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1 | #ifndef _LINUX_VIRTIO_BLK_H |
2 | #define _LINUX_VIRTIO_BLK_H | |
3 | /* This header is BSD licensed so anyone can use the definitions to implement | |
4 | * compatible drivers/servers. | |
5 | * | |
6 | * Redistribution and use in source and binary forms, with or without | |
7 | * modification, are permitted provided that the following conditions | |
8 | * are met: | |
9 | * 1. Redistributions of source code must retain the above copyright | |
10 | * notice, this list of conditions and the following disclaimer. | |
11 | * 2. Redistributions in binary form must reproduce the above copyright | |
12 | * notice, this list of conditions and the following disclaimer in the | |
13 | * documentation and/or other materials provided with the distribution. | |
14 | * 3. Neither the name of IBM nor the names of its contributors | |
15 | * may be used to endorse or promote products derived from this software | |
16 | * without specific prior written permission. | |
17 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND | |
18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
20 | * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE | |
21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
27 | * SUCH DAMAGE. */ | |
28 | #include <linux/types.h> | |
29 | #include <linux/virtio_ids.h> | |
30 | #include <linux/virtio_config.h> | |
31 | #include <linux/virtio_types.h> | |
32 | ||
33 | /* Feature bits */ | |
34 | #define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ | |
35 | #define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */ | |
36 | #define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ | |
37 | #define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ | |
38 | #define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available */ | |
39 | #define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ | |
40 | #define VIRTIO_BLK_F_MQ 12 /* support more than one vq */ | |
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41 | #define VIRTIO_BLK_F_DISCARD 13 /* DISCARD is supported */ |
42 | #define VIRTIO_BLK_F_WRITE_ZEROES 14 /* WRITE ZEROES is supported */ | |
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43 | |
44 | /* Legacy feature bits */ | |
45 | #ifndef VIRTIO_BLK_NO_LEGACY | |
46 | #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ | |
47 | #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ | |
48 | #define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */ | |
49 | #define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ | |
50 | /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */ | |
51 | #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH | |
52 | #endif /* !VIRTIO_BLK_NO_LEGACY */ | |
53 | ||
54 | #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ | |
55 | ||
56 | struct virtio_blk_config { | |
57 | /* The capacity (in 512-byte sectors). */ | |
58 | __u64 capacity; | |
59 | /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ | |
60 | __u32 size_max; | |
61 | /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ | |
62 | __u32 seg_max; | |
63 | /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ | |
64 | struct virtio_blk_geometry { | |
65 | __u16 cylinders; | |
66 | __u8 heads; | |
67 | __u8 sectors; | |
68 | } geometry; | |
69 | ||
70 | /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ | |
71 | __u32 blk_size; | |
72 | ||
73 | /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ | |
74 | /* exponent for physical block per logical block. */ | |
75 | __u8 physical_block_exp; | |
76 | /* alignment offset in logical blocks. */ | |
77 | __u8 alignment_offset; | |
78 | /* minimum I/O size without performance penalty in logical blocks. */ | |
79 | __u16 min_io_size; | |
80 | /* optimal sustained I/O size in logical blocks. */ | |
81 | __u32 opt_io_size; | |
82 | ||
83 | /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ | |
84 | __u8 wce; | |
85 | __u8 unused; | |
86 | ||
87 | /* number of vqs, only available when VIRTIO_BLK_F_MQ is set */ | |
88 | __u16 num_queues; | |
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89 | |
90 | /* the next 3 entries are guarded by VIRTIO_BLK_F_DISCARD */ | |
91 | /* | |
92 | * The maximum discard sectors (in 512-byte sectors) for | |
93 | * one segment. | |
94 | */ | |
95 | __u32 max_discard_sectors; | |
96 | /* | |
97 | * The maximum number of discard segments in a | |
98 | * discard command. | |
99 | */ | |
100 | __u32 max_discard_seg; | |
101 | /* Discard commands must be aligned to this number of sectors. */ | |
102 | __u32 discard_sector_alignment; | |
103 | ||
104 | /* the next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES */ | |
105 | /* | |
106 | * The maximum number of write zeroes sectors (in 512-byte sectors) in | |
107 | * one segment. | |
108 | */ | |
109 | __u32 max_write_zeroes_sectors; | |
110 | /* | |
111 | * The maximum number of segments in a write zeroes | |
112 | * command. | |
113 | */ | |
114 | __u32 max_write_zeroes_seg; | |
115 | /* | |
116 | * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the | |
117 | * deallocation of one or more of the sectors. | |
118 | */ | |
119 | __u8 write_zeroes_may_unmap; | |
120 | ||
121 | __u8 unused1[3]; | |
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122 | } __attribute__((packed)); |
123 | ||
124 | /* | |
125 | * Command types | |
126 | * | |
127 | * Usage is a bit tricky as some bits are used as flags and some are not. | |
128 | * | |
129 | * Rules: | |
130 | * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or | |
131 | * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own | |
132 | * and may not be combined with any of the other flags. | |
133 | */ | |
134 | ||
135 | /* These two define direction. */ | |
136 | #define VIRTIO_BLK_T_IN 0 | |
137 | #define VIRTIO_BLK_T_OUT 1 | |
138 | ||
139 | #ifndef VIRTIO_BLK_NO_LEGACY | |
140 | /* This bit says it's a scsi command, not an actual read or write. */ | |
141 | #define VIRTIO_BLK_T_SCSI_CMD 2 | |
142 | #endif /* VIRTIO_BLK_NO_LEGACY */ | |
143 | ||
144 | /* Cache flush command */ | |
145 | #define VIRTIO_BLK_T_FLUSH 4 | |
146 | ||
147 | /* Get device ID command */ | |
148 | #define VIRTIO_BLK_T_GET_ID 8 | |
149 | ||
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150 | /* Discard command */ |
151 | #define VIRTIO_BLK_T_DISCARD 11 | |
152 | ||
153 | /* Write zeroes command */ | |
154 | #define VIRTIO_BLK_T_WRITE_ZEROES 13 | |
155 | ||
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156 | #ifndef VIRTIO_BLK_NO_LEGACY |
157 | /* Barrier before this op. */ | |
158 | #define VIRTIO_BLK_T_BARRIER 0x80000000 | |
159 | #endif /* !VIRTIO_BLK_NO_LEGACY */ | |
160 | ||
161 | /* | |
162 | * This comes first in the read scatter-gather list. | |
163 | * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, | |
164 | * this is the first element of the read scatter-gather list. | |
165 | */ | |
166 | struct virtio_blk_outhdr { | |
167 | /* VIRTIO_BLK_T* */ | |
168 | __virtio32 type; | |
169 | /* io priority. */ | |
170 | __virtio32 ioprio; | |
171 | /* Sector (ie. 512 byte offset) */ | |
172 | __virtio64 sector; | |
173 | }; | |
174 | ||
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175 | /* Unmap this range (only valid for write zeroes command) */ |
176 | #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 | |
177 | ||
178 | /* Discard/write zeroes range for each request. */ | |
179 | struct virtio_blk_discard_write_zeroes { | |
180 | /* discard/write zeroes start sector */ | |
181 | __le64 sector; | |
182 | /* number of discard/write zeroes sectors */ | |
183 | __le32 num_sectors; | |
184 | /* flags for this range */ | |
185 | __le32 flags; | |
186 | }; | |
187 | ||
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188 | #ifndef VIRTIO_BLK_NO_LEGACY |
189 | struct virtio_scsi_inhdr { | |
190 | __virtio32 errors; | |
191 | __virtio32 data_len; | |
192 | __virtio32 sense_len; | |
193 | __virtio32 residual; | |
194 | }; | |
195 | #endif /* !VIRTIO_BLK_NO_LEGACY */ | |
196 | ||
197 | /* And this is the final byte of the write scatter-gather list. */ | |
198 | #define VIRTIO_BLK_S_OK 0 | |
199 | #define VIRTIO_BLK_S_IOERR 1 | |
200 | #define VIRTIO_BLK_S_UNSUPP 2 | |
201 | #endif /* _LINUX_VIRTIO_BLK_H */ |