LXR qemu/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#define VIRTIO_BLK_F_TOPOLOGY   10      /* Topology information is available */
  36
  37struct virtio_blk_config
  38{
  39    uint64_t capacity;
  40    uint32_t size_max;
  41    uint32_t seg_max;
  42    uint16_t cylinders;
  43    uint8_t heads;
  44    uint8_t sectors;
  45    uint32_t blk_size;
  46    uint8_t physical_block_exp;
  47    uint8_t alignment_offset;
  48    uint16_t min_io_size;
  49    uint32_t opt_io_size;
  50} __attribute__((packed));
  51
  52/* These two define direction. */
  53#define VIRTIO_BLK_T_IN         0
  54#define VIRTIO_BLK_T_OUT        1
  55
  56/* This bit says it's a scsi command, not an actual read or write. */
  57#define VIRTIO_BLK_T_SCSI_CMD   2
  58
  59/* Flush the volatile write cache */
  60#define VIRTIO_BLK_T_FLUSH      4
  61
  62/* return the device ID string */
  63#define VIRTIO_BLK_T_GET_ID     8
  64
  65/* Barrier before this op. */
  66#define VIRTIO_BLK_T_BARRIER    0x80000000
  67
  68/* This is the first element of the read scatter-gather list. */
  69struct virtio_blk_outhdr
  70{
  71    /* VIRTIO_BLK_T* */
  72    uint32_t type;
  73    /* io priority. */
  74    uint32_t ioprio;
  75    /* Sector (ie. 512 byte offset) */
  76    uint64_t sector;
  77};
  78
  79#define VIRTIO_BLK_S_OK         0
  80#define VIRTIO_BLK_S_IOERR      1
  81#define VIRTIO_BLK_S_UNSUPP     2
  82
  83/* This is the last element of the write scatter-gather list */
  84struct virtio_blk_inhdr
  85{
  86    unsigned char status;
  87};
  88
  89/* SCSI pass-through header */
  90struct virtio_scsi_inhdr
  91{
  92    uint32_t errors;
  93    uint32_t data_len;
  94    uint32_t sense_len;
  95    uint32_t residual;
  96};
  97
  98#ifdef __linux__
  99#define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \
 100        DEFINE_VIRTIO_COMMON_FEATURES(_state, _field), \
 101        DEFINE_PROP_BIT("scsi", _state, _field, VIRTIO_BLK_F_SCSI, true)
 102#else
 103#define DEFINE_VIRTIO_BLK_FEATURES(_state, _field) \
 104        DEFINE_VIRTIO_COMMON_FEATURES(_state, _field)
 105#endif
 106#endif
 107