1 /*
2 * This program is free software; you can redistribute it and/or modify
3 * it under the terms of the GNU General Public License as published by
4 * the Free Software Foundation; either version 2 of the License.
5 *
6 * This program is distributed in the hope that it will be useful,
7 * but WITHOUT ANY WARRANTY; without even the implied warranty of
8 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
9 * GNU General Public License for more details.
10 *
11 * You should have received a copy of the GNU General Public License
12 * along with this program; if not, write to the Free Software
13 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
14 */
15
16 #ifndef __KVM_IODEV_H__
17 #define __KVM_IODEV_H__
18
19 #include <linux/kvm_types.h>
20 #include <asm/errno.h>
21
22 struct kvm_io_device;
23
24 /**
25 * kvm_io_device_ops are called under kvm slots_lock.
26 * read and write handlers return 0 if the transaction has been handled,
27 * or non-zero to have it passed to the next device.
28 **/
29 struct kvm_io_device_ops {
30 int (*read)(struct kvm_io_device *this,
31 gpa_t addr,
32 int len,
33 void *val);
34 int (*write)(struct kvm_io_device *this,
35 gpa_t addr,
36 int len,
37 const void *val);
38 void (*destructor)(struct kvm_io_device *this);
39 };
40
41
42 struct kvm_io_device {
43 const struct kvm_io_device_ops *ops;
44 };
45
kvm_iodevice_init(struct kvm_io_device * dev,const struct kvm_io_device_ops * ops)46 static inline void kvm_iodevice_init(struct kvm_io_device *dev,
47 const struct kvm_io_device_ops *ops)
48 {
49 dev->ops = ops;
50 }
51
kvm_iodevice_read(struct kvm_io_device * dev,gpa_t addr,int l,void * v)52 static inline int kvm_iodevice_read(struct kvm_io_device *dev,
53 gpa_t addr, int l, void *v)
54 {
55 return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
56 }
57
kvm_iodevice_write(struct kvm_io_device * dev,gpa_t addr,int l,const void * v)58 static inline int kvm_iodevice_write(struct kvm_io_device *dev,
59 gpa_t addr, int l, const void *v)
60 {
61 return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
62 }
63
kvm_iodevice_destructor(struct kvm_io_device * dev)64 static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
65 {
66 if (dev->ops->destructor)
67 dev->ops->destructor(dev);
68 }
69
70 #endif /* __KVM_IODEV_H__ */
71