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 uint32_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 } BDRVQcowState; 129 130 /* XXX: use std qcow open function ? */ 131 typedef struct QCowCreateState { 132 int cluster_size; 133 int cluster_bits; 134 uint16_t *refcount_block; 135 uint64_t *refcount_table; 136 int64_t l1_table_offset; 137 int64_t refcount_table_offset; 138 int64_t refcount_block_offset; 139 } QCowCreateState; 140 141 struct QCowAIOCB; 142 143 /* XXX This could be private for qcow2-cluster.c */ 144 typedef struct QCowL2Meta 145 { 146 uint64_t offset; 147 uint64_t cluster_offset; 148 int n_start; 149 int nb_available; 150 int nb_clusters; 151 CoQueue dependent_requests; 152 153 QLIST_ENTRY(QCowL2Meta) next_in_flight; 154 } QCowL2Meta; 155 156 static inline int size_to_clusters(BDRVQcowState *s, int64_t size) 157 { 158 return (size + (s->cluster_size - 1)) >> s->cluster_bits; 159 } 160 161 static inline int size_to_l1(BDRVQcowState *s, int64_t size) 162 { 163 int shift = s->cluster_bits + s->l2_bits; 164 return (size + (1ULL << shift) - 1) >> shift; 165 } 166 167 static inline int64_t align_offset(int64_t offset, int n) 168 { 169 offset = (offset + n - 1) & ~(n - 1); 170 return offset; 171 } 172 173 174 // FIXME Need qcow2_ prefix to global functions 175 176 /* qcow2.c functions */ 177 int qcow2_backing_read1(BlockDriverState *bs, QEMUIOVector *qiov, 178 int64_t sector_num, int nb_sectors); 179 180 /* qcow2-refcount.c functions */ 181 int qcow2_refcount_init(BlockDriverState *bs); 182 void qcow2_refcount_close(BlockDriverState *bs); 183 184 int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size); 185 int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size); 186 void qcow2_free_clusters(BlockDriverState *bs, 187 int64_t offset, int64_t size); 188 void qcow2_free_any_clusters(BlockDriverState *bs, 189 uint64_t cluster_offset, int nb_clusters); 190 191 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 bool qcow2_cache_set_writethrough(BlockDriverState *bs, Qcow2Cache *c, 232 bool enable); 233 234 void qcow2_cache_entry_mark_dirty(Qcow2Cache *c, void *table); 235 int qcow2_cache_flush(BlockDriverState *bs, Qcow2Cache *c); 236 int qcow2_cache_set_dependency(BlockDriverState *bs, Qcow2Cache *c, 237 Qcow2Cache *dependency); 238 void qcow2_cache_depends_on_flush(Qcow2Cache *c); 239 240 int qcow2_cache_get(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 241 void **table); 242 int qcow2_cache_get_empty(BlockDriverState *bs, Qcow2Cache *c, uint64_t offset, 243 void **table); 244 int qcow2_cache_put(BlockDriverState *bs, Qcow2Cache *c, void **table); 245 246 #endif 247