/*- * SPDX-License-Identifier: BSD-3-Clause * * This header is BSD licensed so anyone can use the definitions to implement * compatible drivers/servers. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. Neither the name of IBM nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL IBM OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. */ #ifndef _VIRTIO_BLK_H #define _VIRTIO_BLK_H /* Feature bits */ #define VIRTIO_BLK_F_SIZE_MAX 0x0002 /* Indicates maximum segment size */ #define VIRTIO_BLK_F_SEG_MAX 0x0004 /* Indicates maximum # of segments */ #define VIRTIO_BLK_F_GEOMETRY 0x0010 /* Legacy geometry available */ #define VIRTIO_BLK_F_RO 0x0020 /* Disk is read-only */ #define VIRTIO_BLK_F_BLK_SIZE 0x0040 /* Block size of disk is available*/ #define VIRTIO_BLK_F_FLUSH 0x0200 /* Flush command supported */ #define VIRTIO_BLK_F_TOPOLOGY 0x0400 /* Topology information is available */ #define VIRTIO_BLK_F_CONFIG_WCE 0x0800 /* Writeback mode available in config */ #define VIRTIO_BLK_F_MQ 0x1000 /* Support more than one vq */ #define VIRTIO_BLK_F_DISCARD 0x2000 /* DISCARD is supported */ #define VIRTIO_BLK_F_WRITE_ZEROES 0x4000 /* WRITE ZEROES is supported */ /* Legacy feature bits */ #define VIRTIO_BLK_F_BARRIER 0x0001 /* Does host support barriers? */ #define VIRTIO_BLK_F_SCSI 0x0080 /* Supports scsi command passthru */ /* Old (deprecated) name for VIRTIO_BLK_F_FLUSH. */ #define VIRTIO_BLK_F_WCE VIRTIO_BLK_F_FLUSH #define VIRTIO_BLK_ID_BYTES 20 /* ID string length */ struct virtio_blk_config { /* The capacity (in 512-byte sectors). */ uint64_t capacity; /* The maximum segment size (if VIRTIO_BLK_F_SIZE_MAX) */ uint32_t size_max; /* The maximum number of segments (if VIRTIO_BLK_F_SEG_MAX) */ uint32_t seg_max; /* Geometry of the device (if VIRTIO_BLK_F_GEOMETRY) */ struct virtio_blk_geometry { uint16_t cylinders; uint8_t heads; uint8_t sectors; } geometry; /* Block size of device (if VIRTIO_BLK_F_BLK_SIZE) */ uint32_t blk_size; /* Topology of the device (if VIRTIO_BLK_F_TOPOLOGY) */ struct virtio_blk_topology { /* Exponent for physical block per logical block. */ uint8_t physical_block_exp; /* Alignment offset in logical blocks. */ uint8_t alignment_offset; /* Minimum I/O size without performance penalty in logical * blocks. */ uint16_t min_io_size; /* Optimal sustained I/O size in logical blocks. */ uint32_t opt_io_size; } topology; /* Writeback mode (if VIRTIO_BLK_F_CONFIG_WCE) */ uint8_t wce; uint8_t unused; /* Number of vqs, only available when VIRTIO_BLK_F_MQ is set */ uint16_t num_queues; /* * The next 3 entries are guarded by VIRTIO_BLK_F_DISCARD. * * The maximum discard sectors (in 512-byte sectors) for * one segment. */ uint32_t max_discard_sectors; /* * The maximum number of discard segments in a * discard command. */ uint32_t max_discard_seg; /* Discard commands must be aligned to this number of sectors. */ uint32_t discard_sector_alignment; /* * The next 3 entries are guarded by VIRTIO_BLK_F_WRITE_ZEROES * * The maximum number of write zeroes sectors (in 512-byte sectors) in * one segment. */ uint32_t max_write_zeroes_sectors; /* * The maximum number of segments in a write zeroes * command. */ uint32_t max_write_zeroes_seg; /* * Set if a VIRTIO_BLK_T_WRITE_ZEROES request may result in the * deallocation of one or more of the sectors. */ uint8_t write_zeroes_may_unmap; uint8_t unused1[3]; } __packed; /* * Command types * * Usage is a bit tricky as some bits are used as flags and some are not. * * Rules: * VIRTIO_BLK_T_OUT may be combined with VIRTIO_BLK_T_SCSI_CMD or * VIRTIO_BLK_T_BARRIER. VIRTIO_BLK_T_FLUSH is a command of its own * and may not be combined with any of the other flags. */ /* These two define direction. */ #define VIRTIO_BLK_T_IN 0 #define VIRTIO_BLK_T_OUT 1 /* This bit says it's a scsi command, not an actual read or write. */ #define VIRTIO_BLK_T_SCSI_CMD 2 #define VIRTIO_BLK_T_SCSI_CMD_OUT 3 /* Cache flush command */ #define VIRTIO_BLK_T_FLUSH 4 #define VIRTIO_BLK_T_FLUSH_OUT 5 /* Get device ID command */ #define VIRTIO_BLK_T_GET_ID 8 /* Discard command */ #define VIRTIO_BLK_T_DISCARD 11 /* Write zeros command */ #define VIRTIO_BLK_T_WRITE_ZEROES 13 /* Barrier before this op. */ #define VIRTIO_BLK_T_BARRIER 0x80000000 /* Unmap this range (only valid for write zeroes command) */ #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 /* * This comes first in the read scatter-gather list. * For legacy virtio, if VIRTIO_F_ANY_LAYOUT is not negotiated, * this is the first element of the read scatter-gather list. */ struct virtio_blk_outhdr { /* VIRTIO_BLK_T* */ uint32_t type; /* io priority. */ uint32_t ioprio; /* Sector (ie. 512 byte offset) */ uint64_t sector; }; /* Unmap this range (only valid for write zeroes command) */ #define VIRTIO_BLK_WRITE_ZEROES_FLAG_UNMAP 0x00000001 /* Discard/write zeroes range for each request. */ struct virtio_blk_discard_write_zeroes { /* Discard/write zeroes start sector */ uint64_t sector; /* Number of discard/write zeroes sectors */ uint32_t num_sectors; /* Flags for this range */ uint32_t flags; }; struct virtio_scsi_inhdr { uint32_t errors; uint32_t data_len; uint32_t sense_len; uint32_t residual; }; /* And this is the final byte of the write scatter-gather list. */ #define VIRTIO_BLK_S_OK 0 #define VIRTIO_BLK_S_IOERR 1 #define VIRTIO_BLK_S_UNSUPP 2 #endif /* _VIRTIO_BLK_H */
