linux-imx

/* Copyright (C) 2009 Red Hat, Inc.

 * Copyright (C) 2006 Rusty Russell IBM Corporation

 *

 * Author: Michael S. Tsirkin <mst@redhat.com>

 *

 * Inspiration, some code, and most witty comments come from

 * Documentation/virtual/lguest/lguest.c, by Rusty Russell

 *

 * This work is licensed under the terms of the GNU GPL, version 2.

 *

 * Generic code for virtio server in host kernel.

 */

​

#include <linux/eventfd.h>

#include <linux/vhost.h>

#include <linux/uio.h>

#include <linux/mm.h>

#include <linux/mmu_context.h>

#include <linux/miscdevice.h>

#include <linux/mutex.h>

#include <linux/poll.h>

#include <linux/file.h>

#include <linux/highmem.h>

#include <linux/slab.h>

#include <linux/vmalloc.h>

#include <linux/kthread.h>

#include <linux/cgroup.h>

#include <linux/module.h>

#include <linux/sort.h>

#include <linux/sched/mm.h>

#include <linux/sched/signal.h>

#include <linux/interval_tree_generic.h>

#include <linux/nospec.h>

​

#include "vhost.h"

​

static ushort max_mem_regions = 64;

module_param(max_mem_regions, ushort, 0444);

MODULE_PARM_DESC(max_mem_regions,

    "Maximum number of memory regions in memory map. (default: 64)");

static int max_iotlb_entries = 2048;

module_param(max_iotlb_entries, int, 0444);

MODULE_PARM_DESC(max_iotlb_entries,

    "Maximum number of iotlb entries. (default: 2048)");

​

enum {

    VHOST_MEMORY_F_LOG = 0x1,

};

​

#define vhost_used_event(vq) ((__virtio16 __user *)&vq->avail->ring[vq->num])

#define vhost_avail_event(vq) ((__virtio16 __user *)&vq->used->ring[vq->num])

​

INTERVAL_TREE_DEFINE(struct vhost_umem_node,

             rb, __u64, __subtree_last,

             START, LAST, static inline, vhost_umem_interval_tree);

​

#ifdef CONFIG_VHOST_CROSS_ENDIAN_LEGACY

static void vhost_disable_cross_endian(struct vhost_virtqueue *vq)

{

    vq->user_be = !virtio_legacy_is_little_endian();

}

​

static void vhost_enable_cross_endian_big(struct vhost_virtqueue *vq)

{

    vq->user_be = true;

}

​

static void vhost_enable_cross_endian_little(struct vhost_virtqueue *vq)

{

    vq->user_be = false;

}

​

static long vhost_set_vring_endian(struct vhost_virtqueue *vq, int __user *argp)

{

    struct vhost_vring_state s;

​

    if (vq->private_data)

        return -EBUSY;

​

    if (copy_from_user(&s, argp, sizeof(s)))

        return -EFAULT;

​

    if (s.num != VHOST_VRING_LITTLE_ENDIAN &&

        s.num != VHOST_VRING_BIG_ENDIAN)

        return -EINVAL;

​

    if (s.num == VHOST_VRING_BIG_ENDIAN)

        vhost_enable_cross_endian_big(vq);

    else

        vhost_enable_cross_endian_little(vq);

​

    return 0;