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 /* 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_FLUSH 0x0200 /* Cache flush command support */ 43 #define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */ 44 45 #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 46 47 struct virtio_blk_config { 48 /* The capacity (in 512-byte sectors). */ 49 uint64_t capacity; 50 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 51 uint32_t size_max; 52 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 53 uint32_t seg_max; 54 /* geometry the device (if VIRTIO_BLK_F_GEOMETRY) */ 55 struct virtio_blk_geometry { 56 uint16_t cylinders; 57 uint8_t heads; 58 uint8_t sectors; 59 } geometry; 60 61 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 62 uint32_t blk_size; 63 } __packed; 64 65 /* 66 * Command types 67 * 68 * Usage is a bit tricky as some bits are used as flags and some are not. 69 * 70 * Rules: 71 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 72 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 73 * and may not be combined with any of the other flags. 74 */ 75 76 /* These two define direction. */ 77 #define VIRTIO_BLK_T_IN 0 78 #define VIRTIO_BLK_T_OUT 1 79 80 /* This bit says it's a scsi command, not an actual read or write. */ 81 #define VIRTIO_BLK_T_SCSI_CMD 2 82 83 /* Cache flush command */ 84 #define VIRTIO_BLK_T_FLUSH 4 85 86 /* Get device ID command */ 87 #define VIRTIO_BLK_T_GET_ID 8 88 89 /* Barrier before this op. */ 90 #define VIRTIO_BLK_T_BARRIER 0x80000000 91 92 /* ID string length */ 93 #define VIRTIO_BLK_ID_BYTES 20 94 95 /* This is the first element of the read scatter-gather list. */ 96 struct virtio_blk_outhdr { 97 /* VIRTIO_BLK_T* */ 98 uint32_t type; 99 /* io priority. */ 100 uint32_t ioprio; 101 /* Sector (ie. 512 byte offset) */ 102 uint64_t sector; 103 }; 104 105 struct virtio_scsi_inhdr { 106 uint32_t errors; 107 uint32_t data_len; 108 uint32_t sense_len; 109 uint32_t residual; 110 }; 111 112 /* And this is the final byte of the write scatter-gather list. */ 113 #define VIRTIO_BLK_S_OK 0 114 #define VIRTIO_BLK_S_IOERR 1 115 #define VIRTIO_BLK_S_UNSUPP 2 116 117 #endif /* _VIRTIO_BLK_H */ 118