xref: /openbmc/qemu/include/hw/virtio/virtio-blk.h (revision 77a8257e)
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 data_plane;
41     uint32_t request_merging;
42 };
43 
44 struct VirtIOBlockDataPlane;
45 
46 struct VirtIOBlockReq;
47 typedef struct VirtIOBlock {
48     VirtIODevice parent_obj;
49     BlockBackend *blk;
50     VirtQueue *vq;
51     void *rq;
52     QEMUBH *bh;
53     VirtIOBlkConf conf;
54     unsigned short sector_mask;
55     bool original_wce;
56     VMChangeStateEntry *change;
57     /* Function to push to vq and notify guest */
58     void (*complete_request)(struct VirtIOBlockReq *req, unsigned char status);
59     Notifier migration_state_notifier;
60     struct VirtIOBlockDataPlane *dataplane;
61 } VirtIOBlock;
62 
63 typedef struct VirtIOBlockReq {
64     int64_t sector_num;
65     VirtIOBlock *dev;
66     VirtQueueElement elem;
67     struct virtio_blk_inhdr *in;
68     struct virtio_blk_outhdr out;
69     QEMUIOVector qiov;
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
92