linux-stable/include/kvm/iodev.h
Wei Wang 5ea5ca3c2b KVM: destruct kvm_io_device while unregistering it from kvm_io_bus
Current usage of kvm_io_device requires users to destruct it with an extra
call of kvm_iodevice_destructor after the device gets unregistered from
kvm_io_bus. This is not necessary and can cause errors if a user forgot
to make the extra call.

Simplify the usage by combining kvm_iodevice_destructor into
kvm_io_bus_unregister_dev. This reduces LOCs a bit for users and can
avoid the leakage of destructing the device explicitly.

Signed-off-by: Wei Wang <wei.w.wang@intel.com>
Reviewed-by: Sean Christopherson <seanjc@google.com>
Link: https://lore.kernel.org/r/20230207123713.3905-2-wei.w.wang@intel.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2023-06-13 14:18:09 -07:00

59 lines
1.4 KiB
C

/* 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__ */