1#ifndef _LINUX_VIRTIO_BLK_H 2#define _LINUX_VIRTIO_BLK_H 3/* This header is BSD licensed so anyone can use the definitions to implement 4 * compatible drivers/servers. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of IBM nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND 18 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 20 * ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE 21 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 22 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 23 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 24 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 25 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 26 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 27 * SUCH DAMAGE. */ 28#include <linux/types.h> 29#include <linux/virtio_ids.h> 30#include <linux/virtio_config.h> 31#include <linux/virtio_types.h> 32 33/* Feature bits */ 34#define VIRTIO_BLK_F_SIZE_MAX 1 /* Indicates maximum segment size */ 35#define VIRTIO_BLK_F_SEG_MAX 2 /* Indicates maximum # of segments */ 36#define VIRTIO_BLK_F_GEOMETRY 4 /* Legacy geometry available */ 37#define VIRTIO_BLK_F_RO 5 /* Disk is read-only */ 38#define VIRTIO_BLK_F_BLK_SIZE 6 /* Block size of disk is available*/ 39#define VIRTIO_BLK_F_TOPOLOGY 10 /* Topology information is available */ 40#define VIRTIO_BLK_F_MQ 12 /* support more than one vq */ 41 42/* Legacy feature bits */ 43#ifndef VIRTIO_BLK_NO_LEGACY 44#define VIRTIO_BLK_F_BARRIER 0 /* Does host support barriers? */ 45#define VIRTIO_BLK_F_SCSI 7 /* Supports scsi command passthru */ 46#define VIRTIO_BLK_F_FLUSH 9 /* Flush command supported */ 47#define VIRTIO_BLK_F_CONFIG_WCE 11 /* Writeback mode available in config */ 48#ifndef __KERNEL__ 49/* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */ 50#define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH 51#endif 52#endif /* !VIRTIO_BLK_NO_LEGACY */ 53 54#define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ 55 56struct virtio_blk_config { 57 /* The capacity (in 512-byte sectors). */ 58 __u64 capacity; 59 /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ 60 __u32 size_max; 61 /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ 62 __u32 seg_max; 63 /* geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ 64 struct virtio_blk_geometry { 65 __u16 cylinders; 66 __u8 heads; 67 __u8 sectors; 68 } geometry; 69 70 /* block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ 71 __u32 blk_size; 72 73 /* the next 4 entries are guarded by VIRTIO_BLK_F_TOPOLOGY */ 74 /* exponent for physical block per logical block. */ 75 __u8 physical_block_exp; 76 /* alignment offset in logical blocks. */ 77 __u8 alignment_offset; 78 /* minimum I/O size without performance penalty in logical blocks. */ 79 __u16 min_io_size; 80 /* optimal sustained I/O size in logical blocks. */ 81 __u32 opt_io_size; 82 83 /* writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ 84 __u8 wce; 85 __u8 unused; 86 87 /* number of vqs, only available when VIRTIO_BLK_F_MQ is set */ 88 __u16 num_queues; 89} __attribute__((packed)); 90 91/* 92 * Command types 93 * 94 * Usage is a bit tricky as some bits are used as flags and some are not. 95 * 96 * Rules: 97 * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or 98 * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own 99 * and may not be combined with any of the other flags. 100 */ 101 102/* These two define direction. */ 103#define VIRTIO_BLK_T_IN 0 104#define VIRTIO_BLK_T_OUT 1 105 106#ifndef VIRTIO_BLK_NO_LEGACY 107/* This bit says it's a scsi command, not an actual read or write. */ 108#define VIRTIO_BLK_T_SCSI_CMD 2 109#endif /* VIRTIO_BLK_NO_LEGACY */ 110 111/* Cache flush command */ 112#define VIRTIO_BLK_T_FLUSH 4 113 114/* Get device ID command */ 115#define VIRTIO_BLK_T_GET_ID 8 116 117#ifndef VIRTIO_BLK_NO_LEGACY 118/* Barrier before this op. */ 119#define VIRTIO_BLK_T_BARRIER 0x80000000 120#endif /* !VIRTIO_BLK_NO_LEGACY */ 121 122/* 123 * This comes first in the read scatter-gather list. 124 * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, 125 * this is the first element of the read scatter-gather list. 126 */ 127struct virtio_blk_outhdr { 128 /* VIRTIO_BLK_T* */ 129 __virtio32 type; 130 /* io priority. */ 131 __virtio32 ioprio; 132 /* Sector (ie. 512 byte offset) */ 133 __virtio64 sector; 134}; 135 136#ifndef VIRTIO_BLK_NO_LEGACY 137struct virtio_scsi_inhdr { 138 __virtio32 errors; 139 __virtio32 data_len; 140 __virtio32 sense_len; 141 __virtio32 residual; 142}; 143#endif /* !VIRTIO_BLK_NO_LEGACY */ 144 145/* And this is the final byte of the write scatter-gather list. */ 146#define VIRTIO_BLK_S_OK 0 147#define VIRTIO_BLK_S_IOERR 1 148#define VIRTIO_BLK_S_UNSUPP 2 149#endif /* _LINUX_VIRTIO_BLK_H */ 150