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 BDRVQcowState { 91 int cluster_bits; 92 int cluster_size; 93 int cluster_sectors; 94 int l2_bits; 95 int l2_size; 96 int l1_size; 97 int l1_vm_state_index; 98 int csize_shift; 99 int csize_mask; 100 uint64_t cluster_offset_mask; 101 uint64_t l1_table_offset; 102 uint64_t *l1_table; 103 104 Qcow2Cache* l2_table_cache; 105 Qcow2Cache* refcount_block_cache; 106 107 uint8_t *cluster_cache; 108 uint8_t *cluster_data; 109 uint64_t cluster_cache_offset; 110 QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs; 111 112 uint64_t *refcount_table; 113 uint64_t refcount_table_offset; 114 uint32_t refcount_table_size; 115 int64_t free_cluster_index; 116 int64_t free_byte_offset; 117 118 CoMutex lock; 119 120 uint32_t crypt_method; /* current crypt method, 0 if no key yet */ 121 uint32_t crypt_method_header; 122 AES_KEY aes_encrypt_key; 123 AES_KEY aes_decrypt_key; 124 uint64_t snapshots_offset; 125 int snapshots_size; 126 int nb_snapshots; 127 QCowSnapshot *snapshots; 128 129 int flags; 130 } BDRVQcowState; 131 132 /* XXX: use std qcow open function ? */ 133 typedef struct QCowCreateState { 134 int cluster_size; 135 int cluster_bits; 136 uint16_t *refcount_block; 137 uint64_t *refcount_table; 138 int64_t l1_table_offset; 139 int64_t refcount_table_offset; 140 int64_t refcount_block_offset; 141 } QCowCreateState; 142 143 struct QCowAIOCB; 144 145 /* XXX This could be private for qcow2-cluster.c */ 146 typedef struct QCowL2Meta 147 { 148 uint64_t offset; 149 uint64_t cluster_offset; 150 int n_start; 151 int nb_available; 152 int nb_clusters; 153 CoQueue dependent_requests; 154 155 QLIST_ENTRY(QCowL2Meta) next_in_flight; 156 } QCowL2Meta; 157 158 static inline int size_to_clusters(BDRVQcowState *s, int64_t size) 159 { 160 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 161 } 162 163 static inline int size_to_l1(BDRVQcowState *s, int64_t size) 164 { 165 int shift = s->cluster_bits + s->l2_bits; 166 return (size + (1ULL << shift) - 1) >> shift; 167 } 168 169 static inline int64_t align_offset(int64_t offset, int n) 170 { 171 offset = (offset + n - 1) & ~(n - 1); 172 return offset; 173 } 174 175 176 // FIXME Need qcow2_ prefix to global functions 177 178 /* qcow2.c functions */ 179 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, 180 int64_t sector_num, int nb_sectors); 181 182 /* qcow2-refcount.c functions */ 183 int qcow2_refcount_init(BlockDriverState *bs); 184 void qcow2_refcount_close(BlockDriverState *bs); 185 186 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size); 187 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 188 void qcow2_free_clusters(BlockDriverState *bs, 189 int64_t offset, int64_t size); 190 void qcow2_free_any_clusters(BlockDriverState *bs, 191 uint64_t cluster_offset, int nb_clusters); 192 193 int qcow2_update_snapshot_refcount(BlockDriverState *bs, 194 int64_t l1_table_offset, int l1_size, int addend); 195 196 int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res); 197 198 /* qcow2-cluster.c functions */ 199 int qcow2_grow_l1_table(BlockDriverState *bs, int min_size, bool exact_size); 200 void qcow2_l2_cache_reset(BlockDriverState *bs); 201 int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset); 202 void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num, 203 uint8_t *out_buf, const uint8_t *in_buf, 204 int nb_sectors, int enc, 205 const AES_KEY *key); 206 207 int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset, 208 int *num, uint64_t *cluster_offset); 209 int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset, 210 int n_start, int n_end, int *num, QCowL2Meta *m); 211 uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs, 212 uint64_t offset, 213 int compressed_size); 214 215 int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m); 216 int qcow2_discard_clusters(BlockDriverState *bs, uint64_t offset, 217 int nb_sectors); 218 219 /* qcow2-snapshot.c functions */ 220 int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info); 221 int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id); 222 int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id); 223 int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab); 224 int qcow2_snapshot_load_tmp(BlockDriverState *bs, const char *snapshot_name); 225 226 void qcow2_free_snapshots(BlockDriverState *bs); 227 int qcow2_read_snapshots(BlockDriverState *bs); 228 229 /* qcow2-cache.c functions */ 230 Qcow2Cache *qcow2_cache_create(BlockDriverState *bs, int num_tables, 231 bool writethrough); 232 int qcow2_cache_destroy(BlockDriverState* bs, Qcow2Cache *c); 233 bool qcow2_cache_set_writethrough(BlockDriverState *bs, Qcow2Cache *c, 234 bool enable); 235 236 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 237 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 238 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 239 Qcow2Cache *dependency); 240 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 241 242 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 243 void **table); 244 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 245 void **table); 246 int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); 247 248 #endif 249