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
54 typedef 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
70 typedef 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
81 typedef 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 ? */
122 typedef 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
132 struct QCowAIOCB;
133
134 /* XXX This could be private for qcow2-cluster.c */
135 typedef 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
size_to_clusters(BDRVQcowState * s,int64_t size)148 static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
149 {
150 return (size + (s->cluster_size - 1)) >> s->cluster_bits;
151 }
152
size_to_l1(BDRVQcowState * s,int64_t size)153 static 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
align_offset(int64_t offset,int n)159 static 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 */
169 int qcow2_backing_read1(BlockDriverState *bs,
170 int64_t sector_num, uint8_t *buf, int nb_sectors);
171
172 /* qcow2-refcount.c functions */
173 int qcow2_refcount_init(BlockDriverState *bs);
174 void qcow2_refcount_close(BlockDriverState *bs);
175
176 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
177 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
178 void qcow2_free_clusters(BlockDriverState *bs,
179 int64_t offset, int64_t size);
180 void qcow2_free_any_clusters(BlockDriverState *bs,
181 uint64_t cluster_offset, int nb_clusters);
182
183 void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset,
184 int64_t size);
185 int qcow2_update_snapshot_refcount(BlockDriverState *bs,
186 int64_t l1_table_offset, int l1_size, int addend);
187
188 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res);
189
190 /* qcow2-cluster.c functions */
191 int qcow2_grow_l1_table(BlockDriverState *bs, int min_size);
192 void qcow2_l2_cache_reset(BlockDriverState *bs);
193 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
194 void 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
199 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
200 int *num, uint64_t *cluster_offset);
201 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
202 int n_start, int n_end, int *num, QCowL2Meta *m);
203 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
204 uint64_t offset,
205 int compressed_size);
206
207 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
208
209 /* qcow2-snapshot.c functions */
210 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
211 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
212 int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
213 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
214
215 void qcow2_free_snapshots(BlockDriverState *bs);
216 int qcow2_read_snapshots(BlockDriverState *bs);
217
218 #endif
219