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1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright (C) 2009 Red Hat, Inc.
3 * Author: Michael S. Tsirkin <mst@redhat.com>
4 *
5 * test virtio server in host kernel.
6 */
7
8#include <linux/compat.h>
9#include <linux/eventfd.h>
10#include <linux/vhost.h>
11#include <linux/miscdevice.h>
12#include <linux/module.h>
13#include <linux/mutex.h>
14#include <linux/workqueue.h>
15#include <linux/file.h>
16#include <linux/slab.h>
17
18#include "test.h"
19#include "vhost.h"
20
21/* Max number of bytes transferred before requeueing the job.
22 * Using this limit prevents one virtqueue from starving others. */
23#define VHOST_TEST_WEIGHT 0x80000
24
25/* Max number of packets transferred before requeueing the job.
26 * Using this limit prevents one virtqueue from starving others with
27 * pkts.
28 */
29#define VHOST_TEST_PKT_WEIGHT 256
30
31enum {
32 VHOST_TEST_VQ = 0,
33 VHOST_TEST_VQ_MAX = 1,
34};
35
36struct vhost_test {
37 struct vhost_dev dev;
38 struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
39};
40
41/* Expects to be always run from workqueue - which acts as
42 * read-size critical section for our kind of RCU. */
43static void handle_vq(struct vhost_test *n)
44{
45 struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
46 unsigned out, in;
47 int head;
48 size_t len, total_len = 0;
49 void *private;
50
51 mutex_lock(&vq->mutex);
52 private = vhost_vq_get_backend(vq);
53 if (!private) {
54 mutex_unlock(&vq->mutex);
55 return;
56 }
57
58 vhost_disable_notify(&n->dev, vq);
59
60 for (;;) {
61 head = vhost_get_vq_desc(vq, vq->iov,
62 ARRAY_SIZE(vq->iov),
63 &out, &in,
64 NULL, NULL);
65 /* On error, stop handling until the next kick. */
66 if (unlikely(head < 0))
67 break;
68 /* Nothing new? Wait for eventfd to tell us they refilled. */
69 if (head == vq->num) {
70 if (unlikely(vhost_enable_notify(&n->dev, vq))) {
71 vhost_disable_notify(&n->dev, vq);
72 continue;
73 }
74 break;
75 }
76 if (in) {
77 vq_err(vq, "Unexpected descriptor format for TX: "
78 "out %d, int %d\n", out, in);
79 break;
80 }
81 len = iov_length(vq->iov, out);
82 /* Sanity check */
83 if (!len) {
84 vq_err(vq, "Unexpected 0 len for TX\n");
85 break;
86 }
87 vhost_add_used_and_signal(&n->dev, vq, head, 0);
88 total_len += len;
89 if (unlikely(vhost_exceeds_weight(vq, 0, total_len)))
90 break;
91 }
92
93 mutex_unlock(&vq->mutex);
94}
95
96static void handle_vq_kick(struct vhost_work *work)
97{
98 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
99 poll.work);
100 struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);
101
102 handle_vq(n);
103}
104
105static int vhost_test_open(struct inode *inode, struct file *f)
106{
107 struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
108 struct vhost_dev *dev;
109 struct vhost_virtqueue **vqs;
110
111 if (!n)
112 return -ENOMEM;
113 vqs = kmalloc_array(VHOST_TEST_VQ_MAX, sizeof(*vqs), GFP_KERNEL);
114 if (!vqs) {
115 kfree(n);
116 return -ENOMEM;
117 }
118
119 dev = &n->dev;
120 vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
121 n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
122 vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
123 VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, true, NULL);
124
125 f->private_data = n;
126
127 return 0;
128}
129
130static void *vhost_test_stop_vq(struct vhost_test *n,
131 struct vhost_virtqueue *vq)
132{
133 void *private;
134
135 mutex_lock(&vq->mutex);
136 private = vhost_vq_get_backend(vq);
137 vhost_vq_set_backend(vq, NULL);
138 mutex_unlock(&vq->mutex);
139 return private;
140}
141
142static void vhost_test_stop(struct vhost_test *n, void **privatep)
143{
144 *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
145}
146
147static void vhost_test_flush(struct vhost_test *n)
148{
149 vhost_dev_flush(&n->dev);
150}
151
152static int vhost_test_release(struct inode *inode, struct file *f)
153{
154 struct vhost_test *n = f->private_data;
155 void *private;
156
157 vhost_test_stop(n, &private);
158 vhost_test_flush(n);
159 vhost_dev_stop(&n->dev);
160 vhost_dev_cleanup(&n->dev);
161 kfree(n->dev.vqs);
162 kfree(n);
163 return 0;
164}
165
166static 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 = vhost_vq_get_backend(vq);
195 vhost_vq_set_backend(vq, priv);
196
197 r = vhost_vq_init_access(&n->vqs[index]);
198
199 mutex_unlock(&vq->mutex);
200
201 if (r)
202 goto err;
203
204 if (oldpriv) {
205 vhost_test_flush(n);
206 }
207 }
208
209 mutex_unlock(&n->dev.mutex);
210 return 0;
211
212err:
213 mutex_unlock(&n->dev.mutex);
214 return r;
215}
216
217static long vhost_test_reset_owner(struct vhost_test *n)
218{
219 void *priv = NULL;
220 long err;
221 struct vhost_iotlb *umem;
222
223 mutex_lock(&n->dev.mutex);
224 err = vhost_dev_check_owner(&n->dev);
225 if (err)
226 goto done;
227 umem = vhost_dev_reset_owner_prepare();
228 if (!umem) {
229 err = -ENOMEM;
230 goto done;
231 }
232 vhost_test_stop(n, &priv);
233 vhost_test_flush(n);
234 vhost_dev_stop(&n->dev);
235 vhost_dev_reset_owner(&n->dev, umem);
236done:
237 mutex_unlock(&n->dev.mutex);
238 return err;
239}
240
241static int vhost_test_set_features(struct vhost_test *n, u64 features)
242{
243 struct vhost_virtqueue *vq;
244
245 mutex_lock(&n->dev.mutex);
246 if ((features & (1 << VHOST_F_LOG_ALL)) &&
247 !vhost_log_access_ok(&n->dev)) {
248 mutex_unlock(&n->dev.mutex);
249 return -EFAULT;
250 }
251 vq = &n->vqs[VHOST_TEST_VQ];
252 mutex_lock(&vq->mutex);
253 vq->acked_features = features;
254 mutex_unlock(&vq->mutex);
255 mutex_unlock(&n->dev.mutex);
256 return 0;
257}
258
259static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd)
260{
261 static void *backend;
262
263 const bool enable = fd != -1;
264 struct vhost_virtqueue *vq;
265 int r;
266
267 mutex_lock(&n->dev.mutex);
268 r = vhost_dev_check_owner(&n->dev);
269 if (r)
270 goto err;
271
272 if (index >= VHOST_TEST_VQ_MAX) {
273 r = -ENOBUFS;
274 goto err;
275 }
276 vq = &n->vqs[index];
277 mutex_lock(&vq->mutex);
278
279 /* Verify that ring has been setup correctly. */
280 if (!vhost_vq_access_ok(vq)) {
281 r = -EFAULT;
282 goto err_vq;
283 }
284 if (!enable) {
285 vhost_poll_stop(&vq->poll);
286 backend = vhost_vq_get_backend(vq);
287 vhost_vq_set_backend(vq, NULL);
288 } else {
289 vhost_vq_set_backend(vq, backend);
290 r = vhost_vq_init_access(vq);
291 if (r == 0)
292 r = vhost_poll_start(&vq->poll, vq->kick);
293 }
294
295 mutex_unlock(&vq->mutex);
296
297 if (enable) {
298 vhost_test_flush(n);
299 }
300
301 mutex_unlock(&n->dev.mutex);
302 return 0;
303
304err_vq:
305 mutex_unlock(&vq->mutex);
306err:
307 mutex_unlock(&n->dev.mutex);
308 return r;
309}
310
311static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
312 unsigned long arg)
313{
314 struct vhost_vring_file backend;
315 struct vhost_test *n = f->private_data;
316 void __user *argp = (void __user *)arg;
317 u64 __user *featurep = argp;
318 int test;
319 u64 features;
320 int r;
321 switch (ioctl) {
322 case VHOST_TEST_RUN:
323 if (copy_from_user(&test, argp, sizeof test))
324 return -EFAULT;
325 return vhost_test_run(n, test);
326 case VHOST_TEST_SET_BACKEND:
327 if (copy_from_user(&backend, argp, sizeof backend))
328 return -EFAULT;
329 return vhost_test_set_backend(n, backend.index, backend.fd);
330 case VHOST_GET_FEATURES:
331 features = VHOST_FEATURES;
332 if (copy_to_user(featurep, &features, sizeof features))
333 return -EFAULT;
334 return 0;
335 case VHOST_SET_FEATURES:
336 if (copy_from_user(&features, featurep, sizeof features))
337 return -EFAULT;
338 if (features & ~VHOST_FEATURES)
339 return -EOPNOTSUPP;
340 return vhost_test_set_features(n, features);
341 case VHOST_RESET_OWNER:
342 return vhost_test_reset_owner(n);
343 default:
344 mutex_lock(&n->dev.mutex);
345 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
346 if (r == -ENOIOCTLCMD)
347 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
348 vhost_test_flush(n);
349 mutex_unlock(&n->dev.mutex);
350 return r;
351 }
352}
353
354static const struct file_operations vhost_test_fops = {
355 .owner = THIS_MODULE,
356 .release = vhost_test_release,
357 .unlocked_ioctl = vhost_test_ioctl,
358 .compat_ioctl = compat_ptr_ioctl,
359 .open = vhost_test_open,
360 .llseek = noop_llseek,
361};
362
363static struct miscdevice vhost_test_misc = {
364 MISC_DYNAMIC_MINOR,
365 "vhost-test",
366 &vhost_test_fops,
367};
368module_misc_device(vhost_test_misc);
369
370MODULE_VERSION("0.0.1");
371MODULE_LICENSE("GPL v2");
372MODULE_AUTHOR("Michael S. Tsirkin");
373MODULE_DESCRIPTION("Host kernel side for virtio simulator");
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
27enum {
28 VHOST_TEST_VQ = 0,
29 VHOST_TEST_VQ_MAX = 1,
30};
31
32struct 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. */
39static 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);
52 vhost_disable_notify(&n->dev, vq);
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) {
64 if (unlikely(vhost_enable_notify(&n->dev, vq))) {
65 vhost_disable_notify(&n->dev, vq);
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
92static 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
101static 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
123static 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
136static 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
141static void vhost_test_flush_vq(struct vhost_test *n, int index)
142{
143 vhost_poll_flush(&n->dev.vqs[index].poll);
144}
145
146static void vhost_test_flush(struct vhost_test *n)
147{
148 vhost_test_flush_vq(n, VHOST_TEST_VQ);
149}
150
151static 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);
158 vhost_dev_cleanup(&n->dev);
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
166static 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
198 r = vhost_init_used(&n->vqs[index]);
199
200 mutex_unlock(&vq->mutex);
201
202 if (r)
203 goto err;
204
205 if (oldpriv) {
206 vhost_test_flush_vq(n, index);
207 }
208 }
209
210 mutex_unlock(&n->dev.mutex);
211 return 0;
212
213err:
214 mutex_unlock(&n->dev.mutex);
215 return r;
216}
217
218static 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);
229done:
230 mutex_unlock(&n->dev.mutex);
231 return err;
232}
233
234static 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
249static 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
286static 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
293static 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
304static struct miscdevice vhost_test_misc = {
305 MISC_DYNAMIC_MINOR,
306 "vhost-test",
307 &vhost_test_fops,
308};
309
310static int vhost_test_init(void)
311{
312 return misc_register(&vhost_test_misc);
313}
314module_init(vhost_test_init);
315
316static void vhost_test_exit(void)
317{
318 misc_deregister(&vhost_test_misc);
319}
320module_exit(vhost_test_exit);
321
322MODULE_VERSION("0.0.1");
323MODULE_LICENSE("GPL v2");
324MODULE_AUTHOR("Michael S. Tsirkin");
325MODULE_DESCRIPTION("Host kernel side for virtio simulator");