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 */
29typedef 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 * */
75typedef struct BlockBackendPublic {
76 ThrottleGroupMember throttle_group_member;
77} BlockBackendPublic;
78
79BlockBackend *blk_new(AioContext *ctx, uint64_t perm, uint64_t shared_perm);
80BlockBackend *blk_new_open(const char *filename, const char *reference,
81 QDict *options, int flags, Error **errp);
82int blk_get_refcnt(BlockBackend *blk);
83void blk_ref(BlockBackend *blk);
84void blk_unref(BlockBackend *blk);
85void blk_remove_all_bs(void);
86const char *blk_name(const BlockBackend *blk);
87BlockBackend *blk_by_name(const char *name);
88BlockBackend *blk_next(BlockBackend *blk);
89BlockBackend *blk_all_next(BlockBackend *blk);
90bool monitor_add_blk(BlockBackend *blk, const char *name, Error **errp);
91void monitor_remove_blk(BlockBackend *blk);
92
93BlockBackendPublic *blk_get_public(BlockBackend *blk);
94BlockBackend *blk_by_public(BlockBackendPublic *public);
95
96BlockDriverState *blk_bs(BlockBackend *blk);
97void blk_remove_bs(BlockBackend *blk);
98int blk_insert_bs(BlockBackend *blk, BlockDriverState *bs, Error **errp);
99bool bdrv_has_blk(BlockDriverState *bs);
100bool bdrv_is_root_node(BlockDriverState *bs);
101int blk_set_perm(BlockBackend *blk, uint64_t perm, uint64_t shared_perm,
102 Error **errp);
103void blk_get_perm(BlockBackend *blk, uint64_t *perm, uint64_t *shared_perm);
104
105void blk_set_allow_write_beyond_eof(BlockBackend *blk, bool allow);
106void blk_set_allow_aio_context_change(BlockBackend *blk, bool allow);
107void blk_set_disable_request_queuing(BlockBackend *blk, bool disable);
108void blk_iostatus_enable(BlockBackend *blk);
109bool blk_iostatus_is_enabled(const BlockBackend *blk);
110BlockDeviceIoStatus blk_iostatus(const BlockBackend *blk);
111void blk_iostatus_disable(BlockBackend *blk);
112void blk_iostatus_reset(BlockBackend *blk);
113void blk_iostatus_set_err(BlockBackend *blk, int error);
114int blk_attach_dev(BlockBackend *blk, DeviceState *dev);
115void blk_detach_dev(BlockBackend *blk, DeviceState *dev);
116DeviceState *blk_get_attached_dev(BlockBackend *blk);
117char *blk_get_attached_dev_id(BlockBackend *blk);
118BlockBackend *blk_by_dev(void *dev);
119BlockBackend *blk_by_qdev_id(const char *id, Error **errp);
120void blk_set_dev_ops(BlockBackend *blk, const BlockDevOps *ops, void *opaque);
121int coroutine_fn blk_co_preadv(BlockBackend *blk, int64_t offset,
122 unsigned int bytes, QEMUIOVector *qiov,
123 BdrvRequestFlags flags);
124int coroutine_fn blk_co_pwritev(BlockBackend *blk, int64_t offset,
125 unsigned int bytes, QEMUIOVector *qiov,
126 BdrvRequestFlags flags);
127
128static inline int coroutine_fn blk_co_pread(BlockBackend *blk, int64_t offset,
129 unsigned int bytes, void *buf,
130 BdrvRequestFlags flags)
131{
132 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
133
134 return blk_co_preadv(blk, offset, bytes, &qiov, flags);
135}
136
137static inline int coroutine_fn blk_co_pwrite(BlockBackend *blk, int64_t offset,
138 unsigned int bytes, void *buf,
139 BdrvRequestFlags flags)
140{
141 QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, buf, bytes);
142
143 return blk_co_pwritev(blk, offset, bytes, &qiov, flags);
144}
145
146int blk_pwrite_zeroes(BlockBackend *blk, int64_t offset,
147 int bytes, BdrvRequestFlags flags);
148BlockAIOCB *blk_aio_pwrite_zeroes(BlockBackend *blk, int64_t offset,
149 int bytes, BdrvRequestFlags flags,
150 BlockCompletionFunc *cb, void *opaque);
151int blk_make_zero(BlockBackend *blk, BdrvRequestFlags flags);
152int blk_pread(BlockBackend *blk, int64_t offset, void *buf, int bytes);
153int blk_pwrite(BlockBackend *blk, int64_t offset, const void *buf, int bytes,
154 BdrvRequestFlags flags);
155int64_t blk_getlength(BlockBackend *blk);
156void blk_get_geometry(BlockBackend *blk, uint64_t *nb_sectors_ptr);
157int64_t blk_nb_sectors(BlockBackend *blk);
158BlockAIOCB *blk_aio_preadv(BlockBackend *blk, int64_t offset,
159 QEMUIOVector *qiov, BdrvRequestFlags flags,
160 BlockCompletionFunc *cb, void *opaque);
161BlockAIOCB *blk_aio_pwritev(BlockBackend *blk, int64_t offset,
162 QEMUIOVector *qiov, BdrvRequestFlags flags,
163 BlockCompletionFunc *cb, void *opaque);
164BlockAIOCB *blk_aio_flush(BlockBackend *blk,
165 BlockCompletionFunc *cb, void *opaque);
166BlockAIOCB *blk_aio_pdiscard(BlockBackend *blk, int64_t offset, int bytes,
167 BlockCompletionFunc *cb, void *opaque);
168void blk_aio_cancel(BlockAIOCB *acb);
169void blk_aio_cancel_async(BlockAIOCB *acb);
170int blk_co_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
171int blk_ioctl(BlockBackend *blk, unsigned long int req, void *buf);
172BlockAIOCB *blk_aio_ioctl(BlockBackend *blk, unsigned long int req, void *buf,
173 BlockCompletionFunc *cb, void *opaque);
174int blk_co_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
175int blk_co_flush(BlockBackend *blk);
176int blk_flush(BlockBackend *blk);
177int blk_commit_all(void);
178void blk_inc_in_flight(BlockBackend *blk);
179void blk_dec_in_flight(BlockBackend *blk);
180void blk_drain(BlockBackend *blk);
181void blk_drain_all(void);
182void blk_set_on_error(BlockBackend *blk, BlockdevOnError on_read_error,
183 BlockdevOnError on_write_error);
184BlockdevOnError blk_get_on_error(BlockBackend *blk, bool is_read);
185BlockErrorAction blk_get_error_action(BlockBackend *blk, bool is_read,
186 int error);
187void blk_error_action(BlockBackend *blk, BlockErrorAction action,
188 bool is_read, int error);
189bool blk_is_read_only(BlockBackend *blk);
190bool blk_is_sg(BlockBackend *blk);
191bool blk_enable_write_cache(BlockBackend *blk);
192void blk_set_enable_write_cache(BlockBackend *blk, bool wce);
193void blk_invalidate_cache(BlockBackend *blk, Error **errp);
194bool blk_is_inserted(BlockBackend *blk);
195bool blk_is_available(BlockBackend *blk);
196void blk_lock_medium(BlockBackend *blk, bool locked);
197void blk_eject(BlockBackend *blk, bool eject_flag);
198int blk_get_flags(BlockBackend *blk);
199uint32_t blk_get_request_alignment(BlockBackend *blk);
200uint32_t blk_get_max_transfer(BlockBackend *blk);
201int blk_get_max_iov(BlockBackend *blk);
202void blk_set_guest_block_size(BlockBackend *blk, int align);
203void *blk_try_blockalign(BlockBackend *blk, size_t size);
204void *blk_blockalign(BlockBackend *blk, size_t size);
205bool blk_op_is_blocked(BlockBackend *blk, BlockOpType op, Error **errp);
206void blk_op_unblock(BlockBackend *blk, BlockOpType op, Error *reason);
207void blk_op_block_all(BlockBackend *blk, Error *reason);
208void blk_op_unblock_all(BlockBackend *blk, Error *reason);
209AioContext *blk_get_aio_context(BlockBackend *blk);
210int blk_set_aio_context(BlockBackend *blk, AioContext *new_context,
211 Error **errp);
212void blk_add_aio_context_notifier(BlockBackend *blk,
213 void (*attached_aio_context)(AioContext *new_context, void *opaque),
214 void (*detach_aio_context)(void *opaque), void *opaque);
215void blk_remove_aio_context_notifier(BlockBackend *blk,
216 void (*attached_aio_context)(AioContext *,
217 void *),
218 void (*detach_aio_context)(void *),
219 void *opaque);
220void blk_add_remove_bs_notifier(BlockBackend *blk, Notifier *notify);
221void blk_add_insert_bs_notifier(BlockBackend *blk, Notifier *notify);
222void blk_io_plug(BlockBackend *blk);
223void blk_io_unplug(BlockBackend *blk);
224BlockAcctStats *blk_get_stats(BlockBackend *blk);
225BlockBackendRootState *blk_get_root_state(BlockBackend *blk);
226void blk_update_root_state(BlockBackend *blk);
227bool blk_get_detect_zeroes_from_root_state(BlockBackend *blk);
228int blk_get_open_flags_from_root_state(BlockBackend *blk);
229
230void *blk_aio_get(const AIOCBInfo *aiocb_info, BlockBackend *blk,
231 BlockCompletionFunc *cb, void *opaque);
232int coroutine_fn blk_co_pwrite_zeroes(BlockBackend *blk, int64_t offset,
233 int bytes, BdrvRequestFlags flags);
234int blk_pwrite_compressed(BlockBackend *blk, int64_t offset, const void *buf,
235 int bytes);
236int blk_truncate(BlockBackend *blk, int64_t offset, PreallocMode prealloc,
237 Error **errp);
238int blk_pdiscard(BlockBackend *blk, int64_t offset, int bytes);
239int blk_save_vmstate(BlockBackend *blk, const uint8_t *buf,
240 int64_t pos, int size);
241int blk_load_vmstate(BlockBackend *blk, uint8_t *buf, int64_t pos, int size);
242int blk_probe_blocksizes(BlockBackend *blk, BlockSizes *bsz);
243int blk_probe_geometry(BlockBackend *blk, HDGeometry *geo);
244BlockAIOCB *blk_abort_aio_request(BlockBackend *blk,
245 BlockCompletionFunc *cb,
246 void *opaque, int ret);
247
248void blk_set_io_limits(BlockBackend *blk, ThrottleConfig *cfg);
249void blk_io_limits_disable(BlockBackend *blk);
250void blk_io_limits_enable(BlockBackend *blk, const char *group);
251void blk_io_limits_update_group(BlockBackend *blk, const char *group);
252void blk_set_force_allow_inactivate(BlockBackend *blk);
253
254void blk_register_buf(BlockBackend *blk, void *host, size_t size);
255void blk_unregister_buf(BlockBackend *blk, void *host);
256
257int coroutine_fn blk_co_copy_range(BlockBackend *blk_in, int64_t off_in,
258 BlockBackend *blk_out, int64_t off_out,
259 int bytes, BdrvRequestFlags read_flags,
260 BdrvRequestFlags write_flags);
261
262const BdrvChild *blk_root(BlockBackend *blk);
263
264#endif
265