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_BARRIER 0x0001 /* Does host support barriers? */ 38 #define VIRTIO_BLK_F_SIZE_MAX 0x0002 /* Indicates maximum segment size */ 39 #define VIRTIO_BLK_F_SEG_MAX 0x0004 /* Indicates maximum # of segments */ 40 #define VIRTIO_BLK_F_GEOMETRY 0x0010 /* Legacy geometry available */ 41 #define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */ 42 #define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/ 43 #define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */ 44 #define VIRTIO_BLK_F_WCE 0x0200 /* Writeback mode enabled after reset */ 45 #define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */ 46 #define VIRTIO_BLK_F_CONFIG_WCE 0x0800 /* Writeback mode available in config */ 47 48 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 49 50 struct virtio_blk_config { 51 /* The capacity (in 512-byte sectors). */ 52 uint64_t capacity; 53 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 54 uint32_t size_max; 55 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 56 uint32_t seg_max; 57 /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 58 struct virtio_blk_geometry { 59 uint16_t cylinders; 60 uint8_t heads; 61 uint8_t sectors; 62 } geometry; 63 64 /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 65 uint32_t blk_size; 66 67 /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */ 68 struct virtio_blk_topology { 69 uint8_t physical_block_exp; 70 uint8_t alignment_offset; 71 uint16_t min_io_size; 72 uint32_t opt_io_size; 73 } topology; 74 75 /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 76 uint8_t writeback; 77 78 } __packed; 79 80 /* 81 * Command types 82 * 83 * Usage is a bit tricky as some bits are used as flags and some are not. 84 * 85 * Rules: 86 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 87 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 88 * and may not be combined with any of the other flags. 89 */ 90 91 /* These two define direction. */ 92 #define VIRTIO_BLK_T_IN 0 93 #define VIRTIO_BLK_T_OUT 1 94 95 /* This bit says it's a scsi command, not an actual read or write. */ 96 #define VIRTIO_BLK_T_SCSI_CMD 2 97 98 /* Cache flush command */ 99 #define VIRTIO_BLK_T_FLUSH 4 100 101 /* Get device ID command */ 102 #define VIRTIO_BLK_T_GET_ID 8 103 104 /* Barrier before this op. */ 105 #define VIRTIO_BLK_T_BARRIER 0x80000000 106 107 /* ID string length */ 108 #define VIRTIO_BLK_ID_BYTES 20 109 110 /* This is the first element of the read scatter-gather list. */ 111 struct virtio_blk_outhdr { 112 /* VIRTIO_BLK_T* */ 113 uint32_t type; 114 /* io priority. */ 115 uint32_t ioprio; 116 /* Sector (ie. 512 byte offset) */ 117 uint64_t sector; 118 }; 119 120 struct virtio_scsi_inhdr { 121 uint32_t errors; 122 uint32_t data_len; 123 uint32_t sense_len; 124 uint32_t residual; 125 }; 126 127 /* And this is the final byte of the write scatter-gather list. */ 128 #define VIRTIO_BLK_S_OK 0 129 #define VIRTIO_BLK_S_IOERR 1 130 #define VIRTIO_BLK_S_UNSUPP 2 131 132 #endif /* _VIRTIO_BLK_H */ 133