[qemu.git] / block / qcow2.h

/*
 * Block driver for the QCOW version 2 format
 *
 * Copyright (c) 2004-2006 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#ifndef BLOCK_QCOW2_H
#define BLOCK_QCOW2_H

#include "block/aes.h"
#include "block/coroutine.h"

//#define DEBUG_ALLOC
//#define DEBUG_ALLOC2
//#define DEBUG_EXT

#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)

#define QCOW_CRYPT_NONE 0
#define QCOW_CRYPT_AES  1

#define QCOW_MAX_CRYPT_CLUSTERS 32

/* indicate that the refcount of the referenced cluster is exactly one. */
#define QCOW_OFLAG_COPIED     (1LL << 63)
/* indicate that the cluster is compressed (they never have the copied flag) */
#define QCOW_OFLAG_COMPRESSED (1LL << 62)
/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1LL << 0)

#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */

#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21

#define L2_CACHE_SIZE 16

/* Must be at least 4 to cover all cases of refcount table growth */
#define REFCOUNT_CACHE_SIZE 4

#define DEFAULT_CLUSTER_SIZE 65536

typedef struct QCowHeader {
    uint32_t magic;
    uint32_t version;
    uint64_t backing_file_offset;
    uint32_t backing_file_size;
    uint32_t cluster_bits;
    uint64_t size; /* in bytes */
    uint32_t crypt_method;
    uint32_t l1_size; /* XXX: save number of clusters instead ? */
    uint64_t l1_table_offset;
    uint64_t refcount_table_offset;
    uint32_t refcount_table_clusters;
    uint32_t nb_snapshots;
    uint64_t snapshots_offset;

    /* The following fields are only valid for version >= 3 */
    uint64_t incompatible_features;
    uint64_t compatible_features;
    uint64_t autoclear_features;

    uint32_t refcount_order;
    uint32_t header_length;
} QCowHeader;

typedef struct QCowSnapshot {
    uint64_t l1_table_offset;
    uint32_t l1_size;
    char *id_str;
    char *name;
    uint64_t disk_size;
    uint64_t vm_state_size;
    uint32_t date_sec;
    uint32_t date_nsec;
    uint64_t vm_clock_nsec;
} QCowSnapshot;

struct Qcow2Cache;
typedef struct Qcow2Cache Qcow2Cache;

typedef struct Qcow2UnknownHeaderExtension {
    uint32_t magic;
    uint32_t len;
    QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
    uint8_t data[];
} Qcow2UnknownHeaderExtension;

enum {
    QCOW2_FEAT_TYPE_INCOMPATIBLE    = 0,
    QCOW2_FEAT_TYPE_COMPATIBLE      = 1,
    QCOW2_FEAT_TYPE_AUTOCLEAR       = 2,
};

/* Incompatible feature bits */
enum {
    QCOW2_INCOMPAT_DIRTY_BITNR   = 0,
    QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,

    QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY,
};

/* Compatible feature bits */
enum {
    QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
    QCOW2_COMPAT_LAZY_REFCOUNTS       = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,

    QCOW2_COMPAT_FEAT_MASK            = QCOW2_COMPAT_LAZY_REFCOUNTS,
};

typedef struct Qcow2Feature {
    uint8_t type;
    uint8_t bit;
    char    name[46];
} QEMU_PACKED Qcow2Feature;

typedef struct BDRVQcowState {
    int cluster_bits;
    int cluster_size;
    int cluster_sectors;
    int l2_bits;
    int l2_size;
    int l1_size;
    int l1_vm_state_index;
    int csize_shift;
    int csize_mask;
    uint64_t cluster_offset_mask;
    uint64_t l1_table_offset;
    uint64_t *l1_table;

    Qcow2Cache* l2_table_cache;
    Qcow2Cache* refcount_block_cache;

    uint8_t *cluster_cache;
    uint8_t *cluster_data;
    uint64_t cluster_cache_offset;
    QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;

    uint64_t *refcount_table;
    uint64_t refcount_table_offset;
    uint32_t refcount_table_size;
    int64_t free_cluster_index;
    int64_t free_byte_offset;

    CoMutex lock;

    uint32_t crypt_method; /* current crypt method, 0 if no key yet */
    uint32_t crypt_method_header;
    AES_KEY aes_encrypt_key;
    AES_KEY aes_decrypt_key;
    uint64_t snapshots_offset;
    int snapshots_size;
    int nb_snapshots;
    QCowSnapshot *snapshots;

    int flags;
    int qcow_version;

    uint64_t incompatible_features;
    uint64_t compatible_features;
    uint64_t autoclear_features;

    size_t unknown_header_fields_size;
    void* unknown_header_fields;
    QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
} BDRVQcowState;

/* XXX: use std qcow open function ? */
typedef struct QCowCreateState {
    int cluster_size;
    int cluster_bits;
    uint16_t *refcount_block;
    uint64_t *refcount_table;
    int64_t l1_table_offset;
    int64_t refcount_table_offset;
    int64_t refcount_block_offset;
} QCowCreateState;

struct QCowAIOCB;

typedef struct Qcow2COWRegion {
    /**
     * Offset of the COW region in bytes from the start of the first cluster
     * touched by the request.
     */
    uint64_t    offset;

    /** Number of sectors to copy */
    int         nb_sectors;
} Qcow2COWRegion;

/**
 * Describes an in-flight (part of a) write request that writes to clusters
 * that are not referenced in their L2 table yet.
 */
typedef struct QCowL2Meta
{
    /** Guest offset of the first newly allocated cluster */
    uint64_t offset;

    /** Host offset of the first newly allocated cluster */
    uint64_t alloc_offset;

    /**
     * Number of sectors from the start of the first allocated cluster to
     * the end of the (possibly shortened) request
     */
    int nb_available;

    /** Number of newly allocated clusters */
    int nb_clusters;

    /**
     * Requests that overlap with this allocation and wait to be restarted
     * when the allocating request has completed.
     */
    CoQueue dependent_requests;

    /**
     * The COW Region between the start of the first allocated cluster and the
     * area the guest actually writes to.
     */
    Qcow2COWRegion cow_start;

    /**
     * The COW Region between the area the guest actually writes to and the
     * end of the last allocated cluster.
     */
    Qcow2COWRegion cow_end;

    QLIST_ENTRY(QCowL2Meta) next_in_flight;
} QCowL2Meta;

enum {
    QCOW2_CLUSTER_UNALLOCATED,
    QCOW2_CLUSTER_NORMAL,
    QCOW2_CLUSTER_COMPRESSED,
    QCOW2_CLUSTER_ZERO
};

#define L1E_OFFSET_MASK 0x00ffffffffffff00ULL
#define L2E_OFFSET_MASK 0x00ffffffffffff00ULL
#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL

#define REFT_OFFSET_MASK 0xffffffffffffff00ULL

static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
{
    return (size + (s->cluster_size - 1)) >> s->cluster_bits;
}

static inline int size_to_l1(BDRVQcowState *s, int64_t size)
{
    int shift = s->cluster_bits + s->l2_bits;
    return (size + (1ULL << shift) - 1) >> shift;
}

static inline int64_t align_offset(int64_t offset, int n)
{
    offset = (offset + n - 1) & ~(n - 1);
    return offset;
}

static inline int qcow2_get_cluster_type(uint64_t l2_entry)
{
    if (l2_entry & QCOW_OFLAG_COMPRESSED) {
        return QCOW2_CLUSTER_COMPRESSED;
    } else if (l2_entry & QCOW_OFLAG_ZERO) {
        return QCOW2_CLUSTER_ZERO;
    } else if (!(l2_entry & L2E_OFFSET_MASK)) {
        return QCOW2_CLUSTER_UNALLOCATED;
    } else {
        return QCOW2_CLUSTER_NORMAL;
    }
}

/* Check whether refcounts are eager or lazy */
static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
{
    return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
}

// FIXME Need qcow2_ prefix to global functions

/* qcow2.c functions */
int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov,
                  int64_t sector_num, int nb_sectors);

int qcow2_mark_dirty(BlockDriverState *bs);
int qcow2_update_header(BlockDriverState *bs);

/* qcow2-refcount.c functions */
int qcow2_refcount_init(BlockDriverState *bs);
void qcow2_refcount_close(BlockDriverState *bs);

int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
    int nb_clusters);
int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
void qcow2_free_clusters(BlockDriverState *bs,
    int64_t offset, int64_t size);
void qcow2_free_any_clusters(BlockDriverState *bs,
    uint64_t cluster_offset, int nb_clusters);

int qcow2_update_snapshot_refcount(BlockDriverState *bs,
    int64_t l1_table_offset, int l1_size, int addend);

int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res,
                          BdrvCheckMode fix);

/* qcow2-cluster.c functions */
int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size);
void qcow2_l2_cache_reset(BlockDriverState *bs);
int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
                     uint8_t *out_buf, const uint8_t *in_buf,
                     int nb_sectors, int enc,
                     const AES_KEY *key);

int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
    int *num, uint64_t *cluster_offset);
int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
    int n_start, int n_end, int *num, uint64_t *host_offset, QCowL2Meta **m);
uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
                                         uint64_t offset,
                                         int compressed_size);

int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
    int nb_sectors);
int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);

/* qcow2-snapshot.c functions */
int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name);

void qcow2_free_snapshots(BlockDriverState *bs);
int qcow2_read_snapshots(BlockDriverState *bs);

/* qcow2-cache.c functions */
Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables);
int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);

void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table);
int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c);
int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c,
    Qcow2Cache *dependency);
void qcow2_cache_depends_on_flush(Qcow2Cache *c);

int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
    void **table);
int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset,
    void **table);
int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table);

#endif
Commit	Line	Data
f7d0fe02 KW	1	/*
	2	* Block driver for the QCOW version 2 format
	3	*
	4	* Copyright (c) 2004-2006 Fabrice Bellard
	5	*
	6	* Permission is hereby granted, free of charge, to any person obtaining a copy
	7	* of this software and associated documentation files (the "Software"), to deal
	8	* in the Software without restriction, including without limitation the rights
	9	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	10	* copies of the Software, and to permit persons to whom the Software is
	11	* furnished to do so, subject to the following conditions:
	12	*
	13	* The above copyright notice and this permission notice shall be included in
	14	* all copies or substantial portions of the Software.
	15	*
	16	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	17	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	18	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	19	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	20	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	21	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	22	* THE SOFTWARE.
	23	*/
	24
	25	#ifndef BLOCK_QCOW2_H
	26	#define BLOCK_QCOW2_H
	27
737e150e PB	28	#include "block/aes.h"
737e150e PB	29	#include "block/coroutine.h"
f7d0fe02	30
14899cdf FN	31	//#define DEBUG_ALLOC
	32	//#define DEBUG_ALLOC2
	33	//#define DEBUG_EXT
	34
f7d0fe02	35	#define QCOW_MAGIC (('Q' << 24) \| ('F' << 16) \| ('I' << 8) \| 0xfb)
f7d0fe02 KW	36
	37	#define QCOW_CRYPT_NONE 0
	38	#define QCOW_CRYPT_AES 1
	39
	40	#define QCOW_MAX_CRYPT_CLUSTERS 32
	41
	42	/* indicate that the refcount of the referenced cluster is exactly one. */
	43	#define QCOW_OFLAG_COPIED (1LL << 63)
	44	/* indicate that the cluster is compressed (they never have the copied flag) */
	45	#define QCOW_OFLAG_COMPRESSED (1LL << 62)
6377af48 KW	46	/* The cluster reads as all zeros */
6377af48 KW	47	#define QCOW_OFLAG_ZERO (1LL << 0)
f7d0fe02 KW	48
	49	#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
	50
	51	#define MIN_CLUSTER_BITS 9
80ee15a6	52	#define MAX_CLUSTER_BITS 21
f7d0fe02 KW	53
	54	#define L2_CACHE_SIZE 16
	55
29c1a730 KW	56	/* Must be at least 4 to cover all cases of refcount table growth */
	57	#define REFCOUNT_CACHE_SIZE 4
	58
99cce9fa KW	59	#define DEFAULT_CLUSTER_SIZE 65536
99cce9fa KW	60
f7d0fe02 KW	61	typedef struct QCowHeader {
	62	uint32_t magic;
	63	uint32_t version;
	64	uint64_t backing_file_offset;
	65	uint32_t backing_file_size;
	66	uint32_t cluster_bits;
	67	uint64_t size; /* in bytes */
	68	uint32_t crypt_method;
	69	uint32_t l1_size; /* XXX: save number of clusters instead ? */
	70	uint64_t l1_table_offset;
	71	uint64_t refcount_table_offset;
	72	uint32_t refcount_table_clusters;
	73	uint32_t nb_snapshots;
	74	uint64_t snapshots_offset;
6744cbab KW	75
	76	/* The following fields are only valid for version >= 3 */
	77	uint64_t incompatible_features;
	78	uint64_t compatible_features;
	79	uint64_t autoclear_features;
	80
	81	uint32_t refcount_order;
	82	uint32_t header_length;
f7d0fe02 KW	83	} QCowHeader;
	84
	85	typedef struct QCowSnapshot {
	86	uint64_t l1_table_offset;
	87	uint32_t l1_size;
	88	char *id_str;
	89	char *name;
90b27759	90	uint64_t disk_size;
c2c9a466	91	uint64_t vm_state_size;
f7d0fe02 KW	92	uint32_t date_sec;
	93	uint32_t date_nsec;
	94	uint64_t vm_clock_nsec;
	95	} QCowSnapshot;
	96
49381094 KW	97	struct Qcow2Cache;
	98	typedef struct Qcow2Cache Qcow2Cache;
	99
75bab85c KW	100	typedef struct Qcow2UnknownHeaderExtension {
	101	uint32_t magic;
	102	uint32_t len;
	103	QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
	104	uint8_t data[];
	105	} Qcow2UnknownHeaderExtension;
	106
cfcc4c62 KW	107	enum {
	108	QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
	109	QCOW2_FEAT_TYPE_COMPATIBLE = 1,
	110	QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
	111	};
	112
c61d0004 SH	113	/* Incompatible feature bits */
	114	enum {
	115	QCOW2_INCOMPAT_DIRTY_BITNR = 0,
	116	QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
	117
	118	QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY,
	119	};
	120
bfe8043e SH	121	/* Compatible feature bits */
	122	enum {
	123	QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
	124	QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
	125
	126	QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
	127	};
	128
cfcc4c62 KW	129	typedef struct Qcow2Feature {
	130	uint8_t type;
	131	uint8_t bit;
	132	char name[46];
	133	} QEMU_PACKED Qcow2Feature;
	134
f7d0fe02	135	typedef struct BDRVQcowState {
f7d0fe02 KW	136	int cluster_bits;
	137	int cluster_size;
	138	int cluster_sectors;
	139	int l2_bits;
	140	int l2_size;
	141	int l1_size;
	142	int l1_vm_state_index;
	143	int csize_shift;
	144	int csize_mask;
	145	uint64_t cluster_offset_mask;
	146	uint64_t l1_table_offset;
	147	uint64_t *l1_table;
29c1a730 KW	148
	149	Qcow2Cache* l2_table_cache;
	150	Qcow2Cache* refcount_block_cache;
	151
f7d0fe02 KW	152	uint8_t *cluster_cache;
	153	uint8_t *cluster_data;
	154	uint64_t cluster_cache_offset;
72cf2d4f	155	QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
f7d0fe02 KW	156
	157	uint64_t *refcount_table;
	158	uint64_t refcount_table_offset;
	159	uint32_t refcount_table_size;
f7d0fe02 KW	160	int64_t free_cluster_index;
	161	int64_t free_byte_offset;
	162
68d100e9 KW	163	CoMutex lock;
68d100e9 KW	164
f7d0fe02 KW	165	uint32_t crypt_method; /* current crypt method, 0 if no key yet */
	166	uint32_t crypt_method_header;
	167	AES_KEY aes_encrypt_key;
	168	AES_KEY aes_decrypt_key;
	169	uint64_t snapshots_offset;
	170	int snapshots_size;
	171	int nb_snapshots;
	172	QCowSnapshot *snapshots;
06d9260f AL	173
06d9260f AL	174	int flags;
6744cbab KW	175	int qcow_version;
	176
	177	uint64_t incompatible_features;
	178	uint64_t compatible_features;
	179	uint64_t autoclear_features;
	180
	181	size_t unknown_header_fields_size;
	182	void* unknown_header_fields;
75bab85c	183	QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
f7d0fe02 KW	184	} BDRVQcowState;
	185
	186	/* XXX: use std qcow open function ? */
	187	typedef struct QCowCreateState {
	188	int cluster_size;
	189	int cluster_bits;
	190	uint16_t *refcount_block;
	191	uint64_t *refcount_table;
	192	int64_t l1_table_offset;
	193	int64_t refcount_table_offset;
	194	int64_t refcount_block_offset;
	195	} QCowCreateState;
	196
f214978a KW	197	struct QCowAIOCB;
f214978a KW	198
593fb83c KW	199	typedef struct Qcow2COWRegion {
	200	/**
	201	* Offset of the COW region in bytes from the start of the first cluster
	202	* touched by the request.
	203	*/
	204	uint64_t offset;
	205
	206	/** Number of sectors to copy */
	207	int nb_sectors;
	208	} Qcow2COWRegion;
	209
f50f88b9 KW	210	/**
	211	* Describes an in-flight (part of a) write request that writes to clusters
	212	* that are not referenced in their L2 table yet.
	213	*/
45aba42f KW	214	typedef struct QCowL2Meta
45aba42f KW	215	{
1d3afd64	216	/** Guest offset of the first newly allocated cluster */
45aba42f	217	uint64_t offset;
1d3afd64	218
1d3afd64	219	/** Host offset of the first newly allocated cluster */
250196f1	220	uint64_t alloc_offset;
1d3afd64	221
1d3afd64 KW	222	/**
	223	* Number of sectors from the start of the first allocated cluster to
	224	* the end of the (possibly shortened) request
	225	*/
45aba42f	226	int nb_available;
1d3afd64 KW	227
1d3afd64 KW	228	/** Number of newly allocated clusters */
45aba42f	229	int nb_clusters;
1d3afd64 KW	230
	231	/**
	232	* Requests that overlap with this allocation and wait to be restarted
	233	* when the allocating request has completed.
	234	*/
68d100e9	235	CoQueue dependent_requests;
f214978a	236
593fb83c KW	237	/**
	238	* The COW Region between the start of the first allocated cluster and the
	239	* area the guest actually writes to.
	240	*/
	241	Qcow2COWRegion cow_start;
	242
	243	/**
	244	* The COW Region between the area the guest actually writes to and the
	245	* end of the last allocated cluster.
	246	*/
	247	Qcow2COWRegion cow_end;
	248
72cf2d4f	249	QLIST_ENTRY(QCowL2Meta) next_in_flight;
45aba42f KW	250	} QCowL2Meta;
45aba42f KW	251
68d000a3 KW	252	enum {
	253	QCOW2_CLUSTER_UNALLOCATED,
	254	QCOW2_CLUSTER_NORMAL,
	255	QCOW2_CLUSTER_COMPRESSED,
6377af48	256	QCOW2_CLUSTER_ZERO
68d000a3 KW	257	};
	258
	259	#define L1E_OFFSET_MASK 0x00ffffffffffff00ULL
	260	#define L2E_OFFSET_MASK 0x00ffffffffffff00ULL
	261	#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
	262
76dc9e0c KW	263	#define REFT_OFFSET_MASK 0xffffffffffffff00ULL
76dc9e0c KW	264
45aba42f	265	static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
f7d0fe02 KW	266	{
	267	return (size + (s->cluster_size - 1)) >> s->cluster_bits;
	268	}
	269
419b19d9 SH	270	static inline int size_to_l1(BDRVQcowState *s, int64_t size)
	271	{
	272	int shift = s->cluster_bits + s->l2_bits;
	273	return (size + (1ULL << shift) - 1) >> shift;
	274	}
	275
c142442b KW	276	static inline int64_t align_offset(int64_t offset, int n)
	277	{
	278	offset = (offset + n - 1) & ~(n - 1);
	279	return offset;
	280	}
	281
68d000a3 KW	282	static inline int qcow2_get_cluster_type(uint64_t l2_entry)
	283	{
	284	if (l2_entry & QCOW_OFLAG_COMPRESSED) {
	285	return QCOW2_CLUSTER_COMPRESSED;
6377af48 KW	286	} else if (l2_entry & QCOW_OFLAG_ZERO) {
6377af48 KW	287	return QCOW2_CLUSTER_ZERO;
68d000a3 KW	288	} else if (!(l2_entry & L2E_OFFSET_MASK)) {
	289	return QCOW2_CLUSTER_UNALLOCATED;
	290	} else {
	291	return QCOW2_CLUSTER_NORMAL;
	292	}
	293	}
	294
bfe8043e SH	295	/* Check whether refcounts are eager or lazy */
	296	static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
	297	{
	298	return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
	299	}
c142442b	300
f7d0fe02 KW	301	// FIXME Need qcow2_ prefix to global functions
	302
	303	/* qcow2.c functions */
bd28f835 KW	304	int qcow2_backing_read1(BlockDriverState bs, QEMUIOVector qiov,
bd28f835 KW	305	int64_t sector_num, int nb_sectors);
280d3735 KW	306
280d3735 KW	307	int qcow2_mark_dirty(BlockDriverState *bs);
e24e49e6	308	int qcow2_update_header(BlockDriverState *bs);
f7d0fe02 KW	309
f7d0fe02 KW	310	/* qcow2-refcount.c functions */
ed6ccf0f KW	311	int qcow2_refcount_init(BlockDriverState *bs);
ed6ccf0f KW	312	void qcow2_refcount_close(BlockDriverState *bs);
f7d0fe02	313
ed6ccf0f	314	int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
256900b1 KW	315	int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
256900b1 KW	316	int nb_clusters);
ed6ccf0f KW	317	int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
ed6ccf0f KW	318	void qcow2_free_clusters(BlockDriverState *bs,
45aba42f	319	int64_t offset, int64_t size);
ed6ccf0f	320	void qcow2_free_any_clusters(BlockDriverState *bs,
45aba42f	321	uint64_t cluster_offset, int nb_clusters);
f7d0fe02	322
ed6ccf0f KW	323	int qcow2_update_snapshot_refcount(BlockDriverState *bs,
ed6ccf0f KW	324	int64_t l1_table_offset, int l1_size, int addend);
f7d0fe02	325
166acf54 KW	326	int qcow2_check_refcounts(BlockDriverState bs, BdrvCheckResult res,
166acf54 KW	327	BdrvCheckMode fix);
f7d0fe02	328
45aba42f	329	/* qcow2-cluster.c functions */
72893756	330	int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size);
ed6ccf0f	331	void qcow2_l2_cache_reset(BlockDriverState *bs);
66f82cee	332	int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
ed6ccf0f	333	void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
45aba42f KW	334	uint8_t out_buf, const uint8_t in_buf,
	335	int nb_sectors, int enc,
	336	const AES_KEY *key);
	337
1c46efaa KW	338	int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
1c46efaa KW	339	int num, uint64_t cluster_offset);
f4f0d391	340	int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
f50f88b9	341	int n_start, int n_end, int num, uint64_t host_offset, QCowL2Meta **m);
ed6ccf0f	342	uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
45aba42f KW	343	uint64_t offset,
	344	int compressed_size);
	345
148da7ea	346	int qcow2_alloc_cluster_link_l2(BlockDriverState bs, QCowL2Meta m);
5ea929e3 KW	347	int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
5ea929e3 KW	348	int nb_sectors);
621f0589	349	int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
45aba42f	350
c142442b	351	/* qcow2-snapshot.c functions */
ed6ccf0f KW	352	int qcow2_snapshot_create(BlockDriverState bs, QEMUSnapshotInfo sn_info);
	353	int qcow2_snapshot_goto(BlockDriverState bs, const char snapshot_id);
	354	int qcow2_snapshot_delete(BlockDriverState bs, const char snapshot_id);
	355	int qcow2_snapshot_list(BlockDriverState bs, QEMUSnapshotInfo *psn_tab);
51ef6727	356	int qcow2_snapshot_load_tmp(BlockDriverState bs, const char snapshot_name);
c142442b	357
ed6ccf0f KW	358	void qcow2_free_snapshots(BlockDriverState *bs);
ed6ccf0f KW	359	int qcow2_read_snapshots(BlockDriverState *bs);
c142442b	360
49381094	361	/* qcow2-cache.c functions */
6af4e9ea	362	Qcow2Cache qcow2_cache_create(BlockDriverState bs, int num_tables);
49381094 KW	363	int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
	364
	365	void qcow2_cache_entry_mark_dirty(Qcow2Cache c, void table);
	366	int qcow2_cache_flush(BlockDriverState bs, Qcow2Cache c);
	367	int qcow2_cache_set_dependency(BlockDriverState bs, Qcow2Cache c,
	368	Qcow2Cache *dependency);
3de0a294	369	void qcow2_cache_depends_on_flush(Qcow2Cache *c);
49381094 KW	370
	371	int qcow2_cache_get(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	372	void **table);
	373	int qcow2_cache_get_empty(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	374	void **table);
	375	int qcow2_cache_put(BlockDriverState bs, Qcow2Cache c, void **table);
	376
f7d0fe02	377	#endif