drivers/vhost/test.c - maze/linux - Git at Google

 /* 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.c"

 /* 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->dev.vqs[VHOST_TEST_VQ];
 	unsigned out, in;
 	int head;
 	size_t len, total_len = 0;
 	void *private;

 	private = rcu_dereference_check(vq->private_data, 1);
 	if (!private)
 		return;

 	mutex_lock(&vq->mutex);
 	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;
 	int r;

 	if (!n)
 		return -ENOMEM;

 	dev = &n->dev;
 	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
 	r = vhost_dev_init(dev, n->vqs, VHOST_TEST_VQ_MAX);
 	if (r < 0) {
 		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 = rcu_dereference_protected(vq->private_data,
 					 lockdep_is_held(&vq->mutex));
 	rcu_assign_pointer(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->dev.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);
 	/* 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;
 	mutex_lock(&n->dev.mutex);
 	err = vhost_dev_check_owner(&n->dev);
 	if (err)
 		goto done;
 	vhost_test_stop(n, &priv);
 	vhost_test_flush(n);
 	err = vhost_dev_reset_owner(&n->dev);
 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, arg);
 		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");
	/* 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.c"

	/* 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->dev.vqs[VHOST_TEST_VQ];
	unsigned out, in;
	int head;
	size_t len, total_len = 0;
	void *private;

	private = rcu_dereference_check(vq->private_data, 1);
	if (!private)
	return;

	mutex_lock(&vq->mutex);
	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;
	int r;

	if (!n)
	return -ENOMEM;

	dev = &n->dev;
	n->vqs[VHOST_TEST_VQ].handle_kick = handle_vq_kick;
	r = vhost_dev_init(dev, n->vqs, VHOST_TEST_VQ_MAX);
	if (r < 0) {
	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 = rcu_dereference_protected(vq->private_data,
	lockdep_is_held(&vq->mutex));
	rcu_assign_pointer(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->dev.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);
	/* 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;
	mutex_lock(&n->dev.mutex);
	err = vhost_dev_check_owner(&n->dev);
	if (err)
	goto done;
	vhost_test_stop(n, &priv);
	vhost_test_flush(n);
	err = vhost_dev_reset_owner(&n->dev);
	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, arg);
	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");