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"
29
30//#define DEBUG_ALLOC
31//#define DEBUG_ALLOC2
32//#define DEBUG_EXT
33
34#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)
35#define QCOW_VERSION 2
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)
46
47#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */
48
49#define MIN_CLUSTER_BITS 9
50#define MAX_CLUSTER_BITS 21
51
52#define L2_CACHE_SIZE 16
53
54typedef struct QCowHeader {
55    uint32_t magic;
56    uint32_t version;
57    uint64_t backing_file_offset;
58    uint32_t backing_file_size;
59    uint32_t cluster_bits;
60    uint64_t size; /* in bytes */
61    uint32_t crypt_method;
62    uint32_t l1_size; /* XXX: save number of clusters instead ? */
63    uint64_t l1_table_offset;
64    uint64_t refcount_table_offset;
65    uint32_t refcount_table_clusters;
66    uint32_t nb_snapshots;
67    uint64_t snapshots_offset;
68} QCowHeader;
69
70typedef struct QCowSnapshot {
71    uint64_t l1_table_offset;
72    uint32_t l1_size;
73    char *id_str;
74    char *name;
75    uint32_t vm_state_size;
76    uint32_t date_sec;
77    uint32_t date_nsec;
78    uint64_t vm_clock_nsec;
79} QCowSnapshot;
80
81typedef struct BDRVQcowState {
82    BlockDriverState *hd;
83    int cluster_bits;
84    int cluster_size;
85    int cluster_sectors;
86    int l2_bits;
87    int l2_size;
88    int l1_size;
89    int l1_vm_state_index;
90    int csize_shift;
91    int csize_mask;
92    uint64_t cluster_offset_mask;
93    uint64_t l1_table_offset;
94    uint64_t *l1_table;
95    uint64_t *l2_cache;
96    uint64_t l2_cache_offsets[L2_CACHE_SIZE];
97    uint32_t l2_cache_counts[L2_CACHE_SIZE];
98    uint8_t *cluster_cache;
99    uint8_t *cluster_data;
100    uint64_t cluster_cache_offset;
101    QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
102
103    uint64_t *refcount_table;
104    uint64_t refcount_table_offset;
105    uint32_t refcount_table_size;
106    uint64_t refcount_block_cache_offset;
107    uint16_t *refcount_block_cache;
108    int64_t free_cluster_index;
109    int64_t free_byte_offset;
110
111    uint32_t crypt_method; /* current crypt method, 0 if no key yet */
112    uint32_t crypt_method_header;
113    AES_KEY aes_encrypt_key;
114    AES_KEY aes_decrypt_key;
115    uint64_t snapshots_offset;
116    int snapshots_size;
117    int nb_snapshots;
118    QCowSnapshot *snapshots;
119} BDRVQcowState;
120
121/* XXX: use std qcow open function ? */
122typedef struct QCowCreateState {
123    int cluster_size;
124    int cluster_bits;
125    uint16_t *refcount_block;
126    uint64_t *refcount_table;
127    int64_t l1_table_offset;
128    int64_t refcount_table_offset;
129    int64_t refcount_block_offset;
130} QCowCreateState;
131
132struct QCowAIOCB;
133
134/* XXX This could be private for qcow2-cluster.c */
135typedef struct QCowL2Meta
136{
137    uint64_t offset;
138    uint64_t cluster_offset;
139    int n_start;
140    int nb_available;
141    int nb_clusters;
142    struct QCowL2Meta *depends_on;
143    QLIST_HEAD(QCowAioDependencies, QCowAIOCB) dependent_requests;
144
145    QLIST_ENTRY(QCowL2Meta) next_in_flight;
146} QCowL2Meta;
147
148static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
149{
150    return (size + (s->cluster_size - 1)) >> s->cluster_bits;
151}
152
153static inline int size_to_l1(BDRVQcowState *s, int64_t size)
154{
155    int shift = s->cluster_bits + s->l2_bits;
156    return (size + (1ULL << shift) - 1) >> shift;
157}
158
159static inline int64_t align_offset(int64_t offset, int n)
160{
161    offset = (offset + n - 1) & ~(n - 1);
162    return offset;
163}
164
165
166// FIXME Need qcow2_ prefix to global functions
167
168/* qcow2.c functions */
169int qcow2_backing_read1(BlockDriverState *bs,
170                  int64_t sector_num, uint8_t *buf, int nb_sectors);
171
172/* qcow2-refcount.c functions */
173int qcow2_refcount_init(BlockDriverState *bs);
174void qcow2_refcount_close(BlockDriverState *bs);
175
176int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
177int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
178void qcow2_free_clusters(BlockDriverState *bs,
179    int64_t offset, int64_t size);
180void qcow2_free_any_clusters(BlockDriverState *bs,
181    uint64_t cluster_offset, int nb_clusters);
182
183void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset,
184    int64_t size);
185int qcow2_update_snapshot_refcount(BlockDriverState *bs,
186    int64_t l1_table_offset, int l1_size, int addend);
187
188int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res);
189
190/* qcow2-cluster.c functions */
191int qcow2_grow_l1_table(BlockDriverState *bs, int min_size);
192void qcow2_l2_cache_reset(BlockDriverState *bs);
193int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
194void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
195                     uint8_t *out_buf, const uint8_t *in_buf,
196                     int nb_sectors, int enc,
197                     const AES_KEY *key);
198
199int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
200    int *num, uint64_t *cluster_offset);
201int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
202    int n_start, int n_end, int *num, QCowL2Meta *m);
203uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
204                                         uint64_t offset,
205                                         int compressed_size);
206
207int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
208
209/* qcow2-snapshot.c functions */
210int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
211int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
212int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
213int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
214
215void qcow2_free_snapshots(BlockDriverState *bs);
216int qcow2_read_snapshots(BlockDriverState *bs);
217
218#endif
219