Archipelago » qemu

/*

 * Block driver for the QCOW version 2 format

 *

 * Copyright (c) 2004-2006 Fabrice Bellard

 *

 * Permission is hereby granted, free of charge, to any person obtaining a copy

 * of this software and associated documentation files (the "Software"), to deal

 * in the Software without restriction, including without limitation the rights

 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell

 * copies of the Software, and to permit persons to whom the Software is

 * furnished to do so, subject to the following conditions:

 *

 * The above copyright notice and this permission notice shall be included in

 * all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,

 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER

 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,

 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN

 * THE SOFTWARE.

 */

#ifndef BLOCK_QCOW2_H

#define BLOCK_QCOW2_H

#include "aes.h"

#define QCOW_MAGIC (('Q' << 24) | ('F' << 16) | ('I' << 8) | 0xfb)

#define QCOW_VERSION 2

#define QCOW_CRYPT_NONE 0

#define QCOW_CRYPT_AES  1

#define QCOW_MAX_CRYPT_CLUSTERS 32

/* indicate that the refcount of the referenced cluster is exactly one. */

#define QCOW_OFLAG_COPIED     (1LL << 63)

/* indicate that the cluster is compressed (they never have the copied flag) */

#define QCOW_OFLAG_COMPRESSED (1LL << 62)

#define REFCOUNT_SHIFT 1 /* refcount size is 2 bytes */

#define MIN_CLUSTER_BITS 9

#define MAX_CLUSTER_BITS 16

#define L2_CACHE_SIZE 16

typedef struct QCowHeader {

    uint32_t magic;

    uint32_t version;

    uint64_t backing_file_offset;

    uint32_t backing_file_size;

    uint32_t cluster_bits;

    uint64_t size; /* in bytes */

    uint32_t crypt_method;

    uint32_t l1_size; /* XXX: save number of clusters instead ? */

    uint64_t l1_table_offset;

    uint64_t refcount_table_offset;

    uint32_t refcount_table_clusters;

    uint32_t nb_snapshots;

    uint64_t snapshots_offset;

} QCowHeader;

typedef struct QCowSnapshot {

    uint64_t l1_table_offset;

    uint32_t l1_size;

    char *id_str;

    char *name;

    uint32_t vm_state_size;

    uint32_t date_sec;

    uint32_t date_nsec;

    uint64_t vm_clock_nsec;

} QCowSnapshot;

typedef struct BDRVQcowState {

    BlockDriverState *hd;

    int cluster_bits;

    int cluster_size;

    int cluster_sectors;

    int l2_bits;

    int l2_size;

    int l1_size;

    int l1_vm_state_index;

    int csize_shift;

    int csize_mask;

    uint64_t cluster_offset_mask;

    uint64_t l1_table_offset;

    uint64_t *l1_table;

    uint64_t *l2_cache;

    uint64_t l2_cache_offsets[L2_CACHE_SIZE];

    uint32_t l2_cache_counts[L2_CACHE_SIZE];

    uint8_t *cluster_cache;

    uint8_t *cluster_data;

    uint64_t cluster_cache_offset;

    uint64_t *refcount_table;

    uint64_t refcount_table_offset;

    uint32_t refcount_table_size;

    uint64_t refcount_block_cache_offset;

    uint16_t *refcount_block_cache;

    int64_t free_cluster_index;

    int64_t free_byte_offset;

    uint32_t crypt_method; /* current crypt method, 0 if no key yet */

    uint32_t crypt_method_header;

    AES_KEY aes_encrypt_key;

    AES_KEY aes_decrypt_key;

    uint64_t snapshots_offset;

    int snapshots_size;

    int nb_snapshots;

    QCowSnapshot *snapshots;

} BDRVQcowState;

/* XXX: use std qcow open function ? */

typedef struct QCowCreateState {

    int cluster_size;

    int cluster_bits;

    uint16_t *refcount_block;

    uint64_t *refcount_table;

    int64_t l1_table_offset;

    int64_t refcount_table_offset;

    int64_t refcount_block_offset;

} QCowCreateState;

/* XXX This could be private for qcow2-cluster.c */

typedef struct QCowL2Meta

{

    uint64_t offset;

    int n_start;

    int nb_available;

    int nb_clusters;

} QCowL2Meta;

static inline int size_to_clusters(BDRVQcowState *s, int64_t size)

{

    return (size + (s->cluster_size - 1)) >> s->cluster_bits;

}

static inline int64_t align_offset(int64_t offset, int n)

{

    offset = (offset + n - 1) & ~(n - 1);

    return offset;

}

// FIXME Need qcow2_ prefix to global functions

/* qcow2.c functions */

void l2_cache_reset(BlockDriverState *bs);

int backing_read1(BlockDriverState *bs,

                  int64_t sector_num, uint8_t *buf, int nb_sectors);

/* qcow2-refcount.c functions */

int refcount_init(BlockDriverState *bs);

void refcount_close(BlockDriverState *bs);

int64_t alloc_clusters(BlockDriverState *bs, int64_t size);

int64_t alloc_bytes(BlockDriverState *bs, int size);

void free_clusters(BlockDriverState *bs,

    int64_t offset, int64_t size);

void free_any_clusters(BlockDriverState *bs,

    uint64_t cluster_offset, int nb_clusters);

void create_refcount_update(QCowCreateState *s, int64_t offset, int64_t size);

int update_snapshot_refcount(BlockDriverState *bs,

                             int64_t l1_table_offset,

                             int l1_size,

                             int addend);

int check_refcounts(BlockDriverState *bs);

/* qcow2-cluster.c functions */

int grow_l1_table(BlockDriverState *bs, int min_size);

int decompress_cluster(BDRVQcowState *s, uint64_t cluster_offset);

void encrypt_sectors(BDRVQcowState *s, int64_t sector_num,

                     uint8_t *out_buf, const uint8_t *in_buf,

                     int nb_sectors, int enc,

                     const AES_KEY *key);

uint64_t get_cluster_offset(BlockDriverState *bs, uint64_t offset, int *num);

uint64_t alloc_cluster_offset(BlockDriverState *bs,

                              uint64_t offset,

                              int n_start, int n_end,

                              int *num, QCowL2Meta *m);

uint64_t alloc_compressed_cluster_offset(BlockDriverState *bs,

                                         uint64_t offset,

                                         int compressed_size);

int alloc_cluster_link_l2(BlockDriverState *bs, uint64_t cluster_offset,

    QCowL2Meta *m);

/* qcow2-snapshot.c functions */

int qcow_snapshot_create(BlockDriverState *bs, QEMUSnapshotInfo *sn_info);

int qcow_snapshot_goto(BlockDriverState *bs, const char *snapshot_id);

int qcow_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);

int qcow_snapshot_list(BlockDriverState *bs, QEMUSnapshotInfo **psn_tab);

void qcow_free_snapshots(BlockDriverState *bs);

int qcow_read_snapshots(BlockDriverState *bs);

#endif