hw/virtio/vhost-backend.c

   1 /*
   2  * vhost-backend
   3  *
   4  * Copyright (c) 2013 Virtual Open Systems Sarl.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "hw/virtio/vhost.h"
  12 #include "hw/virtio/vhost-backend.h"
  13 #include "qemu/error-report.h"
  14
  15 #include <sys/ioctl.h>
  16
  17 extern const VhostOps user_ops;
  18
  19 static int vhost_kernel_call(struct vhost_dev *dev, unsigned long int request,
  20                              void *arg)
  21 {
  22     int fd = (uintptr_t) dev->opaque;
  23
  24     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  25
  26     return ioctl(fd, request, arg);
  27 }
  28
  29 static int vhost_kernel_init(struct vhost_dev *dev, void *opaque)
  30 {
  31     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  32
  33     dev->opaque = opaque;
  34
  35     return 0;
  36 }
  37
  38 static int vhost_kernel_cleanup(struct vhost_dev *dev)
  39 {
  40     int fd = (uintptr_t) dev->opaque;
  41
  42     assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_KERNEL);
  43
  44     return close(fd);
  45 }
  46
  47 static const VhostOps kernel_ops = {
  48         .backend_type = VHOST_BACKEND_TYPE_KERNEL,
  49         .vhost_call = vhost_kernel_call,
  50         .vhost_backend_init = vhost_kernel_init,
  51         .vhost_backend_cleanup = vhost_kernel_cleanup
  52 };
  53
  54 int vhost_set_backend_type(struct vhost_dev *dev, VhostBackendType backend_type)
  55 {
  56     int r = 0;
  57
  58     switch (backend_type) {
  59     case VHOST_BACKEND_TYPE_KERNEL:
  60         dev->vhost_ops = &kernel_ops;
  61         break;
  62     case VHOST_BACKEND_TYPE_USER:
  63         dev->vhost_ops = &user_ops;
  64         break;
  65     default:
  66         error_report("Unknown vhost backend type\n");
  67         r = -1;
  68     }
  69
  70     return r;
  71 }