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 45 /* Legacy feature bits */ 46 #ifndef VIRTIO_BLK_NO_LEGACY 47 #define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ 48 #define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ 49 #define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */ 50 #define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ 51 #ifndef __KERNEL__ 52 /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */ 53 #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH 54 #endif 55 #endif /* !VIRTIO_BLK_NO_LEGACY */ 56 57 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 58 59 struct virtio_blk_config { 60 /* The capacity (in 512-byte sectors). */ 61 __virtio64 capacity; 62 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 63 __virtio32 size_max; 64 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 65 __virtio32 seg_max; 66 /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 67 struct virtio_blk_geometry { 68 __virtio16 cylinders; 69 __u8 heads; 70 __u8 sectors; 71 } geometry; 72 73 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 74 __virtio32 blk_size; 75 76 /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ 77 /* exponent for physical block per logical block. */ 78 __u8 physical_block_exp; 79 /* alignment offset in logical blocks. */ 80 __u8 alignment_offset; 81 /* minimum I/O size without performance penalty in logical blocks. */ 82 __virtio16 min_io_size; 83 /* optimal sustained I/O size in logical blocks. */ 84 __virtio32 opt_io_size; 85 86 /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 87 __u8 wce; 88 __u8 unused; 89 90 /* number of vqs, only available when VIRTIO_BLK_F_MQ is set */ 91 __virtio16 num_queues; 92 93 /* the next 3 entries are guarded by VIRTIO_BLK_F_DISCARD */ 94 /* 95 * The maximum discard sectors (in 512-byte sectors) for 96 * one segment. 97 */ 98 __virtio32 max_discard_sectors; 99 /* 100 * The maximum number of discard segments in a 101 * discard command. 102 */ 103 __virtio32 max_discard_seg; 104 /* Discard commands must be aligned to this number of sectors. */ 105 __virtio32 discard_sector_alignment; 106 107 /* the next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES */ 108 /* 109 * The maximum number of write zeroes sectors (in 512-byte sectors) in 110 * one segment. 111 */ 112 __virtio32 max_write_zeroes_sectors; 113 /* 114 * The maximum number of segments in a write zeroes 115 * command. 116 */ 117 __virtio32 max_write_zeroes_seg; 118 /* 119 * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the 120 * deallocation of one or more of the sectors. 121 */ 122 __u8 write_zeroes_may_unmap; 123 124 __u8 unused1[3]; 125 126 /* the next 3 entries are guarded by VIRTIO_BLK_F_SECURE_ERASE */ 127 /* 128 * The maximum secure erase sectors (in 512-byte sectors) for 129 * one segment. 130 */ 131 __virtio32 max_secure_erase_sectors; 132 /* 133 * The maximum number of secure erase segments in a 134 * secure erase command. 135 */ 136 __virtio32 max_secure_erase_seg; 137 /* Secure erase commands must be aligned to this number of sectors. */ 138 __virtio32 secure_erase_sector_alignment; 139 140 } __attribute__((packed)); 141 142 /* 143 * Command types 144 * 145 * Usage is a bit tricky as some bits are used as flags and some are not. 146 * 147 * Rules: 148 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 149 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 150 * and may not be combined with any of the other flags. 151 */ 152 153 /* These two define direction. */ 154 #define VIRTIO_BLK_T_IN 0 155 #define VIRTIO_BLK_T_OUT 1 156 157 #ifndef VIRTIO_BLK_NO_LEGACY 158 /* This bit says it's a scsi command, not an actual read or write. */ 159 #define VIRTIO_BLK_T_SCSI_CMD 2 160 #endif /* VIRTIO_BLK_NO_LEGACY */ 161 162 /* Cache flush command */ 163 #define VIRTIO_BLK_T_FLUSH 4 164 165 /* Get device ID command */ 166 #define VIRTIO_BLK_T_GET_ID 8 167 168 /* Discard command */ 169 #define VIRTIO_BLK_T_DISCARD 11 170 171 /* Write zeroes command */ 172 #define VIRTIO_BLK_T_WRITE_ZEROES 13 173 174 /* Secure erase command */ 175 #define VIRTIO_BLK_T_SECURE_ERASE 14 176 177 #ifndef VIRTIO_BLK_NO_LEGACY 178 /* Barrier before this op. */ 179 #define VIRTIO_BLK_T_BARRIER 0x80000000 180 #endif /* !VIRTIO_BLK_NO_LEGACY */ 181 182 /* 183 * This comes first in the read scatter-gather list. 184 * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, 185 * this is the first element of the read scatter-gather list. 186 */ 187 struct virtio_blk_outhdr { 188 /* VIRTIO_BLK_T* */ 189 __virtio32 type; 190 /* io priority. */ 191 __virtio32 ioprio; 192 /* Sector (ie. 512 byte offset) */ 193 __virtio64 sector; 194 }; 195 196 /* Unmap this range (only valid for write zeroes command) */ 197 #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 198 199 /* Discard/write zeroes range for each request. */ 200 struct virtio_blk_discard_write_zeroes { 201 /* discard/write zeroes start sector */ 202 __le64 sector; 203 /* number of discard/write zeroes sectors */ 204 __le32 num_sectors; 205 /* flags for this range */ 206 __le32 flags; 207 }; 208 209 #ifndef VIRTIO_BLK_NO_LEGACY 210 struct virtio_scsi_inhdr { 211 __virtio32 errors; 212 __virtio32 data_len; 213 __virtio32 sense_len; 214 __virtio32 residual; 215 }; 216 #endif /* !VIRTIO_BLK_NO_LEGACY */ 217 218 /* And this is the final byte of the write scatter-gather list. */ 219 #define VIRTIO_BLK_S_OK 0 220 #define VIRTIO_BLK_S_IOERR 1 221 #define VIRTIO_BLK_S_UNSUPP 2 222 #endif /* _LINUX_VIRTIO_BLK_H */ 223
