xref: /linux/include/uapi/linux/virtio_blk.h (revision 1ac731c529cd4d6adbce134754b51ff7d822b145)
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 */
41 #define VIRTIO_BLK_F_DISCARD	13	/* DISCARD is supported */
42 #define VIRTIO_BLK_F_WRITE_ZEROES	14	/* WRITE ZEROES is supported */
43 #define VIRTIO_BLK_F_SECURE_ERASE	16 /* Secure Erase is supported */
44 #define VIRTIO_BLK_F_ZONED		17	/* Zoned block device */
45 
46 /* Legacy feature bits */
47 #ifndef VIRTIO_BLK_NO_LEGACY
48 #define VIRTIO_BLK_F_BARRIER	0	/* Does host support barriers? */
49 #define VIRTIO_BLK_F_SCSI	7	/* Supports scsi command passthru */
50 #define VIRTIO_BLK_F_FLUSH	9	/* Flush command supported */
51 #define VIRTIO_BLK_F_CONFIG_WCE	11	/* Writeback mode available in config */
52 #ifndef __KERNEL__
53 /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */
54 #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH
55 #endif
56 #endif /* !VIRTIO_BLK_NO_LEGACY */
57 
58 #define VIRTIO_BLK_ID_BYTES	20	/* ID string length */
59 
60 struct virtio_blk_config {
61 	/* The capacity (in 512-byte sectors). */
62 	__virtio64 capacity;
63 	/* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
64 	__virtio32 size_max;
65 	/* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
66 	__virtio32 seg_max;
67 	/* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
68 	struct virtio_blk_geometry {
69 		__virtio16 cylinders;
70 		__u8 heads;
71 		__u8 sectors;
72 	} geometry;
73 
74 	/* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
75 	__virtio32 blk_size;
76 
77 	/* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY  */
78 	/* exponent for physical block per logical block. */
79 	__u8 physical_block_exp;
80 	/* alignment offset in logical blocks. */
81 	__u8 alignment_offset;
82 	/* minimum I/O size without performance penalty in logical blocks. */
83 	__virtio16 min_io_size;
84 	/* optimal sustained I/O size in logical blocks. */
85 	__virtio32 opt_io_size;
86 
87 	/* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
88 	__u8 wce;
89 	__u8 unused;
90 
91 	/* number of vqs, only available when VIRTIO_BLK_F_MQ is set */
92 	__virtio16 num_queues;
93 
94 	/* the next 3 entries are guarded by VIRTIO_BLK_F_DISCARD */
95 	/*
96 	 * The maximum discard sectors (in 512-byte sectors) for
97 	 * one segment.
98 	 */
99 	__virtio32 max_discard_sectors;
100 	/*
101 	 * The maximum number of discard segments in a
102 	 * discard command.
103 	 */
104 	__virtio32 max_discard_seg;
105 	/* Discard commands must be aligned to this number of sectors. */
106 	__virtio32 discard_sector_alignment;
107 
108 	/* the next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES */
109 	/*
110 	 * The maximum number of write zeroes sectors (in 512-byte sectors) in
111 	 * one segment.
112 	 */
113 	__virtio32 max_write_zeroes_sectors;
114 	/*
115 	 * The maximum number of segments in a write zeroes
116 	 * command.
117 	 */
118 	__virtio32 max_write_zeroes_seg;
119 	/*
120 	 * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the
121 	 * deallocation of one or more of the sectors.
122 	 */
123 	__u8 write_zeroes_may_unmap;
124 
125 	__u8 unused1[3];
126 
127 	/* the next 3 entries are guarded by VIRTIO_BLK_F_SECURE_ERASE */
128 	/*
129 	 * The maximum secure erase sectors (in 512-byte sectors) for
130 	 * one segment.
131 	 */
132 	__virtio32 max_secure_erase_sectors;
133 	/*
134 	 * The maximum number of secure erase segments in a
135 	 * secure erase command.
136 	 */
137 	__virtio32 max_secure_erase_seg;
138 	/* Secure erase commands must be aligned to this number of sectors. */
139 	__virtio32 secure_erase_sector_alignment;
140 
141 	/* Zoned block device characteristics (if VIRTIO_BLK_F_ZONED) */
142 	struct virtio_blk_zoned_characteristics {
143 		__virtio32 zone_sectors;
144 		__virtio32 max_open_zones;
145 		__virtio32 max_active_zones;
146 		__virtio32 max_append_sectors;
147 		__virtio32 write_granularity;
148 		__u8 model;
149 		__u8 unused2[3];
150 	} zoned;
151 } __attribute__((packed));
152 
153 /*
154  * Command types
155  *
156  * Usage is a bit tricky as some bits are used as flags and some are not.
157  *
158  * Rules:
159  *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
160  *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
161  *   and may not be combined with any of the other flags.
162  */
163 
164 /* These two define direction. */
165 #define VIRTIO_BLK_T_IN		0
166 #define VIRTIO_BLK_T_OUT	1
167 
168 #ifndef VIRTIO_BLK_NO_LEGACY
169 /* This bit says it's a scsi command, not an actual read or write. */
170 #define VIRTIO_BLK_T_SCSI_CMD	2
171 #endif /* VIRTIO_BLK_NO_LEGACY */
172 
173 /* Cache flush command */
174 #define VIRTIO_BLK_T_FLUSH	4
175 
176 /* Get device ID command */
177 #define VIRTIO_BLK_T_GET_ID    8
178 
179 /* Discard command */
180 #define VIRTIO_BLK_T_DISCARD	11
181 
182 /* Write zeroes command */
183 #define VIRTIO_BLK_T_WRITE_ZEROES	13
184 
185 /* Secure erase command */
186 #define VIRTIO_BLK_T_SECURE_ERASE	14
187 
188 /* Zone append command */
189 #define VIRTIO_BLK_T_ZONE_APPEND    15
190 
191 /* Report zones command */
192 #define VIRTIO_BLK_T_ZONE_REPORT    16
193 
194 /* Open zone command */
195 #define VIRTIO_BLK_T_ZONE_OPEN      18
196 
197 /* Close zone command */
198 #define VIRTIO_BLK_T_ZONE_CLOSE     20
199 
200 /* Finish zone command */
201 #define VIRTIO_BLK_T_ZONE_FINISH    22
202 
203 /* Reset zone command */
204 #define VIRTIO_BLK_T_ZONE_RESET     24
205 
206 /* Reset All zones command */
207 #define VIRTIO_BLK_T_ZONE_RESET_ALL 26
208 
209 #ifndef VIRTIO_BLK_NO_LEGACY
210 /* Barrier before this op. */
211 #define VIRTIO_BLK_T_BARRIER	0x80000000
212 #endif /* !VIRTIO_BLK_NO_LEGACY */
213 
214 /*
215  * This comes first in the read scatter-gather list.
216  * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,
217  * this is the first element of the read scatter-gather list.
218  */
219 struct virtio_blk_outhdr {
220 	/* VIRTIO_BLK_T* */
221 	__virtio32 type;
222 	/* io priority. */
223 	__virtio32 ioprio;
224 	/* Sector (ie. 512 byte offset) */
225 	__virtio64 sector;
226 };
227 
228 /*
229  * Supported zoned device models.
230  */
231 
232 /* Regular block device */
233 #define VIRTIO_BLK_Z_NONE      0
234 /* Host-managed zoned device */
235 #define VIRTIO_BLK_Z_HM        1
236 /* Host-aware zoned device */
237 #define VIRTIO_BLK_Z_HA        2
238 
239 /*
240  * Zone descriptor. A part of VIRTIO_BLK_T_ZONE_REPORT command reply.
241  */
242 struct virtio_blk_zone_descriptor {
243 	/* Zone capacity */
244 	__virtio64 z_cap;
245 	/* The starting sector of the zone */
246 	__virtio64 z_start;
247 	/* Zone write pointer position in sectors */
248 	__virtio64 z_wp;
249 	/* Zone type */
250 	__u8 z_type;
251 	/* Zone state */
252 	__u8 z_state;
253 	__u8 reserved[38];
254 };
255 
256 struct virtio_blk_zone_report {
257 	__virtio64 nr_zones;
258 	__u8 reserved[56];
259 	struct virtio_blk_zone_descriptor zones[];
260 };
261 
262 /*
263  * Supported zone types.
264  */
265 
266 /* Conventional zone */
267 #define VIRTIO_BLK_ZT_CONV         1
268 /* Sequential Write Required zone */
269 #define VIRTIO_BLK_ZT_SWR          2
270 /* Sequential Write Preferred zone */
271 #define VIRTIO_BLK_ZT_SWP          3
272 
273 /*
274  * Zone states that are available for zones of all types.
275  */
276 
277 /* Not a write pointer (conventional zones only) */
278 #define VIRTIO_BLK_ZS_NOT_WP       0
279 /* Empty */
280 #define VIRTIO_BLK_ZS_EMPTY        1
281 /* Implicitly Open */
282 #define VIRTIO_BLK_ZS_IOPEN        2
283 /* Explicitly Open */
284 #define VIRTIO_BLK_ZS_EOPEN        3
285 /* Closed */
286 #define VIRTIO_BLK_ZS_CLOSED       4
287 /* Read-Only */
288 #define VIRTIO_BLK_ZS_RDONLY       13
289 /* Full */
290 #define VIRTIO_BLK_ZS_FULL         14
291 /* Offline */
292 #define VIRTIO_BLK_ZS_OFFLINE      15
293 
294 /* Unmap this range (only valid for write zeroes command) */
295 #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP	0x00000001
296 
297 /* Discard/write zeroes range for each request. */
298 struct virtio_blk_discard_write_zeroes {
299 	/* discard/write zeroes start sector */
300 	__le64 sector;
301 	/* number of discard/write zeroes sectors */
302 	__le32 num_sectors;
303 	/* flags for this range */
304 	__le32 flags;
305 };
306 
307 #ifndef VIRTIO_BLK_NO_LEGACY
308 struct virtio_scsi_inhdr {
309 	__virtio32 errors;
310 	__virtio32 data_len;
311 	__virtio32 sense_len;
312 	__virtio32 residual;
313 };
314 #endif /* !VIRTIO_BLK_NO_LEGACY */
315 
316 /* And this is the final byte of the write scatter-gather list. */
317 #define VIRTIO_BLK_S_OK		0
318 #define VIRTIO_BLK_S_IOERR	1
319 #define VIRTIO_BLK_S_UNSUPP	2
320 
321 /* Error codes that are specific to zoned block devices */
322 #define VIRTIO_BLK_S_ZONE_INVALID_CMD     3
323 #define VIRTIO_BLK_S_ZONE_UNALIGNED_WP    4
324 #define VIRTIO_BLK_S_ZONE_OPEN_RESOURCE   5
325 #define VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE 6
326 
327 #endif /* _LINUX_VIRTIO_BLK_H */
328