include/kvm/iodev.h

   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
  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
  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
  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
  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__ */