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 #include "pci.h"
  20
  21 /* from Linux's linux/virtio_blk.h */
  22
  23 /* The ID for virtio_block */
  24 #define VIRTIO_ID_BLOCK 2
  25
  26 /* Feature bits */
  27 #define VIRTIO_BLK_F_BARRIER    0       /* Does host support barriers? */
  28 #define VIRTIO_BLK_F_SIZE_MAX   1       /* Indicates maximum segment size */
  29 #define VIRTIO_BLK_F_SEG_MAX    2       /* Indicates maximum # of segments */
  30 #define VIRTIO_BLK_F_GEOMETRY   4       /* Indicates support of legacy geometry */
  31
  32 struct virtio_blk_config
  33 {
  34     uint64_t capacity;
  35     uint32_t size_max;
  36     uint32_t seg_max;
  37     uint16_t cylinders;
  38     uint8_t heads;
  39     uint8_t sectors;
  40 } __attribute__((packed));
  41
  42 /* These two define direction. */
  43 #define VIRTIO_BLK_T_IN         0
  44 #define VIRTIO_BLK_T_OUT        1
  45
  46 /* This bit says it's a scsi command, not an actual read or write. */
  47 #define VIRTIO_BLK_T_SCSI_CMD   2
  48
  49 /* Barrier before this op. */
  50 #define VIRTIO_BLK_T_BARRIER    0x80000000
  51
  52 /* This is the first element of the read scatter-gather list. */
  53 struct virtio_blk_outhdr
  54 {
  55     /* VIRTIO_BLK_T* */
  56     uint32_t type;
  57     /* io priority. */
  58     uint32_t ioprio;
  59     /* Sector (ie. 512 byte offset) */
  60     uint64_t sector;
  61 };
  62
  63 #define VIRTIO_BLK_S_OK         0
  64 #define VIRTIO_BLK_S_IOERR      1
  65 #define VIRTIO_BLK_S_UNSUPP     2
  66
  67 /* This is the first element of the write scatter-gather list */
  68 struct virtio_blk_inhdr
  69 {
  70     unsigned char status;
  71 };
  72
  73 void *virtio_blk_init(PCIBus *bus, BlockDriverState *bs);
  74
  75 #endif