text: /*
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   */
  
  #ifndef __KVM_IODEV_H__
  #define __KVM_IODEV_H__
  
  #include <linux/kvm_types.h>
  #include <asm/errno.h>
  
  struct kvm_io_device;
  
  /**
   * kvm_io_device_ops are called under kvm slots_lock.
   * read and write handlers return 0 if the transaction has been handled,
   * or non-zero to have it passed to the next device.
   **/
  struct kvm_io_device_ops {
  	int (*read)(struct kvm_io_device *this,
  		    gpa_t addr,
  		    int len,
  		    void *val);
  	int (*write)(struct kvm_io_device *this,
  		     gpa_t addr,
  		     int len,
  		     const void *val);
  	void (*destructor)(struct kvm_io_device *this);
  };
  
  struct kvm_io_device {
  	const struct kvm_io_device_ops *ops;
  };
  
  static inline void kvm_iodevice_init(struct kvm_io_device *dev,
  				     const struct kvm_io_device_ops *ops)
  {
  	dev->ops = ops;
  }
  
  static inline int kvm_iodevice_read(struct kvm_io_device *dev,
  				    gpa_t addr, int l, void *v)
  {
  	return dev->ops->read ? dev->ops->read(dev, addr, l, v) : -EOPNOTSUPP;
  }
  
  static inline int kvm_iodevice_write(struct kvm_io_device *dev,
  				     gpa_t addr, int l, const void *v)
  {
  	return dev->ops->write ? dev->ops->write(dev, addr, l, v) : -EOPNOTSUPP;
  }
  
  static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
  {
  	if (dev->ops->destructor)
  		dev->ops->destructor(dev);
  }
  
  #endif /* __KVM_IODEV_H__ */
  