hw/virtio-blk.h

   1 /*
   2  * Virtio Block Device
   3  *
   4  * Copyright IBM, Corp. 2007
   5  *
   6  * Authors:
   7  *  Anthony Liguori   <aliguori@us.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2.  See
  10  * the COPYING file in the top-level directory.
  11  *
  12  */
  13
  14 #ifndef _QEMU_VIRTIO_BLK_H
  15 #define _QEMU_VIRTIO_BLK_H
  16
  17 #include "virtio.h"
  18 #include "block.h"
  19
  20 /* from Linux's linux/virtio_blk.h */
  21
  22 /* The ID for virtio_block */
  23 #define VIRTIO_ID_BLOCK 2
  24
  25 /* Feature bits */
  26 #define VIRTIO_BLK_F_BARRIER    0       /* Does host support barriers? */
  27 #define VIRTIO_BLK_F_SIZE_MAX   1       /* Indicates maximum segment size */
  28 #define VIRTIO_BLK_F_SEG_MAX    2       /* Indicates maximum # of segments */
  29 #define VIRTIO_BLK_F_GEOMETRY   4       /* Indicates support of legacy geometry */
  30 #define VIRTIO_BLK_F_RO         5       /* Disk is read-only */
  31 #define VIRTIO_BLK_F_BLK_SIZE   6       /* Block size of disk is available*/
  32 #define VIRTIO_BLK_F_SCSI       7       /* Supports scsi command passthru */
  33 /* #define VIRTIO_BLK_F_IDENTIFY   8       ATA IDENTIFY supported, DEPRECATED */
  34 #define VIRTIO_BLK_F_WCACHE     9       /* write cache enabled */
  35
  36 struct virtio_blk_config
  37 {
  38     uint64_t capacity;
  39     uint32_t size_max;
  40     uint32_t seg_max;
  41     uint16_t cylinders;
  42     uint8_t heads;
  43     uint8_t sectors;
  44     uint32_t _blk_size;    /* structure pad, currently unused */
  45 } __attribute__((packed));
  46
  47 /* These two define direction. */
  48 #define VIRTIO_BLK_T_IN         0
  49 #define VIRTIO_BLK_T_OUT        1
  50
  51 /* This bit says it's a scsi command, not an actual read or write. */
  52 #define VIRTIO_BLK_T_SCSI_CMD   2
  53
  54 /* Flush the volatile write cache */
  55 #define VIRTIO_BLK_T_FLUSH      4
  56
  57 /* Barrier before this op. */
  58 #define VIRTIO_BLK_T_BARRIER    0x80000000
  59
  60 /* This is the first element of the read scatter-gather list. */
  61 struct virtio_blk_outhdr
  62 {
  63     /* VIRTIO_BLK_T* */
  64     uint32_t type;
  65     /* io priority. */
  66     uint32_t ioprio;
  67     /* Sector (ie. 512 byte offset) */
  68     uint64_t sector;
  69 };
  70
  71 #define VIRTIO_BLK_S_OK         0
  72 #define VIRTIO_BLK_S_IOERR      1
  73 #define VIRTIO_BLK_S_UNSUPP     2
  74
  75 /* This is the last element of the write scatter-gather list */
  76 struct virtio_blk_inhdr
  77 {
  78     unsigned char status;
  79 };
  80
  81 /* SCSI pass-through header */
  82 struct virtio_scsi_inhdr
  83 {
  84     uint32_t errors;
  85     uint32_t data_len;
  86     uint32_t sense_len;
  87     uint32_t residual;
  88 };
  89
  90 #ifdef __linux__
  91 #define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \
  92         DEFINE_VIRTIO_COMMON_FEATURES(_state, _field), \
  93         DEFINE_PROP_BIT("scsi", _state, _field, VIRTIO_BLK_F_SCSI, true)
  94 #else
  95 #define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \
  96         DEFINE_VIRTIO_COMMON_FEATURES(_state, _field)
  97 #endif
  98 #endif