LXR qemu/block/qcow2.h

   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
  54typedef struct QCowHeader {
  55    uint32_t magic;
  56    uint32_t version;
  57    uint64_t backing_file_offset;
  58    uint32_t backing_file_size;
  59    uint32_t cluster_bits;
  60    uint64_t size; /* in bytes */
  61    uint32_t crypt_method;
  62    uint32_t l1_size; /* XXX: save number of clusters instead ? */
  63    uint64_t l1_table_offset;
  64    uint64_t refcount_table_offset;
  65    uint32_t refcount_table_clusters;
  66    uint32_t nb_snapshots;
  67    uint64_t snapshots_offset;
  68} QCowHeader;
  69
  70typedef struct QCowSnapshot {
  71    uint64_t l1_table_offset;
  72    uint32_t l1_size;
  73    char *id_str;
  74    char *name;
  75    uint32_t vm_state_size;
  76    uint32_t date_sec;
  77    uint32_t date_nsec;
  78    uint64_t vm_clock_nsec;
  79} QCowSnapshot;
  80
  81typedef struct BDRVQcowState {
  82    BlockDriverState *hd;
  83    int cluster_bits;
  84    int cluster_size;
  85    int cluster_sectors;
  86    int l2_bits;
  87    int l2_size;
  88    int l1_size;
  89    int l1_vm_state_index;
  90    int csize_shift;
  91    int csize_mask;
  92    uint64_t cluster_offset_mask;
  93    uint64_t l1_table_offset;
  94    uint64_t *l1_table;
  95    uint64_t *l2_cache;
  96    uint64_t l2_cache_offsets[L2_CACHE_SIZE];
  97    uint32_t l2_cache_counts[L2_CACHE_SIZE];
  98    uint8_t *cluster_cache;
  99    uint8_t *cluster_data;
 100    uint64_t cluster_cache_offset;
 101    QLIST_HEAD(QCowClusterAlloc, QCowL2Meta) cluster_allocs;
 102
 103    uint64_t *refcount_table;
 104    uint64_t refcount_table_offset;
 105    uint32_t refcount_table_size;
 106    uint64_t refcount_block_cache_offset;
 107    uint16_t *refcount_block_cache;
 108    int64_t free_cluster_index;
 109    int64_t free_byte_offset;
 110
 111    uint32_t crypt_method; /* current crypt method, 0 if no key yet */
 112    uint32_t crypt_method_header;
 113    AES_KEY aes_encrypt_key;
 114    AES_KEY aes_decrypt_key;
 115    uint64_t snapshots_offset;
 116    int snapshots_size;
 117    int nb_snapshots;
 118    QCowSnapshot *snapshots;
 119} BDRVQcowState;
 120
 121/* XXX: use std qcow open function ? */
 122typedef struct QCowCreateState {
 123    int cluster_size;
 124    int cluster_bits;
 125    uint16_t *refcount_block;
 126    uint64_t *refcount_table;
 127    int64_t l1_table_offset;
 128    int64_t refcount_table_offset;
 129    int64_t refcount_block_offset;
 130} QCowCreateState;
 131
 132struct QCowAIOCB;
 133
 134/* XXX This could be private for qcow2-cluster.c */
 135typedef struct QCowL2Meta
 136{
 137    uint64_t offset;
 138    uint64_t cluster_offset;
 139    int n_start;
 140    int nb_available;
 141    int nb_clusters;
 142    struct QCowL2Meta *depends_on;
 143    QLIST_HEAD(QCowAioDependencies, QCowAIOCB) dependent_requests;
 144
 145    QLIST_ENTRY(QCowL2Meta) next_in_flight;
 146} QCowL2Meta;
 147
 148static inline int size_to_clusters(BDRVQcowState *s, int64_t size)
 149{
 150    return (size + (s->cluster_size - 1)) >> s->cluster_bits;
 151}
 152
 153static inline int size_to_l1(BDRVQcowState *s, int64_t size)
 154{
 155    int shift = s->cluster_bits + s->l2_bits;
 156    return (size + (1ULL << shift) - 1) >> shift;
 157}
 158
 159static inline int64_t align_offset(int64_t offset, int n)
 160{
 161    offset = (offset + n - 1) & ~(n - 1);
 162    return offset;
 163}
 164
 165
 166// FIXME Need qcow2_ prefix to global functions
 167
 168/* qcow2.c functions */
 169int qcow2_backing_read1(BlockDriverState *bs,
 170                  int64_t sector_num, uint8_t *buf, int nb_sectors);
 171
 172/* qcow2-refcount.c functions */
 173int qcow2_refcount_init(BlockDriverState *bs);
 174void qcow2_refcount_close(BlockDriverState *bs);
 175
 176int64_t qcow2_alloc_clusters(BlockDriverState *bs, int64_t size);
 177int64_t qcow2_alloc_bytes(BlockDriverState *bs, int size);
 178void qcow2_free_clusters(BlockDriverState *bs,
 179    int64_t offset, int64_t size);
 180void qcow2_free_any_clusters(BlockDriverState *bs,
 181    uint64_t cluster_offset, int nb_clusters);
 182
 183void qcow2_create_refcount_update(QCowCreateState *s, int64_t offset,
 184    int64_t size);
 185int qcow2_update_snapshot_refcount(BlockDriverState *bs,
 186    int64_t l1_table_offset, int l1_size, int addend);
 187
 188int qcow2_check_refcounts(BlockDriverState *bs, BdrvCheckResult *res);
 189
 190/* qcow2-cluster.c functions */
 191int qcow2_grow_l1_table(BlockDriverState *bs, int min_size);
 192void qcow2_l2_cache_reset(BlockDriverState *bs);
 193int qcow2_decompress_cluster(BlockDriverState *bs, uint64_t cluster_offset);
 194void qcow2_encrypt_sectors(BDRVQcowState *s, int64_t sector_num,
 195                     uint8_t *out_buf, const uint8_t *in_buf,
 196                     int nb_sectors, int enc,
 197                     const AES_KEY *key);
 198
 199int qcow2_get_cluster_offset(BlockDriverState *bs, uint64_t offset,
 200    int *num, uint64_t *cluster_offset);
 201int qcow2_alloc_cluster_offset(BlockDriverState *bs, uint64_t offset,
 202    int n_start, int n_end, int *num, QCowL2Meta *m);
 203uint64_t qcow2_alloc_compressed_cluster_offset(BlockDriverState *bs,
 204                                         uint64_t offset,
 205                                         int compressed_size);
 206
 207int qcow2_alloc_cluster_link_l2(BlockDriverState *bs, QCowL2Meta *m);
 208
 209/* qcow2-snapshot.c functions */
 210int qcow2_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);
 211int qcow2_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);
 212int qcow2_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
 213int qcow2_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);
 214
 215void qcow2_free_snapshots(BlockDriverState *bs);
 216int qcow2_read_snapshots(BlockDriverState *bs);
 217
 218#endif
 219