iodev.h

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/* SPDX-License-Identifier: GPL-2.0-only */
 
#ifndef __KVM_IODEV_H__
#define __KVM_IODEV_H__
 
#include <linux/kvm_types.h>
#include <linux/errno.h>
 
struct kvm_io_device;
struct kvm_vcpu;
 
/**
 * 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_vcpu *vcpu,
            struct kvm_io_device *this,
            gpa_t addr,
            int len,
            void *val);
    int (*write)(struct kvm_vcpu *vcpu,
             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_vcpu *vcpu,
                    struct kvm_io_device *dev, gpa_t addr,
                    int l, void *v)
{
    return dev->ops->read ? dev->ops->read(vcpu, dev, addr, l, v)
                : -EOPNOTSUPP;
}
 
static inline int kvm_iodevice_write(struct kvm_vcpu *vcpu,
                     struct kvm_io_device *dev, gpa_t addr,
                     int l, const void *v)
{
    return dev->ops->write ? dev->ops->write(vcpu, dev, addr, l, v)
                 : -EOPNOTSUPP;
}
 
#endif /* __KVM_IODEV_H__ */