/drivers/vhost/test.c

  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, 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_vq(struct vhost_test *n, int index)
148{
149	vhost_poll_flush(&n->vqs[index].poll);
150}
151
152static void vhost_test_flush(struct vhost_test *n)
153{
154	vhost_test_flush_vq(n, VHOST_TEST_VQ);
155}
156
157static int vhost_test_release(struct inode *inode, struct file *f)
158{
159	struct vhost_test *n = f->private_data;
160	void  *private;
161
162	vhost_test_stop(n, &private);
163	vhost_test_flush(n);
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. */
168	vhost_test_flush(n);
169	kfree(n);
170	return 0;
171}
172
173static long vhost_test_run(struct vhost_test *n, int test)
174{
175	void *priv, *oldpriv;
176	struct vhost_virtqueue *vq;
177	int r, index;
178
179	if (test < 0 || test > 1)
180		return -EINVAL;
181
182	mutex_lock(&n->dev.mutex);
183	r = vhost_dev_check_owner(&n->dev);
184	if (r)
185		goto err;
186
187	for (index = 0; index < n->dev.nvqs; ++index) {
188		/* Verify that ring has been setup correctly. */
189		if (!vhost_vq_access_ok(&n->vqs[index])) {
190			r = -EFAULT;
191			goto err;
192		}
193	}
194
195	for (index = 0; index < n->dev.nvqs; ++index) {
196		vq = n->vqs + index;
197		mutex_lock(&vq->mutex);
198		priv = test ? n : NULL;
199
200		/* start polling new socket */
201		oldpriv = vhost_vq_get_backend(vq);
202		vhost_vq_set_backend(vq, priv);
203
204		r = vhost_vq_init_access(&n->vqs[index]);
205
206		mutex_unlock(&vq->mutex);
207
208		if (r)
209			goto err;
210
211		if (oldpriv) {
212			vhost_test_flush_vq(n, index);
213		}
214	}
215
216	mutex_unlock(&n->dev.mutex);
217	return 0;
218
219err:
220	mutex_unlock(&n->dev.mutex);
221	return r;
222}
223
224static long vhost_test_reset_owner(struct vhost_test *n)
225{
226	void *priv = NULL;
227	long err;
228	struct vhost_iotlb *umem;
229
230	mutex_lock(&n->dev.mutex);
231	err = vhost_dev_check_owner(&n->dev);
232	if (err)
233		goto done;
234	umem = vhost_dev_reset_owner_prepare();
235	if (!umem) {
236		err = -ENOMEM;
237		goto done;
238	}
239	vhost_test_stop(n, &priv);
240	vhost_test_flush(n);
241	vhost_dev_stop(&n->dev);
242	vhost_dev_reset_owner(&n->dev, umem);
243done:
244	mutex_unlock(&n->dev.mutex);
245	return err;
246}
247
248static int vhost_test_set_features(struct vhost_test *n, u64 features)
249{
250	struct vhost_virtqueue *vq;
251
252	mutex_lock(&n->dev.mutex);
253	if ((features & (1 << VHOST_F_LOG_ALL)) &&
254	    !vhost_log_access_ok(&n->dev)) {
255		mutex_unlock(&n->dev.mutex);
256		return -EFAULT;
257	}
258	vq = &n->vqs[VHOST_TEST_VQ];
259	mutex_lock(&vq->mutex);
260	vq->acked_features = features;
261	mutex_unlock(&vq->mutex);
262	mutex_unlock(&n->dev.mutex);
263	return 0;
264}
265
266static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
267			     unsigned long arg)
268{
269	struct vhost_test *n = f->private_data;
270	void __user *argp = (void __user *)arg;
271	u64 __user *featurep = argp;
272	int test;
273	u64 features;
274	int r;
275	switch (ioctl) {
276	case VHOST_TEST_RUN:
277		if (copy_from_user(&test, argp, sizeof test))
278			return -EFAULT;
279		return vhost_test_run(n, test);
280	case VHOST_GET_FEATURES:
281		features = VHOST_FEATURES;
282		if (copy_to_user(featurep, &features, sizeof features))
283			return -EFAULT;
284		return 0;
285	case VHOST_SET_FEATURES:
286		printk(KERN_ERR "1\n");
287		if (copy_from_user(&features, featurep, sizeof features))
288			return -EFAULT;
289		printk(KERN_ERR "2\n");
290		if (features & ~VHOST_FEATURES)
291			return -EOPNOTSUPP;
292		printk(KERN_ERR "3\n");
293		return vhost_test_set_features(n, features);
294	case VHOST_RESET_OWNER:
295		return vhost_test_reset_owner(n);
296	default:
297		mutex_lock(&n->dev.mutex);
298		r = vhost_dev_ioctl(&n->dev, ioctl, argp);
299                if (r == -ENOIOCTLCMD)
300                        r = vhost_vring_ioctl(&n->dev, ioctl, argp);
301		vhost_test_flush(n);
302		mutex_unlock(&n->dev.mutex);
303		return r;
304	}
305}
306
307static const struct file_operations vhost_test_fops = {
308	.owner          = THIS_MODULE,
309	.release        = vhost_test_release,
310	.unlocked_ioctl = vhost_test_ioctl,
311	.compat_ioctl   = compat_ptr_ioctl,
312	.open           = vhost_test_open,
313	.llseek		= noop_llseek,
314};
315
316static struct miscdevice vhost_test_misc = {
317	MISC_DYNAMIC_MINOR,
318	"vhost-test",
319	&vhost_test_fops,
320};
321module_misc_device(vhost_test_misc);
322
323MODULE_VERSION("0.0.1");
324MODULE_LICENSE("GPL v2");
325MODULE_AUTHOR("Michael S. Tsirkin");
326MODULE_DESCRIPTION("Host kernel side for virtio simulator");