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
  34 struct virtio_blk_config
  35 {
  36     uint64_t capacity;
  37     uint32_t size_max;
  38     uint32_t seg_max;
  39     uint16_t cylinders;
  40     uint8_t heads;
  41     uint8_t sectors;
  42 } __attribute__((packed));
  43
  44 /* These two define direction. */
  45 #define VIRTIO_BLK_T_IN         0
  46 #define VIRTIO_BLK_T_OUT        1
  47
  48 /* This bit says it's a scsi command, not an actual read or write. */
  49 #define VIRTIO_BLK_T_SCSI_CMD   2
  50
  51 /* Barrier before this op. */
  52 #define VIRTIO_BLK_T_BARRIER    0x80000000
  53
  54 /* This is the first element of the read scatter-gather list. */
  55 struct virtio_blk_outhdr
  56 {
  57     /* VIRTIO_BLK_T* */
  58     uint32_t type;
  59     /* io priority. */
  60     uint32_t ioprio;
  61     /* Sector (ie. 512 byte offset) */
  62     uint64_t sector;
  63 };
  64
  65 #define VIRTIO_BLK_S_OK         0
  66 #define VIRTIO_BLK_S_IOERR      1
  67 #define VIRTIO_BLK_S_UNSUPP     2
  68
  69 /* This is the last element of the write scatter-gather list */
  70 struct virtio_blk_inhdr
  71 {
  72     unsigned char status;
  73 };
  74
  75 /* SCSI pass-through header */
  76 struct virtio_scsi_inhdr
  77 {
  78     uint32_t errors;
  79     uint32_t data_len;
  80     uint32_t sense_len;
  81     uint32_t residual;
  82 };
  83
  84 #endif