1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * This header is BSD licensed so anyone can use the definitions to implement 5 * compatible drivers/servers. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. Neither the name of IBM nor the names of its contributors 16 * may be used to endorse or promote products derived from this software 17 * without specific prior written permission. 18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 19 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 20 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 21 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 * 30 * $FreeBSD$ 31 */ 32 33 #ifndef _VIRTIO_BLK_H 34 #define _VIRTIO_BLK_H 35 36 #define VTBLK_BSIZE 512 37 38 /* Feature bits */ 39 40 #define VIRTIO_BLK_F_BARRIER 0x0001 /* Does host support barriers? */ 41 #define VIRTIO_BLK_F_SIZE_MAX 0x0002 /* Indicates maximum segment size */ 42 #define VIRTIO_BLK_F_SEG_MAX 0x0004 /* Indicates maximum # of segments */ 43 #define VIRTIO_BLK_F_GEOMETRY 0x0010 /* Legacy geometry available */ 44 #define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */ 45 #define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/ 46 #define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */ 47 #define VIRTIO_BLK_F_FLUSH 0x0200 /* Flush command supported */ 48 #define VIRTIO_BLK_F_WCE 0x0200 /* Legacy alias for FLUSH */ 49 #define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */ 50 #define VIRTIO_BLK_F_CONFIG_WCE 0x0800 /* Writeback mode available in config */ 51 #define VIRTIO_BLK_F_MQ 0x1000 /* Support more than one vq */ 52 #define VIRTIO_BLK_F_DISCARD 0x2000 /* Trim blocks */ 53 #define VIRTIO_BLK_F_WRITE_ZEROES 0x4000 /* Write zeros */ 54 55 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 56 57 struct virtio_blk_config { 58 /* The capacity (in 512-byte sectors). */ 59 uint64_t capacity; 60 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 61 uint32_t size_max; 62 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 63 uint32_t seg_max; 64 /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 65 struct virtio_blk_geometry { 66 uint16_t cylinders; 67 uint8_t heads; 68 uint8_t sectors; 69 } geometry; 70 71 /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 72 uint32_t blk_size; 73 74 /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */ 75 struct virtio_blk_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 81 * blocks. */ 82 uint16_t min_io_size; 83 /* Optimal sustained I/O size in logical blocks. */ 84 uint32_t opt_io_size; 85 } topology; 86 87 /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 88 uint8_t wce; 89 uint8_t unused; 90 /* Number of vqs, only available when VIRTIO_BLK_F_MQ is set */ 91 uint16_t num_queues; 92 uint32_t max_discard_sectors; 93 uint32_t max_discard_seg; 94 uint32_t discard_sector_alignment; 95 uint32_t max_write_zeroes_sectors; 96 uint32_t max_write_zeroes_seg; 97 uint8_t write_zeroes_may_unmap; 98 uint8_t unused1[3]; 99 } __packed; 100 101 /* 102 * Command types 103 * 104 * Usage is a bit tricky as some bits are used as flags and some are not. 105 * 106 * Rules: 107 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 108 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 109 * and may not be combined with any of the other flags. 110 */ 111 112 /* These two define direction. */ 113 #define VIRTIO_BLK_T_IN 0 114 #define VIRTIO_BLK_T_OUT 1 115 116 /* This bit says it's a scsi command, not an actual read or write. */ 117 #define VIRTIO_BLK_T_SCSI_CMD 2 118 #define VIRTIO_BLK_T_SCSI_CMD_OUT 3 119 120 /* Cache flush command */ 121 #define VIRTIO_BLK_T_FLUSH 4 122 #define VIRTIO_BLK_T_FLUSH_OUT 5 123 124 /* Get device ID command */ 125 #define VIRTIO_BLK_T_GET_ID 8 126 127 /* Discard command */ 128 #define VIRTIO_BLK_T_DISCARD 11 129 130 /* Write zeros command */ 131 #define VIRTIO_BLK_T_WRITE_ZEROES 13 132 133 /* Barrier before this op. */ 134 #define VIRTIO_BLK_T_BARRIER 0x80000000 135 136 /* ID string length */ 137 #define VIRTIO_BLK_ID_BYTES 20 138 139 /* Unmap this range (only valid for write zeroes command) */ 140 #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 141 142 /* This is the first element of the read scatter-gather list. */ 143 struct virtio_blk_outhdr { 144 /* VIRTIO_BLK_T* */ 145 uint32_t type; 146 /* io priority. */ 147 uint32_t ioprio; 148 /* Sector (ie. 512 byte offset) */ 149 uint64_t sector; 150 }; 151 152 struct virtio_blk_discard_write_zeroes { 153 uint64_t sector; 154 uint32_t num_sectors; 155 struct { 156 uint32_t unmap:1; 157 uint32_t reserved:31; 158 } flags; 159 }; 160 161 struct virtio_scsi_inhdr { 162 uint32_t errors; 163 uint32_t data_len; 164 uint32_t sense_len; 165 uint32_t residual; 166 }; 167 168 /* And this is the final byte of the write scatter-gather list. */ 169 #define VIRTIO_BLK_S_OK 0 170 #define VIRTIO_BLK_S_IOERR 1 171 #define VIRTIO_BLK_S_UNSUPP 2 172 173 #endif /* _VIRTIO_BLK_H */ 174