1 /* Copyright (C) 2009 Red Hat, Inc.
2 * Author: Michael S. Tsirkin <mst@redhat.com>
3 *
4 * This work is licensed under the terms of the GNU GPL, version 2.
5 *
6 * test virtio server in host kernel.
7 */
8
9 #include <linux/compat.h>
10 #include <linux/eventfd.h>
11 #include <linux/vhost.h>
12 #include <linux/miscdevice.h>
13 #include <linux/module.h>
14 #include <linux/mutex.h>
15 #include <linux/workqueue.h>
16 #include <linux/file.h>
17 #include <linux/slab.h>
18
19 #include "test.h"
20 #include "vhost.h"
21
22 /* Max number of bytes transferred before requeueing the job.
23 * Using this limit prevents one virtqueue from starving others. */
24 #define VHOST_TEST_WEIGHT 0x80000
25
26 enum {
27 VHOST_TEST_VQ = 0,
28 VHOST_TEST_VQ_MAX = 1,
29 };
30
31 struct vhost_test {
32 struct vhost_dev dev;
33 struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
34 };
35
36 /* Expects to be always run from workqueue - which acts as
37 * read-size critical section for our kind of RCU. */
handle_vq(struct vhost_test * n)38 static void handle_vq(struct vhost_test *n)
39 {
40 struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
41 unsigned out, in;
42 int head;
43 size_t len, total_len = 0;
44 void *private;
45
46 mutex_lock(&vq->mutex);
47 private = vq->private_data;
48 if (!private) {
49 mutex_unlock(&vq->mutex);
50 return;
51 }
52
53 vhost_disable_notify(&n->dev, vq);
54
55 for (;;) {
56 head = vhost_get_vq_desc(vq, vq->iov,
57 ARRAY_SIZE(vq->iov),
58 &out, &in,
59 NULL, NULL);
60 /* On error, stop handling until the next kick. */
61 if (unlikely(head < 0))
62 break;
63 /* Nothing new? Wait for eventfd to tell us they refilled. */
64 if (head == vq->num) {
65 if (unlikely(vhost_enable_notify(&n->dev, vq))) {
66 vhost_disable_notify(&n->dev, vq);
67 continue;
68 }
69 break;
70 }
71 if (in) {
72 vq_err(vq, "Unexpected descriptor format for TX: "
73 "out %d, int %d\n", out, in);
74 break;
75 }
76 len = iov_length(vq->iov, out);
77 /* Sanity check */
78 if (!len) {
79 vq_err(vq, "Unexpected 0 len for TX\n");
80 break;
81 }
82 vhost_add_used_and_signal(&n->dev, vq, head, 0);
83 total_len += len;
84 if (unlikely(total_len >= VHOST_TEST_WEIGHT)) {
85 vhost_poll_queue(&vq->poll);
86 break;
87 }
88 }
89
90 mutex_unlock(&vq->mutex);
91 }
92
handle_vq_kick(struct vhost_work * work)93 static void handle_vq_kick(struct vhost_work *work)
94 {
95 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
96 poll.work);
97 struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);
98
99 handle_vq(n);
100 }
101
vhost_test_open(struct inode * inode,struct file * f)102 static int vhost_test_open(struct inode *inode, struct file *f)
103 {
104 struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
105 struct vhost_dev *dev;
106 struct vhost_virtqueue **vqs;
107
108 if (!n)
109 return -ENOMEM;
110 vqs = kmalloc(VHOST_TEST_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
111 if (!vqs) {
112 kfree(n);
113 return -ENOMEM;
114 }
115
116 dev = &n->dev;
117 vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
118 n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
119 vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX);
120
121 f->private_data = n;
122
123 return 0;
124 }
125
vhost_test_stop_vq(struct vhost_test * n,struct vhost_virtqueue * vq)126 static void *vhost_test_stop_vq(struct vhost_test *n,
127 struct vhost_virtqueue *vq)
128 {
129 void *private;
130
131 mutex_lock(&vq->mutex);
132 private = vq->private_data;
133 vq->private_data = NULL;
134 mutex_unlock(&vq->mutex);
135 return private;
136 }
137
vhost_test_stop(struct vhost_test * n,void ** privatep)138 static void vhost_test_stop(struct vhost_test *n, void **privatep)
139 {
140 *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
141 }
142
vhost_test_flush_vq(struct vhost_test * n,int index)143 static void vhost_test_flush_vq(struct vhost_test *n, int index)
144 {
145 vhost_poll_flush(&n->vqs[index].poll);
146 }
147
vhost_test_flush(struct vhost_test * n)148 static void vhost_test_flush(struct vhost_test *n)
149 {
150 vhost_test_flush_vq(n, VHOST_TEST_VQ);
151 }
152
vhost_test_release(struct inode * inode,struct file * f)153 static int vhost_test_release(struct inode *inode, struct file *f)
154 {
155 struct vhost_test *n = f->private_data;
156 void *private;
157
158 vhost_test_stop(n, &private);
159 vhost_test_flush(n);
160 vhost_dev_cleanup(&n->dev, false);
161 /* We do an extra flush before freeing memory,
162 * since jobs can re-queue themselves. */
163 vhost_test_flush(n);
164 kfree(n);
165 return 0;
166 }
167
vhost_test_run(struct vhost_test * n,int test)168 static long vhost_test_run(struct vhost_test *n, int test)
169 {
170 void *priv, *oldpriv;
171 struct vhost_virtqueue *vq;
172 int r, index;
173
174 if (test < 0 || test > 1)
175 return -EINVAL;
176
177 mutex_lock(&n->dev.mutex);
178 r = vhost_dev_check_owner(&n->dev);
179 if (r)
180 goto err;
181
182 for (index = 0; index < n->dev.nvqs; ++index) {
183 /* Verify that ring has been setup correctly. */
184 if (!vhost_vq_access_ok(&n->vqs[index])) {
185 r = -EFAULT;
186 goto err;
187 }
188 }
189
190 for (index = 0; index < n->dev.nvqs; ++index) {
191 vq = n->vqs + index;
192 mutex_lock(&vq->mutex);
193 priv = test ? n : NULL;
194
195 /* start polling new socket */
196 oldpriv = vq->private_data;
197 vq->private_data = priv;
198
199 r = vhost_vq_init_access(&n->vqs[index]);
200
201 mutex_unlock(&vq->mutex);
202
203 if (r)
204 goto err;
205
206 if (oldpriv) {
207 vhost_test_flush_vq(n, index);
208 }
209 }
210
211 mutex_unlock(&n->dev.mutex);
212 return 0;
213
214 err:
215 mutex_unlock(&n->dev.mutex);
216 return r;
217 }
218
vhost_test_reset_owner(struct vhost_test * n)219 static long vhost_test_reset_owner(struct vhost_test *n)
220 {
221 void *priv = NULL;
222 long err;
223 struct vhost_umem *umem;
224
225 mutex_lock(&n->dev.mutex);
226 err = vhost_dev_check_owner(&n->dev);
227 if (err)
228 goto done;
229 umem = vhost_dev_reset_owner_prepare();
230 if (!umem) {
231 err = -ENOMEM;
232 goto done;
233 }
234 vhost_test_stop(n, &priv);
235 vhost_test_flush(n);
236 vhost_dev_reset_owner(&n->dev, umem);
237 done:
238 mutex_unlock(&n->dev.mutex);
239 return err;
240 }
241
vhost_test_set_features(struct vhost_test * n,u64 features)242 static int vhost_test_set_features(struct vhost_test *n, u64 features)
243 {
244 struct vhost_virtqueue *vq;
245
246 mutex_lock(&n->dev.mutex);
247 if ((features & (1 << VHOST_F_LOG_ALL)) &&
248 !vhost_log_access_ok(&n->dev)) {
249 mutex_unlock(&n->dev.mutex);
250 return -EFAULT;
251 }
252 vq = &n->vqs[VHOST_TEST_VQ];
253 mutex_lock(&vq->mutex);
254 vq->acked_features = features;
255 mutex_unlock(&vq->mutex);
256 mutex_unlock(&n->dev.mutex);
257 return 0;
258 }
259
vhost_test_ioctl(struct file * f,unsigned int ioctl,unsigned long arg)260 static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
261 unsigned long arg)
262 {
263 struct vhost_test *n = f->private_data;
264 void __user *argp = (void __user *)arg;
265 u64 __user *featurep = argp;
266 int test;
267 u64 features;
268 int r;
269 switch (ioctl) {
270 case VHOST_TEST_RUN:
271 if (copy_from_user(&test, argp, sizeof test))
272 return -EFAULT;
273 return vhost_test_run(n, test);
274 case VHOST_GET_FEATURES:
275 features = VHOST_FEATURES;
276 if (copy_to_user(featurep, &features, sizeof features))
277 return -EFAULT;
278 return 0;
279 case VHOST_SET_FEATURES:
280 printk(KERN_ERR "1\n");
281 if (copy_from_user(&features, featurep, sizeof features))
282 return -EFAULT;
283 printk(KERN_ERR "2\n");
284 if (features & ~VHOST_FEATURES)
285 return -EOPNOTSUPP;
286 printk(KERN_ERR "3\n");
287 return vhost_test_set_features(n, features);
288 case VHOST_RESET_OWNER:
289 return vhost_test_reset_owner(n);
290 default:
291 mutex_lock(&n->dev.mutex);
292 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
293 if (r == -ENOIOCTLCMD)
294 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
295 vhost_test_flush(n);
296 mutex_unlock(&n->dev.mutex);
297 return r;
298 }
299 }
300
301 #ifdef CONFIG_COMPAT
vhost_test_compat_ioctl(struct file * f,unsigned int ioctl,unsigned long arg)302 static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl,
303 unsigned long arg)
304 {
305 return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
306 }
307 #endif
308
309 static const struct file_operations vhost_test_fops = {
310 .owner = THIS_MODULE,
311 .release = vhost_test_release,
312 .unlocked_ioctl = vhost_test_ioctl,
313 #ifdef CONFIG_COMPAT
314 .compat_ioctl = vhost_test_compat_ioctl,
315 #endif
316 .open = vhost_test_open,
317 .llseek = noop_llseek,
318 };
319
320 static struct miscdevice vhost_test_misc = {
321 MISC_DYNAMIC_MINOR,
322 "vhost-test",
323 &vhost_test_fops,
324 };
325 module_misc_device(vhost_test_misc);
326
327 MODULE_VERSION("0.0.1");
328 MODULE_LICENSE("GPL v2");
329 MODULE_AUTHOR("Michael S. Tsirkin");
330 MODULE_DESCRIPTION("Host kernel side for virtio simulator");
331