LXR linux/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
  21struct kvm_io_device;
  22struct 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 **/
  29struct 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
  44struct kvm_io_device {
  45        const struct kvm_io_device_ops *ops;
  46};
  47
  48static 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
  54static 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
  62static 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
  70static 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