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 #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 51 #define MAX_CLUSTER_BITS 21 52 53 #define L2_CACHE_SIZE 16 54 55 /* Must be at least 4 to cover all cases of refcount table growth */ 56 #define REFCOUNT_CACHE_SIZE 4 57 58 #define DEFAULT_CLUSTER_SIZE 65536 59 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; 81 uint64_t vm_state_size; 82 uint32_t date_sec; 83 uint32_t date_nsec; 84 uint64_t vm_clock_nsec; 85 } QCowSnapshot; 86 87 struct Qcow2Cache; 88 typedef struct Qcow2Cache Qcow2Cache; 89 90 typedef struct Qcow2UnknownHeaderExtension { 91 uint32_t magic; 92 uint32_t len; 93 QLIST_ENTRY(Qcow2UnknownHeaderExtension) next; 94 uint8_t data[]; 95 } Qcow2UnknownHeaderExtension; 96 97 typedef struct BDRVQcowState { 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; 110 111 Qcow2Cache* l2_table_cache; 112 Qcow2Cache* refcount_block_cache; 113 114 uint8_t *cluster_cache; 115 uint8_t *cluster_data; 116 uint64_t cluster_cache_offset; 117 QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs; 118 119 uint64_t *refcount_table; 120 uint64_t refcount_table_offset; 121 uint32_t refcount_table_size; 122 int64_t free_cluster_index; 123 int64_t free_byte_offset; 124 125 CoMutex lock; 126 127 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; 135 136 int flags; 137 QLIST_HEAD(, Qcow2UnknownHeaderExtension) unknown_header_ext; 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; 150 151 struct QCowAIOCB; 152 153 /* XXX This could be private for qcow2-cluster.c */ 154 typedef struct QCowL2Meta 155 { 156 uint64_t offset; 157 uint64_t cluster_offset; 158 int n_start; 159 int nb_available; 160 int nb_clusters; 161 CoQueue dependent_requests; 162 163 QLIST_ENTRY(QCowL2Meta) next_in_flight; 164 } QCowL2Meta; 165 166 static inline int size_to_clusters(BDRVQcowState *s, int64_t size) 167 { 168 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 169 } 170 171 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 } 176 177 static inline int64_t align_offset(int64_t offset, int n) 178 { 179 offset = (offset + n - 1) & ~(n - 1); 180 return offset; 181 } 182 183 184 // FIXME Need qcow2_ prefix to global functions 185 186 /* qcow2.c functions */ 187 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, 188 int64_t sector_num, int nb_sectors); 189 int qcow2_update_header(BlockDriverState *bs); 190 191 /* qcow2-refcount.c functions */ 192 int qcow2_refcount_init(BlockDriverState *bs); 193 void qcow2_refcount_close(BlockDriverState *bs); 194 195 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size); 196 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 197 void qcow2_free_clusters(BlockDriverState *bs, 198 int64_t offset, int64_t size); 199 void qcow2_free_any_clusters(BlockDriverState *bs, 200 uint64_t cluster_offset, int nb_clusters); 201 202 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 203 int64_t l1_table_offset, int l1_size, int addend); 204 205 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res); 206 207 /* qcow2-cluster.c functions */ 208 int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size); 209 void qcow2_l2_cache_reset(BlockDriverState *bs); 210 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 211 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, 212 uint8_t *out_buf, const uint8_t *in_buf, 213 int nb_sectors, int enc, 214 const AES_KEY *key); 215 216 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 217 int *num, uint64_t *cluster_offset); 218 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 219 int n_start, int n_end, int *num, QCowL2Meta *m); 220 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 221 uint64_t offset, 222 int compressed_size); 223 224 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 225 int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, 226 int nb_sectors); 227 228 /* qcow2-snapshot.c functions */ 229 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 230 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 231 int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); 232 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 233 int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name); 234 235 void qcow2_free_snapshots(BlockDriverState *bs); 236 int qcow2_read_snapshots(BlockDriverState *bs); 237 238 /* qcow2-cache.c functions */ 239 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, 240 bool writethrough); 241 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c); 242 bool qcow2_cache_set_writethrough(BlockDriverState *bs, Qcow2Cache *c, 243 bool enable); 244 245 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 246 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 247 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 248 Qcow2Cache *dependency); 249 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 250 251 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 252 void **table); 253 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 254 void **table); 255 int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); 256 257 #endif 258