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From:   Jason Wang <jasowang@redhat.com>
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        christophe.de.dinechin@gmail.com, kevin.tian@intel.com,
        stefanha@redhat.com, Jason Wang <jasowang@redhat.com>
Subject: [PATCH V6 3/6] mdev: introduce device specific ops
Date:   Wed, 30 Oct 2019 14:44:41 +0800
Message-Id: <20191030064444.21166-4-jasowang@redhat.com>
In-Reply-To: <20191030064444.21166-1-jasowang@redhat.com>
References: <20191030064444.21166-1-jasowang@redhat.com>
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Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

Currently, except for the create and remove, the rest of
mdev_parent_ops is designed for vfio-mdev driver only and may not help
for kernel mdev driver. With the help of class id, this patch
introduces device specific callbacks inside mdev_device
structure. This allows different set of callback to be used by
vfio-mdev and virtio-mdev.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 .../driver-api/vfio-mediated-device.rst       | 35 +++++++++----
 MAINTAINERS                                   |  1 +
 drivers/gpu/drm/i915/gvt/kvmgt.c              | 18 ++++---
 drivers/s390/cio/vfio_ccw_ops.c               | 18 ++++---
 drivers/s390/crypto/vfio_ap_ops.c             | 14 +++--
 drivers/vfio/mdev/mdev_core.c                 | 25 ++++++++-
 drivers/vfio/mdev/mdev_private.h              |  5 ++
 drivers/vfio/mdev/vfio_mdev.c                 | 37 ++++++-------
 include/linux/mdev.h                          | 43 ++++-----------
 include/linux/vfio_mdev_ops.h                 | 52 +++++++++++++++++++
 samples/vfio-mdev/mbochs.c                    | 20 ++++---
 samples/vfio-mdev/mdpy.c                      | 20 ++++---
 samples/vfio-mdev/mtty.c                      | 18 ++++---
 13 files changed, 206 insertions(+), 100 deletions(-)
 create mode 100644 include/linux/vfio_mdev_ops.h

diff --git a/Documentation/driver-api/vfio-mediated-device.rst b/Documentat=
ion/driver-api/vfio-mediated-device.rst
index 6709413bee29..0d8f9e7d7983 100644
--- a/Documentation/driver-api/vfio-mediated-device.rst
+++ b/Documentation/driver-api/vfio-mediated-device.rst
@@ -152,15 +152,6 @@ callbacks per mdev parent device, per mdev type, or an=
y other categorization.
 Vendor drivers are expected to be fully asynchronous in this respect or
 provide their own internal resource protection.)
=20
-The callbacks in the mdev_parent_ops structure are as follows:
-
-* open: open callback of mediated device
-* close: close callback of mediated device
-* ioctl: ioctl callback of mediated device
-* read : read emulation callback
-* write: write emulation callback
-* mmap: mmap emulation callback
-
 A driver should use the mdev_parent_ops structure in the function call to
 register itself with the mdev core driver::
=20
@@ -172,10 +163,34 @@ that a driver should use to unregister itself with th=
e mdev core driver::
=20
 =09extern void mdev_unregister_device(struct device *dev);
=20
-It is also required to specify the class_id in create() callback through::
+As multiple types of mediated devices may be supported, class id needs
+to be specified in the create callback(). This could be done
+explicitly for the device that does not use on mdev bus for its
+operation through:
=20
 =09int mdev_set_class(struct mdev_device *mdev, u16 id);
=20
+For the device that uses on the mdev bus for its operation, the class
+should provide helper function to set class id and device specific
+ops. E.g for vfio-mdev devices, the function to be called is::
+
+=09int mdev_set_vfio_ops(struct mdev_device *mdev,
+                              const struct vfio_mdev_ops *vfio_ops);
+
+The class id (set by this function to MDEV_CLASS_ID_VFIO) is used to
+match a device with an mdev driver via its id table. The device
+specific callbacks (specified in *vfio_ops) are obtainable via
+mdev_get_vfio_ops() (for use by the mdev bus driver). A vfio-mdev
+device (class id MDEV_CLASS_ID_VFIO) uses the following
+device-specific ops:
+
+* open: open callback of vfio mediated device
+* close: close callback of vfio mediated device
+* ioctl: ioctl callback of vfio mediated device
+* read : read emulation callback
+* write: write emulation callback
+* mmap: mmap emulation callback
+
 Mediated Device Management Interface Through sysfs
 =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D
=20
diff --git a/MAINTAINERS b/MAINTAINERS
index e51a68bf8ca8..9e10ae9c2b4d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -17121,6 +17121,7 @@ S:=09Maintained
 F:=09Documentation/driver-api/vfio-mediated-device.rst
 F:=09drivers/vfio/mdev/
 F:=09include/linux/mdev.h
+F:=09include/linux/vfio_mdev_ops.h
 F:=09samples/vfio-mdev/
=20
 VFIO PLATFORM DRIVER
diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kv=
mgt.c
index 6420f0dbd31b..c2b7f9dbe4d1 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -42,6 +42,7 @@
 #include <linux/kvm_host.h>
 #include <linux/vfio.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/debugfs.h>
=20
 #include <linux/nospec.h>
@@ -643,6 +644,8 @@ static void kvmgt_put_vfio_device(void *vgpu)
 =09vfio_device_put(((struct intel_vgpu *)vgpu)->vdev.vfio_device);
 }
=20
+static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops;
+
 static int intel_vgpu_create(struct kobject *kobj, struct mdev_device *mde=
v)
 {
 =09struct intel_vgpu *vgpu =3D NULL;
@@ -678,7 +681,7 @@ static int intel_vgpu_create(struct kobject *kobj, stru=
ct mdev_device *mdev)
 =09=09     dev_name(mdev_dev(mdev)));
 =09ret =3D 0;
=20
-=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev_set_vfio_ops(mdev, &intel_vfio_vgpu_dev_ops);
 out:
 =09return ret;
 }
@@ -1599,20 +1602,21 @@ static const struct attribute_group *intel_vgpu_gro=
ups[] =3D {
 =09NULL,
 };
=20
-static struct mdev_parent_ops intel_vgpu_ops =3D {
-=09.mdev_attr_groups       =3D intel_vgpu_groups,
-=09.create=09=09=09=3D intel_vgpu_create,
-=09.remove=09=09=09=3D intel_vgpu_remove,
-
+static const struct vfio_mdev_device_ops intel_vfio_vgpu_dev_ops =3D {
 =09.open=09=09=09=3D intel_vgpu_open,
 =09.release=09=09=3D intel_vgpu_release,
-
 =09.read=09=09=09=3D intel_vgpu_read,
 =09.write=09=09=09=3D intel_vgpu_write,
 =09.mmap=09=09=09=3D intel_vgpu_mmap,
 =09.ioctl=09=09=09=3D intel_vgpu_ioctl,
 };
=20
+static struct mdev_parent_ops intel_vgpu_ops =3D {
+=09.mdev_attr_groups       =3D intel_vgpu_groups,
+=09.create=09=09=09=3D intel_vgpu_create,
+=09.remove=09=09=09=3D intel_vgpu_remove,
+};
+
 static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
 {
 =09struct attribute **kvm_type_attrs;
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_op=
s.c
index cf2c013ae32f..c36e6ca9ee65 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -12,6 +12,7 @@
=20
 #include <linux/vfio.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/nospec.h>
 #include <linux/slab.h>
=20
@@ -110,6 +111,8 @@ static struct attribute_group *mdev_type_groups[] =3D {
 =09NULL,
 };
=20
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
 static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *=
mdev)
 {
 =09struct vfio_ccw_private *private =3D
@@ -129,7 +132,7 @@ static int vfio_ccw_mdev_create(struct kobject *kobj, s=
truct mdev_device *mdev)
 =09=09=09   private->sch->schid.ssid,
 =09=09=09   private->sch->schid.sch_no);
=20
-=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
 =09return 0;
 }
=20
@@ -575,11 +578,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device =
*mdev,
 =09}
 }
=20
-static const struct mdev_parent_ops vfio_ccw_mdev_ops =3D {
-=09.owner=09=09=09=3D THIS_MODULE,
-=09.supported_type_groups  =3D mdev_type_groups,
-=09.create=09=09=09=3D vfio_ccw_mdev_create,
-=09.remove=09=09=09=3D vfio_ccw_mdev_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops =3D {
 =09.open=09=09=09=3D vfio_ccw_mdev_open,
 =09.release=09=09=3D vfio_ccw_mdev_release,
 =09.read=09=09=09=3D vfio_ccw_mdev_read,
@@ -587,6 +586,13 @@ static const struct mdev_parent_ops vfio_ccw_mdev_ops =
=3D {
 =09.ioctl=09=09=09=3D vfio_ccw_mdev_ioctl,
 };
=20
+static const struct mdev_parent_ops vfio_ccw_mdev_ops =3D {
+=09.owner=09=09=09=3D THIS_MODULE,
+=09.supported_type_groups  =3D mdev_type_groups,
+=09.create=09=09=09=3D vfio_ccw_mdev_create,
+=09.remove=09=09=09=3D vfio_ccw_mdev_remove,
+};
+
 int vfio_ccw_mdev_reg(struct subchannel *sch)
 {
 =09return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_a=
p_ops.c
index 07c31070afeb..ed68d4f7c0a9 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -16,6 +16,7 @@
 #include <linux/bitops.h>
 #include <linux/kvm_host.h>
 #include <linux/module.h>
+#include <linux/vfio_mdev_ops.h>
 #include <asm/kvm.h>
 #include <asm/zcrypt.h>
=20
@@ -321,6 +322,8 @@ static void vfio_ap_matrix_init(struct ap_config_info *=
info,
 =09matrix->adm_max =3D info->apxa ? info->Nd : 15;
 }
=20
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
 static int vfio_ap_mdev_create(struct kobject *kobj, struct mdev_device *m=
dev)
 {
 =09struct ap_matrix_mdev *matrix_mdev;
@@ -343,7 +346,7 @@ static int vfio_ap_mdev_create(struct kobject *kobj, st=
ruct mdev_device *mdev)
 =09list_add(&matrix_mdev->node, &matrix_dev->mdev_list);
 =09mutex_unlock(&matrix_dev->lock);
=20
-=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
 =09return 0;
 }
=20
@@ -1281,15 +1284,18 @@ static ssize_t vfio_ap_mdev_ioctl(struct mdev_devic=
e *mdev,
 =09return ret;
 }
=20
+static const struct vfio_mdev_device_ops vfio_mdev_ops =3D {
+=09.open=09=09=09=3D vfio_ap_mdev_open,
+=09.release=09=09=3D vfio_ap_mdev_release,
+=09.ioctl=09=09=09=3D vfio_ap_mdev_ioctl,
+};
+
 static const struct mdev_parent_ops vfio_ap_matrix_ops =3D {
 =09.owner=09=09=09=3D THIS_MODULE,
 =09.supported_type_groups=09=3D vfio_ap_mdev_type_groups,
 =09.mdev_attr_groups=09=3D vfio_ap_mdev_attr_groups,
 =09.create=09=09=09=3D vfio_ap_mdev_create,
 =09.remove=09=09=09=3D vfio_ap_mdev_remove,
-=09.open=09=09=09=3D vfio_ap_mdev_open,
-=09.release=09=09=3D vfio_ap_mdev_release,
-=09.ioctl=09=09=09=3D vfio_ap_mdev_ioctl,
 };
=20
 int vfio_ap_mdev_register(void)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index d23ca39e3be6..ab6cf5a5ff9f 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -45,9 +45,10 @@ void mdev_set_drvdata(struct mdev_device *mdev, void *da=
ta)
 }
 EXPORT_SYMBOL(mdev_set_drvdata);
=20
+
 /* Specify the class for the mdev device, this must be called during
- * create() callback.
- */
+ * create() callback explicitly or implicity through the helpers
+ * provided by each class. */
 void mdev_set_class(struct mdev_device *mdev, u16 id)
 {
 =09WARN_ON(mdev->class_id);
@@ -55,6 +56,26 @@ void mdev_set_class(struct mdev_device *mdev, u16 id)
 }
 EXPORT_SYMBOL(mdev_set_class);
=20
+/* Specify the mdev device to be a VFIO mdev device, and set VFIO
+ * device ops for it. This must be called from the create() callback
+ * for VFIO mdev device.
+ */
+void mdev_set_vfio_ops(struct mdev_device *mdev,
+=09=09       const struct vfio_mdev_device_ops *vfio_ops)
+{
+=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev->vfio_ops =3D vfio_ops;
+}
+EXPORT_SYMBOL(mdev_set_vfio_ops);
+
+/* Get the VFIO device ops for the mdev device. */
+const struct vfio_mdev_device_ops *mdev_get_vfio_ops(struct mdev_device *m=
dev)
+{
+=09WARN_ON(mdev->class_id !=3D MDEV_CLASS_ID_VFIO);
+=09return mdev->vfio_ops;
+}
+EXPORT_SYMBOL(mdev_get_vfio_ops);
+
 struct device *mdev_dev(struct mdev_device *mdev)
 {
 =09return &mdev->dev;
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_priv=
ate.h
index c65f436c1869..0770410ded2a 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -10,6 +10,8 @@
 #ifndef MDEV_PRIVATE_H
 #define MDEV_PRIVATE_H
=20
+#include <linux/vfio_mdev_ops.h>
+
 int  mdev_bus_register(void);
 void mdev_bus_unregister(void);
=20
@@ -34,6 +36,9 @@ struct mdev_device {
 =09struct device *iommu_device;
 =09bool active;
 =09u16 class_id;
+=09union {
+=09=09const struct vfio_mdev_device_ops *vfio_ops;
+=09};
 };
=20
 #define to_mdev_device(dev)=09container_of(dev, struct mdev_device, dev)
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index a6641cd8b5a3..1e30f086071a 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -14,6 +14,7 @@
 #include <linux/slab.h>
 #include <linux/vfio.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
=20
 #include "mdev_private.h"
=20
@@ -24,16 +25,16 @@
 static int vfio_mdev_open(void *device_data)
 {
 =09struct mdev_device *mdev =3D device_data;
-=09struct mdev_parent *parent =3D mdev->parent;
+=09const struct vfio_mdev_device_ops *ops =3D mdev_get_vfio_ops(mdev);
 =09int ret;
=20
-=09if (unlikely(!parent->ops->open))
+=09if (unlikely(!ops->open))
 =09=09return -EINVAL;
=20
 =09if (!try_module_get(THIS_MODULE))
 =09=09return -ENODEV;
=20
-=09ret =3D parent->ops->open(mdev);
+=09ret =3D ops->open(mdev);
 =09if (ret)
 =09=09module_put(THIS_MODULE);
=20
@@ -43,10 +44,10 @@ static int vfio_mdev_open(void *device_data)
 static void vfio_mdev_release(void *device_data)
 {
 =09struct mdev_device *mdev =3D device_data;
-=09struct mdev_parent *parent =3D mdev->parent;
+=09const struct vfio_mdev_device_ops *ops =3D mdev_get_vfio_ops(mdev);
=20
-=09if (likely(parent->ops->release))
-=09=09parent->ops->release(mdev);
+=09if (likely(ops->release))
+=09=09ops->release(mdev);
=20
 =09module_put(THIS_MODULE);
 }
@@ -55,47 +56,47 @@ static long vfio_mdev_unlocked_ioctl(void *device_data,
 =09=09=09=09     unsigned int cmd, unsigned long arg)
 {
 =09struct mdev_device *mdev =3D device_data;
-=09struct mdev_parent *parent =3D mdev->parent;
+=09const struct vfio_mdev_device_ops *ops =3D mdev_get_vfio_ops(mdev);
=20
-=09if (unlikely(!parent->ops->ioctl))
+=09if (unlikely(!ops->ioctl))
 =09=09return -EINVAL;
=20
-=09return parent->ops->ioctl(mdev, cmd, arg);
+=09return ops->ioctl(mdev, cmd, arg);
 }
=20
 static ssize_t vfio_mdev_read(void *device_data, char __user *buf,
 =09=09=09      size_t count, loff_t *ppos)
 {
 =09struct mdev_device *mdev =3D device_data;
-=09struct mdev_parent *parent =3D mdev->parent;
+=09const struct vfio_mdev_device_ops *ops =3D mdev_get_vfio_ops(mdev);
=20
-=09if (unlikely(!parent->ops->read))
+=09if (unlikely(!ops->read))
 =09=09return -EINVAL;
=20
-=09return parent->ops->read(mdev, buf, count, ppos);
+=09return ops->read(mdev, buf, count, ppos);
 }
=20
 static ssize_t vfio_mdev_write(void *device_data, const char __user *buf,
 =09=09=09       size_t count, loff_t *ppos)
 {
 =09struct mdev_device *mdev =3D device_data;
-=09struct mdev_parent *parent =3D mdev->parent;
+=09const struct vfio_mdev_device_ops *ops =3D mdev_get_vfio_ops(mdev);
=20
-=09if (unlikely(!parent->ops->write))
+=09if (unlikely(!ops->write))
 =09=09return -EINVAL;
=20
-=09return parent->ops->write(mdev, buf, count, ppos);
+=09return ops->write(mdev, buf, count, ppos);
 }
=20
 static int vfio_mdev_mmap(void *device_data, struct vm_area_struct *vma)
 {
 =09struct mdev_device *mdev =3D device_data;
-=09struct mdev_parent *parent =3D mdev->parent;
+=09const struct vfio_mdev_device_ops *ops =3D mdev_get_vfio_ops(mdev);
=20
-=09if (unlikely(!parent->ops->mmap))
+=09if (unlikely(!ops->mmap))
 =09=09return -EINVAL;
=20
-=09return parent->ops->mmap(mdev, vma);
+=09return ops->mmap(mdev, vma);
 }
=20
 static const struct vfio_device_ops vfio_mdev_dev_ops =3D {
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 78b69d09eb54..4625f1a11014 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -10,7 +10,13 @@
 #ifndef MDEV_H
 #define MDEV_H
=20
+#include <linux/types.h>
+#include <linux/device.h>
+#include <linux/mdev.h>
+#include <uapi/linux/uuid.h>
+
 struct mdev_device;
+struct vfio_mdev_device_ops;
=20
 /*
  * Called by the parent device driver to set the device which represents
@@ -48,30 +54,7 @@ struct device *mdev_get_iommu_device(struct device *dev)=
;
  *=09=09=09@mdev: mdev_device device structure which is being
  *=09=09=09       destroyed
  *=09=09=09Returns integer: success (0) or error (< 0)
- * @open:=09=09Open mediated device.
- *=09=09=09@mdev: mediated device.
- *=09=09=09Returns integer: success (0) or error (< 0)
- * @release:=09=09release mediated device
- *=09=09=09@mdev: mediated device.
- * @read:=09=09Read emulation callback
- *=09=09=09@mdev: mediated device structure
- *=09=09=09@buf: read buffer
- *=09=09=09@count: number of bytes to read
- *=09=09=09@ppos: address.
- *=09=09=09Retuns number on bytes read on success or error.
- * @write:=09=09Write emulation callback
- *=09=09=09@mdev: mediated device structure
- *=09=09=09@buf: write buffer
- *=09=09=09@count: number of bytes to be written
- *=09=09=09@ppos: address.
- *=09=09=09Retuns number on bytes written on success or error.
- * @ioctl:=09=09IOCTL callback
- *=09=09=09@mdev: mediated device structure
- *=09=09=09@cmd: ioctl command
- *=09=09=09@arg: arguments to ioctl
- * @mmap:=09=09mmap callback
- *=09=09=09@mdev: mediated device structure
- *=09=09=09@vma: vma structure
+ *
  * Parent device that support mediated device should be registered with md=
ev
  * module with mdev_parent_ops structure.
  **/
@@ -83,15 +66,6 @@ struct mdev_parent_ops {
=20
 =09int     (*create)(struct kobject *kobj, struct mdev_device *mdev);
 =09int     (*remove)(struct mdev_device *mdev);
-=09int     (*open)(struct mdev_device *mdev);
-=09void    (*release)(struct mdev_device *mdev);
-=09ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
-=09=09=09size_t count, loff_t *ppos);
-=09ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
-=09=09=09 size_t count, loff_t *ppos);
-=09long=09(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
-=09=09=09 unsigned long arg);
-=09int=09(*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
 };
=20
 /* interface for exporting mdev supported type attributes */
@@ -135,6 +109,9 @@ void *mdev_get_drvdata(struct mdev_device *mdev);
 void mdev_set_drvdata(struct mdev_device *mdev, void *data);
 const guid_t *mdev_uuid(struct mdev_device *mdev);
 void mdev_set_class(struct mdev_device *mdev, u16 id);
+void mdev_set_vfio_ops(struct mdev_device *mdev,
+=09=09       const struct vfio_mdev_device_ops *vfio_ops);
+const struct vfio_mdev_device_ops *mdev_get_vfio_ops(struct mdev_device *m=
dev);
=20
 extern struct bus_type mdev_bus_type;
=20
diff --git a/include/linux/vfio_mdev_ops.h b/include/linux/vfio_mdev_ops.h
new file mode 100644
index 000000000000..3907c5371c2b
--- /dev/null
+++ b/include/linux/vfio_mdev_ops.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * VFIO Mediated device definition
+ */
+
+#ifndef VFIO_MDEV_H
+#define VFIO_MDEV_H
+
+#include <linux/mdev.h>
+
+/**
+ * struct vfio_mdev_device_ops - Structure to be registered for each
+ * mdev device to register the device to vfio-mdev module.
+ *
+ * @open:=09=09Open mediated device.
+ *=09=09=09@mdev: mediated device.
+ *=09=09=09Returns integer: success (0) or error (< 0)
+ * @release:=09=09release mediated device
+ *=09=09=09@mdev: mediated device.
+ * @read:=09=09Read emulation callback
+ *=09=09=09@mdev: mediated device structure
+ *=09=09=09@buf: read buffer
+ *=09=09=09@count: number of bytes to read
+ *=09=09=09@ppos: address.
+ *=09=09=09Retuns number on bytes read on success or error.
+ * @write:=09=09Write emulation callback
+ *=09=09=09@mdev: mediated device structure
+ *=09=09=09@buf: write buffer
+ *=09=09=09@count: number of bytes to be written
+ *=09=09=09@ppos: address.
+ *=09=09=09Retuns number on bytes written on success or error.
+ * @ioctl:=09=09IOCTL callback
+ *=09=09=09@mdev: mediated device structure
+ *=09=09=09@cmd: ioctl command
+ *=09=09=09@arg: arguments to ioctl
+ * @mmap:=09=09mmap callback
+ *=09=09=09@mdev: mediated device structure
+ *=09=09=09@vma: vma structure
+ */
+struct vfio_mdev_device_ops {
+=09int     (*open)(struct mdev_device *mdev);
+=09void    (*release)(struct mdev_device *mdev);
+=09ssize_t (*read)(struct mdev_device *mdev, char __user *buf,
+=09=09=09size_t count, loff_t *ppos);
+=09ssize_t (*write)(struct mdev_device *mdev, const char __user *buf,
+=09=09=09 size_t count, loff_t *ppos);
+=09long=09(*ioctl)(struct mdev_device *mdev, unsigned int cmd,
+=09=09=09 unsigned long arg);
+=09int=09(*mmap)(struct mdev_device *mdev, struct vm_area_struct *vma);
+};
+
+#endif
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index 115bc5074656..1afec20bf0c5 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -30,6 +30,7 @@
 #include <linux/iommu.h>
 #include <linux/sysfs.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/pci.h>
 #include <linux/dma-buf.h>
 #include <linux/highmem.h>
@@ -516,6 +517,8 @@ static int mbochs_reset(struct mdev_device *mdev)
 =09return 0;
 }
=20
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
 static int mbochs_create(struct kobject *kobj, struct mdev_device *mdev)
 {
 =09const struct mbochs_type *type =3D mbochs_find_type(kobj);
@@ -561,7 +564,7 @@ static int mbochs_create(struct kobject *kobj, struct m=
dev_device *mdev)
 =09mbochs_reset(mdev);
=20
 =09mbochs_used_mbytes +=3D type->mbytes;
-=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
 =09return 0;
=20
 err_mem:
@@ -1419,12 +1422,7 @@ static struct attribute_group *mdev_type_groups[] =
=3D {
 =09NULL,
 };
=20
-static const struct mdev_parent_ops mdev_fops =3D {
-=09.owner=09=09=09=3D THIS_MODULE,
-=09.mdev_attr_groups=09=3D mdev_dev_groups,
-=09.supported_type_groups=09=3D mdev_type_groups,
-=09.create=09=09=09=3D mbochs_create,
-=09.remove=09=09=09=3D mbochs_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops =3D {
 =09.open=09=09=09=3D mbochs_open,
 =09.release=09=09=3D mbochs_close,
 =09.read=09=09=09=3D mbochs_read,
@@ -1433,6 +1431,14 @@ static const struct mdev_parent_ops mdev_fops =3D {
 =09.mmap=09=09=09=3D mbochs_mmap,
 };
=20
+static const struct mdev_parent_ops mdev_fops =3D {
+=09.owner=09=09=09=3D THIS_MODULE,
+=09.mdev_attr_groups=09=3D mdev_dev_groups,
+=09.supported_type_groups=09=3D mdev_type_groups,
+=09.create=09=09=09=3D mbochs_create,
+=09.remove=09=09=09=3D mbochs_remove,
+};
+
 static const struct file_operations vd_fops =3D {
 =09.owner=09=09=3D THIS_MODULE,
 };
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 665614574d50..d571fb65f50f 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -26,6 +26,7 @@
 #include <linux/iommu.h>
 #include <linux/sysfs.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/pci.h>
 #include <drm/drm_fourcc.h>
 #include "mdpy-defs.h"
@@ -226,6 +227,8 @@ static int mdpy_reset(struct mdev_device *mdev)
 =09return 0;
 }
=20
+static const struct vfio_mdev_device_ops vfio_mdev_ops;
+
 static int mdpy_create(struct kobject *kobj, struct mdev_device *mdev)
 {
 =09const struct mdpy_type *type =3D mdpy_find_type(kobj);
@@ -269,7 +272,7 @@ static int mdpy_create(struct kobject *kobj, struct mde=
v_device *mdev)
 =09mdpy_reset(mdev);
=20
 =09mdpy_count++;
-=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev_set_vfio_ops(mdev, &vfio_mdev_ops);
 =09return 0;
 }
=20
@@ -726,12 +729,7 @@ static struct attribute_group *mdev_type_groups[] =3D =
{
 =09NULL,
 };
=20
-static const struct mdev_parent_ops mdev_fops =3D {
-=09.owner=09=09=09=3D THIS_MODULE,
-=09.mdev_attr_groups=09=3D mdev_dev_groups,
-=09.supported_type_groups=09=3D mdev_type_groups,
-=09.create=09=09=09=3D mdpy_create,
-=09.remove=09=09=09=3D mdpy_remove,
+static const struct vfio_mdev_device_ops vfio_mdev_ops =3D {
 =09.open=09=09=09=3D mdpy_open,
 =09.release=09=09=3D mdpy_close,
 =09.read=09=09=09=3D mdpy_read,
@@ -740,6 +738,14 @@ static const struct mdev_parent_ops mdev_fops =3D {
 =09.mmap=09=09=09=3D mdpy_mmap,
 };
=20
+static const struct mdev_parent_ops mdev_fops =3D {
+=09.owner=09=09=09=3D THIS_MODULE,
+=09.mdev_attr_groups=09=3D mdev_dev_groups,
+=09.supported_type_groups=09=3D mdev_type_groups,
+=09.create=09=09=09=3D mdpy_create,
+=09.remove=09=09=09=3D mdpy_remove,
+};
+
 static const struct file_operations vd_fops =3D {
 =09.owner=09=09=3D THIS_MODULE,
 };
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 90da12ff7fd9..4048b242c636 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -27,6 +27,7 @@
 #include <linux/ctype.h>
 #include <linux/file.h>
 #include <linux/mdev.h>
+#include <linux/vfio_mdev_ops.h>
 #include <linux/pci.h>
 #include <linux/serial.h>
 #include <uapi/linux/serial_reg.h>
@@ -708,6 +709,8 @@ static ssize_t mdev_access(struct mdev_device *mdev, u8=
 *buf, size_t count,
 =09return ret;
 }
=20
+static const struct vfio_mdev_device_ops vfio_dev_ops;
+
 static int mtty_create(struct kobject *kobj, struct mdev_device *mdev)
 {
 =09struct mdev_state *mdev_state;
@@ -755,7 +758,7 @@ static int mtty_create(struct kobject *kobj, struct mde=
v_device *mdev)
 =09list_add(&mdev_state->next, &mdev_devices_list);
 =09mutex_unlock(&mdev_list_lock);
=20
-=09mdev_set_class(mdev, MDEV_CLASS_ID_VFIO);
+=09mdev_set_vfio_ops(mdev, &vfio_dev_ops);
 =09return 0;
 }
=20
@@ -1388,6 +1391,14 @@ static struct attribute_group *mdev_type_groups[] =
=3D {
 =09NULL,
 };
=20
+static const struct vfio_mdev_device_ops vfio_dev_ops =3D {
+=09.open=09=09=3D mtty_open,
+=09.release=09=3D mtty_close,
+=09.read=09=09=3D mtty_read,
+=09.write=09=09=3D mtty_write,
+=09.ioctl=09=09=3D mtty_ioctl,
+};
+
 static const struct mdev_parent_ops mdev_fops =3D {
 =09.owner                  =3D THIS_MODULE,
 =09.dev_attr_groups        =3D mtty_dev_groups,
@@ -1395,11 +1406,6 @@ static const struct mdev_parent_ops mdev_fops =3D {
 =09.supported_type_groups  =3D mdev_type_groups,
 =09.create                 =3D mtty_create,
 =09.remove=09=09=09=3D mtty_remove,
-=09.open                   =3D mtty_open,
-=09.release                =3D mtty_close,
-=09.read                   =3D mtty_read,
-=09.write                  =3D mtty_write,
-=09.ioctl=09=09        =3D mtty_ioctl,
 };
=20
 static void mtty_device_release(struct device *dev)
--=20
2.19.1