Commit 71ccc212 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin

vhost test module

This adds a test module for vhost infrastructure.
Intentionally not tied to kbuild to prevent people
from installing and loading it accidentally.
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 28831ee6
/* 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(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(vq))) {
vhost_disable_notify(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);
mutex_unlock(&vq->mutex);
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");
#ifndef LINUX_VHOST_TEST_H
#define LINUX_VHOST_TEST_H
/* Start a given test on the virtio null device. 0 stops all tests. */
#define VHOST_TEST_RUN _IOW(VHOST_VIRTIO, 0x31, int)
#endif
obj-m += vhost_test.o
EXTRA_CFLAGS += -Idrivers/vhost
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment