1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2009 Red Hat, Inc.
3 * Author: Michael S. Tsirkin <mst@redhat.com>
5 * test virtio server in host kernel.
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>
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
25 /* Max number of packets transferred before requeueing the job.
26 * Using this limit prevents one virtqueue from starving others with
29 #define VHOST_TEST_PKT_WEIGHT 256
33 VHOST_TEST_VQ_MAX = 1,
38 struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
41 /* Expects to be always run from workqueue - which acts as
42 * read-size critical section for our kind of RCU. */
43 static void handle_vq(struct vhost_test *n)
45 struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
48 size_t len, total_len = 0;
51 mutex_lock(&vq->mutex);
52 private = vhost_vq_get_backend(vq);
54 mutex_unlock(&vq->mutex);
58 vhost_disable_notify(&n->dev, vq);
61 head = vhost_get_vq_desc(vq, vq->iov,
65 /* On error, stop handling until the next kick. */
66 if (unlikely(head < 0))
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);
77 vq_err(vq, "Unexpected descriptor format for TX: "
78 "out %d, int %d\n", out, in);
81 len = iov_length(vq->iov, out);
84 vq_err(vq, "Unexpected 0 len for TX\n");
87 vhost_add_used_and_signal(&n->dev, vq, head, 0);
89 if (unlikely(vhost_exceeds_weight(vq, 0, total_len)))
93 mutex_unlock(&vq->mutex);
96 static void handle_vq_kick(struct vhost_work *work)
98 struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
100 struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);
105 static int vhost_test_open(struct inode *inode, struct file *f)
107 struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
108 struct vhost_dev *dev;
109 struct vhost_virtqueue **vqs;
113 vqs = kmalloc_array(VHOST_TEST_VQ_MAX, sizeof(*vqs), GFP_KERNEL);
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);
130 static void *vhost_test_stop_vq(struct vhost_test *n,
131 struct vhost_virtqueue *vq)
135 mutex_lock(&vq->mutex);
136 private = vhost_vq_get_backend(vq);
137 vhost_vq_set_backend(vq, NULL);
138 mutex_unlock(&vq->mutex);
142 static void vhost_test_stop(struct vhost_test *n, void **privatep)
144 *privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
147 static void vhost_test_flush_vq(struct vhost_test *n, int index)
149 vhost_poll_flush(&n->vqs[index].poll);
152 static void vhost_test_flush(struct vhost_test *n)
154 vhost_test_flush_vq(n, VHOST_TEST_VQ);
157 static int vhost_test_release(struct inode *inode, struct file *f)
159 struct vhost_test *n = f->private_data;
162 vhost_test_stop(n, &private);
164 vhost_dev_stop(&n->dev);
165 vhost_dev_cleanup(&n->dev);
166 /* We do an extra flush before freeing memory,
167 * since jobs can re-queue themselves. */
174 static long vhost_test_run(struct vhost_test *n, int test)
176 void *priv, *oldpriv;
177 struct vhost_virtqueue *vq;
180 if (test < 0 || test > 1)
183 mutex_lock(&n->dev.mutex);
184 r = vhost_dev_check_owner(&n->dev);
188 for (index = 0; index < n->dev.nvqs; ++index) {
189 /* Verify that ring has been setup correctly. */
190 if (!vhost_vq_access_ok(&n->vqs[index])) {
196 for (index = 0; index < n->dev.nvqs; ++index) {
198 mutex_lock(&vq->mutex);
199 priv = test ? n : NULL;
201 /* start polling new socket */
202 oldpriv = vhost_vq_get_backend(vq);
203 vhost_vq_set_backend(vq, priv);
205 r = vhost_vq_init_access(&n->vqs[index]);
207 mutex_unlock(&vq->mutex);
213 vhost_test_flush_vq(n, index);
217 mutex_unlock(&n->dev.mutex);
221 mutex_unlock(&n->dev.mutex);
225 static long vhost_test_reset_owner(struct vhost_test *n)
229 struct vhost_iotlb *umem;
231 mutex_lock(&n->dev.mutex);
232 err = vhost_dev_check_owner(&n->dev);
235 umem = vhost_dev_reset_owner_prepare();
240 vhost_test_stop(n, &priv);
242 vhost_dev_stop(&n->dev);
243 vhost_dev_reset_owner(&n->dev, umem);
245 mutex_unlock(&n->dev.mutex);
249 static int vhost_test_set_features(struct vhost_test *n, u64 features)
251 struct vhost_virtqueue *vq;
253 mutex_lock(&n->dev.mutex);
254 if ((features & (1 << VHOST_F_LOG_ALL)) &&
255 !vhost_log_access_ok(&n->dev)) {
256 mutex_unlock(&n->dev.mutex);
259 vq = &n->vqs[VHOST_TEST_VQ];
260 mutex_lock(&vq->mutex);
261 vq->acked_features = features;
262 mutex_unlock(&vq->mutex);
263 mutex_unlock(&n->dev.mutex);
267 static long vhost_test_set_backend(struct vhost_test *n, unsigned index, int fd)
269 static void *backend;
271 const bool enable = fd != -1;
272 struct vhost_virtqueue *vq;
275 mutex_lock(&n->dev.mutex);
276 r = vhost_dev_check_owner(&n->dev);
280 if (index >= VHOST_TEST_VQ_MAX) {
285 mutex_lock(&vq->mutex);
287 /* Verify that ring has been setup correctly. */
288 if (!vhost_vq_access_ok(vq)) {
293 vhost_poll_stop(&vq->poll);
294 backend = vhost_vq_get_backend(vq);
295 vhost_vq_set_backend(vq, NULL);
297 vhost_vq_set_backend(vq, backend);
298 r = vhost_vq_init_access(vq);
300 r = vhost_poll_start(&vq->poll, vq->kick);
303 mutex_unlock(&vq->mutex);
306 vhost_test_flush_vq(n, index);
309 mutex_unlock(&n->dev.mutex);
313 mutex_unlock(&vq->mutex);
315 mutex_unlock(&n->dev.mutex);
319 static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
322 struct vhost_vring_file backend;
323 struct vhost_test *n = f->private_data;
324 void __user *argp = (void __user *)arg;
325 u64 __user *featurep = argp;
331 if (copy_from_user(&test, argp, sizeof test))
333 return vhost_test_run(n, test);
334 case VHOST_TEST_SET_BACKEND:
335 if (copy_from_user(&backend, argp, sizeof backend))
337 return vhost_test_set_backend(n, backend.index, backend.fd);
338 case VHOST_GET_FEATURES:
339 features = VHOST_FEATURES;
340 if (copy_to_user(featurep, &features, sizeof features))
343 case VHOST_SET_FEATURES:
344 printk(KERN_ERR "1\n");
345 if (copy_from_user(&features, featurep, sizeof features))
347 printk(KERN_ERR "2\n");
348 if (features & ~VHOST_FEATURES)
350 printk(KERN_ERR "3\n");
351 return vhost_test_set_features(n, features);
352 case VHOST_RESET_OWNER:
353 return vhost_test_reset_owner(n);
355 mutex_lock(&n->dev.mutex);
356 r = vhost_dev_ioctl(&n->dev, ioctl, argp);
357 if (r == -ENOIOCTLCMD)
358 r = vhost_vring_ioctl(&n->dev, ioctl, argp);
360 mutex_unlock(&n->dev.mutex);
365 static const struct file_operations vhost_test_fops = {
366 .owner = THIS_MODULE,
367 .release = vhost_test_release,
368 .unlocked_ioctl = vhost_test_ioctl,
369 .compat_ioctl = compat_ptr_ioctl,
370 .open = vhost_test_open,
371 .llseek = noop_llseek,
374 static struct miscdevice vhost_test_misc = {
379 module_misc_device(vhost_test_misc);
381 MODULE_VERSION("0.0.1");
382 MODULE_LICENSE("GPL v2");
383 MODULE_AUTHOR("Michael S. Tsirkin");
384 MODULE_DESCRIPTION("Host kernel side for virtio simulator");