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 /* Must be at least 4 to cover all cases of refcount table growth */ 55 #define REFCOUNT_CACHE_SIZE 4 56 57 #define DEFAULT_CLUSTER_SIZE 65536 58 59 typedef struct QCowHeader { 60 uint32_t magic; 61 uint32_t version; 62 uint64_t backing_file_offset; 63 uint32_t backing_file_size; 64 uint32_t cluster_bits; 65 uint64_t size; /* in bytes */ 66 uint32_t crypt_method; 67 uint32_t l1_size; /* XXX: save number of clusters instead ? */ 68 uint64_t l1_table_offset; 69 uint64_t refcount_table_offset; 70 uint32_t refcount_table_clusters; 71 uint32_t nb_snapshots; 72 uint64_t snapshots_offset; 73 } QCowHeader; 74 75 typedef struct QCowSnapshot { 76 uint64_t l1_table_offset; 77 uint32_t l1_size; 78 char *id_str; 79 char *name; 80 uint32_t vm_state_size; 81 uint32_t date_sec; 82 uint32_t date_nsec; 83 uint64_t vm_clock_nsec; 84 } QCowSnapshot; 85 86 struct Qcow2Cache; 87 typedef struct Qcow2Cache Qcow2Cache; 88 89 typedef struct BDRVQcowState { 90 int cluster_bits; 91 int cluster_size; 92 int cluster_sectors; 93 int l2_bits; 94 int l2_size; 95 int l1_size; 96 int l1_vm_state_index; 97 int csize_shift; 98 int csize_mask; 99 uint64_t cluster_offset_mask; 100 uint64_t l1_table_offset; 101 uint64_t *l1_table; 102 103 Qcow2Cache* l2_table_cache; 104 Qcow2Cache* refcount_block_cache; 105 106 uint8_t *cluster_cache; 107 uint8_t *cluster_data; 108 uint64_t cluster_cache_offset; 109 QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs; 110 111 uint64_t *refcount_table; 112 uint64_t refcount_table_offset; 113 uint32_t refcount_table_size; 114 int64_t free_cluster_index; 115 int64_t free_byte_offset; 116 117 uint32_t crypt_method; /* current crypt method, 0 if no key yet */ 118 uint32_t crypt_method_header; 119 AES_KEY aes_encrypt_key; 120 AES_KEY aes_decrypt_key; 121 uint64_t snapshots_offset; 122 int snapshots_size; 123 int nb_snapshots; 124 QCowSnapshot *snapshots; 125 } BDRVQcowState; 126 127 /* XXX: use std qcow open function ? */ 128 typedef struct QCowCreateState { 129 int cluster_size; 130 int cluster_bits; 131 uint16_t *refcount_block; 132 uint64_t *refcount_table; 133 int64_t l1_table_offset; 134 int64_t refcount_table_offset; 135 int64_t refcount_block_offset; 136 } QCowCreateState; 137 138 struct QCowAIOCB; 139 140 /* XXX This could be private for qcow2-cluster.c */ 141 typedef struct QCowL2Meta 142 { 143 uint64_t offset; 144 uint64_t cluster_offset; 145 int n_start; 146 int nb_available; 147 int nb_clusters; 148 struct QCowL2Meta *depends_on; 149 QLIST_HEAD(QCowAioDependencies, QCowAIOCB) dependent_requests; 150 151 QLIST_ENTRY(QCowL2Meta) next_in_flight; 152 } QCowL2Meta; 153 154 static inline int size_to_clusters(BDRVQcowState *s, int64_t size) 155 { 156 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 157 } 158 159 static inline int size_to_l1(BDRVQcowState *s, int64_t size) 160 { 161 int shift = s->cluster_bits + s->l2_bits; 162 return (size + (1ULL << shift) - 1) >> shift; 163 } 164 165 static inline int64_t align_offset(int64_t offset, int n) 166 { 167 offset = (offset + n - 1) & ~(n - 1); 168 return offset; 169 } 170 171 172 // FIXME Need qcow2_ prefix to global functions 173 174 /* qcow2.c functions */ 175 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, 176 int64_t sector_num, int nb_sectors); 177 178 /* qcow2-refcount.c functions */ 179 int qcow2_refcount_init(BlockDriverState *bs); 180 void qcow2_refcount_close(BlockDriverState *bs); 181 182 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size); 183 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 184 void qcow2_free_clusters(BlockDriverState *bs, 185 int64_t offset, int64_t size); 186 void qcow2_free_any_clusters(BlockDriverState *bs, 187 uint64_t cluster_offset, int nb_clusters); 188 189 void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset, 190 int64_t size); 191 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 192 int64_t l1_table_offset, int l1_size, int addend); 193 194 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res); 195 196 /* qcow2-cluster.c functions */ 197 int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size); 198 void qcow2_l2_cache_reset(BlockDriverState *bs); 199 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 200 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, 201 uint8_t *out_buf, const uint8_t *in_buf, 202 int nb_sectors, int enc, 203 const AES_KEY *key); 204 205 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 206 int *num, uint64_t *cluster_offset); 207 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 208 int n_start, int n_end, int *num, QCowL2Meta *m); 209 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 210 uint64_t offset, 211 int compressed_size); 212 213 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 214 int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, 215 int nb_sectors); 216 217 /* qcow2-snapshot.c functions */ 218 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 219 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 220 int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); 221 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 222 int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name); 223 224 void qcow2_free_snapshots(BlockDriverState *bs); 225 int qcow2_read_snapshots(BlockDriverState *bs); 226 227 /* qcow2-cache.c functions */ 228 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, 229 bool writethrough); 230 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c); 231 232 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 233 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 234 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 235 Qcow2Cache *dependency); 236 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 237 238 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 239 void **table); 240 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 241 void **table); 242 int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); 243 244 #endif 245