https://github.com/torvalds/linux
Tip revision: b3a9e3b9622ae10064826dccb4f7a52bd88c7407 authored by Linus Torvalds on 14 June 2020, 19:45:04 UTC
Linux 5.8-rc1
Linux 5.8-rc1
Tip revision: b3a9e3b
test.c
// SPDX-License-Identifier: GPL-2.0-only
/* Copyright (C) 2009 Red Hat, Inc.
* Author: Michael S. Tsirkin <mst@redhat.com>
*
* 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/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
/* Max number of packets transferred before requeueing the job.
* Using this limit prevents one virtqueue from starving others with
* pkts.
*/
#define VHOST_TEST_PKT_WEIGHT 256
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 = vhost_vq_get_backend(vq);
if (!private) {
mutex_unlock(&vq->mutex);
return;
}
vhost_disable_notify(&n->dev, vq);
for (;;) {
head = vhost_get_vq_desc(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(vhost_exceeds_weight(vq, 0, total_len)))
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;
if (!n)
return -ENOMEM;
vqs = kmalloc_array(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;
vhost_dev_init(dev, vqs, VHOST_TEST_VQ_MAX, UIO_MAXIOV,
VHOST_TEST_PKT_WEIGHT, VHOST_TEST_WEIGHT, true, NULL);
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 = vhost_vq_get_backend(vq);
vhost_vq_set_backend(vq, 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_stop(&n->dev);
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 = vhost_vq_get_backend(vq);
vhost_vq_set_backend(vq, priv);
r = vhost_vq_init_access(&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_iotlb *umem;
mutex_lock(&n->dev.mutex);
err = vhost_dev_check_owner(&n->dev);
if (err)
goto done;
umem = vhost_dev_reset_owner_prepare();
if (!umem) {
err = -ENOMEM;
goto done;
}
vhost_test_stop(n, &priv);
vhost_test_flush(n);
vhost_dev_stop(&n->dev);
vhost_dev_reset_owner(&n->dev, umem);
done:
mutex_unlock(&n->dev.mutex);
return err;
}
static int vhost_test_set_features(struct vhost_test *n, u64 features)
{
struct vhost_virtqueue *vq;
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;
}
vq = &n->vqs[VHOST_TEST_VQ];
mutex_lock(&vq->mutex);
vq->acked_features = features;
mutex_unlock(&vq->mutex);
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:
printk(KERN_ERR "1\n");
if (copy_from_user(&features, featurep, sizeof features))
return -EFAULT;
printk(KERN_ERR "2\n");
if (features & ~VHOST_FEATURES)
return -EOPNOTSUPP;
printk(KERN_ERR "3\n");
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;
}
}
static const struct file_operations vhost_test_fops = {
.owner = THIS_MODULE,
.release = vhost_test_release,
.unlocked_ioctl = vhost_test_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.open = vhost_test_open,
.llseek = noop_llseek,
};
static struct miscdevice vhost_test_misc = {
MISC_DYNAMIC_MINOR,
"vhost-test",
&vhost_test_fops,
};
module_misc_device(vhost_test_misc);
MODULE_VERSION("0.0.1");
MODULE_LICENSE("GPL v2");
MODULE_AUTHOR("Michael S. Tsirkin");
MODULE_DESCRIPTION("Host kernel side for virtio simulator");