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 #include "qemu-coroutine.h" 30 31 //#define DEBUG_ALLOC 32 //#define DEBUG_ALLOC2 33 //#define DEBUG_EXT 34 35 #define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb) 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 /* The cluster reads as all zeros */ 47 #define QCOW_OFLAG_ZERO (1LL << 0) 48 49 #define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */ 50 51 #define MIN_CLUSTER_BITS 9 52 #define MAX_CLUSTER_BITS 21 53 54 #define L2_CACHE_SIZE 16 55 56 /* Must be at least 4 to cover all cases of refcount table growth */ 57 #define REFCOUNT_CACHE_SIZE 4 58 59 #define DEFAULT_CLUSTER_SIZE 65536 60 61 typedef struct QCowHeader { 62 uint32_t magic; 63 uint32_t version; 64 uint64_t backing_file_offset; 65 uint32_t backing_file_size; 66 uint32_t cluster_bits; 67 uint64_t size; /* in bytes */ 68 uint32_t crypt_method; 69 uint32_t l1_size; /* XXX: save number of clusters instead ? */ 70 uint64_t l1_table_offset; 71 uint64_t refcount_table_offset; 72 uint32_t refcount_table_clusters; 73 uint32_t nb_snapshots; 74 uint64_t snapshots_offset; 75 76 /* The following fields are only valid for version >= 3 */ 77 uint64_t incompatible_features; 78 uint64_t compatible_features; 79 uint64_t autoclear_features; 80 81 uint32_t refcount_order; 82 uint32_t header_length; 83 } QCowHeader; 84 85 typedef struct QCowSnapshot { 86 uint64_t l1_table_offset; 87 uint32_t l1_size; 88 char *id_str; 89 char *name; 90 uint64_t disk_size; 91 uint64_t vm_state_size; 92 uint32_t date_sec; 93 uint32_t date_nsec; 94 uint64_t vm_clock_nsec; 95 } QCowSnapshot; 96 97 struct Qcow2Cache; 98 typedef struct Qcow2Cache Qcow2Cache; 99 100 typedef struct Qcow2UnknownHeaderExtension { 101 uint32_t magic; 102 uint32_t len; 103 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; 104 uint8_t data[]; 105 } Qcow2UnknownHeaderExtension; 106 107 enum { 108 QCOW2_FEAT_TYPE_INCOMPATIBLE = 0, 109 QCOW2_FEAT_TYPE_COMPATIBLE = 1, 110 QCOW2_FEAT_TYPE_AUTOCLEAR = 2, 111 }; 112 113 typedef struct Qcow2Feature { 114 uint8_t type; 115 uint8_t bit; 116 char name[46]; 117 } QEMU_PACKED Qcow2Feature; 118 119 typedef struct BDRVQcowState { 120 int cluster_bits; 121 int cluster_size; 122 int cluster_sectors; 123 int l2_bits; 124 int l2_size; 125 int l1_size; 126 int l1_vm_state_index; 127 int csize_shift; 128 int csize_mask; 129 uint64_t cluster_offset_mask; 130 uint64_t l1_table_offset; 131 uint64_t *l1_table; 132 133 Qcow2Cache* l2_table_cache; 134 Qcow2Cache* refcount_block_cache; 135 136 uint8_t *cluster_cache; 137 uint8_t *cluster_data; 138 uint64_t cluster_cache_offset; 139 QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs; 140 141 uint64_t *refcount_table; 142 uint64_t refcount_table_offset; 143 uint32_t refcount_table_size; 144 int64_t free_cluster_index; 145 int64_t free_byte_offset; 146 147 CoMutex lock; 148 149 uint32_t crypt_method; /* current crypt method, 0 if no key yet */ 150 uint32_t crypt_method_header; 151 AES_KEY aes_encrypt_key; 152 AES_KEY aes_decrypt_key; 153 uint64_t snapshots_offset; 154 int snapshots_size; 155 int nb_snapshots; 156 QCowSnapshot *snapshots; 157 158 int flags; 159 int qcow_version; 160 161 uint64_t incompatible_features; 162 uint64_t compatible_features; 163 uint64_t autoclear_features; 164 165 size_t unknown_header_fields_size; 166 void* unknown_header_fields; 167 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; 168 } BDRVQcowState; 169 170 /* XXX: use std qcow open function ? */ 171 typedef struct QCowCreateState { 172 int cluster_size; 173 int cluster_bits; 174 uint16_t *refcount_block; 175 uint64_t *refcount_table; 176 int64_t l1_table_offset; 177 int64_t refcount_table_offset; 178 int64_t refcount_block_offset; 179 } QCowCreateState; 180 181 struct QCowAIOCB; 182 183 /* XXX This could be private for qcow2-cluster.c */ 184 typedef struct QCowL2Meta 185 { 186 uint64_t offset; 187 uint64_t cluster_offset; 188 uint64_t alloc_offset; 189 int n_start; 190 int nb_available; 191 int nb_clusters; 192 CoQueue dependent_requests; 193 194 QLIST_ENTRY(QCowL2Meta) next_in_flight; 195 } QCowL2Meta; 196 197 enum { 198 QCOW2_CLUSTER_UNALLOCATED, 199 QCOW2_CLUSTER_NORMAL, 200 QCOW2_CLUSTER_COMPRESSED, 201 QCOW2_CLUSTER_ZERO 202 }; 203 204 #define L1E_OFFSET_MASK 0x00ffffffffffff00ULL 205 #define L2E_OFFSET_MASK 0x00ffffffffffff00ULL 206 #define L2E_COMPRESSED_OFFSET_SIZE_MASK 0x3fffffffffffffffULL 207 208 #define REFT_OFFSET_MASK 0xffffffffffffff00ULL 209 210 static inline int size_to_clusters(BDRVQcowState *s, int64_t size) 211 { 212 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 213 } 214 215 static inline int size_to_l1(BDRVQcowState *s, int64_t size) 216 { 217 int shift = s->cluster_bits + s->l2_bits; 218 return (size + (1ULL << shift) - 1) >> shift; 219 } 220 221 static inline int64_t align_offset(int64_t offset, int n) 222 { 223 offset = (offset + n - 1) & ~(n - 1); 224 return offset; 225 } 226 227 static inline int qcow2_get_cluster_type(uint64_t l2_entry) 228 { 229 if (l2_entry & QCOW_OFLAG_COMPRESSED) { 230 return QCOW2_CLUSTER_COMPRESSED; 231 } else if (l2_entry & QCOW_OFLAG_ZERO) { 232 return QCOW2_CLUSTER_ZERO; 233 } else if (!(l2_entry & L2E_OFFSET_MASK)) { 234 return QCOW2_CLUSTER_UNALLOCATED; 235 } else { 236 return QCOW2_CLUSTER_NORMAL; 237 } 238 } 239 240 241 // FIXME Need qcow2_ prefix to global functions 242 243 /* qcow2.c functions */ 244 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, 245 int64_t sector_num, int nb_sectors); 246 int qcow2_update_header(BlockDriverState *bs); 247 248 /* qcow2-refcount.c functions */ 249 int qcow2_refcount_init(BlockDriverState *bs); 250 void qcow2_refcount_close(BlockDriverState *bs); 251 252 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size); 253 int qcow2_alloc_clusters_at(BlockDriverState *bs, uint64_t offset, 254 int nb_clusters); 255 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 256 void qcow2_free_clusters(BlockDriverState *bs, 257 int64_t offset, int64_t size); 258 void qcow2_free_any_clusters(BlockDriverState *bs, 259 uint64_t cluster_offset, int nb_clusters); 260 261 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 262 int64_t l1_table_offset, int l1_size, int addend); 263 264 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res, 265 BdrvCheckMode fix); 266 267 /* qcow2-cluster.c functions */ 268 int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size); 269 void qcow2_l2_cache_reset(BlockDriverState *bs); 270 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 271 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, 272 uint8_t *out_buf, const uint8_t *in_buf, 273 int nb_sectors, int enc, 274 const AES_KEY *key); 275 276 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 277 int *num, uint64_t *cluster_offset); 278 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 279 int n_start, int n_end, int *num, QCowL2Meta *m); 280 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 281 uint64_t offset, 282 int compressed_size); 283 284 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 285 int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, 286 int nb_sectors); 287 int qcow2_zero_clusters(BlockDriverState *bs, uint64_t offset, int nb_sectors); 288 289 /* qcow2-snapshot.c functions */ 290 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 291 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 292 int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); 293 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 294 int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name); 295 296 void qcow2_free_snapshots(BlockDriverState *bs); 297 int qcow2_read_snapshots(BlockDriverState *bs); 298 299 /* qcow2-cache.c functions */ 300 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables); 301 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c); 302 303 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 304 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 305 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 306 Qcow2Cache *dependency); 307 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 308 309 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 310 void **table); 311 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 312 void **table); 313 int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); 314 315 #endif 316