linux-imx

/* 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/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(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. */