xref: /openbmc/qemu/include/sysemu/block-backend.h (revision c2387413)
1 /*
2  * QEMU Block backends
3  *
4  * Copyright (C) 2014-2016 Red Hat, Inc.
5  *
6  * Authors:
7  *  Markus Armbruster <armbru@redhat.com>,
8  *
9  * This work is licensed under the terms of the GNU LGPL, version 2.1
10  * or later.  See the COPYING.LIB file in the top-level directory.
11  */
12 
13 #ifndef BLOCK_BACKEND_H
14 #define BLOCK_BACKEND_H
15 
16 #include "qemu/iov.h"
17 #include "block/throttle-groups.h"
18 
19 /*
20  * TODO Have to include block/block.h for a bunch of block layer
21  * types.  Unfortunately, this pulls in the whole BlockDriverState
22  * API, which we don't want used by many BlockBackend users.  Some of
23  * the types belong here, and the rest should be split into a common
24  * header and one for the BlockDriverState API.
25  */
26 #include "block/block.h"
27 
28 /* Callbacks for block device models */
29 typedef struct BlockDevOps {
30     /*
31      * Runs when virtual media changed (monitor commands eject, change)
32      * Argument load is true on load and false on eject.
33      * Beware: doesn't run when a host device's physical media
34      * changes.  Sure would be useful if it did.
35      * Device models with removable media must implement this callback.
36      */
37     void (*change_media_cb)(void *opaque, bool load, Error **errp);
38     /*
39      * Runs when an eject request is issued from the monitor, the tray
40      * is closed, and the medium is locked.
41      * Device models that do not implement is_medium_locked will not need
42      * this callback.  Device models that can lock the medium or tray might
43      * want to implement the callback and unlock the tray when "force" is
44      * true, even if they do not support eject requests.
45      */
46     void (*eject_request_cb)(void *opaque, bool force);
47     /*
48      * Is the virtual tray open?
49      * Device models implement this only when the device has a tray.
50      */
51     bool (*is_tray_open)(void *opaque);
52     /*
53      * Is the virtual medium locked into the device?
54      * Device models implement this only when device has such a lock.
55      */
56     bool (*is_medium_locked)(void *opaque);
57     /*
58      * Runs when the size changed (e.g. monitor command block_resize)
59      */
60     void (*resize_cb)(void *opaque);
61     /*
62      * Runs when the backend receives a drain request.
63      */
64     void (*drained_begin)(void *opaque);
65     /*
66      * Runs when the backend's last drain request ends.
67      */
68     void (*drained_end)(void *opaque);
69 } BlockDevOps;
70 
71 /* This struct is embedded in (the private) BlockBackend struct and contains
72  * fields that must be public. This is in particular for QLIST_ENTRY() and
73  * friends so that BlockBackends can be kept in lists outside block-backend.c
74  * */
75 typedef struct BlockBackendPublic {
76     ThrottleGroupMember throttle_group_member;
77 } BlockBackendPublic;
78 
79 BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm);
80 BlockBackend *blk_new_with_bs(BlockDriverState *bs, uint64_t perm,
81                               uint64_t shared_perm, Error **errp);
82 BlockBackend *blk_new_open(const char *filename, const char *reference,
83                            QDict *options, int flags, Error **errp);
84 int blk_get_refcnt(BlockBackend *blk);
85 void blk_ref(BlockBackend *blk);
86 void blk_unref(BlockBackend *blk);
87 void blk_remove_all_bs(void);
88 const char *blk_name(const BlockBackend *blk);
89 BlockBackend *blk_by_name(const char *name);
90 BlockBackend *blk_next(BlockBackend *blk);
91 BlockBackend *blk_all_next(BlockBackend *blk);
92 bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
93 void monitor_remove_blk(BlockBackend *blk);
94 
95 BlockBackendPublic *blk_get_public(BlockBackend *blk);
96 BlockBackend *blk_by_public(BlockBackendPublic *public);
97 
98 BlockDriverState *blk_bs(BlockBackend *blk);
99 void blk_remove_bs(BlockBackend *blk);
100 int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
101 bool bdrv_has_blk(BlockDriverState *bs);
102 bool bdrv_is_root_node(BlockDriverState *bs);
103 int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
104                  Error **errp);
105 void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
106 
107 void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
108 void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
109 void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
110 void blk_iostatus_enable(BlockBackend *blk);
111 bool blk_iostatus_is_enabled(const BlockBackend *blk);
112 BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
113 void blk_iostatus_disable(BlockBackend *blk);
114 void blk_iostatus_reset(BlockBackend *blk);
115 void blk_iostatus_set_err(BlockBackend *blk, int error);
116 int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
117 void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
118 DeviceState *blk_get_attached_dev(BlockBackend *blk);
119 char *blk_get_attached_dev_id(BlockBackend *blk);
120 BlockBackend *blk_by_dev(void *dev);
121 BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
122 void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
123 int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
124                                unsigned int bytes, QEMUIOVector *qiov,
125                                BdrvRequestFlags flags);
126 int coroutine_fn blk_co_pwritev_part(BlockBackend *blk, int64_t offset,
127                                      unsigned int bytes,
128                                      QEMUIOVector *qiov, size_t qiov_offset,
129                                      BdrvRequestFlags flags);
130 int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
131                                unsigned int bytes, QEMUIOVector *qiov,
132                                BdrvRequestFlags flags);
133 
134 static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
135                                             unsigned int bytes, void *buf,
136                                             BdrvRequestFlags flags)
137 {
138     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
139 
140     return blk_co_preadv(blk, offset, bytes, &qiov, flags);
141 }
142 
143 static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
144                                              unsigned int bytes, void *buf,
145                                              BdrvRequestFlags flags)
146 {
147     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
148 
149     return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
150 }
151 
152 int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
153                       int bytes, BdrvRequestFlags flags);
154 BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
155                                   int bytes, BdrvRequestFlags flags,
156                                   BlockCompletionFunc *cb, void *opaque);
157 int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
158 int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
159 int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
160                BdrvRequestFlags flags);
161 int64_t blk_getlength(BlockBackend *blk);
162 void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
163 int64_t blk_nb_sectors(BlockBackend *blk);
164 BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
165                            QEMUIOVector *qiov, BdrvRequestFlags flags,
166                            BlockCompletionFunc *cb, void *opaque);
167 BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
168                             QEMUIOVector *qiov, BdrvRequestFlags flags,
169                             BlockCompletionFunc *cb, void *opaque);
170 BlockAIOCB *blk_aio_flush(BlockBackend *blk,
171                           BlockCompletionFunc *cb, void *opaque);
172 BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes,
173                              BlockCompletionFunc *cb, void *opaque);
174 void blk_aio_cancel(BlockAIOCB *acb);
175 void blk_aio_cancel_async(BlockAIOCB *acb);
176 int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
177 BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
178                           BlockCompletionFunc *cb, void *opaque);
179 int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
180 int blk_co_flush(BlockBackend *blk);
181 int blk_flush(BlockBackend *blk);
182 int blk_commit_all(void);
183 void blk_inc_in_flight(BlockBackend *blk);
184 void blk_dec_in_flight(BlockBackend *blk);
185 void blk_drain(BlockBackend *blk);
186 void blk_drain_all(void);
187 void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
188                       BlockdevOnError on_write_error);
189 BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
190 BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
191                                       int error);
192 void blk_error_action(BlockBackend *blk, BlockErrorAction action,
193                       bool is_read, int error);
194 bool blk_supports_write_perm(BlockBackend *blk);
195 bool blk_is_writable(BlockBackend *blk);
196 bool blk_is_sg(BlockBackend *blk);
197 bool blk_enable_write_cache(BlockBackend *blk);
198 void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
199 void blk_invalidate_cache(BlockBackend *blk, Error **errp);
200 bool blk_is_inserted(BlockBackend *blk);
201 bool blk_is_available(BlockBackend *blk);
202 void blk_lock_medium(BlockBackend *blk, bool locked);
203 void blk_eject(BlockBackend *blk, bool eject_flag);
204 int blk_get_flags(BlockBackend *blk);
205 uint32_t blk_get_request_alignment(BlockBackend *blk);
206 uint32_t blk_get_max_transfer(BlockBackend *blk);
207 int blk_get_max_iov(BlockBackend *blk);
208 void blk_set_guest_block_size(BlockBackend *blk, int align);
209 void *blk_try_blockalign(BlockBackend *blk, size_t size);
210 void *blk_blockalign(BlockBackend *blk, size_t size);
211 bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
212 void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
213 void blk_op_block_all(BlockBackend *blk, Error *reason);
214 void blk_op_unblock_all(BlockBackend *blk, Error *reason);
215 AioContext *blk_get_aio_context(BlockBackend *blk);
216 int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
217                         Error **errp);
218 void blk_add_aio_context_notifier(BlockBackend *blk,
219         void (*attached_aio_context)(AioContext *new_context, void *opaque),
220         void (*detach_aio_context)(void *opaque), void *opaque);
221 void blk_remove_aio_context_notifier(BlockBackend *blk,
222                                      void (*attached_aio_context)(AioContext *,
223                                                                   void *),
224                                      void (*detach_aio_context)(void *),
225                                      void *opaque);
226 void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
227 void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
228 void blk_io_plug(BlockBackend *blk);
229 void blk_io_unplug(BlockBackend *blk);
230 BlockAcctStats *blk_get_stats(BlockBackend *blk);
231 BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
232 void blk_update_root_state(BlockBackend *blk);
233 bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
234 int blk_get_open_flags_from_root_state(BlockBackend *blk);
235 
236 void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
237                   BlockCompletionFunc *cb, void *opaque);
238 int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
239                                       int bytes, BdrvRequestFlags flags);
240 int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
241                           int bytes);
242 int blk_truncate(BlockBackend *blk, int64_t offset, bool exact,
243                  PreallocMode prealloc, BdrvRequestFlags flags, Error **errp);
244 int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
245 int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
246                      int64_t pos, int size);
247 int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
248 int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
249 int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
250 BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
251                                   BlockCompletionFunc *cb,
252                                   void *opaque, int ret);
253 
254 void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
255 void blk_io_limits_disable(BlockBackend *blk);
256 void blk_io_limits_enable(BlockBackend *blk, const char *group);
257 void blk_io_limits_update_group(BlockBackend *blk, const char *group);
258 void blk_set_force_allow_inactivate(BlockBackend *blk);
259 
260 void blk_register_buf(BlockBackend *blk, void *host, size_t size);
261 void blk_unregister_buf(BlockBackend *blk, void *host);
262 
263 int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
264                                    BlockBackend *blk_out, int64_t off_out,
265                                    int bytes, BdrvRequestFlags read_flags,
266                                    BdrvRequestFlags write_flags);
267 
268 const BdrvChild *blk_root(BlockBackend *blk);
269 
270 int blk_make_empty(BlockBackend *blk, Error **errp);
271 
272 #endif
273