[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 "aes.h"
#include "qemu-coroutine.h"

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

#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
#define QCOW_VERSION 2

#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)

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

#define MIN_CLUSTER_BITS 9
#define MAX_CLUSTER_BITS 21

#define L2_CACHE_SIZE 16

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

#define DEFAULT_CLUSTER_SIZE 65536

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

typedef struct QCowSnapshot {
    uint64_t l1_table_offset;
    uint32_t l1_size;
    char *id_str;
    char *name;
    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;

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;
    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;

/* XXX This could be private for qcow2-cluster.c */
typedef struct QCowL2Meta
{
    uint64_t offset;
    uint64_t cluster_offset;
    int n_start;
    int nb_available;
    int nb_clusters;
    CoQueue dependent_requests;

    QLIST_ENTRY(QCowL2Meta) next_in_flight;
} QCowL2Meta;

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

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

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


// 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_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);

/* 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, 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);

/* 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,
    bool writethrough);
int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
bool qcow2_cache_set_writethrough(BlockDriverState *bs, Qcow2Cache *c,
    bool enable);

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
	28	#include "aes.h"
68d100e9	29	#include "qemu-coroutine.h"
f7d0fe02	30
14899cdf FN	31	//#define DEBUG_ALLOC
	32	//#define DEBUG_ALLOC2
	33	//#define DEBUG_EXT
	34
f7d0fe02 KW	35	#define QCOW_MAGIC (('Q' << 24) \| ('F' << 16) \| ('I' << 8) \| 0xfb)
	36	#define QCOW_VERSION 2
	37
	38	#define QCOW_CRYPT_NONE 0
	39	#define QCOW_CRYPT_AES 1
	40
	41	#define QCOW_MAX_CRYPT_CLUSTERS 32
	42
	43	/* indicate that the refcount of the referenced cluster is exactly one. */
	44	#define QCOW_OFLAG_COPIED (1LL << 63)
	45	/* indicate that the cluster is compressed (they never have the copied flag) */
	46	#define QCOW_OFLAG_COMPRESSED (1LL << 62)
	47
	48	#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
	49
	50	#define MIN_CLUSTER_BITS 9
80ee15a6	51	#define MAX_CLUSTER_BITS 21
f7d0fe02 KW	52
	53	#define L2_CACHE_SIZE 16
	54
29c1a730 KW	55	/* Must be at least 4 to cover all cases of refcount table growth */
	56	#define REFCOUNT_CACHE_SIZE 4
	57
99cce9fa KW	58	#define DEFAULT_CLUSTER_SIZE 65536
99cce9fa KW	59
f7d0fe02 KW	60	typedef struct QCowHeader {
	61	uint32_t magic;
	62	uint32_t version;
	63	uint64_t backing_file_offset;
	64	uint32_t backing_file_size;
	65	uint32_t cluster_bits;
	66	uint64_t size; /* in bytes */
	67	uint32_t crypt_method;
	68	uint32_t l1_size; /* XXX: save number of clusters instead ? */
	69	uint64_t l1_table_offset;
	70	uint64_t refcount_table_offset;
	71	uint32_t refcount_table_clusters;
	72	uint32_t nb_snapshots;
	73	uint64_t snapshots_offset;
	74	} QCowHeader;
	75
	76	typedef struct QCowSnapshot {
	77	uint64_t l1_table_offset;
	78	uint32_t l1_size;
	79	char *id_str;
	80	char *name;
c2c9a466	81	uint64_t vm_state_size;
f7d0fe02 KW	82	uint32_t date_sec;
	83	uint32_t date_nsec;
	84	uint64_t vm_clock_nsec;
	85	} QCowSnapshot;
	86
49381094 KW	87	struct Qcow2Cache;
	88	typedef struct Qcow2Cache Qcow2Cache;
	89
75bab85c KW	90	typedef struct Qcow2UnknownHeaderExtension {
	91	uint32_t magic;
	92	uint32_t len;
	93	QLIST_ENTRY(Qcow2UnknownHeaderExtension) next;
	94	uint8_t data[];
	95	} Qcow2UnknownHeaderExtension;
	96
f7d0fe02	97	typedef struct BDRVQcowState {
f7d0fe02 KW	98	int cluster_bits;
	99	int cluster_size;
	100	int cluster_sectors;
	101	int l2_bits;
	102	int l2_size;
	103	int l1_size;
	104	int l1_vm_state_index;
	105	int csize_shift;
	106	int csize_mask;
	107	uint64_t cluster_offset_mask;
	108	uint64_t l1_table_offset;
	109	uint64_t *l1_table;
29c1a730 KW	110
	111	Qcow2Cache* l2_table_cache;
	112	Qcow2Cache* refcount_block_cache;
	113
f7d0fe02 KW	114	uint8_t *cluster_cache;
	115	uint8_t *cluster_data;
	116	uint64_t cluster_cache_offset;
72cf2d4f	117	QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
f7d0fe02 KW	118
	119	uint64_t *refcount_table;
	120	uint64_t refcount_table_offset;
	121	uint32_t refcount_table_size;
f7d0fe02 KW	122	int64_t free_cluster_index;
	123	int64_t free_byte_offset;
	124
68d100e9 KW	125	CoMutex lock;
68d100e9 KW	126
f7d0fe02 KW	127	uint32_t crypt_method; /* current crypt method, 0 if no key yet */
	128	uint32_t crypt_method_header;
	129	AES_KEY aes_encrypt_key;
	130	AES_KEY aes_decrypt_key;
	131	uint64_t snapshots_offset;
	132	int snapshots_size;
	133	int nb_snapshots;
	134	QCowSnapshot *snapshots;
06d9260f AL	135
06d9260f AL	136	int flags;
75bab85c	137	QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext;
f7d0fe02 KW	138	} BDRVQcowState;
	139
	140	/* XXX: use std qcow open function ? */
	141	typedef struct QCowCreateState {
	142	int cluster_size;
	143	int cluster_bits;
	144	uint16_t *refcount_block;
	145	uint64_t *refcount_table;
	146	int64_t l1_table_offset;
	147	int64_t refcount_table_offset;
	148	int64_t refcount_block_offset;
	149	} QCowCreateState;
	150
f214978a KW	151	struct QCowAIOCB;
f214978a KW	152
45aba42f KW	153	/* XXX This could be private for qcow2-cluster.c */
	154	typedef struct QCowL2Meta
	155	{
	156	uint64_t offset;
148da7ea	157	uint64_t cluster_offset;
45aba42f KW	158	int n_start;
	159	int nb_available;
	160	int nb_clusters;
68d100e9	161	CoQueue dependent_requests;
f214978a	162
72cf2d4f	163	QLIST_ENTRY(QCowL2Meta) next_in_flight;
45aba42f KW	164	} QCowL2Meta;
	165
	166	static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
f7d0fe02 KW	167	{
	168	return (size + (s->cluster_size - 1)) >> s->cluster_bits;
	169	}
	170
419b19d9 SH	171	static inline int size_to_l1(BDRVQcowState *s, int64_t size)
	172	{
	173	int shift = s->cluster_bits + s->l2_bits;
	174	return (size + (1ULL << shift) - 1) >> shift;
	175	}
	176
c142442b KW	177	static inline int64_t align_offset(int64_t offset, int n)
	178	{
	179	offset = (offset + n - 1) & ~(n - 1);
	180	return offset;
	181	}
	182
	183
f7d0fe02 KW	184	// FIXME Need qcow2_ prefix to global functions
	185
	186	/* qcow2.c functions */
bd28f835 KW	187	int qcow2_backing_read1(BlockDriverState bs, QEMUIOVector qiov,
bd28f835 KW	188	int64_t sector_num, int nb_sectors);
e24e49e6	189	int qcow2_update_header(BlockDriverState *bs);
f7d0fe02 KW	190
f7d0fe02 KW	191	/* qcow2-refcount.c functions */
ed6ccf0f KW	192	int qcow2_refcount_init(BlockDriverState *bs);
ed6ccf0f KW	193	void qcow2_refcount_close(BlockDriverState *bs);
f7d0fe02	194
ed6ccf0f	195	int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
256900b1 KW	196	int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset,
256900b1 KW	197	int nb_clusters);
ed6ccf0f KW	198	int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
ed6ccf0f KW	199	void qcow2_free_clusters(BlockDriverState *bs,
45aba42f	200	int64_t offset, int64_t size);
ed6ccf0f	201	void qcow2_free_any_clusters(BlockDriverState *bs,
45aba42f	202	uint64_t cluster_offset, int nb_clusters);
f7d0fe02	203
ed6ccf0f KW	204	int qcow2_update_snapshot_refcount(BlockDriverState *bs,
ed6ccf0f KW	205	int64_t l1_table_offset, int l1_size, int addend);
f7d0fe02	206
9ac228e0	207	int qcow2_check_refcounts(BlockDriverState bs, BdrvCheckResult res);
f7d0fe02	208
45aba42f	209	/* qcow2-cluster.c functions */
72893756	210	int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size);
ed6ccf0f	211	void qcow2_l2_cache_reset(BlockDriverState *bs);
66f82cee	212	int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
ed6ccf0f	213	void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
45aba42f KW	214	uint8_t out_buf, const uint8_t in_buf,
	215	int nb_sectors, int enc,
	216	const AES_KEY *key);
	217
1c46efaa KW	218	int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
1c46efaa KW	219	int num, uint64_t cluster_offset);
f4f0d391 KW	220	int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
f4f0d391 KW	221	int n_start, int n_end, int num, QCowL2Meta m);
ed6ccf0f	222	uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
45aba42f KW	223	uint64_t offset,
	224	int compressed_size);
	225
148da7ea	226	int qcow2_alloc_cluster_link_l2(BlockDriverState bs, QCowL2Meta m);
5ea929e3 KW	227	int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset,
5ea929e3 KW	228	int nb_sectors);
45aba42f	229
c142442b	230	/* qcow2-snapshot.c functions */
ed6ccf0f KW	231	int qcow2_snapshot_create(BlockDriverState bs, QEMUSnapshotInfo sn_info);
	232	int qcow2_snapshot_goto(BlockDriverState bs, const char snapshot_id);
	233	int qcow2_snapshot_delete(BlockDriverState bs, const char snapshot_id);
	234	int qcow2_snapshot_list(BlockDriverState bs, QEMUSnapshotInfo *psn_tab);
51ef6727	235	int qcow2_snapshot_load_tmp(BlockDriverState bs, const char snapshot_name);
c142442b	236
ed6ccf0f KW	237	void qcow2_free_snapshots(BlockDriverState *bs);
ed6ccf0f KW	238	int qcow2_read_snapshots(BlockDriverState *bs);
c142442b	239
49381094 KW	240	/* qcow2-cache.c functions */
	241	Qcow2Cache qcow2_cache_create(BlockDriverState bs, int num_tables,
	242	bool writethrough);
	243	int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c);
93913dfd KW	244	bool qcow2_cache_set_writethrough(BlockDriverState bs, Qcow2Cache c,
93913dfd KW	245	bool enable);
49381094 KW	246
	247	void qcow2_cache_entry_mark_dirty(Qcow2Cache c, void table);
	248	int qcow2_cache_flush(BlockDriverState bs, Qcow2Cache c);
	249	int qcow2_cache_set_dependency(BlockDriverState bs, Qcow2Cache c,
	250	Qcow2Cache *dependency);
3de0a294	251	void qcow2_cache_depends_on_flush(Qcow2Cache *c);
49381094 KW	252
	253	int qcow2_cache_get(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	254	void **table);
	255	int qcow2_cache_get_empty(BlockDriverState bs, Qcow2Cache c, uint64_t offset,
	256	void **table);
	257	int qcow2_cache_put(BlockDriverState bs, Qcow2Cache c, void **table);
	258
f7d0fe02	259	#endif