1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
|
/*
* Common code for block device models
*
* Copyright (C) 2012 Red Hat, Inc.
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* later. See the COPYING file in the top-level directory.
*/
#include "qemu/osdep.h"
#include "sysemu/blockdev.h"
#include "sysemu/block-backend.h"
#include "hw/block/block.h"
#include "qapi/error.h"
#include "qapi/qapi-types-block.h"
/*
* Read the entire contents of @blk into @buf.
* @blk's contents must be @size bytes, and @size must be at most
* BDRV_REQUEST_MAX_BYTES.
* On success, return true.
* On failure, store an error through @errp and return false.
* Note that the error messages do not identify the block backend.
* TODO Since callers don't either, this can result in confusing
* errors.
* This function not intended for actual block devices, which read on
* demand. It's for things like memory devices that (ab)use a block
* backend to provide persistence.
*/
bool blk_check_size_and_read_all(BlockBackend *blk, void *buf, hwaddr size,
Error **errp)
{
int64_t blk_len;
int ret;
blk_len = blk_getlength(blk);
if (blk_len < 0) {
error_setg_errno(errp, -blk_len,
"can't get size of block backend");
return false;
}
if (blk_len != size) {
error_setg(errp, "device requires %" HWADDR_PRIu " bytes, "
"block backend provides %" PRIu64 " bytes",
size, blk_len);
return false;
}
/*
* We could loop for @size > BDRV_REQUEST_MAX_BYTES, but if we
* ever get to the point we want to read *gigabytes* here, we
* should probably rework the device to be more like an actual
* block device and read only on demand.
*/
assert(size <= BDRV_REQUEST_MAX_BYTES);
ret = blk_pread(blk, 0, buf, size);
if (ret < 0) {
error_setg_errno(errp, -ret, "can't read block backend");
return false;
}
return true;
}
bool blkconf_blocksizes(BlockConf *conf, Error **errp)
{
BlockBackend *blk = conf->blk;
BlockSizes blocksizes;
BlockDriverState *bs;
bool use_blocksizes;
bool use_bs;
switch (conf->backend_defaults) {
case ON_OFF_AUTO_AUTO:
use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
use_bs = false;
break;
case ON_OFF_AUTO_ON:
use_blocksizes = !blk_probe_blocksizes(blk, &blocksizes);
bs = blk_bs(blk);
use_bs = bs;
break;
case ON_OFF_AUTO_OFF:
use_blocksizes = false;
use_bs = false;
break;
default:
abort();
}
/* fill in detected values if they are not defined via qemu command line */
if (!conf->physical_block_size) {
if (use_blocksizes) {
conf->physical_block_size = blocksizes.phys;
} else {
conf->physical_block_size = BDRV_SECTOR_SIZE;
}
}
if (!conf->logical_block_size) {
if (use_blocksizes) {
conf->logical_block_size = blocksizes.log;
} else {
conf->logical_block_size = BDRV_SECTOR_SIZE;
}
}
if (use_bs) {
if (!conf->opt_io_size) {
conf->opt_io_size = bs->bl.opt_transfer;
}
if (conf->discard_granularity == -1) {
if (bs->bl.pdiscard_alignment) {
conf->discard_granularity = bs->bl.pdiscard_alignment;
} else if (bs->bl.request_alignment != 1) {
conf->discard_granularity = bs->bl.request_alignment;
}
}
}
if (conf->logical_block_size > conf->physical_block_size) {
error_setg(errp,
"logical_block_size > physical_block_size not supported");
return false;
}
if (!QEMU_IS_ALIGNED(conf->min_io_size, conf->logical_block_size)) {
error_setg(errp,
"min_io_size must be a multiple of logical_block_size");
return false;
}
/*
* all devices which support min_io_size (scsi and virtio-blk) expose it to
* the guest as a uint16_t in units of logical blocks
*/
if (conf->min_io_size / conf->logical_block_size > UINT16_MAX) {
error_setg(errp, "min_io_size must not exceed %u logical blocks",
UINT16_MAX);
return false;
}
if (!QEMU_IS_ALIGNED(conf->opt_io_size, conf->logical_block_size)) {
error_setg(errp,
"opt_io_size must be a multiple of logical_block_size");
return false;
}
if (conf->discard_granularity != -1 &&
!QEMU_IS_ALIGNED(conf->discard_granularity,
conf->logical_block_size)) {
error_setg(errp, "discard_granularity must be "
"a multiple of logical_block_size");
return false;
}
return true;
}
bool blkconf_apply_backend_options(BlockConf *conf, bool readonly,
bool resizable, Error **errp)
{
BlockBackend *blk = conf->blk;
BlockdevOnError rerror, werror;
uint64_t perm, shared_perm;
bool wce;
int ret;
perm = BLK_PERM_CONSISTENT_READ;
if (!readonly) {
perm |= BLK_PERM_WRITE;
}
shared_perm = BLK_PERM_CONSISTENT_READ | BLK_PERM_WRITE_UNCHANGED |
BLK_PERM_GRAPH_MOD;
if (resizable) {
shared_perm |= BLK_PERM_RESIZE;
}
if (conf->share_rw) {
shared_perm |= BLK_PERM_WRITE;
}
ret = blk_set_perm(blk, perm, shared_perm, errp);
if (ret < 0) {
return false;
}
switch (conf->wce) {
case ON_OFF_AUTO_ON: wce = true; break;
case ON_OFF_AUTO_OFF: wce = false; break;
case ON_OFF_AUTO_AUTO: wce = blk_enable_write_cache(blk); break;
default:
abort();
}
rerror = conf->rerror;
if (rerror == BLOCKDEV_ON_ERROR_AUTO) {
rerror = blk_get_on_error(blk, true);
}
werror = conf->werror;
if (werror == BLOCKDEV_ON_ERROR_AUTO) {
werror = blk_get_on_error(blk, false);
}
blk_set_enable_write_cache(blk, wce);
blk_set_on_error(blk, rerror, werror);
return true;
}
bool blkconf_geometry(BlockConf *conf, int *ptrans,
unsigned cyls_max, unsigned heads_max, unsigned secs_max,
Error **errp)
{
if (!conf->cyls && !conf->heads && !conf->secs) {
hd_geometry_guess(conf->blk,
&conf->cyls, &conf->heads, &conf->secs,
ptrans);
} else if (ptrans && *ptrans == BIOS_ATA_TRANSLATION_AUTO) {
*ptrans = hd_bios_chs_auto_trans(conf->cyls, conf->heads, conf->secs);
}
if (conf->cyls || conf->heads || conf->secs) {
if (conf->cyls < 1 || conf->cyls > cyls_max) {
error_setg(errp, "cyls must be between 1 and %u", cyls_max);
return false;
}
if (conf->heads < 1 || conf->heads > heads_max) {
error_setg(errp, "heads must be between 1 and %u", heads_max);
return false;
}
if (conf->secs < 1 || conf->secs > secs_max) {
error_setg(errp, "secs must be between 1 and %u", secs_max);
return false;
}
}
return true;
}
|
