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 #include "qom/object.h"
  23
  24 #define TYPE_VIRTIO_BLK "virtio-blk-device"
  25 OBJECT_DECLARE_SIMPLE_TYPE(VirtIOBlock, 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 #define VIRTIO_BLK_AUTO_NUM_QUEUES UINT16_MAX
  34
  35 struct VirtIOBlkConf
  36 {
  37     BlockConf conf;
  38     IOThread *iothread;
  39     char *serial;
  40     uint32_t request_merging;
  41     uint16_t num_queues;
  42     uint16_t queue_size;
  43     bool seg_max_adjust;
  44     uint32_t max_discard_sectors;
  45     uint32_t max_write_zeroes_sectors;
  46     bool x_enable_wce_if_config_wce;
  47 };
  48
  49 struct VirtIOBlockDataPlane;
  50
  51 struct VirtIOBlockReq;
  52 struct VirtIOBlock {
  53     VirtIODevice parent_obj;
  54     BlockBackend *blk;
  55     void *rq;
  56     QEMUBH *bh;
  57     VirtIOBlkConf conf;
  58     unsigned short sector_mask;
  59     bool original_wce;
  60     VMChangeStateEntry *change;
  61     bool dataplane_disabled;
  62     bool dataplane_started;
  63     struct VirtIOBlockDataPlane *dataplane;
  64     uint64_t host_features;
  65     size_t config_size;
  66 };
  67
  68 typedef struct VirtIOBlockReq {
  69     VirtQueueElement elem;
  70     int64_t sector_num;
  71     VirtIOBlock *dev;
  72     VirtQueue *vq;
  73     IOVDiscardUndo inhdr_undo;
  74     IOVDiscardUndo outhdr_undo;
  75     struct virtio_blk_inhdr *in;
  76     struct virtio_blk_outhdr out;
  77     QEMUIOVector qiov;
  78     size_t in_len;
  79     struct VirtIOBlockReq *next;
  80     struct VirtIOBlockReq *mr_next;
  81     BlockAcctCookie acct;
  82 } VirtIOBlockReq;
  83
  84 #define VIRTIO_BLK_MAX_MERGE_REQS 32
  85
  86 typedef struct MultiReqBuffer {
  87     VirtIOBlockReq *reqs[VIRTIO_BLK_MAX_MERGE_REQS];
  88     unsigned int num_reqs;
  89     bool is_write;
  90 } MultiReqBuffer;
  91
  92 bool virtio_blk_handle_vq(VirtIOBlock *s, VirtQueue *vq);
  93 void virtio_blk_process_queued_requests(VirtIOBlock *s, bool is_bh);
  94
  95 #endif