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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/rcupdate.h> | |
17 | #include <linux/file.h> | |
18 | #include <linux/slab.h> | |
19 | ||
20 | #include "test.h" | |
21 | #include "vhost.c" | |
22 | ||
23 | /* Max number of bytes transferred before requeueing the job. | |
24 | * Using this limit prevents one virtqueue from starving others. */ | |
25 | #define VHOST_TEST_WEIGHT 0x80000 | |
26 | ||
27 | enum { | |
28 | VHOST_TEST_VQ = 0, | |
29 | VHOST_TEST_VQ_MAX = 1, | |
30 | }; | |
31 | ||
32 | struct vhost_test { | |
33 | struct vhost_dev dev; | |
34 | struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX]; | |
35 | }; | |
36 | ||
37 | /* Expects to be always run from workqueue - which acts as | |
38 | * read-size critical section for our kind of RCU. */ | |
39 | static void handle_vq(struct vhost_test *n) | |
40 | { | |
41 | struct vhost_virtqueue *vq = &n->dev.vqs[VHOST_TEST_VQ]; | |
42 | unsigned out, in; | |
43 | int head; | |
44 | size_t len, total_len = 0; | |
45 | void *private; | |
46 | ||
47 | private = rcu_dereference_check(vq->private_data, 1); | |
48 | if (!private) | |
49 | return; | |
50 | ||
51 | mutex_lock(&vq->mutex); | |
8ea8cf89 | 52 | vhost_disable_notify(&n->dev, vq); |
71ccc212 MT |
53 | |
54 | for (;;) { | |
55 | head = vhost_get_vq_desc(&n->dev, vq, vq->iov, | |
56 | ARRAY_SIZE(vq->iov), | |
57 | &out, &in, | |
58 | NULL, NULL); | |
59 | /* On error, stop handling until the next kick. */ | |
60 | if (unlikely(head < 0)) | |
61 | break; | |
62 | /* Nothing new? Wait for eventfd to tell us they refilled. */ | |
63 | if (head == vq->num) { | |
8ea8cf89 MT |
64 | if (unlikely(vhost_enable_notify(&n->dev, vq))) { |
65 | vhost_disable_notify(&n->dev, vq); | |
71ccc212 MT |
66 | continue; |
67 | } | |
68 | break; | |
69 | } | |
70 | if (in) { | |
71 | vq_err(vq, "Unexpected descriptor format for TX: " | |
72 | "out %d, int %d\n", out, in); | |
73 | break; | |
74 | } | |
75 | len = iov_length(vq->iov, out); | |
76 | /* Sanity check */ | |
77 | if (!len) { | |
78 | vq_err(vq, "Unexpected 0 len for TX\n"); | |
79 | break; | |
80 | } | |
81 | vhost_add_used_and_signal(&n->dev, vq, head, 0); | |
82 | total_len += len; | |
83 | if (unlikely(total_len >= VHOST_TEST_WEIGHT)) { | |
84 | vhost_poll_queue(&vq->poll); | |
85 | break; | |
86 | } | |
87 | } | |
88 | ||
89 | mutex_unlock(&vq->mutex); | |
90 | } | |
91 | ||
92 | static void handle_vq_kick(struct vhost_work *work) | |
93 | { | |
94 | struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue, | |
95 | poll.work); | |
96 | struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev); | |
97 | ||
98 | handle_vq(n); | |
99 | } | |
100 | ||
101 | static int vhost_test_open(struct inode *inode, struct file *f) | |
102 | { | |
103 | struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL); | |
104 | struct vhost_dev *dev; | |
105 | int r; | |
106 | ||
107 | if (!n) | |
108 | return -ENOMEM; | |
109 | ||
110 | dev = &n->dev; | |
111 | n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick; | |
112 | r = vhost_dev_init(dev, n->vqs, VHOST_TEST_VQ_MAX); | |
113 | if (r < 0) { | |
114 | kfree(n); | |
115 | return r; | |
116 | } | |
117 | ||
118 | f->private_data = n; | |
119 | ||
120 | return 0; | |
121 | } | |
122 | ||
123 | static void *vhost_test_stop_vq(struct vhost_test *n, | |
124 | struct vhost_virtqueue *vq) | |
125 | { | |
126 | void *private; | |
127 | ||
128 | mutex_lock(&vq->mutex); | |
129 | private = rcu_dereference_protected(vq->private_data, | |
130 | lockdep_is_held(&vq->mutex)); | |
131 | rcu_assign_pointer(vq->private_data, NULL); | |
132 | mutex_unlock(&vq->mutex); | |
133 | return private; | |
134 | } | |
135 | ||
136 | static void vhost_test_stop(struct vhost_test *n, void **privatep) | |
137 | { | |
138 | *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ); | |
139 | } | |
140 | ||
141 | static void vhost_test_flush_vq(struct vhost_test *n, int index) | |
142 | { | |
143 | vhost_poll_flush(&n->dev.vqs[index].poll); | |
144 | } | |
145 | ||
146 | static void vhost_test_flush(struct vhost_test *n) | |
147 | { | |
148 | vhost_test_flush_vq(n, VHOST_TEST_VQ); | |
149 | } | |
150 | ||
151 | static int vhost_test_release(struct inode *inode, struct file *f) | |
152 | { | |
153 | struct vhost_test *n = f->private_data; | |
154 | void *private; | |
155 | ||
156 | vhost_test_stop(n, &private); | |
157 | vhost_test_flush(n); | |
5e7045b0 | 158 | vhost_dev_cleanup(&n->dev, false); |
71ccc212 MT |
159 | /* We do an extra flush before freeing memory, |
160 | * since jobs can re-queue themselves. */ | |
161 | vhost_test_flush(n); | |
162 | kfree(n); | |
163 | return 0; | |
164 | } | |
165 | ||
166 | static long vhost_test_run(struct vhost_test *n, int test) | |
167 | { | |
168 | void *priv, *oldpriv; | |
169 | struct vhost_virtqueue *vq; | |
170 | int r, index; | |
171 | ||
172 | if (test < 0 || test > 1) | |
173 | return -EINVAL; | |
174 | ||
175 | mutex_lock(&n->dev.mutex); | |
176 | r = vhost_dev_check_owner(&n->dev); | |
177 | if (r) | |
178 | goto err; | |
179 | ||
180 | for (index = 0; index < n->dev.nvqs; ++index) { | |
181 | /* Verify that ring has been setup correctly. */ | |
182 | if (!vhost_vq_access_ok(&n->vqs[index])) { | |
183 | r = -EFAULT; | |
184 | goto err; | |
185 | } | |
186 | } | |
187 | ||
188 | for (index = 0; index < n->dev.nvqs; ++index) { | |
189 | vq = n->vqs + index; | |
190 | mutex_lock(&vq->mutex); | |
191 | priv = test ? n : NULL; | |
192 | ||
193 | /* start polling new socket */ | |
194 | oldpriv = rcu_dereference_protected(vq->private_data, | |
195 | lockdep_is_held(&vq->mutex)); | |
196 | rcu_assign_pointer(vq->private_data, priv); | |
197 | ||
f59281da JW |
198 | r = vhost_init_used(&n->vqs[index]); |
199 | ||
71ccc212 MT |
200 | mutex_unlock(&vq->mutex); |
201 | ||
f59281da JW |
202 | if (r) |
203 | goto err; | |
204 | ||
71ccc212 MT |
205 | if (oldpriv) { |
206 | vhost_test_flush_vq(n, index); | |
207 | } | |
208 | } | |
209 | ||
210 | mutex_unlock(&n->dev.mutex); | |
211 | return 0; | |
212 | ||
213 | err: | |
214 | mutex_unlock(&n->dev.mutex); | |
215 | return r; | |
216 | } | |
217 | ||
218 | static long vhost_test_reset_owner(struct vhost_test *n) | |
219 | { | |
220 | void *priv = NULL; | |
221 | long err; | |
222 | mutex_lock(&n->dev.mutex); | |
223 | err = vhost_dev_check_owner(&n->dev); | |
224 | if (err) | |
225 | goto done; | |
226 | vhost_test_stop(n, &priv); | |
227 | vhost_test_flush(n); | |
228 | err = vhost_dev_reset_owner(&n->dev); | |
229 | done: | |
230 | mutex_unlock(&n->dev.mutex); | |
231 | return err; | |
232 | } | |
233 | ||
234 | static int vhost_test_set_features(struct vhost_test *n, u64 features) | |
235 | { | |
236 | mutex_lock(&n->dev.mutex); | |
237 | if ((features & (1 << VHOST_F_LOG_ALL)) && | |
238 | !vhost_log_access_ok(&n->dev)) { | |
239 | mutex_unlock(&n->dev.mutex); | |
240 | return -EFAULT; | |
241 | } | |
242 | n->dev.acked_features = features; | |
243 | smp_wmb(); | |
244 | vhost_test_flush(n); | |
245 | mutex_unlock(&n->dev.mutex); | |
246 | return 0; | |
247 | } | |
248 | ||
249 | static long vhost_test_ioctl(struct file *f, unsigned int ioctl, | |
250 | unsigned long arg) | |
251 | { | |
252 | struct vhost_test *n = f->private_data; | |
253 | void __user *argp = (void __user *)arg; | |
254 | u64 __user *featurep = argp; | |
255 | int test; | |
256 | u64 features; | |
257 | int r; | |
258 | switch (ioctl) { | |
259 | case VHOST_TEST_RUN: | |
260 | if (copy_from_user(&test, argp, sizeof test)) | |
261 | return -EFAULT; | |
262 | return vhost_test_run(n, test); | |
263 | case VHOST_GET_FEATURES: | |
264 | features = VHOST_FEATURES; | |
265 | if (copy_to_user(featurep, &features, sizeof features)) | |
266 | return -EFAULT; | |
267 | return 0; | |
268 | case VHOST_SET_FEATURES: | |
269 | if (copy_from_user(&features, featurep, sizeof features)) | |
270 | return -EFAULT; | |
271 | if (features & ~VHOST_FEATURES) | |
272 | return -EOPNOTSUPP; | |
273 | return vhost_test_set_features(n, features); | |
274 | case VHOST_RESET_OWNER: | |
275 | return vhost_test_reset_owner(n); | |
276 | default: | |
277 | mutex_lock(&n->dev.mutex); | |
278 | r = vhost_dev_ioctl(&n->dev, ioctl, arg); | |
279 | vhost_test_flush(n); | |
280 | mutex_unlock(&n->dev.mutex); | |
281 | return r; | |
282 | } | |
283 | } | |
284 | ||
285 | #ifdef CONFIG_COMPAT | |
286 | static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl, | |
287 | unsigned long arg) | |
288 | { | |
289 | return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg)); | |
290 | } | |
291 | #endif | |
292 | ||
293 | static const struct file_operations vhost_test_fops = { | |
294 | .owner = THIS_MODULE, | |
295 | .release = vhost_test_release, | |
296 | .unlocked_ioctl = vhost_test_ioctl, | |
297 | #ifdef CONFIG_COMPAT | |
298 | .compat_ioctl = vhost_test_compat_ioctl, | |
299 | #endif | |
300 | .open = vhost_test_open, | |
301 | .llseek = noop_llseek, | |
302 | }; | |
303 | ||
304 | static struct miscdevice vhost_test_misc = { | |
305 | MISC_DYNAMIC_MINOR, | |
306 | "vhost-test", | |
307 | &vhost_test_fops, | |
308 | }; | |
309 | ||
310 | static int vhost_test_init(void) | |
311 | { | |
312 | return misc_register(&vhost_test_misc); | |
313 | } | |
314 | module_init(vhost_test_init); | |
315 | ||
316 | static void vhost_test_exit(void) | |
317 | { | |
318 | misc_deregister(&vhost_test_misc); | |
319 | } | |
320 | module_exit(vhost_test_exit); | |
321 | ||
322 | MODULE_VERSION("0.0.1"); | |
323 | MODULE_LICENSE("GPL v2"); | |
324 | MODULE_AUTHOR("Michael S. Tsirkin"); | |
325 | MODULE_DESCRIPTION("Host kernel side for virtio simulator"); |