include/kvm/iodev.h

   1 /* SPDX-License-Identifier: GPL-2.0-only */
   2
   3 #ifndef __KVM_IODEV_H__
   4 #define __KVM_IODEV_H__
   5
   6 #include <linux/kvm_types.h>
   7 #include <linux/errno.h>
   8
   9 struct kvm_io_device;
  10 struct kvm_vcpu;
  11
  12 /**
  13  * kvm_io_device_ops are called under kvm slots_lock.
  14  * read and write handlers return 0 if the transaction has been handled,
  15  * or non-zero to have it passed to the next device.
  16  **/
  17 struct kvm_io_device_ops {
  18         int (*read)(struct kvm_vcpu *vcpu,
  19                     struct kvm_io_device *this,
  20                     gpa_t addr,
  21                     int len,
  22                     void *val);
  23         int (*write)(struct kvm_vcpu *vcpu,
  24                      struct kvm_io_device *this,
  25                      gpa_t addr,
  26                      int len,
  27                      const void *val);
  28         void (*destructor)(struct kvm_io_device *this);
  29 };
  30
  31
  32 struct kvm_io_device {
  33         const struct kvm_io_device_ops *ops;
  34 };
  35
  36 static inline void kvm_iodevice_init(struct kvm_io_device *dev,
  37                                      const struct kvm_io_device_ops *ops)
  38 {
  39         dev->ops = ops;
  40 }
  41
  42 static inline int kvm_iodevice_read(struct kvm_vcpu *vcpu,
  43                                     struct kvm_io_device *dev, gpa_t addr,
  44                                     int l, void *v)
  45 {
  46         return dev->ops->read ? dev->ops->read(vcpu, dev, addr, l, v)
  47                                 : -EOPNOTSUPP;
  48 }
  49
  50 static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu,
  51                                      struct kvm_io_device *dev, gpa_t addr,
  52                                      int l, const void *v)
  53 {
  54         return dev->ops->write ? dev->ops->write(vcpu, dev, addr, l, v)
  55                                  : -EOPNOTSUPP;
  56 }
  57
  58 static inline void kvm_iodevice_destructor(struct kvm_io_device *dev)
  59 {
  60         if (dev->ops->destructor)
  61                 dev->ops->destructor(dev);
  62 }
  63
  64 #endif /* __KVM_IODEV_H__ */