xref: /openbmc/qemu/hw/virtio/vhost-backend.c (revision 07a32d6b)
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 }
72