1 /*- 2 * This header is BSD licensed so anyone can use the definitions to implement 3 * compatible drivers/servers. 4 * 5 * Redistribution and use in source and binary forms, with or without 6 * modification, are permitted provided that the following conditions 7 * are met: 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of IBM nor the names of its contributors 14 * may be used to endorse or promote products derived from this software 15 * without specific prior written permission. 16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 18 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 19 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD: head/sys/dev/virtio/block/virtio_blk.h 252703 2013-07-04 17:53:02Z bryanv $ 29 */ 30 31 #ifndef _VIRTIO_BLK_H 32 #define _VIRTIO_BLK_H 33 34 /* Feature bits */ 35 #define VIRTIO_BLK_F_BARRIER 0x0001 /* Does host support barriers? */ 36 #define VIRTIO_BLK_F_SIZE_MAX 0x0002 /* Indicates maximum segment size */ 37 #define VIRTIO_BLK_F_SEG_MAX 0x0004 /* Indicates maximum # of segments */ 38 #define VIRTIO_BLK_F_GEOMETRY 0x0010 /* Legacy geometry available */ 39 #define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */ 40 #define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/ 41 #define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */ 42 #define VIRTIO_BLK_F_WCE 0x0200 /* Writeback mode enabled after reset */ 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 46 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 47 48 struct virtio_blk_config { 49 /* The capacity (in 512-byte sectors). */ 50 uint64_t capacity; 51 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 52 uint32_t size_max; 53 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 54 uint32_t seg_max; 55 /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 56 struct virtio_blk_geometry { 57 uint16_t cylinders; 58 uint8_t heads; 59 uint8_t sectors; 60 } geometry; 61 62 /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 63 uint32_t blk_size; 64 65 /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */ 66 struct virtio_blk_topology { 67 uint8_t physical_block_exp; 68 uint8_t alignment_offset; 69 uint16_t min_io_size; 70 uint32_t opt_io_size; 71 } topology; 72 73 /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 74 uint8_t writeback; 75 76 } __packed; 77 78 /* 79 * Command types 80 * 81 * Usage is a bit tricky as some bits are used as flags and some are not. 82 * 83 * Rules: 84 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 85 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 86 * and may not be combined with any of the other flags. 87 */ 88 89 /* These two define direction. */ 90 #define VIRTIO_BLK_T_IN 0 91 #define VIRTIO_BLK_T_OUT 1 92 93 /* This bit says it's a scsi command, not an actual read or write. */ 94 #define VIRTIO_BLK_T_SCSI_CMD 2 95 96 /* Cache flush command */ 97 #define VIRTIO_BLK_T_FLUSH 4 98 99 /* Get device ID command */ 100 #define VIRTIO_BLK_T_GET_ID 8 101 102 /* Barrier before this op. */ 103 #define VIRTIO_BLK_T_BARRIER 0x80000000 104 105 /* ID string length */ 106 #define VIRTIO_BLK_ID_BYTES 20 107 108 /* This is the first element of the read scatter-gather list. */ 109 struct virtio_blk_outhdr { 110 /* VIRTIO_BLK_T* */ 111 uint32_t type; 112 /* io priority. */ 113 uint32_t ioprio; 114 /* Sector (ie. 512 byte offset) */ 115 uint64_t sector; 116 }; 117 118 struct virtio_scsi_inhdr { 119 uint32_t errors; 120 uint32_t data_len; 121 uint32_t sense_len; 122 uint32_t residual; 123 }; 124 125 /* And this is the final byte of the write scatter-gather list. */ 126 #define VIRTIO_BLK_S_OK 0 127 #define VIRTIO_BLK_S_IOERR 1 128 #define VIRTIO_BLK_S_UNSUPP 2 129 130 #endif /* _VIRTIO_BLK_H */ 131