include/uapi/linux/virtio_blk.h

   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 */