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 * $FreeBSD$ 29 */ 30 31 #ifndef _VIRTIO_BLK_H 32 #define _VIRTIO_BLK_H 33 34 #include <sys/types.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_FLUSH 0x0200 /* Cache flush command support */ 45 #define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */ 46 47 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 48 49 struct virtio_blk_config { 50 /* The capacity (in 512-byte sectors). */ 51 uint64_t capacity; 52 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 53 uint32_t size_max; 54 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 55 uint32_t seg_max; 56 /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */ 57 struct virtio_blk_geometry { 58 uint16_t cylinders; 59 uint8_t heads; 60 uint8_t sectors; 61 } geometry; 62 63 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 64 uint32_t blk_size; 65 } __packed; 66 67 /* 68 * Command types 69 * 70 * Usage is a bit tricky as some bits are used as flags and some are not. 71 * 72 * Rules: 73 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 74 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 75 * and may not be combined with any of the other flags. 76 */ 77 78 /* These two define direction. */ 79 #define VIRTIO_BLK_T_IN 0 80 #define VIRTIO_BLK_T_OUT 1 81 82 /* This bit says it's a scsi command, not an actual read or write. */ 83 #define VIRTIO_BLK_T_SCSI_CMD 2 84 85 /* Cache flush command */ 86 #define VIRTIO_BLK_T_FLUSH 4 87 88 /* Get device ID command */ 89 #define VIRTIO_BLK_T_GET_ID 8 90 91 /* Barrier before this op. */ 92 #define VIRTIO_BLK_T_BARRIER 0x80000000 93 94 /* ID string length */ 95 #define VIRTIO_BLK_ID_BYTES 20 96 97 /* This is the first element of the read scatter-gather list. */ 98 struct virtio_blk_outhdr { 99 /* VIRTIO_BLK_T* */ 100 uint32_t type; 101 /* io priority. */ 102 uint32_t ioprio; 103 /* Sector (ie. 512 byte offset) */ 104 uint64_t sector; 105 }; 106 107 struct virtio_scsi_inhdr { 108 uint32_t errors; 109 uint32_t data_len; 110 uint32_t sense_len; 111 uint32_t residual; 112 }; 113 114 /* And this is the final byte of the write scatter-gather list. */ 115 #define VIRTIO_BLK_S_OK 0 116 #define VIRTIO_BLK_S_IOERR 1 117 #define VIRTIO_BLK_S_UNSUPP 2 118 119 #endif /* _VIRTIO_BLK_H */ 120