[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"
#define QCOW2_OPT_OVERLAP "overlap-check"
#define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
#define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
#define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
#define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
#define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
#define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
#define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
#define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"

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;
} QEMU_PACKED 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];

    int overlap_check; /* bitmask of Qcow2MetadataOverlap values */

    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 can be done in constant time */
#define QCOW2_OL_CONSTANT \
    (QCOW2_OL_MAIN_HEADER | QCOW2_OL_ACTIVE_L1 | QCOW2_OL_REFCOUNT_TABLE | \
     QCOW2_OL_SNAPSHOT_TABLE)

/* Perform all overlap checks which don't require disk access */
#define QCOW2_OL_CACHED \
    (QCOW2_OL_CONSTANT | QCOW2_OL_ACTIVE_L2 | QCOW2_OL_REFCOUNT_BLOCK | \
     QCOW2_OL_INACTIVE_L1)

/* Perform all overlap checks */
#define QCOW2_OL_ALL \
    (QCOW2_OL_CACHED | QCOW2_OL_INACTIVE_L2)

#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 ign, int64_t offset,
                                 int64_t size);
int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, 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"
05de7e86 MR	66	#define QCOW2_OPT_OVERLAP "overlap-check"
	67	#define QCOW2_OPT_OVERLAP_MAIN_HEADER "overlap-check.main-header"
	68	#define QCOW2_OPT_OVERLAP_ACTIVE_L1 "overlap-check.active-l1"
	69	#define QCOW2_OPT_OVERLAP_ACTIVE_L2 "overlap-check.active-l2"
	70	#define QCOW2_OPT_OVERLAP_REFCOUNT_TABLE "overlap-check.refcount-table"
	71	#define QCOW2_OPT_OVERLAP_REFCOUNT_BLOCK "overlap-check.refcount-block"
	72	#define QCOW2_OPT_OVERLAP_SNAPSHOT_TABLE "overlap-check.snapshot-table"
	73	#define QCOW2_OPT_OVERLAP_INACTIVE_L1 "overlap-check.inactive-l1"
	74	#define QCOW2_OPT_OVERLAP_INACTIVE_L2 "overlap-check.inactive-l2"
acdfb480	75
f7d0fe02 KW	76	typedef struct QCowHeader {
	77	uint32_t magic;
	78	uint32_t version;
	79	uint64_t backing_file_offset;
	80	uint32_t backing_file_size;
	81	uint32_t cluster_bits;
	82	uint64_t size; /* in bytes */
	83	uint32_t crypt_method;
	84	uint32_t l1_size; /* XXX: save number of clusters instead ? */
	85	uint64_t l1_table_offset;
	86	uint64_t refcount_table_offset;
	87	uint32_t refcount_table_clusters;
	88	uint32_t nb_snapshots;
	89	uint64_t snapshots_offset;
6744cbab KW	90
	91	/* The following fields are only valid for version >= 3 */
	92	uint64_t incompatible_features;
	93	uint64_t compatible_features;
	94	uint64_t autoclear_features;
	95
	96	uint32_t refcount_order;
	97	uint32_t header_length;
c4217f64	98	} QEMU_PACKED QCowHeader;
f7d0fe02 KW	99
	100	typedef struct QCowSnapshot {
	101	uint64_t l1_table_offset;
	102	uint32_t l1_size;
	103	char *id_str;
	104	char *name;
90b27759	105	uint64_t disk_size;
c2c9a466	106	uint64_t vm_state_size;
f7d0fe02 KW	107	uint32_t date_sec;
	108	uint32_t date_nsec;
	109	uint64_t vm_clock_nsec;
	110	} QCowSnapshot;
	111
49381094 KW	112	struct Qcow2Cache;
	113	typedef struct Qcow2Cache Qcow2Cache;
	114
75bab85c KW	115	typedef struct Qcow2UnknownHeaderExtension {
	116	uint32_t magic;
	117	uint32_t len;
	118	QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
	119	uint8_t data[];
	120	} Qcow2UnknownHeaderExtension;
	121
cfcc4c62 KW	122	enum {
	123	QCOW2_FEAT_TYPE_INCOMPATIBLE = 0,
	124	QCOW2_FEAT_TYPE_COMPATIBLE = 1,
	125	QCOW2_FEAT_TYPE_AUTOCLEAR = 2,
	126	};
	127
c61d0004 SH	128	/* Incompatible feature bits */
	129	enum {
	130	QCOW2_INCOMPAT_DIRTY_BITNR = 0,
69c98726	131	QCOW2_INCOMPAT_CORRUPT_BITNR = 1,
c61d0004	132	QCOW2_INCOMPAT_DIRTY = 1 << QCOW2_INCOMPAT_DIRTY_BITNR,
69c98726	133	QCOW2_INCOMPAT_CORRUPT = 1 << QCOW2_INCOMPAT_CORRUPT_BITNR,
c61d0004	134
69c98726 MR	135	QCOW2_INCOMPAT_MASK = QCOW2_INCOMPAT_DIRTY
69c98726 MR	136	\| QCOW2_INCOMPAT_CORRUPT,
c61d0004 SH	137	};
c61d0004 SH	138
bfe8043e SH	139	/* Compatible feature bits */
	140	enum {
	141	QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR = 0,
	142	QCOW2_COMPAT_LAZY_REFCOUNTS = 1 << QCOW2_COMPAT_LAZY_REFCOUNTS_BITNR,
	143
	144	QCOW2_COMPAT_FEAT_MASK = QCOW2_COMPAT_LAZY_REFCOUNTS,
	145	};
	146
6cfcb9b8 KW	147	enum qcow2_discard_type {
	148	QCOW2_DISCARD_NEVER = 0,
	149	QCOW2_DISCARD_ALWAYS,
	150	QCOW2_DISCARD_REQUEST,
	151	QCOW2_DISCARD_SNAPSHOT,
	152	QCOW2_DISCARD_OTHER,
	153	QCOW2_DISCARD_MAX
	154	};
	155
cfcc4c62 KW	156	typedef struct Qcow2Feature {
	157	uint8_t type;
	158	uint8_t bit;
	159	char name[46];
	160	} QEMU_PACKED Qcow2Feature;
	161
0b919fae KW	162	typedef struct Qcow2DiscardRegion {
	163	BlockDriverState *bs;
	164	uint64_t offset;
	165	uint64_t bytes;
	166	QTAILQ_ENTRY(Qcow2DiscardRegion) next;
	167	} Qcow2DiscardRegion;
	168
f7d0fe02	169	typedef struct BDRVQcowState {
f7d0fe02 KW	170	int cluster_bits;
	171	int cluster_size;
	172	int cluster_sectors;
	173	int l2_bits;
	174	int l2_size;
	175	int l1_size;
	176	int l1_vm_state_index;
	177	int csize_shift;
	178	int csize_mask;
	179	uint64_t cluster_offset_mask;
	180	uint64_t l1_table_offset;
	181	uint64_t *l1_table;
29c1a730 KW	182
	183	Qcow2Cache* l2_table_cache;
	184	Qcow2Cache* refcount_block_cache;
	185
f7d0fe02 KW	186	uint8_t *cluster_cache;
	187	uint8_t *cluster_data;
	188	uint64_t cluster_cache_offset;
72cf2d4f	189	QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
f7d0fe02 KW	190
	191	uint64_t *refcount_table;
	192	uint64_t refcount_table_offset;
	193	uint32_t refcount_table_size;
f7d0fe02 KW	194	int64_t free_cluster_index;
	195	int64_t free_byte_offset;
	196
68d100e9 KW	197	CoMutex lock;
68d100e9 KW	198
f7d0fe02 KW	199	uint32_t crypt_method; /* current crypt method, 0 if no key yet */
	200	uint32_t crypt_method_header;
	201	AES_KEY aes_encrypt_key;
	202	AES_KEY aes_decrypt_key;
	203	uint64_t snapshots_offset;
	204	int snapshots_size;
	205	int nb_snapshots;
	206	QCowSnapshot *snapshots;
06d9260f AL	207
06d9260f AL	208	int flags;
6744cbab	209	int qcow_version;
74c4510a	210	bool use_lazy_refcounts;
b6481f37	211	int refcount_order;
6744cbab	212
67af674e KW	213	bool discard_passthrough[QCOW2_DISCARD_MAX];
67af674e KW	214
3e355390 MR	215	int overlap_check; /* bitmask of Qcow2MetadataOverlap values */
3e355390 MR	216
6744cbab KW	217	uint64_t incompatible_features;
	218	uint64_t compatible_features;
	219	uint64_t autoclear_features;
	220
	221	size_t unknown_header_fields_size;
	222	void* unknown_header_fields;
75bab85c	223	QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
0b919fae KW	224	QTAILQ_HEAD (, Qcow2DiscardRegion) discards;
0b919fae KW	225	bool cache_discards;
f7d0fe02 KW	226	} BDRVQcowState;
	227
	228	/* XXX: use std qcow open function ? */
	229	typedef struct QCowCreateState {
	230	int cluster_size;
	231	int cluster_bits;
	232	uint16_t *refcount_block;
	233	uint64_t *refcount_table;
	234	int64_t l1_table_offset;
	235	int64_t refcount_table_offset;
	236	int64_t refcount_block_offset;
	237	} QCowCreateState;
	238
f214978a KW	239	struct QCowAIOCB;
f214978a KW	240
593fb83c KW	241	typedef struct Qcow2COWRegion {
	242	/**
	243	* Offset of the COW region in bytes from the start of the first cluster
	244	* touched by the request.
	245	*/
	246	uint64_t offset;
	247
	248	/** Number of sectors to copy */
	249	int nb_sectors;
	250	} Qcow2COWRegion;
	251
f50f88b9 KW	252	/**
	253	* Describes an in-flight (part of a) write request that writes to clusters
	254	* that are not referenced in their L2 table yet.
	255	*/
45aba42f KW	256	typedef struct QCowL2Meta
45aba42f KW	257	{
1d3afd64	258	/** Guest offset of the first newly allocated cluster */
45aba42f	259	uint64_t offset;
1d3afd64	260
1d3afd64	261	/** Host offset of the first newly allocated cluster */
250196f1	262	uint64_t alloc_offset;
1d3afd64	263
1d3afd64 KW	264	/**
	265	* Number of sectors from the start of the first allocated cluster to
	266	* the end of the (possibly shortened) request
	267	*/
45aba42f	268	int nb_available;
1d3afd64 KW	269
1d3afd64 KW	270	/** Number of newly allocated clusters */
45aba42f	271	int nb_clusters;
1d3afd64 KW	272
	273	/**
	274	* Requests that overlap with this allocation and wait to be restarted
	275	* when the allocating request has completed.
	276	*/
68d100e9	277	CoQueue dependent_requests;
f214978a	278
593fb83c KW	279	/**
	280	* The COW Region between the start of the first allocated cluster and the
	281	* area the guest actually writes to.
	282	*/
	283	Qcow2COWRegion cow_start;
	284
	285	/**
	286	* The COW Region between the area the guest actually writes to and the
	287	* end of the last allocated cluster.
	288	*/
	289	Qcow2COWRegion cow_end;
	290
88c6588c KW	291	/** Pointer to next L2Meta of the same write request */
	292	struct QCowL2Meta *next;
	293
72cf2d4f	294	QLIST_ENTRY(QCowL2Meta) next_in_flight;
45aba42f KW	295	} QCowL2Meta;
45aba42f KW	296
68d000a3 KW	297	enum {
	298	QCOW2_CLUSTER_UNALLOCATED,
	299	QCOW2_CLUSTER_NORMAL,
	300	QCOW2_CLUSTER_COMPRESSED,
6377af48	301	QCOW2_CLUSTER_ZERO
68d000a3 KW	302	};
68d000a3 KW	303
a40f1c2a MR	304	typedef enum QCow2MetadataOverlap {
	305	QCOW2_OL_MAIN_HEADER_BITNR = 0,
	306	QCOW2_OL_ACTIVE_L1_BITNR = 1,
	307	QCOW2_OL_ACTIVE_L2_BITNR = 2,
	308	QCOW2_OL_REFCOUNT_TABLE_BITNR = 3,
	309	QCOW2_OL_REFCOUNT_BLOCK_BITNR = 4,
	310	QCOW2_OL_SNAPSHOT_TABLE_BITNR = 5,
	311	QCOW2_OL_INACTIVE_L1_BITNR = 6,
	312	QCOW2_OL_INACTIVE_L2_BITNR = 7,
	313
	314	QCOW2_OL_MAX_BITNR = 8,
	315
	316	QCOW2_OL_NONE = 0,
	317	QCOW2_OL_MAIN_HEADER = (1 << QCOW2_OL_MAIN_HEADER_BITNR),
	318	QCOW2_OL_ACTIVE_L1 = (1 << QCOW2_OL_ACTIVE_L1_BITNR),
	319	QCOW2_OL_ACTIVE_L2 = (1 << QCOW2_OL_ACTIVE_L2_BITNR),
	320	QCOW2_OL_REFCOUNT_TABLE = (1 << QCOW2_OL_REFCOUNT_TABLE_BITNR),
	321	QCOW2_OL_REFCOUNT_BLOCK = (1 << QCOW2_OL_REFCOUNT_BLOCK_BITNR),
	322	QCOW2_OL_SNAPSHOT_TABLE = (1 << QCOW2_OL_SNAPSHOT_TABLE_BITNR),
	323	QCOW2_OL_INACTIVE_L1 = (1 << QCOW2_OL_INACTIVE_L1_BITNR),
	324	/* NOTE: Checking overlaps with inactive L2 tables will result in bdrv
	325	* reads. */
	326	QCOW2_OL_INACTIVE_L2 = (1 << QCOW2_OL_INACTIVE_L2_BITNR),
	327	} QCow2MetadataOverlap;
	328
4a273c39 MR	329	/* Perform all overlap checks which can be done in constant time */
	330	#define QCOW2_OL_CONSTANT \
	331	(QCOW2_OL_MAIN_HEADER \| QCOW2_OL_ACTIVE_L1 \| QCOW2_OL_REFCOUNT_TABLE \| \
	332	QCOW2_OL_SNAPSHOT_TABLE)
	333
a40f1c2a MR	334	/* Perform all overlap checks which don't require disk access */
a40f1c2a MR	335	#define QCOW2_OL_CACHED \
4a273c39 MR	336	(QCOW2_OL_CONSTANT \| QCOW2_OL_ACTIVE_L2 \| QCOW2_OL_REFCOUNT_BLOCK \| \
	337	QCOW2_OL_INACTIVE_L1)
	338
	339	/* Perform all overlap checks */
	340	#define QCOW2_OL_ALL \
	341	(QCOW2_OL_CACHED \| QCOW2_OL_INACTIVE_L2)
a40f1c2a	342
68d000a3 KW	343	#define L1E_OFFSET_MASK 0x00ffffffffffff00ULL
	344	#define L2E_OFFSET_MASK 0x00ffffffffffff00ULL
	345	#define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL
	346
76dc9e0c KW	347	#define REFT_OFFSET_MASK 0xffffffffffffff00ULL
76dc9e0c KW	348
3b8e2e26 KW	349	static inline int64_t start_of_cluster(BDRVQcowState *s, int64_t offset)
	350	{
	351	return offset & ~(s->cluster_size - 1);
	352	}
	353
c37f4cd7 KW	354	static inline int64_t offset_into_cluster(BDRVQcowState *s, int64_t offset)
	355	{
	356	return offset & (s->cluster_size - 1);
	357	}
	358
45aba42f	359	static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
f7d0fe02 KW	360	{
	361	return (size + (s->cluster_size - 1)) >> s->cluster_bits;
	362	}
	363
2cf7cfa1	364	static inline int64_t size_to_l1(BDRVQcowState *s, int64_t size)
419b19d9 SH	365	{
	366	int shift = s->cluster_bits + s->l2_bits;
	367	return (size + (1ULL << shift) - 1) >> shift;
	368	}
	369
17a71e58 KW	370	static inline int offset_to_l2_index(BDRVQcowState *s, int64_t offset)
	371	{
	372	return (offset >> s->cluster_bits) & (s->l2_size - 1);
	373	}
	374
c142442b KW	375	static inline int64_t align_offset(int64_t offset, int n)
	376	{
	377	offset = (offset + n - 1) & ~(n - 1);
	378	return offset;
	379	}
	380
1ebf561c KW	381	static inline int64_t qcow2_vm_state_offset(BDRVQcowState *s)
	382	{
	383	return (int64_t)s->l1_vm_state_index << (s->cluster_bits + s->l2_bits);
	384	}
	385
68d000a3 KW	386	static inline int qcow2_get_cluster_type(uint64_t l2_entry)
	387	{
	388	if (l2_entry & QCOW_OFLAG_COMPRESSED) {
	389	return QCOW2_CLUSTER_COMPRESSED;
6377af48 KW	390	} else if (l2_entry & QCOW_OFLAG_ZERO) {
6377af48 KW	391	return QCOW2_CLUSTER_ZERO;
68d000a3 KW	392	} else if (!(l2_entry & L2E_OFFSET_MASK)) {
	393	return QCOW2_CLUSTER_UNALLOCATED;
	394	} else {
	395	return QCOW2_CLUSTER_NORMAL;
	396	}
	397	}
	398
bfe8043e SH	399	/* Check whether refcounts are eager or lazy */
	400	static inline bool qcow2_need_accurate_refcounts(BDRVQcowState *s)
	401	{
	402	return !(s->incompatible_features & QCOW2_INCOMPAT_DIRTY);
	403	}
c142442b	404
65eb2e35 KW	405	static inline uint64_t l2meta_cow_start(QCowL2Meta *m)
	406	{
	407	return m->offset + m->cow_start.offset;
	408	}
	409
	410	static inline uint64_t l2meta_cow_end(QCowL2Meta *m)
	411	{
	412	return m->offset + m->cow_end.offset
	413	+ (m->cow_end.nb_sectors << BDRV_SECTOR_BITS);
	414	}
	415
f7d0fe02 KW	416	// FIXME Need qcow2_ prefix to global functions
	417
	418	/* qcow2.c functions */
bd28f835 KW	419	int qcow2_backing_read1(BlockDriverState bs, QEMUIOVector qiov,
bd28f835 KW	420	int64_t sector_num, int nb_sectors);
280d3735 KW	421
280d3735 KW	422	int qcow2_mark_dirty(BlockDriverState *bs);
69c98726 MR	423	int qcow2_mark_corrupt(BlockDriverState *bs);
69c98726 MR	424	int qcow2_mark_consistent(BlockDriverState *bs);
e24e49e6	425	int qcow2_update_header(BlockDriverState *bs);
f7d0fe02 KW	426
f7d0fe02 KW	427	/* qcow2-refcount.c functions */
ed6ccf0f KW	428	int qcow2_refcount_init(BlockDriverState *bs);
ed6ccf0f KW	429	void qcow2_refcount_close(BlockDriverState *bs);
f7d0fe02	430
32b6444d MR	431	int qcow2_update_cluster_refcount(BlockDriverState *bs, int64_t cluster_index,
	432	int addend, enum qcow2_discard_type type);
	433
ed6ccf0f	434	int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
256900b1 KW	435	int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
256900b1 KW	436	int nb_clusters);
ed6ccf0f KW	437	int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
ed6ccf0f KW	438	void qcow2_free_clusters(BlockDriverState *bs,
6cfcb9b8 KW	439	int64_t offset, int64_t size,
	440	enum qcow2_discard_type type);
	441	void qcow2_free_any_clusters(BlockDriverState *bs, uint64_t l2_entry,
	442	int nb_clusters, enum qcow2_discard_type type);
f7d0fe02	443
ed6ccf0f KW	444	int qcow2_update_snapshot_refcount(BlockDriverState *bs,
ed6ccf0f KW	445	int64_t l1_table_offset, int l1_size, int addend);
f7d0fe02	446
166acf54 KW	447	int qcow2_check_refcounts(BlockDriverState bs, BdrvCheckResult res,
166acf54 KW	448	BdrvCheckMode fix);
f7d0fe02	449
0b919fae KW	450	void qcow2_process_discards(BlockDriverState *bs, int ret);
0b919fae KW	451
231bb267	452	int qcow2_check_metadata_overlap(BlockDriverState *bs, int ign, int64_t offset,
a40f1c2a	453	int64_t size);
231bb267	454	int qcow2_pre_write_overlap_check(BlockDriverState *bs, int ign, int64_t offset,
a40f1c2a MR	455	int64_t size);
a40f1c2a MR	456
45aba42f	457	/* qcow2-cluster.c functions */
2cf7cfa1 KW	458	int qcow2_grow_l1_table(BlockDriverState *bs, uint64_t min_size,
2cf7cfa1 KW	459	bool exact_size);
e23e400e	460	int qcow2_write_l1_entry(BlockDriverState *bs, int l1_index);
ed6ccf0f	461	void qcow2_l2_cache_reset(BlockDriverState *bs);
66f82cee	462	int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
ed6ccf0f	463	void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
45aba42f KW	464	uint8_t out_buf, const uint8_t in_buf,
	465	int nb_sectors, int enc,
	466	const AES_KEY *key);
	467
1c46efaa KW	468	int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
1c46efaa KW	469	int num, uint64_t cluster_offset);
f4f0d391	470	int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
f50f88b9	471	int n_start, int n_end, int num, uint64_t host_offset, QCowL2Meta **m);
ed6ccf0f	472	uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
45aba42f KW	473	uint64_t offset,
	474	int compressed_size);
	475
148da7ea	476	int qcow2_alloc_cluster_link_l2(BlockDriverState bs, QCowL2Meta m);
5ea929e3	477	int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
670df5e3	478	int nb_sectors, enum qcow2_discard_type type);
621f0589	479	int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors);
45aba42f	480
32b6444d MR	481	int qcow2_expand_zero_clusters(BlockDriverState *bs);
32b6444d MR	482
c142442b	483	/* qcow2-snapshot.c functions */
ed6ccf0f KW	484	int qcow2_snapshot_create(BlockDriverState bs, QEMUSnapshotInfo sn_info);
ed6ccf0f KW	485	int qcow2_snapshot_goto(BlockDriverState bs, const char snapshot_id);
a89d89d3 WX	486	int qcow2_snapshot_delete(BlockDriverState *bs,
	487	const char *snapshot_id,
	488	const char *name,
	489	Error **errp);
ed6ccf0f	490	int qcow2_snapshot_list(BlockDriverState bs, QEMUSnapshotInfo *psn_tab);
51ef6727	491	int qcow2_snapshot_load_tmp(BlockDriverState bs, const char snapshot_name);
c142442b	492
ed6ccf0f KW	493	void qcow2_free_snapshots(BlockDriverState *bs);
ed6ccf0f KW	494	int qcow2_read_snapshots(BlockDriverState *bs);
c142442b	495
49381094	496	/* qcow2-cache.c functions */
6af4e9ea	497	Qcow2Cache qcow2_cache_create(BlockDriverState bs, int num_tables);
49381094 KW	498	int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
	499
	500	void qcow2_cache_entry_mark_dirty(Qcow2Cache c, void table);
	501	int qcow2_cache_flush(BlockDriverState bs, Qcow2Cache c);
	502	int qcow2_cache_set_dependency(BlockDriverState bs, Qcow2Cache c,
	503	Qcow2Cache *dependency);
3de0a294	504	void qcow2_cache_depends_on_flush(Qcow2Cache *c);
49381094	505
e7108fea MR	506	int qcow2_cache_empty(BlockDriverState bs, Qcow2Cache c);
e7108fea MR	507
49381094 KW	508	int qcow2_cache_get(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	509	void **table);
	510	int qcow2_cache_get_empty(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	511	void **table);
	512	int qcow2_cache_put(BlockDriverState bs, Qcow2Cache c, void **table);
	513
f7d0fe02	514	#endif