include/standard-headers/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 "standard-headers/linux/types.h"
  29 #include "standard-headers/linux/virtio_ids.h"
  30 #include "standard-headers/linux/virtio_config.h"
  31 #include "standard-headers/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 /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */
  53 #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH
  54 #endif /* !VIRTIO_BLK_NO_LEGACY */
  55
  56 #define VIRTIO_BLK_ID_BYTES     20      /* ID string length */
  57
  58 struct virtio_blk_config {
  59         /* The capacity (in 512-byte sectors). */
  60         __virtio64 capacity;
  61         /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */
  62         __virtio32 size_max;
  63         /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */
  64         __virtio32 seg_max;
  65         /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */
  66         struct virtio_blk_geometry {
  67                 __virtio16 cylinders;
  68                 uint8_t heads;
  69                 uint8_t sectors;
  70         } geometry;
  71
  72         /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */
  73         __virtio32 blk_size;
  74
  75         /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY  */
  76         /* exponent for physical block per logical block. */
  77         uint8_t physical_block_exp;
  78         /* alignment offset in logical blocks. */
  79         uint8_t alignment_offset;
  80         /* minimum I/O size without performance penalty in logical blocks. */
  81         __virtio16 min_io_size;
  82         /* optimal sustained I/O size in logical blocks. */
  83         __virtio32 opt_io_size;
  84
  85         /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */
  86         uint8_t wce;
  87         uint8_t unused;
  88
  89         /* number of vqs, only available when VIRTIO_BLK_F_MQ is set */
  90         __virtio16 num_queues;
  91
  92         /* the next 3 entries are guarded by VIRTIO_BLK_F_DISCARD */
  93         /*
  94          * The maximum discard sectors (in 512-byte sectors) for
  95          * one segment.
  96          */
  97         __virtio32 max_discard_sectors;
  98         /*
  99          * The maximum number of discard segments in a
 100          * discard command.
 101          */
 102         __virtio32 max_discard_seg;
 103         /* Discard commands must be aligned to this number of sectors. */
 104         __virtio32 discard_sector_alignment;
 105
 106         /* the next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES */
 107         /*
 108          * The maximum number of write zeroes sectors (in 512-byte sectors) in
 109          * one segment.
 110          */
 111         __virtio32 max_write_zeroes_sectors;
 112         /*
 113          * The maximum number of segments in a write zeroes
 114          * command.
 115          */
 116         __virtio32 max_write_zeroes_seg;
 117         /*
 118          * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the
 119          * deallocation of one or more of the sectors.
 120          */
 121         uint8_t write_zeroes_may_unmap;
 122
 123         uint8_t unused1[3];
 124
 125         /* the next 3 entries are guarded by VIRTIO_BLK_F_SECURE_ERASE */
 126         /*
 127          * The maximum secure erase sectors (in 512-byte sectors) for
 128          * one segment.
 129          */
 130         __virtio32 max_secure_erase_sectors;
 131         /*
 132          * The maximum number of secure erase segments in a
 133          * secure erase command.
 134          */
 135         __virtio32 max_secure_erase_seg;
 136         /* Secure erase commands must be aligned to this number of sectors. */
 137         __virtio32 secure_erase_sector_alignment;
 138
 139         /* Zoned block device characteristics (if VIRTIO_BLK_F_ZONED) */
 140         struct virtio_blk_zoned_characteristics {
 141                 __virtio32 zone_sectors;
 142                 __virtio32 max_open_zones;
 143                 __virtio32 max_active_zones;
 144                 __virtio32 max_append_sectors;
 145                 __virtio32 write_granularity;
 146                 uint8_t model;
 147                 uint8_t unused2[3];
 148         } zoned;
 149 } QEMU_PACKED;
 150
 151 /*
 152  * Command types
 153  *
 154  * Usage is a bit tricky as some bits are used as flags and some are not.
 155  *
 156  * Rules:
 157  *   VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or
 158  *   VIRTIO_BLK_T_BARRIER.  VIRTIO_BLK_T_FLUSH is a command of its own
 159  *   and may not be combined with any of the other flags.
 160  */
 161
 162 /* These two define direction. */
 163 #define VIRTIO_BLK_T_IN         0
 164 #define VIRTIO_BLK_T_OUT        1
 165
 166 #ifndef VIRTIO_BLK_NO_LEGACY
 167 /* This bit says it's a scsi command, not an actual read or write. */
 168 #define VIRTIO_BLK_T_SCSI_CMD   2
 169 #endif /* VIRTIO_BLK_NO_LEGACY */
 170
 171 /* Cache flush command */
 172 #define VIRTIO_BLK_T_FLUSH      4
 173
 174 /* Get device ID command */
 175 #define VIRTIO_BLK_T_GET_ID    8
 176
 177 /* Discard command */
 178 #define VIRTIO_BLK_T_DISCARD    11
 179
 180 /* Write zeroes command */
 181 #define VIRTIO_BLK_T_WRITE_ZEROES       13
 182
 183 /* Secure erase command */
 184 #define VIRTIO_BLK_T_SECURE_ERASE       14
 185
 186 /* Zone append command */
 187 #define VIRTIO_BLK_T_ZONE_APPEND    15
 188
 189 /* Report zones command */
 190 #define VIRTIO_BLK_T_ZONE_REPORT    16
 191
 192 /* Open zone command */
 193 #define VIRTIO_BLK_T_ZONE_OPEN      18
 194
 195 /* Close zone command */
 196 #define VIRTIO_BLK_T_ZONE_CLOSE     20
 197
 198 /* Finish zone command */
 199 #define VIRTIO_BLK_T_ZONE_FINISH    22
 200
 201 /* Reset zone command */
 202 #define VIRTIO_BLK_T_ZONE_RESET     24
 203
 204 /* Reset All zones command */
 205 #define VIRTIO_BLK_T_ZONE_RESET_ALL 26
 206
 207 #ifndef VIRTIO_BLK_NO_LEGACY
 208 /* Barrier before this op. */
 209 #define VIRTIO_BLK_T_BARRIER    0x80000000
 210 #endif /* !VIRTIO_BLK_NO_LEGACY */
 211
 212 /*
 213  * This comes first in the read scatter-gather list.
 214  * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated,
 215  * this is the first element of the read scatter-gather list.
 216  */
 217 struct virtio_blk_outhdr {
 218         /* VIRTIO_BLK_T* */
 219         __virtio32 type;
 220         /* io priority. */
 221         __virtio32 ioprio;
 222         /* Sector (ie. 512 byte offset) */
 223         __virtio64 sector;
 224 };
 225
 226 /*
 227  * Supported zoned device models.
 228  */
 229
 230 /* Regular block device */
 231 #define VIRTIO_BLK_Z_NONE      0
 232 /* Host-managed zoned device */
 233 #define VIRTIO_BLK_Z_HM        1
 234 /* Host-aware zoned device */
 235 #define VIRTIO_BLK_Z_HA        2
 236
 237 /*
 238  * Zone descriptor. A part of VIRTIO_BLK_T_ZONE_REPORT command reply.
 239  */
 240 struct virtio_blk_zone_descriptor {
 241         /* Zone capacity */
 242         __virtio64 z_cap;
 243         /* The starting sector of the zone */
 244         __virtio64 z_start;
 245         /* Zone write pointer position in sectors */
 246         __virtio64 z_wp;
 247         /* Zone type */
 248         uint8_t z_type;
 249         /* Zone state */
 250         uint8_t z_state;
 251         uint8_t reserved[38];
 252 };
 253
 254 struct virtio_blk_zone_report {
 255         __virtio64 nr_zones;
 256         uint8_t reserved[56];
 257         struct virtio_blk_zone_descriptor zones[];
 258 };
 259
 260 /*
 261  * Supported zone types.
 262  */
 263
 264 /* Conventional zone */
 265 #define VIRTIO_BLK_ZT_CONV         1
 266 /* Sequential Write Required zone */
 267 #define VIRTIO_BLK_ZT_SWR          2
 268 /* Sequential Write Preferred zone */
 269 #define VIRTIO_BLK_ZT_SWP          3
 270
 271 /*
 272  * Zone states that are available for zones of all types.
 273  */
 274
 275 /* Not a write pointer (conventional zones only) */
 276 #define VIRTIO_BLK_ZS_NOT_WP       0
 277 /* Empty */
 278 #define VIRTIO_BLK_ZS_EMPTY        1
 279 /* Implicitly Open */
 280 #define VIRTIO_BLK_ZS_IOPEN        2
 281 /* Explicitly Open */
 282 #define VIRTIO_BLK_ZS_EOPEN        3
 283 /* Closed */
 284 #define VIRTIO_BLK_ZS_CLOSED       4
 285 /* Read-Only */
 286 #define VIRTIO_BLK_ZS_RDONLY       13
 287 /* Full */
 288 #define VIRTIO_BLK_ZS_FULL         14
 289 /* Offline */
 290 #define VIRTIO_BLK_ZS_OFFLINE      15
 291
 292 /* Unmap this range (only valid for write zeroes command) */
 293 #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP      0x00000001
 294
 295 /* Discard/write zeroes range for each request. */
 296 struct virtio_blk_discard_write_zeroes {
 297         /* discard/write zeroes start sector */
 298         uint64_t sector;
 299         /* number of discard/write zeroes sectors */
 300         uint32_t num_sectors;
 301         /* flags for this range */
 302         uint32_t flags;
 303 };
 304
 305 #ifndef VIRTIO_BLK_NO_LEGACY
 306 struct virtio_scsi_inhdr {
 307         __virtio32 errors;
 308         __virtio32 data_len;
 309         __virtio32 sense_len;
 310         __virtio32 residual;
 311 };
 312 #endif /* !VIRTIO_BLK_NO_LEGACY */
 313
 314 /* And this is the final byte of the write scatter-gather list. */
 315 #define VIRTIO_BLK_S_OK         0
 316 #define VIRTIO_BLK_S_IOERR      1
 317 #define VIRTIO_BLK_S_UNSUPP     2
 318
 319 /* Error codes that are specific to zoned block devices */
 320 #define VIRTIO_BLK_S_ZONE_INVALID_CMD     3
 321 #define VIRTIO_BLK_S_ZONE_UNALIGNED_WP    4
 322 #define VIRTIO_BLK_S_ZONE_OPEN_RESOURCE   5
 323 #define VIRTIO_BLK_S_ZONE_ACTIVE_RESOURCE 6
 324
 325 #endif /* _LINUX_VIRTIO_BLK_H */