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, see <http://www.gnu.org/licenses/>.
13  */
14 
15 #ifndef __KVM_IODEV_H__
16 #define __KVM_IODEV_H__
17 
18 #include <linux/kvm_types.h>
19 #include <linux/errno.h>
20 
21 struct kvm_io_device;
22 struct kvm_vcpu;
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_vcpu *vcpu,
31 		    struct kvm_io_device *this,
32 		    gpa_t addr,
33 		    int len,
34 		    void *val);
35 	int (*write)(struct kvm_vcpu *vcpu,
36 		     struct kvm_io_device *this,
37 		     gpa_t addr,
38 		     int len,
39 		     const void *val);
40 	void (*destructor)(struct kvm_io_device *this);
41 };
42 
43 
44 struct kvm_io_device {
45 	const struct kvm_io_device_ops *ops;
46 };
47 
kvm_iodevice_init(struct kvm_io_device * dev,const struct kvm_io_device_ops * ops)48 static inline void kvm_iodevice_init(struct kvm_io_device *dev,
49 				     const struct kvm_io_device_ops *ops)
50 {
51 	dev->ops = ops;
52 }
53 
kvm_iodevice_read(struct kvm_vcpu * vcpu,struct kvm_io_device * dev,gpa_t addr,int l,void * v)54 static inline int kvm_iodevice_read(struct kvm_vcpu *vcpu,
55 				    struct kvm_io_device *dev, gpa_t addr,
56 				    int l, void *v)
57 {
58 	return dev->ops->read ? dev->ops->read(vcpu, dev, addr, l, v)
59 				: -EOPNOTSUPP;
60 }
61 
kvm_iodevice_write(struct kvm_vcpu * vcpu,struct kvm_io_device * dev,gpa_t addr,int l,const void * v)62 static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu,
63 				     struct kvm_io_device *dev, gpa_t addr,
64 				     int l, const void *v)
65 {
66 	return dev->ops->write ? dev->ops->write(vcpu, dev, addr, l, v)
67 				 : -EOPNOTSUPP;
68 }
69 
kvm_iodevice_destructor(struct kvm_io_device * dev)70 static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
71 {
72 	if (dev->ops->destructor)
73 		dev->ops->destructor(dev);
74 }
75 
76 #endif /* __KVM_IODEV_H__ */
77