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/* Feature bits */ 37#define VIRTIO_BLK_F_SIZE_MAX 0x0002 /* Indicates maximum segment size */ 38#define VIRTIO_BLK_F_SEG_MAX 0x0004 /* Indicates maximum # of segments */ 39#define VIRTIO_BLK_F_GEOMETRY 0x0010 /* Legacy geometry available */ 40#define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */ 41#define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/ 42#define VIRTIO_BLK_F_FLUSH 0x0200 /* Flush command supported */ 43#define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */ 44#define VIRTIO_BLK_F_CONFIG_WCE 0x0800 /* Writeback mode available in config */ 45#define VIRTIO_BLK_F_MQ 0x1000 /* Support more than one vq */ 46#define VIRTIO_BLK_F_DISCARD 0x2000 /* DISCARD is supported */ 47#define VIRTIO_BLK_F_WRITE_ZEROES 0x4000 /* WRITE ZEROES is supported */ 48 49/* Legacy feature bits */ 50#define VIRTIO_BLK_F_BARRIER 0x0001 /* Does host support barriers? */ 51#define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */ 52 53/* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */ 54#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH 55 56#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 57 58struct virtio_blk_config { 59 /* The capacity (in 512-byte sectors). */ 60 uint64_t capacity; 61 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 62 uint32_t size_max; 63 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 64 uint32_t seg_max; 65 /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 66 struct virtio_blk_geometry { 67 uint16_t cylinders; 68 uint8_t heads; 69 uint8_t sectors; 70 } geometry; 71 72 /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 73 uint32_t blk_size; 74 75 /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */ 76 struct virtio_blk_topology { 77 /* Exponent for physical block per logical block. */ 78 uint8_t physical_block_exp; 79 /* Alignment offset in logical blocks. */ 80 uint8_t alignment_offset; 81 /* Minimum I/O size without performance penalty in logical 82 * blocks. */ 83 uint16_t min_io_size; 84 /* Optimal sustained I/O size in logical blocks. */ 85 uint32_t opt_io_size; 86 } topology; 87 88 /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 89 uint8_t wce; 90 uint8_t unused; 91 92 /* Number of vqs, only available when VIRTIO_BLK_F_MQ is set */ 93 uint16_t num_queues; 94 95 /* 96 * The next 3 entries are guarded by VIRTIO_BLK_F_DISCARD. 97 * 98 * The maximum discard sectors (in 512-byte sectors) for 99 * one segment. 100 */ 101 uint32_t max_discard_sectors; 102 /* 103 * The maximum number of discard segments in a 104 * discard command. 105 */ 106 uint32_t max_discard_seg; 107 /* Discard commands must be aligned to this number of sectors. */ 108 uint32_t discard_sector_alignment; 109 110 /* 111 * The next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES 112 * 113 * The maximum number of write zeroes sectors (in 512-byte sectors) in 114 * one segment. 115 */ 116 uint32_t max_write_zeroes_sectors; 117 /* 118 * The maximum number of segments in a write zeroes 119 * command. 120 */ 121 uint32_t max_write_zeroes_seg; 122 /* 123 * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the 124 * deallocation of one or more of the sectors. 125 */ 126 uint8_t write_zeroes_may_unmap; 127 128 uint8_t unused1[3]; 129} __packed; 130 131/* 132 * Command types 133 * 134 * Usage is a bit tricky as some bits are used as flags and some are not. 135 * 136 * Rules: 137 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 138 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 139 * and may not be combined with any of the other flags. 140 */ 141 142/* These two define direction. */ 143#define VIRTIO_BLK_T_IN 0 144#define VIRTIO_BLK_T_OUT 1 145 146/* This bit says it's a scsi command, not an actual read or write. */ 147#define VIRTIO_BLK_T_SCSI_CMD 2 148#define VIRTIO_BLK_T_SCSI_CMD_OUT 3 149 150/* Cache flush command */ 151#define VIRTIO_BLK_T_FLUSH 4 152#define VIRTIO_BLK_T_FLUSH_OUT 5 153 154/* Get device ID command */ 155#define VIRTIO_BLK_T_GET_ID 8 156 157/* Discard command */ 158#define VIRTIO_BLK_T_DISCARD 11 159 160/* Write zeros command */ 161#define VIRTIO_BLK_T_WRITE_ZEROES 13 162 163/* Barrier before this op. */ 164#define VIRTIO_BLK_T_BARRIER 0x80000000 165 166/* Unmap this range (only valid for write zeroes command) */ 167#define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 168 169/* 170 * This comes first in the read scatter-gather list. 171 * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, 172 * this is the first element of the read scatter-gather list. 173 */ 174struct virtio_blk_outhdr { 175 /* VIRTIO_BLK_T* */ 176 uint32_t type; 177 /* io priority. */ 178 uint32_t ioprio; 179 /* Sector (ie. 512 byte offset) */ 180 uint64_t sector; 181}; 182 183/* Unmap this range (only valid for write zeroes command) */ 184#define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 185 186/* Discard/write zeroes range for each request. */ 187struct virtio_blk_discard_write_zeroes { 188 /* Discard/write zeroes start sector */ 189 uint64_t sector; 190 /* Number of discard/write zeroes sectors */ 191 uint32_t num_sectors; 192 /* Flags for this range */ 193 uint32_t flags; 194}; 195 196struct virtio_scsi_inhdr { 197 uint32_t errors; 198 uint32_t data_len; 199 uint32_t sense_len; 200 uint32_t residual; 201}; 202 203/* And this is the final byte of the write scatter-gather list. */ 204#define VIRTIO_BLK_S_OK 0 205#define VIRTIO_BLK_S_IOERR 1 206#define VIRTIO_BLK_S_UNSUPP 2 207 208#endif /* _VIRTIO_BLK_H */ 209