2 * VFIO-KVM bridge pseudo device
4 * Copyright (C) 2013 Red Hat, Inc. All rights reserved.
5 * Author: Alex Williamson <alex.williamson@redhat.com>
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
12 #include <linux/errno.h>
13 #include <linux/file.h>
14 #include <linux/kvm_host.h>
15 #include <linux/list.h>
16 #include <linux/module.h>
17 #include <linux/mutex.h>
18 #include <linux/slab.h>
19 #include <linux/uaccess.h>
20 #include <linux/vfio.h>
22 struct kvm_vfio_group
{
23 struct list_head node
;
24 struct vfio_group
*vfio_group
;
28 struct list_head group_list
;
32 static struct vfio_group
*kvm_vfio_group_get_external_user(struct file
*filep
)
34 struct vfio_group
*vfio_group
;
35 struct vfio_group
*(*fn
)(struct file
*);
37 fn
= symbol_get(vfio_group_get_external_user
);
39 return ERR_PTR(-EINVAL
);
41 vfio_group
= fn(filep
);
43 symbol_put(vfio_group_get_external_user
);
48 static void kvm_vfio_group_put_external_user(struct vfio_group
*vfio_group
)
50 void (*fn
)(struct vfio_group
*);
52 fn
= symbol_get(vfio_group_put_external_user
);
58 symbol_put(vfio_group_put_external_user
);
61 static int kvm_vfio_set_group(struct kvm_device
*dev
, long attr
, u64 arg
)
63 struct kvm_vfio
*kv
= dev
->private;
64 struct vfio_group
*vfio_group
;
65 struct kvm_vfio_group
*kvg
;
66 void __user
*argp
= (void __user
*)arg
;
72 case KVM_DEV_VFIO_GROUP_ADD
:
73 if (get_user(fd
, (int32_t __user
*)argp
))
80 vfio_group
= kvm_vfio_group_get_external_user(f
.file
);
83 if (IS_ERR(vfio_group
))
84 return PTR_ERR(vfio_group
);
86 mutex_lock(&kv
->lock
);
88 list_for_each_entry(kvg
, &kv
->group_list
, node
) {
89 if (kvg
->vfio_group
== vfio_group
) {
90 mutex_unlock(&kv
->lock
);
91 kvm_vfio_group_put_external_user(vfio_group
);
96 kvg
= kzalloc(sizeof(*kvg
), GFP_KERNEL
);
98 mutex_unlock(&kv
->lock
);
99 kvm_vfio_group_put_external_user(vfio_group
);
103 list_add_tail(&kvg
->node
, &kv
->group_list
);
104 kvg
->vfio_group
= vfio_group
;
106 mutex_unlock(&kv
->lock
);
110 case KVM_DEV_VFIO_GROUP_DEL
:
111 if (get_user(fd
, (int32_t __user
*)argp
))
118 vfio_group
= kvm_vfio_group_get_external_user(f
.file
);
121 if (IS_ERR(vfio_group
))
122 return PTR_ERR(vfio_group
);
126 mutex_lock(&kv
->lock
);
128 list_for_each_entry(kvg
, &kv
->group_list
, node
) {
129 if (kvg
->vfio_group
!= vfio_group
)
132 list_del(&kvg
->node
);
133 kvm_vfio_group_put_external_user(kvg
->vfio_group
);
139 mutex_unlock(&kv
->lock
);
141 kvm_vfio_group_put_external_user(vfio_group
);
149 static int kvm_vfio_set_attr(struct kvm_device
*dev
,
150 struct kvm_device_attr
*attr
)
152 switch (attr
->group
) {
153 case KVM_DEV_VFIO_GROUP
:
154 return kvm_vfio_set_group(dev
, attr
->attr
, attr
->addr
);
160 static int kvm_vfio_has_attr(struct kvm_device
*dev
,
161 struct kvm_device_attr
*attr
)
163 switch (attr
->group
) {
164 case KVM_DEV_VFIO_GROUP
:
165 switch (attr
->attr
) {
166 case KVM_DEV_VFIO_GROUP_ADD
:
167 case KVM_DEV_VFIO_GROUP_DEL
:
177 static void kvm_vfio_destroy(struct kvm_device
*dev
)
179 struct kvm_vfio
*kv
= dev
->private;
180 struct kvm_vfio_group
*kvg
, *tmp
;
182 list_for_each_entry_safe(kvg
, tmp
, &kv
->group_list
, node
) {
183 kvm_vfio_group_put_external_user(kvg
->vfio_group
);
184 list_del(&kvg
->node
);
189 kfree(dev
); /* alloc by kvm_ioctl_create_device, free by .destroy */
192 static int kvm_vfio_create(struct kvm_device
*dev
, u32 type
)
194 struct kvm_device
*tmp
;
197 /* Only one VFIO "device" per VM */
198 list_for_each_entry(tmp
, &dev
->kvm
->devices
, vm_node
)
199 if (tmp
->ops
== &kvm_vfio_ops
)
202 kv
= kzalloc(sizeof(*kv
), GFP_KERNEL
);
206 INIT_LIST_HEAD(&kv
->group_list
);
207 mutex_init(&kv
->lock
);
214 struct kvm_device_ops kvm_vfio_ops
= {
216 .create
= kvm_vfio_create
,
217 .destroy
= kvm_vfio_destroy
,
218 .set_attr
= kvm_vfio_set_attr
,
219 .has_attr
= kvm_vfio_has_attr
,