1 /* SPDX-License-Identifier: BSD-3-Clause
2 * Copyright(c) 2010-2019 Intel Corporation
3 */
4
5 /**
6 * This work is largely based on the "vhost-user-blk" implementation by
7 * SPDK(https://github.com/spdk/spdk).
8 */
9
10 #include <stdio.h>
11 #include <stdint.h>
12 #include <unistd.h>
13 #include <assert.h>
14 #include <ctype.h>
15 #include <string.h>
16 #include <stddef.h>
17
18 #include <rte_cycles.h>
19 #include <rte_log.h>
20 #include <rte_malloc.h>
21 #include <rte_byteorder.h>
22 #include <rte_string_fns.h>
23
24 #include "vhost_blk.h"
25 #include "blk_spec.h"
26
27 static void
vhost_strcpy_pad(void * dst,const char * src,size_t size,int pad)28 vhost_strcpy_pad(void *dst, const char *src, size_t size, int pad)
29 {
30 size_t len;
31
32 len = strlen(src);
33 if (len < size) {
34 memcpy(dst, src, len);
35 memset((char *)dst + len, pad, size - len);
36 } else {
37 memcpy(dst, src, size);
38 }
39 }
40
41 static int
vhost_bdev_blk_readwrite(struct vhost_block_dev * bdev,struct vhost_blk_task * task,uint64_t lba_512,__rte_unused uint32_t xfer_len)42 vhost_bdev_blk_readwrite(struct vhost_block_dev *bdev,
43 struct vhost_blk_task *task,
44 uint64_t lba_512, __rte_unused uint32_t xfer_len)
45 {
46 uint32_t i;
47 uint64_t offset;
48 uint32_t nbytes = 0;
49
50 offset = lba_512 * 512;
51
52 /* iovs[0] is the head and iovs[iovs_cnt - 1] is the tail
53 * Middle is the data range
54 */
55 for (i = 1; i < task->iovs_cnt - 1; i++) {
56 if (task->dxfer_dir == BLK_DIR_TO_DEV)
57 memcpy(bdev->data + offset, task->iovs[i].iov_base,
58 task->iovs[i].iov_len);
59 else
60 memcpy(task->iovs[i].iov_base, bdev->data + offset,
61 task->iovs[i].iov_len);
62 offset += task->iovs[i].iov_len;
63 nbytes += task->iovs[i].iov_len;
64 }
65
66 return nbytes;
67 }
68
69 int
vhost_bdev_process_blk_commands(struct vhost_block_dev * bdev,struct vhost_blk_task * task)70 vhost_bdev_process_blk_commands(struct vhost_block_dev *bdev,
71 struct vhost_blk_task *task)
72 {
73 size_t used_len;
74
75 if (unlikely(task->data_len > (bdev->blockcnt * bdev->blocklen))) {
76 fprintf(stderr, "read or write beyond capacity\n");
77 return VIRTIO_BLK_S_UNSUPP;
78 }
79
80 switch (task->req->type) {
81 case VIRTIO_BLK_T_IN:
82 if (unlikely(task->data_len == 0 ||
83 (task->data_len & (512 - 1)) != 0)) {
84 fprintf(stderr,
85 "%s - passed IO buffer is not multiple of 512b"
86 "(req_idx = %"PRIu16").\n",
87 task->req->type ? "WRITE" : "READ",
88 task->req_idx);
89 return VIRTIO_BLK_S_UNSUPP;
90 }
91
92 task->dxfer_dir = BLK_DIR_FROM_DEV;
93 vhost_bdev_blk_readwrite(bdev, task,
94 task->req->sector, task->data_len);
95 break;
96 case VIRTIO_BLK_T_OUT:
97 if (unlikely(task->data_len == 0 ||
98 (task->data_len & (512 - 1)) != 0)) {
99 fprintf(stderr,
100 "%s - passed IO buffer is not multiple of 512b"
101 "(req_idx = %"PRIu16").\n",
102 task->req->type ? "WRITE" : "READ",
103 task->req_idx);
104 return VIRTIO_BLK_S_UNSUPP;
105 }
106
107 task->dxfer_dir = BLK_DIR_TO_DEV;
108 vhost_bdev_blk_readwrite(bdev, task,
109 task->req->sector, task->data_len);
110 break;
111 case VIRTIO_BLK_T_GET_ID:
112 if (!task->iovs_cnt || task->data_len)
113 return VIRTIO_BLK_S_UNSUPP;
114 used_len = RTE_MIN((size_t)VIRTIO_BLK_ID_BYTES, task->data_len);
115 vhost_strcpy_pad(task->iovs[0].iov_base,
116 bdev->product_name, used_len, ' ');
117 break;
118 default:
119 fprintf(stderr, "unsupported cmd\n");
120 return VIRTIO_BLK_S_UNSUPP;
121 }
122
123 return VIRTIO_BLK_S_OK;
124 }
125