1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/*
* A virtio device implementing a hardware random number generator.
*
* Based on virtio-rng.c of QEMU project
* Copyright 2012 Red Hat, Inc.
* Copyright 2012 Amit Shah <amit.shah@redhat.com>
*
* Copyright 2022 Virtual Open Systems SAS.
*
* This work is licensed under the terms of the GNU GPL, version 2 or
* (at your option) any later version. See the COPYING file in the
* top-level directory.
*/
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>
#include <sys/param.h>
/* Project header files */
#include "virtio_loopback.h"
#include "virtio_rng.h"
#ifdef DEBUG
#define DBG(...) printf("virtio-rng: " __VA_ARGS__)
#else
#define DBG(...)
#endif /* DEBUG */
bool is_guest_ready(VirtIORNG *vrng)
{
VirtIODevice *vdev = vrng->parent_obj;
if (virtio_queue_ready(vrng->vq)
&& (vdev->status & VIRTIO_CONFIG_S_DRIVER_OK)) {
return true;
}
return false;
}
size_t get_request_size(VirtQueue *vq, unsigned quota)
{
unsigned int in, out;
virtqueue_get_avail_bytes(vq, &in, &out, quota, 0);
return in;
}
void virtio_rng_set_status(VirtIODevice *vdev, uint8_t status)
{
VirtIORNG *vrng = vdev->vrng;
vdev->status = status;
/* Something changed, try to process buffers */
virtio_rng_process(vrng);
}
/* Send data from a char device over to the guest */
void chr_read(VirtIORNG *vrng, const void *buf, size_t size)
{
VirtIODevice *vdev = vrng->parent_obj;
VirtQueueElement *elem;
size_t len;
int offset;
if (!is_guest_ready(vrng)) {
return;
}
vrng->quota_remaining -= size;
offset = 0;
while (offset < size) {
elem = virtqueue_pop(vrng->vq, sizeof(VirtQueueElement));
if (!elem) {
break;
}
len = qemu_iov_from_buf(elem->in_sg, elem->in_num,
0, buf + offset, size - offset);
offset += len;
virtqueue_push(vrng->vq, elem, len);
/*
* TODO: We need tp free the elem
*
* g_free(elem);
*/
}
virtio_notify(vdev, vrng->vq);
if (!virtio_queue_empty(vrng->vq)) {
/*
* If we didn't drain the queue, call virtio_rng_process
* to take care of asking for more data as appropriate.
*/
virtio_rng_process(vrng);
}
}
const char test_str[64] = {0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
20, 21, 22, 23, 24, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35, 36, 37, 38, 39,
40, 41, 42, 43, 44, 45, 46, 47, 48, 49,
50, 51, 52, 53, 54, 55, 56, 57, 58, 59,
60, 61, 62, 63};
void virtio_rng_process(VirtIORNG *vrng)
{
size_t size;
unsigned quota;
if (!is_guest_ready(vrng)) {
return;
}
if (vrng->quota_remaining < 0) {
quota = 0;
} else {
quota = MIN((uint64_t)vrng->quota_remaining, (uint64_t)UINT32_MAX);
}
size = get_request_size(vrng->vq, quota);
size = MIN(vrng->quota_remaining, size);
if (size) {
chr_read(vrng, &test_str, size);
}
}
void handle_input(VirtIODevice *vdev, VirtQueue *vq)
{
virtio_rng_process(vdev->vrng);
}
static void virtio_dev_class_init(VirtIODevice *vdev)
{
vdev->vdev_class = (VirtioDeviceClass *)malloc(sizeof(VirtioDeviceClass));
vdev->vdev_class->parent = vdev;
vdev->vdev_class->set_status = virtio_rng_set_status;
}
void virtio_rng_init(VirtIODevice *vdev)
{
VirtIORNG *vrng = (VirtIORNG *)malloc(sizeof(VirtIORNG));
vdev->vrng = vrng;
vrng->parent_obj = vdev;
vrng->vq = vdev->vq;
vrng->quota_remaining = LONG_MAX;
/* Prepare dev_class */
virtio_dev_class_init(vdev);
}
void virtio_rng_realize(void)
{
/* prepare procy and virtio dev*/
proxy = (VirtIOMMIOProxy *)malloc(sizeof(VirtIOMMIOProxy));
virtio_dev_init(global_vdev, "virtio-rng", 4, 0);
virtio_rng_init(global_vdev);
global_vdev->vq = virtio_add_queue(global_vdev, 8, handle_input);
global_vdev->host_features = 0x39000000;
*proxy = (VirtIOMMIOProxy) {
.legacy = 1,
};
}
|
