[mirror_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


#define QCOW2_OPT_LAZY_REFCOUNTS "lazy_refcounts"

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;
    bool use_lazy_refcounts;

    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 int64_t start_of_cluster(BDRVQcowState *s, int64_t offset)
{
    return offset & ~(s->cluster_size - 1);
}

static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
{
    return offset & (s->cluster_size - 1);
}

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 int offset_to_l2_index(BDRVQcowState *s, int64_t offset)
{
    return (offset >> s->cluster_bits) & (s->l2_size - 1);
}

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);
}

static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
{
    return m->offset + m->cow_start.offset;
}

static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
{
    return m->offset + m->cow_end.offset
        + (m->cow_end.nb_sectors << BDRV_SECTOR_BITS);
}

// 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
acdfb480 KW	61
	62	#define QCOW2_OPT_LAZY_REFCOUNTS "lazy_refcounts"
	63
f7d0fe02 KW	64	typedef struct QCowHeader {
	65	uint32_t magic;
	66	uint32_t version;
	67	uint64_t backing_file_offset;
	68	uint32_t backing_file_size;
	69	uint32_t cluster_bits;
	70	uint64_t size; /* in bytes */
	71	uint32_t crypt_method;
	72	uint32_t l1_size; /* XXX: save number of clusters instead ? */
	73	uint64_t l1_table_offset;
	74	uint64_t refcount_table_offset;
	75	uint32_t refcount_table_clusters;
	76	uint32_t nb_snapshots;
	77	uint64_t snapshots_offset;
6744cbab KW	78
	79	/* The following fields are only valid for version >= 3 */
	80	uint64_t incompatible_features;
	81	uint64_t compatible_features;
	82	uint64_t autoclear_features;
	83
	84	uint32_t refcount_order;
	85	uint32_t header_length;
f7d0fe02 KW	86	} QCowHeader;
	87
	88	typedef struct QCowSnapshot {
	89	uint64_t l1_table_offset;
	90	uint32_t l1_size;
	91	char *id_str;
	92	char *name;
90b27759	93	uint64_t disk_size;
c2c9a466	94	uint64_t vm_state_size;
f7d0fe02 KW	95	uint32_t date_sec;
	96	uint32_t date_nsec;
	97	uint64_t vm_clock_nsec;
	98	} QCowSnapshot;
	99
49381094 KW	100	struct Qcow2Cache;
	101	typedef struct Qcow2Cache Qcow2Cache;
	102
75bab85c KW	103	typedef struct Qcow2UnknownHeaderExtension {
	104	uint32_t magic;
	105	uint32_t len;
	106	QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
	107	uint8_t data[];
	108	} Qcow2UnknownHeaderExtension;
	109
cfcc4c62 KW	110	enum {
	111	QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
	112	QCOW2_FEAT_TYPE_COMPATIBLE = 1,
	113	QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
	114	};
	115
c61d0004 SH	116	/* Incompatible feature bits */
	117	enum {
	118	QCOW2_INCOMPAT_DIRTY_BITNR = 0,
	119	QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
	120
	121	QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY,
	122	};
	123
bfe8043e SH	124	/* Compatible feature bits */
	125	enum {
	126	QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
	127	QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
	128
	129	QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
	130	};
	131
cfcc4c62 KW	132	typedef struct Qcow2Feature {
	133	uint8_t type;
	134	uint8_t bit;
	135	char name[46];
	136	} QEMU_PACKED Qcow2Feature;
	137
f7d0fe02	138	typedef struct BDRVQcowState {
f7d0fe02 KW	139	int cluster_bits;
	140	int cluster_size;
	141	int cluster_sectors;
	142	int l2_bits;
	143	int l2_size;
	144	int l1_size;
	145	int l1_vm_state_index;
	146	int csize_shift;
	147	int csize_mask;
	148	uint64_t cluster_offset_mask;
	149	uint64_t l1_table_offset;
	150	uint64_t *l1_table;
29c1a730 KW	151
	152	Qcow2Cache* l2_table_cache;
	153	Qcow2Cache* refcount_block_cache;
	154
f7d0fe02 KW	155	uint8_t *cluster_cache;
	156	uint8_t *cluster_data;
	157	uint64_t cluster_cache_offset;
72cf2d4f	158	QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
f7d0fe02 KW	159
	160	uint64_t *refcount_table;
	161	uint64_t refcount_table_offset;
	162	uint32_t refcount_table_size;
f7d0fe02 KW	163	int64_t free_cluster_index;
	164	int64_t free_byte_offset;
	165
68d100e9 KW	166	CoMutex lock;
68d100e9 KW	167
f7d0fe02 KW	168	uint32_t crypt_method; /* current crypt method, 0 if no key yet */
	169	uint32_t crypt_method_header;
	170	AES_KEY aes_encrypt_key;
	171	AES_KEY aes_decrypt_key;
	172	uint64_t snapshots_offset;
	173	int snapshots_size;
	174	int nb_snapshots;
	175	QCowSnapshot *snapshots;
06d9260f AL	176
06d9260f AL	177	int flags;
6744cbab	178	int qcow_version;
74c4510a	179	bool use_lazy_refcounts;
6744cbab KW	180
	181	uint64_t incompatible_features;
	182	uint64_t compatible_features;
	183	uint64_t autoclear_features;
	184
	185	size_t unknown_header_fields_size;
	186	void* unknown_header_fields;
75bab85c	187	QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
f7d0fe02 KW	188	} BDRVQcowState;
	189
	190	/* XXX: use std qcow open function ? */
	191	typedef struct QCowCreateState {
	192	int cluster_size;
	193	int cluster_bits;
	194	uint16_t *refcount_block;
	195	uint64_t *refcount_table;
	196	int64_t l1_table_offset;
	197	int64_t refcount_table_offset;
	198	int64_t refcount_block_offset;
	199	} QCowCreateState;
	200
f214978a KW	201	struct QCowAIOCB;
f214978a KW	202
593fb83c KW	203	typedef struct Qcow2COWRegion {
	204	/**
	205	* Offset of the COW region in bytes from the start of the first cluster
	206	* touched by the request.
	207	*/
	208	uint64_t offset;
	209
	210	/** Number of sectors to copy */
	211	int nb_sectors;
	212	} Qcow2COWRegion;
	213
f50f88b9 KW	214	/**
	215	* Describes an in-flight (part of a) write request that writes to clusters
	216	* that are not referenced in their L2 table yet.
	217	*/
45aba42f KW	218	typedef struct QCowL2Meta
45aba42f KW	219	{
1d3afd64	220	/** Guest offset of the first newly allocated cluster */
45aba42f	221	uint64_t offset;
1d3afd64	222
1d3afd64	223	/** Host offset of the first newly allocated cluster */
250196f1	224	uint64_t alloc_offset;
1d3afd64	225
1d3afd64 KW	226	/**
	227	* Number of sectors from the start of the first allocated cluster to
	228	* the end of the (possibly shortened) request
	229	*/
45aba42f	230	int nb_available;
1d3afd64 KW	231
1d3afd64 KW	232	/** Number of newly allocated clusters */
45aba42f	233	int nb_clusters;
1d3afd64 KW	234
	235	/**
	236	* Requests that overlap with this allocation and wait to be restarted
	237	* when the allocating request has completed.
	238	*/
68d100e9	239	CoQueue dependent_requests;
f214978a	240
593fb83c KW	241	/**
	242	* The COW Region between the start of the first allocated cluster and the
	243	* area the guest actually writes to.
	244	*/
	245	Qcow2COWRegion cow_start;
	246
	247	/**
	248	* The COW Region between the area the guest actually writes to and the
	249	* end of the last allocated cluster.
	250	*/
	251	Qcow2COWRegion cow_end;
	252
72cf2d4f	253	QLIST_ENTRY(QCowL2Meta) next_in_flight;
45aba42f KW	254	} QCowL2Meta;
45aba42f KW	255
68d000a3 KW	256	enum {
	257	QCOW2_CLUSTER_UNALLOCATED,
	258	QCOW2_CLUSTER_NORMAL,
	259	QCOW2_CLUSTER_COMPRESSED,
6377af48	260	QCOW2_CLUSTER_ZERO
68d000a3 KW	261	};
	262
	263	#define L1E_OFFSET_MASK 0x00ffffffffffff00ULL
	264	#define L2E_OFFSET_MASK 0x00ffffffffffff00ULL
	265	#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
	266
76dc9e0c KW	267	#define REFT_OFFSET_MASK 0xffffffffffffff00ULL
76dc9e0c KW	268
3b8e2e26 KW	269	static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset)
	270	{
	271	return offset & ~(s->cluster_size - 1);
	272	}
	273
c37f4cd7 KW	274	static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
	275	{
	276	return offset & (s->cluster_size - 1);
	277	}
	278
45aba42f	279	static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
f7d0fe02 KW	280	{
	281	return (size + (s->cluster_size - 1)) >> s->cluster_bits;
	282	}
	283
419b19d9 SH	284	static inline int size_to_l1(BDRVQcowState *s, int64_t size)
	285	{
	286	int shift = s->cluster_bits + s->l2_bits;
	287	return (size + (1ULL << shift) - 1) >> shift;
	288	}
	289
17a71e58 KW	290	static inline int offset_to_l2_index(BDRVQcowState *s, int64_t offset)
	291	{
	292	return (offset >> s->cluster_bits) & (s->l2_size - 1);
	293	}
	294
c142442b KW	295	static inline int64_t align_offset(int64_t offset, int n)
	296	{
	297	offset = (offset + n - 1) & ~(n - 1);
	298	return offset;
	299	}
	300
68d000a3 KW	301	static inline int qcow2_get_cluster_type(uint64_t l2_entry)
	302	{
	303	if (l2_entry & QCOW_OFLAG_COMPRESSED) {
	304	return QCOW2_CLUSTER_COMPRESSED;
6377af48 KW	305	} else if (l2_entry & QCOW_OFLAG_ZERO) {
6377af48 KW	306	return QCOW2_CLUSTER_ZERO;
68d000a3 KW	307	} else if (!(l2_entry & L2E_OFFSET_MASK)) {
	308	return QCOW2_CLUSTER_UNALLOCATED;
	309	} else {
	310	return QCOW2_CLUSTER_NORMAL;
	311	}
	312	}
	313
bfe8043e SH	314	/* Check whether refcounts are eager or lazy */
	315	static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
	316	{
	317	return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
	318	}
c142442b	319
65eb2e35 KW	320	static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
	321	{
	322	return m->offset + m->cow_start.offset;
	323	}
	324
	325	static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
	326	{
	327	return m->offset + m->cow_end.offset
	328	+ (m->cow_end.nb_sectors << BDRV_SECTOR_BITS);
	329	}
	330
f7d0fe02 KW	331	// FIXME Need qcow2_ prefix to global functions
	332
	333	/* qcow2.c functions */
bd28f835 KW	334	int qcow2_backing_read1(BlockDriverState bs, QEMUIOVector qiov,
bd28f835 KW	335	int64_t sector_num, int nb_sectors);
280d3735 KW	336
280d3735 KW	337	int qcow2_mark_dirty(BlockDriverState *bs);
e24e49e6	338	int qcow2_update_header(BlockDriverState *bs);
f7d0fe02 KW	339
f7d0fe02 KW	340	/* qcow2-refcount.c functions */
ed6ccf0f KW	341	int qcow2_refcount_init(BlockDriverState *bs);
ed6ccf0f KW	342	void qcow2_refcount_close(BlockDriverState *bs);
f7d0fe02	343
ed6ccf0f	344	int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
256900b1 KW	345	int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
256900b1 KW	346	int nb_clusters);
ed6ccf0f KW	347	int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
ed6ccf0f KW	348	void qcow2_free_clusters(BlockDriverState *bs,
45aba42f	349	int64_t offset, int64_t size);
ed6ccf0f	350	void qcow2_free_any_clusters(BlockDriverState *bs,
45aba42f	351	uint64_t cluster_offset, int nb_clusters);
f7d0fe02	352
ed6ccf0f KW	353	int qcow2_update_snapshot_refcount(BlockDriverState *bs,
ed6ccf0f KW	354	int64_t l1_table_offset, int l1_size, int addend);
f7d0fe02	355
166acf54 KW	356	int qcow2_check_refcounts(BlockDriverState bs, BdrvCheckResult res,
166acf54 KW	357	BdrvCheckMode fix);
f7d0fe02	358
45aba42f	359	/* qcow2-cluster.c functions */
72893756	360	int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size);
ed6ccf0f	361	void qcow2_l2_cache_reset(BlockDriverState *bs);
66f82cee	362	int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
ed6ccf0f	363	void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
45aba42f KW	364	uint8_t out_buf, const uint8_t in_buf,
	365	int nb_sectors, int enc,
	366	const AES_KEY *key);
	367
1c46efaa KW	368	int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
1c46efaa KW	369	int num, uint64_t cluster_offset);
f4f0d391	370	int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
f50f88b9	371	int n_start, int n_end, int num, uint64_t host_offset, QCowL2Meta **m);
ed6ccf0f	372	uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
45aba42f KW	373	uint64_t offset,
	374	int compressed_size);
	375
148da7ea	376	int qcow2_alloc_cluster_link_l2(BlockDriverState bs, QCowL2Meta m);
5ea929e3 KW	377	int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
5ea929e3 KW	378	int nb_sectors);
621f0589	379	int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
45aba42f	380
c142442b	381	/* qcow2-snapshot.c functions */
ed6ccf0f KW	382	int qcow2_snapshot_create(BlockDriverState bs, QEMUSnapshotInfo sn_info);
	383	int qcow2_snapshot_goto(BlockDriverState bs, const char snapshot_id);
	384	int qcow2_snapshot_delete(BlockDriverState bs, const char snapshot_id);
	385	int qcow2_snapshot_list(BlockDriverState bs, QEMUSnapshotInfo *psn_tab);
51ef6727	386	int qcow2_snapshot_load_tmp(BlockDriverState bs, const char snapshot_name);
c142442b	387
ed6ccf0f KW	388	void qcow2_free_snapshots(BlockDriverState *bs);
ed6ccf0f KW	389	int qcow2_read_snapshots(BlockDriverState *bs);
c142442b	390
49381094	391	/* qcow2-cache.c functions */
6af4e9ea	392	Qcow2Cache qcow2_cache_create(BlockDriverState bs, int num_tables);
49381094 KW	393	int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
	394
	395	void qcow2_cache_entry_mark_dirty(Qcow2Cache c, void table);
	396	int qcow2_cache_flush(BlockDriverState bs, Qcow2Cache c);
	397	int qcow2_cache_set_dependency(BlockDriverState bs, Qcow2Cache c,
	398	Qcow2Cache *dependency);
3de0a294	399	void qcow2_cache_depends_on_flush(Qcow2Cache *c);
49381094 KW	400
	401	int qcow2_cache_get(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	402	void **table);
	403	int qcow2_cache_get_empty(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	404	void **table);
	405	int qcow2_cache_put(BlockDriverState bs, Qcow2Cache c, void **table);
	406
f7d0fe02	407	#endif