qcow2: Make cache=writethrough default
[qemu] / block.h
1 #ifndef BLOCK_H
2 #define BLOCK_H
3
4 #include "qemu-aio.h"
5 #include "qemu-common.h"
6 #include "qemu-option.h"
7
8 /* block.c */
9 typedef struct BlockDriver BlockDriver;
10
11 typedef struct BlockDriverInfo {
12     /* in bytes, 0 if irrelevant */
13     int cluster_size;
14     /* offset at which the VM state can be saved (0 if not possible) */
15     int64_t vm_state_offset;
16 } BlockDriverInfo;
17
18 typedef struct QEMUSnapshotInfo {
19     char id_str[128]; /* unique snapshot id */
20     /* the following fields are informative. They are not needed for
21        the consistency of the snapshot */
22     char name[256]; /* user choosen name */
23     uint32_t vm_state_size; /* VM state info size */
24     uint32_t date_sec; /* UTC date of the snapshot */
25     uint32_t date_nsec;
26     uint64_t vm_clock_nsec; /* VM clock relative to boot */
27 } QEMUSnapshotInfo;
28
29 #define BDRV_O_RDONLY      0x0000
30 #define BDRV_O_RDWR        0x0002
31 #define BDRV_O_ACCESS      0x0003
32 #define BDRV_O_CREAT       0x0004 /* create an empty file */
33 #define BDRV_O_SNAPSHOT    0x0008 /* open the file read only and save writes in a snapshot */
34 #define BDRV_O_FILE        0x0010 /* open as a raw file (do not try to
35                                      use a disk image format on top of
36                                      it (default for
37                                      bdrv_file_open()) */
38 #define BDRV_O_NOCACHE     0x0020 /* do not use the host page cache */
39 #define BDRV_O_CACHE_WB    0x0040 /* use write-back caching */
40
41 #define BDRV_O_CACHE_MASK  (BDRV_O_NOCACHE | BDRV_O_CACHE_WB)
42
43 void bdrv_info(Monitor *mon);
44 void bdrv_info_stats(Monitor *mon);
45
46 void bdrv_init(void);
47 BlockDriver *bdrv_find_format(const char *format_name);
48 int bdrv_create(BlockDriver *drv, const char* filename,
49     QEMUOptionParameter *options);
50 int bdrv_create2(BlockDriver *drv,
51                  const char *filename, int64_t size_in_sectors,
52                  const char *backing_file, const char *backing_format,
53                  int flags);
54 BlockDriverState *bdrv_new(const char *device_name);
55 void bdrv_delete(BlockDriverState *bs);
56 int bdrv_file_open(BlockDriverState **pbs, const char *filename, int flags);
57 int bdrv_open(BlockDriverState *bs, const char *filename, int flags);
58 int bdrv_open2(BlockDriverState *bs, const char *filename, int flags,
59                BlockDriver *drv);
60 int bdrv_open3(BlockDriverState *bs, const char *filename, int flags,
61                BlockDriver *drv);
62 void bdrv_close(BlockDriverState *bs);
63 int bdrv_check(BlockDriverState *bs);
64 int bdrv_read(BlockDriverState *bs, int64_t sector_num,
65               uint8_t *buf, int nb_sectors);
66 int bdrv_write(BlockDriverState *bs, int64_t sector_num,
67                const uint8_t *buf, int nb_sectors);
68 int bdrv_pread(BlockDriverState *bs, int64_t offset,
69                void *buf, int count);
70 int bdrv_pwrite(BlockDriverState *bs, int64_t offset,
71                 const void *buf, int count);
72 int bdrv_truncate(BlockDriverState *bs, int64_t offset);
73 int64_t bdrv_getlength(BlockDriverState *bs);
74 void bdrv_get_geometry(BlockDriverState *bs, uint64_t *nb_sectors_ptr);
75 void bdrv_guess_geometry(BlockDriverState *bs, int *pcyls, int *pheads, int *psecs);
76 int bdrv_commit(BlockDriverState *bs);
77 void bdrv_register(BlockDriver *bdrv);
78
79 /* async block I/O */
80 typedef struct BlockDriverAIOCB BlockDriverAIOCB;
81 typedef void BlockDriverCompletionFunc(void *opaque, int ret);
82
83 BlockDriverAIOCB *bdrv_aio_readv(BlockDriverState *bs, int64_t sector_num,
84                                  QEMUIOVector *iov, int nb_sectors,
85                                  BlockDriverCompletionFunc *cb, void *opaque);
86 BlockDriverAIOCB *bdrv_aio_writev(BlockDriverState *bs, int64_t sector_num,
87                                   QEMUIOVector *iov, int nb_sectors,
88                                   BlockDriverCompletionFunc *cb, void *opaque);
89 void bdrv_aio_cancel(BlockDriverAIOCB *acb);
90
91 /* sg packet commands */
92 int bdrv_ioctl(BlockDriverState *bs, unsigned long int req, void *buf);
93 BlockDriverAIOCB *bdrv_aio_ioctl(BlockDriverState *bs,
94         unsigned long int req, void *buf,
95         BlockDriverCompletionFunc *cb, void *opaque);
96
97 /* Ensure contents are flushed to disk.  */
98 void bdrv_flush(BlockDriverState *bs);
99 void bdrv_flush_all(void);
100
101 int bdrv_is_allocated(BlockDriverState *bs, int64_t sector_num, int nb_sectors,
102         int *pnum);
103
104 #define BDRV_TYPE_HD     0
105 #define BDRV_TYPE_CDROM  1
106 #define BDRV_TYPE_FLOPPY 2
107 #define BIOS_ATA_TRANSLATION_AUTO   0
108 #define BIOS_ATA_TRANSLATION_NONE   1
109 #define BIOS_ATA_TRANSLATION_LBA    2
110 #define BIOS_ATA_TRANSLATION_LARGE  3
111 #define BIOS_ATA_TRANSLATION_RECHS  4
112
113 void bdrv_set_geometry_hint(BlockDriverState *bs,
114                             int cyls, int heads, int secs);
115 void bdrv_set_type_hint(BlockDriverState *bs, int type);
116 void bdrv_set_translation_hint(BlockDriverState *bs, int translation);
117 void bdrv_get_geometry_hint(BlockDriverState *bs,
118                             int *pcyls, int *pheads, int *psecs);
119 int bdrv_get_type_hint(BlockDriverState *bs);
120 int bdrv_get_translation_hint(BlockDriverState *bs);
121 int bdrv_is_removable(BlockDriverState *bs);
122 int bdrv_is_read_only(BlockDriverState *bs);
123 int bdrv_is_sg(BlockDriverState *bs);
124 int bdrv_is_inserted(BlockDriverState *bs);
125 int bdrv_media_changed(BlockDriverState *bs);
126 int bdrv_is_locked(BlockDriverState *bs);
127 void bdrv_set_locked(BlockDriverState *bs, int locked);
128 int bdrv_eject(BlockDriverState *bs, int eject_flag);
129 void bdrv_set_change_cb(BlockDriverState *bs,
130                         void (*change_cb)(void *opaque), void *opaque);
131 void bdrv_get_format(BlockDriverState *bs, char *buf, int buf_size);
132 BlockDriverState *bdrv_find(const char *name);
133 void bdrv_iterate(void (*it)(void *opaque, BlockDriverState *bs),
134                   void *opaque);
135 int bdrv_is_encrypted(BlockDriverState *bs);
136 int bdrv_key_required(BlockDriverState *bs);
137 int bdrv_set_key(BlockDriverState *bs, const char *key);
138 int bdrv_query_missing_keys(void);
139 void bdrv_iterate_format(void (*it)(void *opaque, const char *name),
140                          void *opaque);
141 const char *bdrv_get_device_name(BlockDriverState *bs);
142 int bdrv_write_compressed(BlockDriverState *bs, int64_t sector_num,
143                           const uint8_t *buf, int nb_sectors);
144 int bdrv_get_info(BlockDriverState *bs, BlockDriverInfo *bdi);
145
146 const char *bdrv_get_encrypted_filename(BlockDriverState *bs);
147 void bdrv_get_backing_filename(BlockDriverState *bs,
148                                char *filename, int filename_size);
149 int bdrv_snapshot_create(BlockDriverState *bs,
150                          QEMUSnapshotInfo *sn_info);
151 int bdrv_snapshot_goto(BlockDriverState *bs,
152                        const char *snapshot_id);
153 int bdrv_snapshot_delete(BlockDriverState *bs, const char *snapshot_id);
154 int bdrv_snapshot_list(BlockDriverState *bs,
155                        QEMUSnapshotInfo **psn_info);
156 char *bdrv_snapshot_dump(char *buf, int buf_size, QEMUSnapshotInfo *sn);
157
158 char *get_human_readable_size(char *buf, int buf_size, int64_t size);
159 int path_is_absolute(const char *path);
160 void path_combine(char *dest, int dest_size,
161                   const char *base_path,
162                   const char *filename);
163
164 int bdrv_put_buffer(BlockDriverState *bs, const uint8_t *buf,
165                     int64_t pos, int size);
166
167 int bdrv_get_buffer(BlockDriverState *bs, uint8_t *buf, int64_t pos, int size);
168
169 #endif