[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 "qemu/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     (1ULL << 63)
/* indicate that the cluster is compressed (they never have the copied flag) */
#define QCOW_OFLAG_COMPRESSED (1ULL << 62)
/* The cluster reads as all zeros */
#define QCOW_OFLAG_ZERO (1ULL << 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"
#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
#define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"

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_CORRUPT_BITNR = 1,
    QCOW2_INCOMPAT_DIRTY         = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
    QCOW2_INCOMPAT_CORRUPT       = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,

    QCOW2_INCOMPAT_MASK          = QCOW2_INCOMPAT_DIRTY
                                 | QCOW2_INCOMPAT_CORRUPT,
};

/* 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,
};

enum qcow2_discard_type {
    QCOW2_DISCARD_NEVER = 0,
    QCOW2_DISCARD_ALWAYS,
    QCOW2_DISCARD_REQUEST,
    QCOW2_DISCARD_SNAPSHOT,
    QCOW2_DISCARD_OTHER,
    QCOW2_DISCARD_MAX
};

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

typedef struct Qcow2DiscardRegion {
    BlockDriverState *bs;
    uint64_t offset;
    uint64_t bytes;
    QTAILQ_ENTRY(Qcow2DiscardRegion) next;
} Qcow2DiscardRegion;

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;
    int refcount_order;

    bool discard_passthrough[QCOW2_DISCARD_MAX];

    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;
    QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
    bool cache_discards;
} 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;

    /** Pointer to next L2Meta of the same write request */
    struct QCowL2Meta *next;

    QLIST_ENTRY(QCowL2Meta) next_in_flight;
} QCowL2Meta;

enum {
    QCOW2_CLUSTER_UNALLOCATED,
    QCOW2_CLUSTER_NORMAL,
    QCOW2_CLUSTER_COMPRESSED,
    QCOW2_CLUSTER_ZERO
};

typedef enum QCow2MetadataOverlap {
    QCOW2_OL_MAIN_HEADER_BITNR    = 0,
    QCOW2_OL_ACTIVE_L1_BITNR      = 1,
    QCOW2_OL_ACTIVE_L2_BITNR      = 2,
    QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
    QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
    QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
    QCOW2_OL_INACTIVE_L1_BITNR    = 6,
    QCOW2_OL_INACTIVE_L2_BITNR    = 7,

    QCOW2_OL_MAX_BITNR            = 8,

    QCOW2_OL_NONE           = 0,
    QCOW2_OL_MAIN_HEADER    = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
    QCOW2_OL_ACTIVE_L1      = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
    QCOW2_OL_ACTIVE_L2      = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
    QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
    QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
    QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
    QCOW2_OL_INACTIVE_L1    = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
    /* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
     * reads. */
    QCOW2_OL_INACTIVE_L2    = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
} QCow2MetadataOverlap;

/* Perform all overlap checks which don't require disk access */
#define QCOW2_OL_CACHED \
    (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_ACTIVE_L2 | \
     QCOW2_OL_REFCOUNT_TABLE | QCOW2_OL_REFCOUNT_BLOCK | \
     QCOW2_OL_SNAPSHOT_TABLE | QCOW2_OL_INACTIVE_L1)

/* The default checks to perform */
#define QCOW2_OL_DEFAULT QCOW2_OL_CACHED

#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 int64_t 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 int64_t qcow2_vm_state_offset(BDRVQcowState *s)
{
    return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
}

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_mark_corrupt(BlockDriverState *bs);
int qcow2_mark_consistent(BlockDriverState *bs);
int qcow2_update_header(BlockDriverState *bs);

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

int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
                                  int addend, enum qcow2_discard_type type);

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,
                          enum qcow2_discard_type type);
void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
                             int nb_clusters, enum qcow2_discard_type type);

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);

void qcow2_process_discards(BlockDriverState *bs, int ret);

int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,
                                 int64_t size);
int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,
                                  int64_t size);

/* qcow2-cluster.c functions */
int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
                        bool exact_size);
int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
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, enum qcow2_discard_type type);
int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);

int qcow2_expand_zero_clusters(BlockDriverState *bs);

/* 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,
                          const char *name,
                          Error **errp);
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_empty(BlockDriverState *bs, 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
753d9b82	28	#include "qemu/aes.h"
737e150e	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. */
127c84e1	43	#define QCOW_OFLAG_COPIED (1ULL << 63)
f7d0fe02	44	/* indicate that the cluster is compressed (they never have the copied flag) */
127c84e1	45	#define QCOW_OFLAG_COMPRESSED (1ULL << 62)
6377af48	46	/* The cluster reads as all zeros */
127c84e1	47	#define QCOW_OFLAG_ZERO (1ULL << 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	61
64aa99d3 KW	62	#define QCOW2_OPT_LAZY_REFCOUNTS "lazy-refcounts"
	63	#define QCOW2_OPT_DISCARD_REQUEST "pass-discard-request"
	64	#define QCOW2_OPT_DISCARD_SNAPSHOT "pass-discard-snapshot"
	65	#define QCOW2_OPT_DISCARD_OTHER "pass-discard-other"
acdfb480	66
f7d0fe02 KW	67	typedef struct QCowHeader {
	68	uint32_t magic;
	69	uint32_t version;
	70	uint64_t backing_file_offset;
	71	uint32_t backing_file_size;
	72	uint32_t cluster_bits;
	73	uint64_t size; /* in bytes */
	74	uint32_t crypt_method;
	75	uint32_t l1_size; /* XXX: save number of clusters instead ? */
	76	uint64_t l1_table_offset;
	77	uint64_t refcount_table_offset;
	78	uint32_t refcount_table_clusters;
	79	uint32_t nb_snapshots;
	80	uint64_t snapshots_offset;
6744cbab KW	81
	82	/* The following fields are only valid for version >= 3 */
	83	uint64_t incompatible_features;
	84	uint64_t compatible_features;
	85	uint64_t autoclear_features;
	86
	87	uint32_t refcount_order;
	88	uint32_t header_length;
f7d0fe02 KW	89	} QCowHeader;
	90
	91	typedef struct QCowSnapshot {
	92	uint64_t l1_table_offset;
	93	uint32_t l1_size;
	94	char *id_str;
	95	char *name;
90b27759	96	uint64_t disk_size;
c2c9a466	97	uint64_t vm_state_size;
f7d0fe02 KW	98	uint32_t date_sec;
	99	uint32_t date_nsec;
	100	uint64_t vm_clock_nsec;
	101	} QCowSnapshot;
	102
49381094 KW	103	struct Qcow2Cache;
	104	typedef struct Qcow2Cache Qcow2Cache;
	105
75bab85c KW	106	typedef struct Qcow2UnknownHeaderExtension {
	107	uint32_t magic;
	108	uint32_t len;
	109	QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
	110	uint8_t data[];
	111	} Qcow2UnknownHeaderExtension;
	112
cfcc4c62 KW	113	enum {
	114	QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
	115	QCOW2_FEAT_TYPE_COMPATIBLE = 1,
	116	QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
	117	};
	118
c61d0004 SH	119	/* Incompatible feature bits */
	120	enum {
	121	QCOW2_INCOMPAT_DIRTY_BITNR = 0,
69c98726	122	QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
c61d0004	123	QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
69c98726	124	QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
c61d0004	125
69c98726 MR	126	QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
69c98726 MR	127	\| QCOW2_INCOMPAT_CORRUPT,
c61d0004 SH	128	};
c61d0004 SH	129
bfe8043e SH	130	/* Compatible feature bits */
	131	enum {
	132	QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
	133	QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
	134
	135	QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
	136	};
	137
6cfcb9b8 KW	138	enum qcow2_discard_type {
	139	QCOW2_DISCARD_NEVER = 0,
	140	QCOW2_DISCARD_ALWAYS,
	141	QCOW2_DISCARD_REQUEST,
	142	QCOW2_DISCARD_SNAPSHOT,
	143	QCOW2_DISCARD_OTHER,
	144	QCOW2_DISCARD_MAX
	145	};
	146
cfcc4c62 KW	147	typedef struct Qcow2Feature {
	148	uint8_t type;
	149	uint8_t bit;
	150	char name[46];
	151	} QEMU_PACKED Qcow2Feature;
	152
0b919fae KW	153	typedef struct Qcow2DiscardRegion {
	154	BlockDriverState *bs;
	155	uint64_t offset;
	156	uint64_t bytes;
	157	QTAILQ_ENTRY(Qcow2DiscardRegion) next;
	158	} Qcow2DiscardRegion;
	159
f7d0fe02	160	typedef struct BDRVQcowState {
f7d0fe02 KW	161	int cluster_bits;
	162	int cluster_size;
	163	int cluster_sectors;
	164	int l2_bits;
	165	int l2_size;
	166	int l1_size;
	167	int l1_vm_state_index;
	168	int csize_shift;
	169	int csize_mask;
	170	uint64_t cluster_offset_mask;
	171	uint64_t l1_table_offset;
	172	uint64_t *l1_table;
29c1a730 KW	173
	174	Qcow2Cache* l2_table_cache;
	175	Qcow2Cache* refcount_block_cache;
	176
f7d0fe02 KW	177	uint8_t *cluster_cache;
	178	uint8_t *cluster_data;
	179	uint64_t cluster_cache_offset;
72cf2d4f	180	QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
f7d0fe02 KW	181
	182	uint64_t *refcount_table;
	183	uint64_t refcount_table_offset;
	184	uint32_t refcount_table_size;
f7d0fe02 KW	185	int64_t free_cluster_index;
	186	int64_t free_byte_offset;
	187
68d100e9 KW	188	CoMutex lock;
68d100e9 KW	189
f7d0fe02 KW	190	uint32_t crypt_method; /* current crypt method, 0 if no key yet */
	191	uint32_t crypt_method_header;
	192	AES_KEY aes_encrypt_key;
	193	AES_KEY aes_decrypt_key;
	194	uint64_t snapshots_offset;
	195	int snapshots_size;
	196	int nb_snapshots;
	197	QCowSnapshot *snapshots;
06d9260f AL	198
06d9260f AL	199	int flags;
6744cbab	200	int qcow_version;
74c4510a	201	bool use_lazy_refcounts;
b6481f37	202	int refcount_order;
6744cbab	203
67af674e KW	204	bool discard_passthrough[QCOW2_DISCARD_MAX];
67af674e KW	205
6744cbab KW	206	uint64_t incompatible_features;
	207	uint64_t compatible_features;
	208	uint64_t autoclear_features;
	209
	210	size_t unknown_header_fields_size;
	211	void* unknown_header_fields;
75bab85c	212	QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
0b919fae KW	213	QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
0b919fae KW	214	bool cache_discards;
f7d0fe02 KW	215	} BDRVQcowState;
	216
	217	/* XXX: use std qcow open function ? */
	218	typedef struct QCowCreateState {
	219	int cluster_size;
	220	int cluster_bits;
	221	uint16_t *refcount_block;
	222	uint64_t *refcount_table;
	223	int64_t l1_table_offset;
	224	int64_t refcount_table_offset;
	225	int64_t refcount_block_offset;
	226	} QCowCreateState;
	227
f214978a KW	228	struct QCowAIOCB;
f214978a KW	229
593fb83c KW	230	typedef struct Qcow2COWRegion {
	231	/**
	232	* Offset of the COW region in bytes from the start of the first cluster
	233	* touched by the request.
	234	*/
	235	uint64_t offset;
	236
	237	/** Number of sectors to copy */
	238	int nb_sectors;
	239	} Qcow2COWRegion;
	240
f50f88b9 KW	241	/**
	242	* Describes an in-flight (part of a) write request that writes to clusters
	243	* that are not referenced in their L2 table yet.
	244	*/
45aba42f KW	245	typedef struct QCowL2Meta
45aba42f KW	246	{
1d3afd64	247	/** Guest offset of the first newly allocated cluster */
45aba42f	248	uint64_t offset;
1d3afd64	249
1d3afd64	250	/** Host offset of the first newly allocated cluster */
250196f1	251	uint64_t alloc_offset;
1d3afd64	252
1d3afd64 KW	253	/**
	254	* Number of sectors from the start of the first allocated cluster to
	255	* the end of the (possibly shortened) request
	256	*/
45aba42f	257	int nb_available;
1d3afd64 KW	258
1d3afd64 KW	259	/** Number of newly allocated clusters */
45aba42f	260	int nb_clusters;
1d3afd64 KW	261
	262	/**
	263	* Requests that overlap with this allocation and wait to be restarted
	264	* when the allocating request has completed.
	265	*/
68d100e9	266	CoQueue dependent_requests;
f214978a	267
593fb83c KW	268	/**
	269	* The COW Region between the start of the first allocated cluster and the
	270	* area the guest actually writes to.
	271	*/
	272	Qcow2COWRegion cow_start;
	273
	274	/**
	275	* The COW Region between the area the guest actually writes to and the
	276	* end of the last allocated cluster.
	277	*/
	278	Qcow2COWRegion cow_end;
	279
88c6588c KW	280	/** Pointer to next L2Meta of the same write request */
	281	struct QCowL2Meta *next;
	282
72cf2d4f	283	QLIST_ENTRY(QCowL2Meta) next_in_flight;
45aba42f KW	284	} QCowL2Meta;
45aba42f KW	285
68d000a3 KW	286	enum {
	287	QCOW2_CLUSTER_UNALLOCATED,
	288	QCOW2_CLUSTER_NORMAL,
	289	QCOW2_CLUSTER_COMPRESSED,
6377af48	290	QCOW2_CLUSTER_ZERO
68d000a3 KW	291	};
68d000a3 KW	292
a40f1c2a MR	293	typedef enum QCow2MetadataOverlap {
	294	QCOW2_OL_MAIN_HEADER_BITNR = 0,
	295	QCOW2_OL_ACTIVE_L1_BITNR = 1,
	296	QCOW2_OL_ACTIVE_L2_BITNR = 2,
	297	QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
	298	QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
	299	QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
	300	QCOW2_OL_INACTIVE_L1_BITNR = 6,
	301	QCOW2_OL_INACTIVE_L2_BITNR = 7,
	302
	303	QCOW2_OL_MAX_BITNR = 8,
	304
	305	QCOW2_OL_NONE = 0,
	306	QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
	307	QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
	308	QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
	309	QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
	310	QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
	311	QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
	312	QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
	313	/* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
	314	* reads. */
	315	QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
	316	} QCow2MetadataOverlap;
	317
	318	/* Perform all overlap checks which don't require disk access */
	319	#define QCOW2_OL_CACHED \
	320	(QCOW2_OL_MAIN_HEADER \| QCOW2_OL_ACTIVE_L1 \| QCOW2_OL_ACTIVE_L2 \| \
	321	QCOW2_OL_REFCOUNT_TABLE \| QCOW2_OL_REFCOUNT_BLOCK \| \
	322	QCOW2_OL_SNAPSHOT_TABLE \| QCOW2_OL_INACTIVE_L1)
	323
	324	/* The default checks to perform */
	325	#define QCOW2_OL_DEFAULT QCOW2_OL_CACHED
	326
68d000a3 KW	327	#define L1E_OFFSET_MASK 0x00ffffffffffff00ULL
	328	#define L2E_OFFSET_MASK 0x00ffffffffffff00ULL
	329	#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
	330
76dc9e0c KW	331	#define REFT_OFFSET_MASK 0xffffffffffffff00ULL
76dc9e0c KW	332
3b8e2e26 KW	333	static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset)
	334	{
	335	return offset & ~(s->cluster_size - 1);
	336	}
	337
c37f4cd7 KW	338	static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
	339	{
	340	return offset & (s->cluster_size - 1);
	341	}
	342
45aba42f	343	static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
f7d0fe02 KW	344	{
	345	return (size + (s->cluster_size - 1)) >> s->cluster_bits;
	346	}
	347
2cf7cfa1	348	static inline int64_t size_to_l1(BDRVQcowState *s, int64_t size)
419b19d9 SH	349	{
	350	int shift = s->cluster_bits + s->l2_bits;
	351	return (size + (1ULL << shift) - 1) >> shift;
	352	}
	353
17a71e58 KW	354	static inline int offset_to_l2_index(BDRVQcowState *s, int64_t offset)
	355	{
	356	return (offset >> s->cluster_bits) & (s->l2_size - 1);
	357	}
	358
c142442b KW	359	static inline int64_t align_offset(int64_t offset, int n)
	360	{
	361	offset = (offset + n - 1) & ~(n - 1);
	362	return offset;
	363	}
	364
1ebf561c KW	365	static inline int64_t qcow2_vm_state_offset(BDRVQcowState *s)
	366	{
	367	return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
	368	}
	369
68d000a3 KW	370	static inline int qcow2_get_cluster_type(uint64_t l2_entry)
	371	{
	372	if (l2_entry & QCOW_OFLAG_COMPRESSED) {
	373	return QCOW2_CLUSTER_COMPRESSED;
6377af48 KW	374	} else if (l2_entry & QCOW_OFLAG_ZERO) {
6377af48 KW	375	return QCOW2_CLUSTER_ZERO;
68d000a3 KW	376	} else if (!(l2_entry & L2E_OFFSET_MASK)) {
	377	return QCOW2_CLUSTER_UNALLOCATED;
	378	} else {
	379	return QCOW2_CLUSTER_NORMAL;
	380	}
	381	}
	382
bfe8043e SH	383	/* Check whether refcounts are eager or lazy */
	384	static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
	385	{
	386	return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
	387	}
c142442b	388
65eb2e35 KW	389	static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
	390	{
	391	return m->offset + m->cow_start.offset;
	392	}
	393
	394	static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
	395	{
	396	return m->offset + m->cow_end.offset
	397	+ (m->cow_end.nb_sectors << BDRV_SECTOR_BITS);
	398	}
	399
f7d0fe02 KW	400	// FIXME Need qcow2_ prefix to global functions
	401
	402	/* qcow2.c functions */
bd28f835 KW	403	int qcow2_backing_read1(BlockDriverState bs, QEMUIOVector qiov,
bd28f835 KW	404	int64_t sector_num, int nb_sectors);
280d3735 KW	405
280d3735 KW	406	int qcow2_mark_dirty(BlockDriverState *bs);
69c98726 MR	407	int qcow2_mark_corrupt(BlockDriverState *bs);
69c98726 MR	408	int qcow2_mark_consistent(BlockDriverState *bs);
e24e49e6	409	int qcow2_update_header(BlockDriverState *bs);
f7d0fe02 KW	410
f7d0fe02 KW	411	/* qcow2-refcount.c functions */
ed6ccf0f KW	412	int qcow2_refcount_init(BlockDriverState *bs);
ed6ccf0f KW	413	void qcow2_refcount_close(BlockDriverState *bs);
f7d0fe02	414
32b6444d MR	415	int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
	416	int addend, enum qcow2_discard_type type);
	417
ed6ccf0f	418	int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
256900b1 KW	419	int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
256900b1 KW	420	int nb_clusters);
ed6ccf0f KW	421	int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
ed6ccf0f KW	422	void qcow2_free_clusters(BlockDriverState *bs,
6cfcb9b8 KW	423	int64_t offset, int64_t size,
	424	enum qcow2_discard_type type);
	425	void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
	426	int nb_clusters, enum qcow2_discard_type type);
f7d0fe02	427
ed6ccf0f KW	428	int qcow2_update_snapshot_refcount(BlockDriverState *bs,
ed6ccf0f KW	429	int64_t l1_table_offset, int l1_size, int addend);
f7d0fe02	430
166acf54 KW	431	int qcow2_check_refcounts(BlockDriverState bs, BdrvCheckResult res,
166acf54 KW	432	BdrvCheckMode fix);
f7d0fe02	433
0b919fae KW	434	void qcow2_process_discards(BlockDriverState *bs, int ret);
0b919fae KW	435
a40f1c2a MR	436	int qcow2_check_metadata_overlap(BlockDriverState *bs, int chk, int64_t offset,
	437	int64_t size);
	438	int qcow2_pre_write_overlap_check(BlockDriverState *bs, int chk, int64_t offset,
	439	int64_t size);
	440
45aba42f	441	/* qcow2-cluster.c functions */
2cf7cfa1 KW	442	int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
2cf7cfa1 KW	443	bool exact_size);
e23e400e	444	int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
ed6ccf0f	445	void qcow2_l2_cache_reset(BlockDriverState *bs);
66f82cee	446	int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
ed6ccf0f	447	void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
45aba42f KW	448	uint8_t out_buf, const uint8_t in_buf,
	449	int nb_sectors, int enc,
	450	const AES_KEY *key);
	451
1c46efaa KW	452	int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
1c46efaa KW	453	int num, uint64_t cluster_offset);
f4f0d391	454	int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
f50f88b9	455	int n_start, int n_end, int num, uint64_t host_offset, QCowL2Meta **m);
ed6ccf0f	456	uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
45aba42f KW	457	uint64_t offset,
	458	int compressed_size);
	459
148da7ea	460	int qcow2_alloc_cluster_link_l2(BlockDriverState bs, QCowL2Meta m);
5ea929e3	461	int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
670df5e3	462	int nb_sectors, enum qcow2_discard_type type);
621f0589	463	int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
45aba42f	464
32b6444d MR	465	int qcow2_expand_zero_clusters(BlockDriverState *bs);
32b6444d MR	466
c142442b	467	/* qcow2-snapshot.c functions */
ed6ccf0f KW	468	int qcow2_snapshot_create(BlockDriverState bs, QEMUSnapshotInfo sn_info);
ed6ccf0f KW	469	int qcow2_snapshot_goto(BlockDriverState bs, const char snapshot_id);
a89d89d3 WX	470	int qcow2_snapshot_delete(BlockDriverState *bs,
	471	const char *snapshot_id,
	472	const char *name,
	473	Error **errp);
ed6ccf0f	474	int qcow2_snapshot_list(BlockDriverState bs, QEMUSnapshotInfo *psn_tab);
51ef6727	475	int qcow2_snapshot_load_tmp(BlockDriverState bs, const char snapshot_name);
c142442b	476
ed6ccf0f KW	477	void qcow2_free_snapshots(BlockDriverState *bs);
ed6ccf0f KW	478	int qcow2_read_snapshots(BlockDriverState *bs);
c142442b	479
49381094	480	/* qcow2-cache.c functions */
6af4e9ea	481	Qcow2Cache qcow2_cache_create(BlockDriverState bs, int num_tables);
49381094 KW	482	int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
	483
	484	void qcow2_cache_entry_mark_dirty(Qcow2Cache c, void table);
	485	int qcow2_cache_flush(BlockDriverState bs, Qcow2Cache c);
	486	int qcow2_cache_set_dependency(BlockDriverState bs, Qcow2Cache c,
	487	Qcow2Cache *dependency);
3de0a294	488	void qcow2_cache_depends_on_flush(Qcow2Cache *c);
49381094	489
e7108fea MR	490	int qcow2_cache_empty(BlockDriverState bs, Qcow2Cache c);
e7108fea MR	491
49381094 KW	492	int qcow2_cache_get(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	493	void **table);
	494	int qcow2_cache_get_empty(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	495	void **table);
	496	int qcow2_cache_put(BlockDriverState bs, Qcow2Cache c, void **table);
	497
f7d0fe02	498	#endif