[mirror_ubuntu-zesty-kernel.git] / drivers / vhost / test.c

/* Copyright (C) 2009 Red Hat, Inc.
 * Author: Michael S. Tsirkin <mst@redhat.com>
 *
 * This work is licensed under the terms of the GNU GPL, version 2.
 *
 * test virtio server in host kernel.
 */

#include <linux/compat.h>
#include <linux/eventfd.h>
#include <linux/vhost.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/workqueue.h>
#include <linux/rcupdate.h>
#include <linux/file.h>
#include <linux/slab.h>

#include "test.h"
#include "vhost.h"

/* Max number of bytes transferred before requeueing the job.
 * Using this limit prevents one virtqueue from starving others. */
#define VHOST_TEST_WEIGHT 0x80000

enum {
	VHOST_TEST_VQ = 0,
	VHOST_TEST_VQ_MAX = 1,
};

struct vhost_test {
	struct vhost_dev dev;
	struct vhost_virtqueue vqs[VHOST_TEST_VQ_MAX];
};

/* Expects to be always run from workqueue - which acts as
 * read-size critical section for our kind of RCU. */
static void handle_vq(struct vhost_test *n)
{
	struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
	unsigned out, in;
	int head;
	size_t len, total_len = 0;
	void *private;

	mutex_lock(&vq->mutex);
	private = vq->private_data;
	if (!private) {
		mutex_unlock(&vq->mutex);
		return;
	}

	vhost_disable_notify(&n->dev, vq);

	for (;;) {
		head = vhost_get_vq_desc(&n->dev, vq, vq->iov,
					 ARRAY_SIZE(vq->iov),
					 &out, &in,
					 NULL, NULL);
		/* On error, stop handling until the next kick. */
		if (unlikely(head < 0))
			break;
		/* Nothing new?  Wait for eventfd to tell us they refilled. */
		if (head == vq->num) {
			if (unlikely(vhost_enable_notify(&n->dev, vq))) {
				vhost_disable_notify(&n->dev, vq);
				continue;
			}
			break;
		}
		if (in) {
			vq_err(vq, "Unexpected descriptor format for TX: "
			       "out %d, int %d\n", out, in);
			break;
		}
		len = iov_length(vq->iov, out);
		/* Sanity check */
		if (!len) {
			vq_err(vq, "Unexpected 0 len for TX\n");
			break;
		}
		vhost_add_used_and_signal(&n->dev, vq, head, 0);
		total_len += len;
		if (unlikely(total_len >= VHOST_TEST_WEIGHT)) {
			vhost_poll_queue(&vq->poll);
			break;
		}
	}

	mutex_unlock(&vq->mutex);
}

static void handle_vq_kick(struct vhost_work *work)
{
	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
						  poll.work);
	struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);

	handle_vq(n);
}

static int vhost_test_open(struct inode *inode, struct file *f)
{
	struct vhost_test *n = kmalloc(sizeof *n, GFP_KERNEL);
	struct vhost_dev *dev;
	struct vhost_virtqueue **vqs;
	int r;

	if (!n)
		return -ENOMEM;
	vqs = kmalloc(VHOST_TEST_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
	if (!vqs) {
		kfree(n);
		return -ENOMEM;
	}

	dev = &n->dev;
	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
	r = vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX);
	if (r < 0) {
		kfree(vqs);
		kfree(n);
		return r;
	}

	f->private_data = n;

	return 0;
}

static void *vhost_test_stop_vq(struct vhost_test *n,
				struct vhost_virtqueue *vq)
{
	void *private;

	mutex_lock(&vq->mutex);
	private = vq->private_data;
	vq->private_data = NULL;
	mutex_unlock(&vq->mutex);
	return private;
}

static void vhost_test_stop(struct vhost_test *n, void **privatep)
{
	*privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
}

static void vhost_test_flush_vq(struct vhost_test *n, int index)
{
	vhost_poll_flush(&n->vqs[index].poll);
}

static void vhost_test_flush(struct vhost_test *n)
{
	vhost_test_flush_vq(n, VHOST_TEST_VQ);
}

static int vhost_test_release(struct inode *inode, struct file *f)
{
	struct vhost_test *n = f->private_data;
	void  *private;

	vhost_test_stop(n, &private);
	vhost_test_flush(n);
	vhost_dev_cleanup(&n->dev, false);
	/* We do an extra flush before freeing memory,
	 * since jobs can re-queue themselves. */
	vhost_test_flush(n);
	kfree(n);
	return 0;
}

static long vhost_test_run(struct vhost_test *n, int test)
{
	void *priv, *oldpriv;
	struct vhost_virtqueue *vq;
	int r, index;

	if (test < 0 || test > 1)
		return -EINVAL;

	mutex_lock(&n->dev.mutex);
	r = vhost_dev_check_owner(&n->dev);
	if (r)
		goto err;

	for (index = 0; index < n->dev.nvqs; ++index) {
		/* Verify that ring has been setup correctly. */
		if (!vhost_vq_access_ok(&n->vqs[index])) {
			r = -EFAULT;
			goto err;
		}
	}

	for (index = 0; index < n->dev.nvqs; ++index) {
		vq = n->vqs + index;
		mutex_lock(&vq->mutex);
		priv = test ? n : NULL;

		/* start polling new socket */
		oldpriv = rcu_dereference_protected(vq->private_data,
						    lockdep_is_held(&vq->mutex));
		rcu_assign_pointer(vq->private_data, priv);

		r = vhost_init_used(&n->vqs[index]);

		mutex_unlock(&vq->mutex);

		if (r)
			goto err;

		if (oldpriv) {
			vhost_test_flush_vq(n, index);
		}
	}

	mutex_unlock(&n->dev.mutex);
	return 0;

err:
	mutex_unlock(&n->dev.mutex);
	return r;
}

static long vhost_test_reset_owner(struct vhost_test *n)
{
	void *priv = NULL;
	long err;
	struct vhost_memory *memory;

	mutex_lock(&n->dev.mutex);
	err = vhost_dev_check_owner(&n->dev);
	if (err)
		goto done;
	memory = vhost_dev_reset_owner_prepare();
	if (!memory) {
		err = -ENOMEM;
		goto done;
	}
	vhost_test_stop(n, &priv);
	vhost_test_flush(n);
	vhost_dev_reset_owner(&n->dev, memory);
done:
	mutex_unlock(&n->dev.mutex);
	return err;
}

static int vhost_test_set_features(struct vhost_test *n, u64 features)
{
	mutex_lock(&n->dev.mutex);
	if ((features & (1 << VHOST_F_LOG_ALL)) &&
	    !vhost_log_access_ok(&n->dev)) {
		mutex_unlock(&n->dev.mutex);
		return -EFAULT;
	}
	n->dev.acked_features = features;
	smp_wmb();
	vhost_test_flush(n);
	mutex_unlock(&n->dev.mutex);
	return 0;
}

static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
			     unsigned long arg)
{
	struct vhost_test *n = f->private_data;
	void __user *argp = (void __user *)arg;
	u64 __user *featurep = argp;
	int test;
	u64 features;
	int r;
	switch (ioctl) {
	case VHOST_TEST_RUN:
		if (copy_from_user(&test, argp, sizeof test))
			return -EFAULT;
		return vhost_test_run(n, test);
	case VHOST_GET_FEATURES:
		features = VHOST_FEATURES;
		if (copy_to_user(featurep, &features, sizeof features))
			return -EFAULT;
		return 0;
	case VHOST_SET_FEATURES:
		if (copy_from_user(&features, featurep, sizeof features))
			return -EFAULT;
		if (features & ~VHOST_FEATURES)
			return -EOPNOTSUPP;
		return vhost_test_set_features(n, features);
	case VHOST_RESET_OWNER:
		return vhost_test_reset_owner(n);
	default:
		mutex_lock(&n->dev.mutex);
		r = vhost_dev_ioctl(&n->dev, ioctl, argp);
                if (r == -ENOIOCTLCMD)
                        r = vhost_vring_ioctl(&n->dev, ioctl, argp);
		vhost_test_flush(n);
		mutex_unlock(&n->dev.mutex);
		return r;
	}
}

#ifdef CONFIG_COMPAT
static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl,
				   unsigned long arg)
{
	return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
}
#endif

static const struct file_operations vhost_test_fops = {
	.owner          = THIS_MODULE,
	.release        = vhost_test_release,
	.unlocked_ioctl = vhost_test_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl   = vhost_test_compat_ioctl,
#endif
	.open           = vhost_test_open,
	.llseek		= noop_llseek,
};

static struct miscdevice vhost_test_misc = {
	MISC_DYNAMIC_MINOR,
	"vhost-test",
	&vhost_test_fops,
};

static int vhost_test_init(void)
{
	return misc_register(&vhost_test_misc);
}
module_init(vhost_test_init);

static void vhost_test_exit(void)
{
	misc_deregister(&vhost_test_misc);
}
module_exit(vhost_test_exit);

MODULE_VERSION("0.0.1");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Michael S. Tsirkin");
MODULE_DESCRIPTION("Host kernel side for virtio simulator");
Commit	Line	Data
71ccc212 MT	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"
6ac1afbf	21	#include "vhost.h"
71ccc212 MT	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	{
09a34c84	41	struct vhost_virtqueue *vq = &n->vqs[VHOST_TEST_VQ];
71ccc212 MT	42	unsigned out, in;
	43	int head;
	44	size_t len, total_len = 0;
	45	void *private;
	46
09a34c84 MT	47	mutex_lock(&vq->mutex);
	48	private = vq->private_data;
	49	if (!private) {
	50	mutex_unlock(&vq->mutex);
71ccc212	51	return;
09a34c84	52	}
71ccc212	53
8ea8cf89	54	vhost_disable_notify(&n->dev, vq);
71ccc212 MT	55
	56	for (;;) {
	57	head = vhost_get_vq_desc(&n->dev, vq, vq->iov,
	58	ARRAY_SIZE(vq->iov),
	59	&out, &in,
	60	NULL, NULL);
	61	/* On error, stop handling until the next kick. */
	62	if (unlikely(head < 0))
	63	break;
	64	/* Nothing new? Wait for eventfd to tell us they refilled. */
	65	if (head == vq->num) {
8ea8cf89 MT	66	if (unlikely(vhost_enable_notify(&n->dev, vq))) {
8ea8cf89 MT	67	vhost_disable_notify(&n->dev, vq);
71ccc212 MT	68	continue;
	69	}
	70	break;
	71	}
	72	if (in) {
	73	vq_err(vq, "Unexpected descriptor format for TX: "
	74	"out %d, int %d\n", out, in);
	75	break;
	76	}
	77	len = iov_length(vq->iov, out);
	78	/* Sanity check */
	79	if (!len) {
	80	vq_err(vq, "Unexpected 0 len for TX\n");
	81	break;
	82	}
	83	vhost_add_used_and_signal(&n->dev, vq, head, 0);
	84	total_len += len;
	85	if (unlikely(total_len >= VHOST_TEST_WEIGHT)) {
	86	vhost_poll_queue(&vq->poll);
	87	break;
	88	}
	89	}
	90
	91	mutex_unlock(&vq->mutex);
	92	}
	93
	94	static void handle_vq_kick(struct vhost_work *work)
	95	{
	96	struct vhost_virtqueue *vq = container_of(work, struct vhost_virtqueue,
	97	poll.work);
	98	struct vhost_test *n = container_of(vq->dev, struct vhost_test, dev);
	99
	100	handle_vq(n);
	101	}
	102
	103	static int vhost_test_open(struct inode inode, struct file f)
	104	{
	105	struct vhost_test n = kmalloc(sizeof n, GFP_KERNEL);
	106	struct vhost_dev *dev;
09a34c84	107	struct vhost_virtqueue **vqs;
71ccc212 MT	108	int r;
	109
	110	if (!n)
	111	return -ENOMEM;
09a34c84 MT	112	vqs = kmalloc(VHOST_TEST_VQ_MAX * sizeof(*vqs), GFP_KERNEL);
	113	if (!vqs) {
	114	kfree(n);
	115	return -ENOMEM;
	116	}
71ccc212 MT	117
71ccc212 MT	118	dev = &n->dev;
09a34c84	119	vqs[VHOST_TEST_VQ] = &n->vqs[VHOST_TEST_VQ];
71ccc212	120	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
09a34c84	121	r = vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX);
71ccc212	122	if (r < 0) {
09a34c84	123	kfree(vqs);
71ccc212 MT	124	kfree(n);
	125	return r;
	126	}
	127
	128	f->private_data = n;
	129
	130	return 0;
	131	}
	132
	133	static void vhost_test_stop_vq(struct vhost_test n,
	134	struct vhost_virtqueue *vq)
	135	{
	136	void *private;
	137
	138	mutex_lock(&vq->mutex);
09a34c84 MT	139	private = vq->private_data;
09a34c84 MT	140	vq->private_data = NULL;
71ccc212 MT	141	mutex_unlock(&vq->mutex);
	142	return private;
	143	}
	144
	145	static void vhost_test_stop(struct vhost_test n, void *privatep)
	146	{
	147	*privatep = vhost_test_stop_vq(n, n->vqs + VHOST_TEST_VQ);
	148	}
	149
	150	static void vhost_test_flush_vq(struct vhost_test *n, int index)
	151	{
09a34c84	152	vhost_poll_flush(&n->vqs[index].poll);
71ccc212 MT	153	}
	154
	155	static void vhost_test_flush(struct vhost_test *n)
	156	{
	157	vhost_test_flush_vq(n, VHOST_TEST_VQ);
	158	}
	159
	160	static int vhost_test_release(struct inode inode, struct file f)
	161	{
	162	struct vhost_test *n = f->private_data;
	163	void *private;
	164
	165	vhost_test_stop(n, &private);
	166	vhost_test_flush(n);
5e7045b0	167	vhost_dev_cleanup(&n->dev, false);
71ccc212 MT	168	/* We do an extra flush before freeing memory,
	169	* since jobs can re-queue themselves. */
	170	vhost_test_flush(n);
	171	kfree(n);
	172	return 0;
	173	}
	174
	175	static long vhost_test_run(struct vhost_test *n, int test)
	176	{
	177	void priv, oldpriv;
	178	struct vhost_virtqueue *vq;
	179	int r, index;
	180
	181	if (test < 0 \|\| test > 1)
	182	return -EINVAL;
	183
	184	mutex_lock(&n->dev.mutex);
	185	r = vhost_dev_check_owner(&n->dev);
	186	if (r)
	187	goto err;
	188
	189	for (index = 0; index < n->dev.nvqs; ++index) {
	190	/* Verify that ring has been setup correctly. */
	191	if (!vhost_vq_access_ok(&n->vqs[index])) {
	192	r = -EFAULT;
	193	goto err;
	194	}
	195	}
	196
	197	for (index = 0; index < n->dev.nvqs; ++index) {
	198	vq = n->vqs + index;
	199	mutex_lock(&vq->mutex);
	200	priv = test ? n : NULL;
	201
	202	/* start polling new socket */
	203	oldpriv = rcu_dereference_protected(vq->private_data,
	204	lockdep_is_held(&vq->mutex));
	205	rcu_assign_pointer(vq->private_data, priv);
	206
f59281da JW	207	r = vhost_init_used(&n->vqs[index]);
f59281da JW	208
71ccc212 MT	209	mutex_unlock(&vq->mutex);
71ccc212 MT	210
f59281da JW	211	if (r)
	212	goto err;
	213
71ccc212 MT	214	if (oldpriv) {
	215	vhost_test_flush_vq(n, index);
	216	}
	217	}
	218
	219	mutex_unlock(&n->dev.mutex);
	220	return 0;
	221
	222	err:
	223	mutex_unlock(&n->dev.mutex);
	224	return r;
	225	}
	226
	227	static long vhost_test_reset_owner(struct vhost_test *n)
	228	{
	229	void *priv = NULL;
	230	long err;
150b9e51 MT	231	struct vhost_memory *memory;
150b9e51 MT	232
71ccc212 MT	233	mutex_lock(&n->dev.mutex);
	234	err = vhost_dev_check_owner(&n->dev);
	235	if (err)
	236	goto done;
150b9e51 MT	237	memory = vhost_dev_reset_owner_prepare();
	238	if (!memory) {
	239	err = -ENOMEM;
	240	goto done;
	241	}
71ccc212 MT	242	vhost_test_stop(n, &priv);
71ccc212 MT	243	vhost_test_flush(n);
150b9e51	244	vhost_dev_reset_owner(&n->dev, memory);
71ccc212 MT	245	done:
	246	mutex_unlock(&n->dev.mutex);
	247	return err;
	248	}
	249
	250	static int vhost_test_set_features(struct vhost_test *n, u64 features)
	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	n->dev.acked_features = features;
	259	smp_wmb();
	260	vhost_test_flush(n);
	261	mutex_unlock(&n->dev.mutex);
	262	return 0;
	263	}
	264
	265	static long vhost_test_ioctl(struct file *f, unsigned int ioctl,
	266	unsigned long arg)
	267	{
	268	struct vhost_test *n = f->private_data;
	269	void __user argp = (void __user )arg;
	270	u64 __user *featurep = argp;
	271	int test;
	272	u64 features;
	273	int r;
	274	switch (ioctl) {
	275	case VHOST_TEST_RUN:
	276	if (copy_from_user(&test, argp, sizeof test))
	277	return -EFAULT;
	278	return vhost_test_run(n, test);
	279	case VHOST_GET_FEATURES:
09a34c84	280	features = VHOST_FEATURES;
71ccc212 MT	281	if (copy_to_user(featurep, &features, sizeof features))
	282	return -EFAULT;
	283	return 0;
	284	case VHOST_SET_FEATURES:
	285	if (copy_from_user(&features, featurep, sizeof features))
	286	return -EFAULT;
09a34c84	287	if (features & ~VHOST_FEATURES)
71ccc212 MT	288	return -EOPNOTSUPP;
	289	return vhost_test_set_features(n, features);
	290	case VHOST_RESET_OWNER:
	291	return vhost_test_reset_owner(n);
	292	default:
	293	mutex_lock(&n->dev.mutex);
73640c99 MT	294	r = vhost_dev_ioctl(&n->dev, ioctl, argp);
	295	if (r == -ENOIOCTLCMD)
	296	r = vhost_vring_ioctl(&n->dev, ioctl, argp);
71ccc212 MT	297	vhost_test_flush(n);
	298	mutex_unlock(&n->dev.mutex);
	299	return r;
	300	}
	301	}
	302
	303	#ifdef CONFIG_COMPAT
	304	static long vhost_test_compat_ioctl(struct file *f, unsigned int ioctl,
	305	unsigned long arg)
	306	{
	307	return vhost_test_ioctl(f, ioctl, (unsigned long)compat_ptr(arg));
	308	}
	309	#endif
	310
	311	static const struct file_operations vhost_test_fops = {
	312	.owner = THIS_MODULE,
	313	.release = vhost_test_release,
	314	.unlocked_ioctl = vhost_test_ioctl,
	315	#ifdef CONFIG_COMPAT
	316	.compat_ioctl = vhost_test_compat_ioctl,
	317	#endif
	318	.open = vhost_test_open,
	319	.llseek = noop_llseek,
	320	};
	321
	322	static struct miscdevice vhost_test_misc = {
	323	MISC_DYNAMIC_MINOR,
	324	"vhost-test",
	325	&vhost_test_fops,
	326	};
	327
	328	static int vhost_test_init(void)
	329	{
	330	return misc_register(&vhost_test_misc);
	331	}
	332	module_init(vhost_test_init);
	333
	334	static void vhost_test_exit(void)
	335	{
	336	misc_deregister(&vhost_test_misc);
	337	}
	338	module_exit(vhost_test_exit);
	339
	340	MODULE_VERSION("0.0.1");
	341	MODULE_LICENSE("GPL v2");
	342	MODULE_AUTHOR("Michael S. Tsirkin");
	343	MODULE_DESCRIPTION("Host kernel side for virtio simulator");