include/hw/virtio/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 "standard-headers/linux/virtio_blk.h"
  18 #include "hw/virtio/virtio.h"
  19 #include "hw/block/block.h"
  20 #include "sysemu/iothread.h"
  21 #include "sysemu/block-backend.h"
  22
  23 #define TYPE_VIRTIO_BLK "virtio-blk-device"
  24 #define VIRTIO_BLK(obj) \
  25         OBJECT_CHECK(VirtIOBlock, (obj), TYPE_VIRTIO_BLK)
  26
  27 /* This is the last element of the write scatter-gather list */
  28 struct virtio_blk_inhdr
  29 {
  30     unsigned char status;
  31 };
  32
  33 struct VirtIOBlkConf
  34 {
  35     BlockConf conf;
  36     IOThread *iothread;
  37     char *serial;
  38     uint32_t scsi;
  39     uint32_t config_wce;
  40     uint32_t request_merging;
  41 };
  42
  43 struct VirtIOBlockDataPlane;
  44
  45 struct VirtIOBlockReq;
  46 typedef struct VirtIOBlock {
  47     VirtIODevice parent_obj;
  48     BlockBackend *blk;
  49     VirtQueue *vq;
  50     void *rq;
  51     QEMUBH *bh;
  52     VirtIOBlkConf conf;
  53     unsigned short sector_mask;
  54     bool original_wce;
  55     VMChangeStateEntry *change;
  56     /* Function to push to vq and notify guest */
  57     void (*complete_request)(struct VirtIOBlockReq *req, unsigned char status);
  58     Notifier migration_state_notifier;
  59     struct VirtIOBlockDataPlane *dataplane;
  60 } VirtIOBlock;
  61
  62 typedef struct VirtIOBlockReq {
  63     VirtQueueElement elem;
  64     int64_t sector_num;
  65     VirtIOBlock *dev;
  66     struct virtio_blk_inhdr *in;
  67     struct virtio_blk_outhdr out;
  68     QEMUIOVector qiov;
  69     size_t in_len;
  70     struct VirtIOBlockReq *next;
  71     struct VirtIOBlockReq *mr_next;
  72     BlockAcctCookie acct;
  73 } VirtIOBlockReq;
  74
  75 #define VIRTIO_BLK_MAX_MERGE_REQS 32
  76
  77 typedef struct MultiReqBuffer {
  78     VirtIOBlockReq *reqs[VIRTIO_BLK_MAX_MERGE_REQS];
  79     unsigned int num_reqs;
  80     bool is_write;
  81 } MultiReqBuffer;
  82
  83 VirtIOBlockReq *virtio_blk_alloc_request(VirtIOBlock *s);
  84
  85 void virtio_blk_free_request(VirtIOBlockReq *req);
  86
  87 void virtio_blk_handle_request(VirtIOBlockReq *req, MultiReqBuffer *mrb);
  88
  89 void virtio_blk_submit_multireq(BlockBackend *blk, MultiReqBuffer *mrb);
  90
  91 #endif