +-------------------------------------------------+
* | Data Block 1 |
* +-------------------------------------------------+
* | ... |
* +-------------------------------------------------+
* | Data Block n |
* +-------------------------------------------------+
* | HD Footer (511 bytes) |
* +-------------------------------------------------+
*/
#endif
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