[RFC,1/2] mdev: device id support
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Message ID 20190912094012.29653-2-jasowang@redhat.com
State New
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Series
  • Mdev: support mutiple kinds of devices
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Commit Message

Jason Wang Sept. 12, 2019, 9:40 a.m. UTC
Mdev bus only support vfio driver right now, so it doesn't implement
match method. But in the future, we may add drivers other than vfio,
one example is virtio-mdev[1] driver. This means we need to add device
id support in bus match method to pair the mdev device and mdev driver
correctly.

So this patch add id_table to mdev_driver and id for mdev parent, and
implement the match method for mdev bus.

[1] https://lkml.org/lkml/2019/9/10/135

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/gpu/drm/i915/gvt/kvmgt.c  |  2 +-
 drivers/s390/cio/vfio_ccw_ops.c   |  2 +-
 drivers/s390/crypto/vfio_ap_ops.c |  3 ++-
 drivers/vfio/mdev/mdev_core.c     | 14 ++++++++++++--
 drivers/vfio/mdev/mdev_driver.c   | 14 ++++++++++++++
 drivers/vfio/mdev/mdev_private.h  |  1 +
 drivers/vfio/mdev/vfio_mdev.c     |  6 ++++++
 include/linux/mdev.h              |  6 +++++-
 include/linux/mod_devicetable.h   |  6 ++++++
 samples/vfio-mdev/mbochs.c        |  2 +-
 samples/vfio-mdev/mdpy.c          |  2 +-
 samples/vfio-mdev/mtty.c          |  2 +-
 12 files changed, 51 insertions(+), 9 deletions(-)

Comments

Tian, Kevin Sept. 17, 2019, 7:55 a.m. UTC | #1
> From: Jason Wang
> Sent: Thursday, September 12, 2019 5:40 PM
> 
> Mdev bus only support vfio driver right now, so it doesn't implement
> match method. But in the future, we may add drivers other than vfio,
> one example is virtio-mdev[1] driver. This means we need to add device
> id support in bus match method to pair the mdev device and mdev driver
> correctly.

"device id" sound a bit confusing to me - it usually means something
unique to each device, while here it is used to indicate expected driver
types (vfio, virtio, etc.). but using "bus id" is also not good - we have
only one mdev bus here. Then what about "class id"?

> 
> So this patch add id_table to mdev_driver and id for mdev parent, and
> implement the match method for mdev bus.
> 
> [1] https://lkml.org/lkml/2019/9/10/135
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/gpu/drm/i915/gvt/kvmgt.c  |  2 +-
>  drivers/s390/cio/vfio_ccw_ops.c   |  2 +-
>  drivers/s390/crypto/vfio_ap_ops.c |  3 ++-
>  drivers/vfio/mdev/mdev_core.c     | 14 ++++++++++++--
>  drivers/vfio/mdev/mdev_driver.c   | 14 ++++++++++++++
>  drivers/vfio/mdev/mdev_private.h  |  1 +
>  drivers/vfio/mdev/vfio_mdev.c     |  6 ++++++
>  include/linux/mdev.h              |  6 +++++-
>  include/linux/mod_devicetable.h   |  6 ++++++
>  samples/vfio-mdev/mbochs.c        |  2 +-
>  samples/vfio-mdev/mdpy.c          |  2 +-
>  samples/vfio-mdev/mtty.c          |  2 +-
>  12 files changed, 51 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
> b/drivers/gpu/drm/i915/gvt/kvmgt.c
> index 23aa3e50cbf8..19d51a35f019 100644
> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
> @@ -1625,7 +1625,7 @@ static int kvmgt_host_init(struct device *dev, void
> *gvt, const void *ops)
>  		return -EFAULT;
>  	intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
> 
> -	return mdev_register_device(dev, &intel_vgpu_ops);
> +	return mdev_register_vfio_device(dev, &intel_vgpu_ops);
>  }
> 
>  static void kvmgt_host_exit(struct device *dev)
> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
> b/drivers/s390/cio/vfio_ccw_ops.c
> index 5eb61116ca6f..f87d9409e290 100644
> --- a/drivers/s390/cio/vfio_ccw_ops.c
> +++ b/drivers/s390/cio/vfio_ccw_ops.c
> @@ -578,7 +578,7 @@ static const struct mdev_parent_ops
> vfio_ccw_mdev_ops = {
> 
>  int vfio_ccw_mdev_reg(struct subchannel *sch)
>  {
> -	return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
> +	return mdev_register_vfio_device(&sch->dev,
> &vfio_ccw_mdev_ops);
>  }
> 
>  void vfio_ccw_mdev_unreg(struct subchannel *sch)
> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
> b/drivers/s390/crypto/vfio_ap_ops.c
> index 0604b49a4d32..eacbde3c7a97 100644
> --- a/drivers/s390/crypto/vfio_ap_ops.c
> +++ b/drivers/s390/crypto/vfio_ap_ops.c
> @@ -1295,7 +1295,8 @@ int vfio_ap_mdev_register(void)
>  {
>  	atomic_set(&matrix_dev->available_instances,
> MAX_ZDEV_ENTRIES_EXT);
> 
> -	return mdev_register_device(&matrix_dev->device,
> &vfio_ap_matrix_ops);
> +	return mdev_register_vfio_device(&matrix_dev->device,
> +					 &vfio_ap_matrix_ops);
>  }
> 
>  void vfio_ap_mdev_unregister(void)
> diff --git a/drivers/vfio/mdev/mdev_core.c
> b/drivers/vfio/mdev/mdev_core.c
> index b558d4cfd082..fc07ff3ebe96 100644
> --- a/drivers/vfio/mdev/mdev_core.c
> +++ b/drivers/vfio/mdev/mdev_core.c
> @@ -135,11 +135,14 @@ static int mdev_device_remove_cb(struct device
> *dev, void *data)
>   * mdev_register_device : Register a device
>   * @dev: device structure representing parent device.
>   * @ops: Parent device operation structure to be registered.
> + * @id: device id.
>   *
>   * Add device to list of registered parent devices.
>   * Returns a negative value on error, otherwise 0.
>   */
> -int mdev_register_device(struct device *dev, const struct
> mdev_parent_ops *ops)
> +int mdev_register_device(struct device *dev,
> +			 const struct mdev_parent_ops *ops,
> +			 u8 id)
>  {
>  	int ret;
>  	struct mdev_parent *parent;
> @@ -175,6 +178,7 @@ int mdev_register_device(struct device *dev, const
> struct mdev_parent_ops *ops)
> 
>  	parent->dev = dev;
>  	parent->ops = ops;
> +	parent->device_id = id;
> 
>  	if (!mdev_bus_compat_class) {
>  		mdev_bus_compat_class =
> class_compat_register("mdev_bus");
> @@ -208,7 +212,13 @@ int mdev_register_device(struct device *dev, const
> struct mdev_parent_ops *ops)
>  		put_device(dev);
>  	return ret;
>  }
> -EXPORT_SYMBOL(mdev_register_device);
> +
> +int mdev_register_vfio_device(struct device *dev,
> +			      const struct mdev_parent_ops *ops)
> +{
> +	return mdev_register_device(dev, ops, MDEV_ID_VFIO);
> +}
> +EXPORT_SYMBOL(mdev_register_vfio_device);
> 
>  /*
>   * mdev_unregister_device : Unregister a parent device
> diff --git a/drivers/vfio/mdev/mdev_driver.c
> b/drivers/vfio/mdev/mdev_driver.c
> index 0d3223aee20b..fd5e9541d18e 100644
> --- a/drivers/vfio/mdev/mdev_driver.c
> +++ b/drivers/vfio/mdev/mdev_driver.c
> @@ -69,8 +69,22 @@ static int mdev_remove(struct device *dev)
>  	return 0;
>  }
> 
> +static int mdev_match(struct device *dev, struct device_driver *drv)
> +{
> +	unsigned int i;
> +	struct mdev_device *mdev = to_mdev_device(dev);
> +	struct mdev_driver *mdrv = to_mdev_driver(drv);
> +	const struct mdev_device_id *ids = mdrv->id_table;
> +
> +	for (i = 0; ids[i].id; i++)
> +		if (ids[i].id == mdev->parent->device_id)
> +			return 1;
> +	return 0;
> +}
> +
>  struct bus_type mdev_bus_type = {
>  	.name		= "mdev",
> +	.match		= mdev_match,
>  	.probe		= mdev_probe,
>  	.remove		= mdev_remove,
>  };
> diff --git a/drivers/vfio/mdev/mdev_private.h
> b/drivers/vfio/mdev/mdev_private.h
> index 7d922950caaf..7fc8153671e0 100644
> --- a/drivers/vfio/mdev/mdev_private.h
> +++ b/drivers/vfio/mdev/mdev_private.h
> @@ -22,6 +22,7 @@ struct mdev_parent {
>  	struct list_head type_list;
>  	/* Synchronize device creation/removal with parent unregistration
> */
>  	struct rw_semaphore unreg_sem;
> +	u8 device_id;
>  };
> 
>  struct mdev_device {
> diff --git a/drivers/vfio/mdev/vfio_mdev.c
> b/drivers/vfio/mdev/vfio_mdev.c
> index 30964a4e0a28..887c57f10880 100644
> --- a/drivers/vfio/mdev/vfio_mdev.c
> +++ b/drivers/vfio/mdev/vfio_mdev.c
> @@ -120,10 +120,16 @@ static void vfio_mdev_remove(struct device *dev)
>  	vfio_del_group_dev(dev);
>  }
> 
> +static struct mdev_device_id id_table[] = {
> +	{ MDEV_ID_VFIO },
> +	{ 0 },
> +};
> +
>  static struct mdev_driver vfio_mdev_driver = {
>  	.name	= "vfio_mdev",
>  	.probe	= vfio_mdev_probe,
>  	.remove	= vfio_mdev_remove,
> +	.id_table = id_table,
>  };
> 
>  static int __init vfio_mdev_init(void)
> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
> index 0ce30ca78db0..f85045392120 100644
> --- a/include/linux/mdev.h
> +++ b/include/linux/mdev.h
> @@ -118,6 +118,7 @@ struct mdev_type_attribute
> mdev_type_attr_##_name =		\
>   * @probe: called when new device created
>   * @remove: called when device removed
>   * @driver: device driver structure
> + * @id_table: the ids serviced by this driver.
>   *
>   **/
>  struct mdev_driver {
> @@ -125,6 +126,7 @@ struct mdev_driver {
>  	int  (*probe)(struct device *dev);
>  	void (*remove)(struct device *dev);
>  	struct device_driver driver;
> +	const struct mdev_device_id *id_table;
>  };
> 
>  #define to_mdev_driver(drv)	container_of(drv, struct mdev_driver, driver)
> @@ -135,7 +137,7 @@ const guid_t *mdev_uuid(struct mdev_device
> *mdev);
> 
>  extern struct bus_type mdev_bus_type;
> 
> -int mdev_register_device(struct device *dev, const struct
> mdev_parent_ops *ops);
> +int mdev_register_vfio_device(struct device *dev, const struct
> mdev_parent_ops *ops);
>  void mdev_unregister_device(struct device *dev);
> 
>  int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
> @@ -145,4 +147,6 @@ struct device *mdev_parent_dev(struct
> mdev_device *mdev);
>  struct device *mdev_dev(struct mdev_device *mdev);
>  struct mdev_device *mdev_from_dev(struct device *dev);
> 
> +#define MDEV_ID_VFIO 1 /* VFIO device */
> +
>  #endif /* MDEV_H */
> diff --git a/include/linux/mod_devicetable.h
> b/include/linux/mod_devicetable.h
> index 5714fd35a83c..f1fc143df042 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -821,4 +821,10 @@ struct wmi_device_id {
>  	const void *context;
>  };
> 
> +/* MDEV */
> +
> +struct mdev_device_id {
> +	__u8 id;
> +};
> +
>  #endif /* LINUX_MOD_DEVICETABLE_H */
> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
> index ac5c8c17b1ff..71a4469be85d 100644
> --- a/samples/vfio-mdev/mbochs.c
> +++ b/samples/vfio-mdev/mbochs.c
> @@ -1468,7 +1468,7 @@ static int __init mbochs_dev_init(void)
>  	if (ret)
>  		goto failed2;
> 
> -	ret = mdev_register_device(&mbochs_dev, &mdev_fops);
> +	ret = mdev_register_vfio_device(&mbochs_dev, &mdev_fops);
>  	if (ret)
>  		goto failed3;
> 
> diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
> index cc86bf6566e4..d3029dd27d91 100644
> --- a/samples/vfio-mdev/mdpy.c
> +++ b/samples/vfio-mdev/mdpy.c
> @@ -775,7 +775,7 @@ static int __init mdpy_dev_init(void)
>  	if (ret)
>  		goto failed2;
> 
> -	ret = mdev_register_device(&mdpy_dev, &mdev_fops);
> +	ret = mdev_register_vfio_device(&mdpy_dev, &mdev_fops);
>  	if (ret)
>  		goto failed3;
> 
> diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
> index 92e770a06ea2..744c88a6b22c 100644
> --- a/samples/vfio-mdev/mtty.c
> +++ b/samples/vfio-mdev/mtty.c
> @@ -1468,7 +1468,7 @@ static int __init mtty_dev_init(void)
>  	if (ret)
>  		goto failed2;
> 
> -	ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
> +	ret = mdev_register_vfio_device(&mtty_dev.dev, &mdev_fops);
>  	if (ret)
>  		goto failed3;
> 
> --
> 2.19.1
> 
> _______________________________________________
> intel-gvt-dev mailing list
> intel-gvt-dev@lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
Jason Wang Sept. 17, 2019, 10:14 a.m. UTC | #2
On 2019/9/17 下午3:55, Tian, Kevin wrote:
>> From: Jason Wang
>> Sent: Thursday, September 12, 2019 5:40 PM
>>
>> Mdev bus only support vfio driver right now, so it doesn't implement
>> match method. But in the future, we may add drivers other than vfio,
>> one example is virtio-mdev[1] driver. This means we need to add device
>> id support in bus match method to pair the mdev device and mdev driver
>> correctly.
> "device id" sound a bit confusing to me - it usually means something
> unique to each device, while here it is used to indicate expected driver
> types (vfio, virtio, etc.). but using "bus id" is also not good - we have
> only one mdev bus here. Then what about "class id"?


I'm fine with this.

Thanks


>
>> So this patch add id_table to mdev_driver and id for mdev parent, and
>> implement the match method for mdev bus.
>>
>> [1] https://lkml.org/lkml/2019/9/10/135
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>>   drivers/gpu/drm/i915/gvt/kvmgt.c  |  2 +-
>>   drivers/s390/cio/vfio_ccw_ops.c   |  2 +-
>>   drivers/s390/crypto/vfio_ap_ops.c |  3 ++-
>>   drivers/vfio/mdev/mdev_core.c     | 14 ++++++++++++--
>>   drivers/vfio/mdev/mdev_driver.c   | 14 ++++++++++++++
>>   drivers/vfio/mdev/mdev_private.h  |  1 +
>>   drivers/vfio/mdev/vfio_mdev.c     |  6 ++++++
>>   include/linux/mdev.h              |  6 +++++-
>>   include/linux/mod_devicetable.h   |  6 ++++++
>>   samples/vfio-mdev/mbochs.c        |  2 +-
>>   samples/vfio-mdev/mdpy.c          |  2 +-
>>   samples/vfio-mdev/mtty.c          |  2 +-
>>   12 files changed, 51 insertions(+), 9 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c
>> b/drivers/gpu/drm/i915/gvt/kvmgt.c
>> index 23aa3e50cbf8..19d51a35f019 100644
>> --- a/drivers/gpu/drm/i915/gvt/kvmgt.c
>> +++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
>> @@ -1625,7 +1625,7 @@ static int kvmgt_host_init(struct device *dev, void
>> *gvt, const void *ops)
>>   		return -EFAULT;
>>   	intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
>>
>> -	return mdev_register_device(dev, &intel_vgpu_ops);
>> +	return mdev_register_vfio_device(dev, &intel_vgpu_ops);
>>   }
>>
>>   static void kvmgt_host_exit(struct device *dev)
>> diff --git a/drivers/s390/cio/vfio_ccw_ops.c
>> b/drivers/s390/cio/vfio_ccw_ops.c
>> index 5eb61116ca6f..f87d9409e290 100644
>> --- a/drivers/s390/cio/vfio_ccw_ops.c
>> +++ b/drivers/s390/cio/vfio_ccw_ops.c
>> @@ -578,7 +578,7 @@ static const struct mdev_parent_ops
>> vfio_ccw_mdev_ops = {
>>
>>   int vfio_ccw_mdev_reg(struct subchannel *sch)
>>   {
>> -	return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
>> +	return mdev_register_vfio_device(&sch->dev,
>> &vfio_ccw_mdev_ops);
>>   }
>>
>>   void vfio_ccw_mdev_unreg(struct subchannel *sch)
>> diff --git a/drivers/s390/crypto/vfio_ap_ops.c
>> b/drivers/s390/crypto/vfio_ap_ops.c
>> index 0604b49a4d32..eacbde3c7a97 100644
>> --- a/drivers/s390/crypto/vfio_ap_ops.c
>> +++ b/drivers/s390/crypto/vfio_ap_ops.c
>> @@ -1295,7 +1295,8 @@ int vfio_ap_mdev_register(void)
>>   {
>>   	atomic_set(&matrix_dev->available_instances,
>> MAX_ZDEV_ENTRIES_EXT);
>>
>> -	return mdev_register_device(&matrix_dev->device,
>> &vfio_ap_matrix_ops);
>> +	return mdev_register_vfio_device(&matrix_dev->device,
>> +					 &vfio_ap_matrix_ops);
>>   }
>>
>>   void vfio_ap_mdev_unregister(void)
>> diff --git a/drivers/vfio/mdev/mdev_core.c
>> b/drivers/vfio/mdev/mdev_core.c
>> index b558d4cfd082..fc07ff3ebe96 100644
>> --- a/drivers/vfio/mdev/mdev_core.c
>> +++ b/drivers/vfio/mdev/mdev_core.c
>> @@ -135,11 +135,14 @@ static int mdev_device_remove_cb(struct device
>> *dev, void *data)
>>    * mdev_register_device : Register a device
>>    * @dev: device structure representing parent device.
>>    * @ops: Parent device operation structure to be registered.
>> + * @id: device id.
>>    *
>>    * Add device to list of registered parent devices.
>>    * Returns a negative value on error, otherwise 0.
>>    */
>> -int mdev_register_device(struct device *dev, const struct
>> mdev_parent_ops *ops)
>> +int mdev_register_device(struct device *dev,
>> +			 const struct mdev_parent_ops *ops,
>> +			 u8 id)
>>   {
>>   	int ret;
>>   	struct mdev_parent *parent;
>> @@ -175,6 +178,7 @@ int mdev_register_device(struct device *dev, const
>> struct mdev_parent_ops *ops)
>>
>>   	parent->dev = dev;
>>   	parent->ops = ops;
>> +	parent->device_id = id;
>>
>>   	if (!mdev_bus_compat_class) {
>>   		mdev_bus_compat_class =
>> class_compat_register("mdev_bus");
>> @@ -208,7 +212,13 @@ int mdev_register_device(struct device *dev, const
>> struct mdev_parent_ops *ops)
>>   		put_device(dev);
>>   	return ret;
>>   }
>> -EXPORT_SYMBOL(mdev_register_device);
>> +
>> +int mdev_register_vfio_device(struct device *dev,
>> +			      const struct mdev_parent_ops *ops)
>> +{
>> +	return mdev_register_device(dev, ops, MDEV_ID_VFIO);
>> +}
>> +EXPORT_SYMBOL(mdev_register_vfio_device);
>>
>>   /*
>>    * mdev_unregister_device : Unregister a parent device
>> diff --git a/drivers/vfio/mdev/mdev_driver.c
>> b/drivers/vfio/mdev/mdev_driver.c
>> index 0d3223aee20b..fd5e9541d18e 100644
>> --- a/drivers/vfio/mdev/mdev_driver.c
>> +++ b/drivers/vfio/mdev/mdev_driver.c
>> @@ -69,8 +69,22 @@ static int mdev_remove(struct device *dev)
>>   	return 0;
>>   }
>>
>> +static int mdev_match(struct device *dev, struct device_driver *drv)
>> +{
>> +	unsigned int i;
>> +	struct mdev_device *mdev = to_mdev_device(dev);
>> +	struct mdev_driver *mdrv = to_mdev_driver(drv);
>> +	const struct mdev_device_id *ids = mdrv->id_table;
>> +
>> +	for (i = 0; ids[i].id; i++)
>> +		if (ids[i].id == mdev->parent->device_id)
>> +			return 1;
>> +	return 0;
>> +}
>> +
>>   struct bus_type mdev_bus_type = {
>>   	.name		= "mdev",
>> +	.match		= mdev_match,
>>   	.probe		= mdev_probe,
>>   	.remove		= mdev_remove,
>>   };
>> diff --git a/drivers/vfio/mdev/mdev_private.h
>> b/drivers/vfio/mdev/mdev_private.h
>> index 7d922950caaf..7fc8153671e0 100644
>> --- a/drivers/vfio/mdev/mdev_private.h
>> +++ b/drivers/vfio/mdev/mdev_private.h
>> @@ -22,6 +22,7 @@ struct mdev_parent {
>>   	struct list_head type_list;
>>   	/* Synchronize device creation/removal with parent unregistration
>> */
>>   	struct rw_semaphore unreg_sem;
>> +	u8 device_id;
>>   };
>>
>>   struct mdev_device {
>> diff --git a/drivers/vfio/mdev/vfio_mdev.c
>> b/drivers/vfio/mdev/vfio_mdev.c
>> index 30964a4e0a28..887c57f10880 100644
>> --- a/drivers/vfio/mdev/vfio_mdev.c
>> +++ b/drivers/vfio/mdev/vfio_mdev.c
>> @@ -120,10 +120,16 @@ static void vfio_mdev_remove(struct device *dev)
>>   	vfio_del_group_dev(dev);
>>   }
>>
>> +static struct mdev_device_id id_table[] = {
>> +	{ MDEV_ID_VFIO },
>> +	{ 0 },
>> +};
>> +
>>   static struct mdev_driver vfio_mdev_driver = {
>>   	.name	= "vfio_mdev",
>>   	.probe	= vfio_mdev_probe,
>>   	.remove	= vfio_mdev_remove,
>> +	.id_table = id_table,
>>   };
>>
>>   static int __init vfio_mdev_init(void)
>> diff --git a/include/linux/mdev.h b/include/linux/mdev.h
>> index 0ce30ca78db0..f85045392120 100644
>> --- a/include/linux/mdev.h
>> +++ b/include/linux/mdev.h
>> @@ -118,6 +118,7 @@ struct mdev_type_attribute
>> mdev_type_attr_##_name =		\
>>    * @probe: called when new device created
>>    * @remove: called when device removed
>>    * @driver: device driver structure
>> + * @id_table: the ids serviced by this driver.
>>    *
>>    **/
>>   struct mdev_driver {
>> @@ -125,6 +126,7 @@ struct mdev_driver {
>>   	int  (*probe)(struct device *dev);
>>   	void (*remove)(struct device *dev);
>>   	struct device_driver driver;
>> +	const struct mdev_device_id *id_table;
>>   };
>>
>>   #define to_mdev_driver(drv)	container_of(drv, struct mdev_driver, driver)
>> @@ -135,7 +137,7 @@ const guid_t *mdev_uuid(struct mdev_device
>> *mdev);
>>
>>   extern struct bus_type mdev_bus_type;
>>
>> -int mdev_register_device(struct device *dev, const struct
>> mdev_parent_ops *ops);
>> +int mdev_register_vfio_device(struct device *dev, const struct
>> mdev_parent_ops *ops);
>>   void mdev_unregister_device(struct device *dev);
>>
>>   int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
>> @@ -145,4 +147,6 @@ struct device *mdev_parent_dev(struct
>> mdev_device *mdev);
>>   struct device *mdev_dev(struct mdev_device *mdev);
>>   struct mdev_device *mdev_from_dev(struct device *dev);
>>
>> +#define MDEV_ID_VFIO 1 /* VFIO device */
>> +
>>   #endif /* MDEV_H */
>> diff --git a/include/linux/mod_devicetable.h
>> b/include/linux/mod_devicetable.h
>> index 5714fd35a83c..f1fc143df042 100644
>> --- a/include/linux/mod_devicetable.h
>> +++ b/include/linux/mod_devicetable.h
>> @@ -821,4 +821,10 @@ struct wmi_device_id {
>>   	const void *context;
>>   };
>>
>> +/* MDEV */
>> +
>> +struct mdev_device_id {
>> +	__u8 id;
>> +};
>> +
>>   #endif /* LINUX_MOD_DEVICETABLE_H */
>> diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
>> index ac5c8c17b1ff..71a4469be85d 100644
>> --- a/samples/vfio-mdev/mbochs.c
>> +++ b/samples/vfio-mdev/mbochs.c
>> @@ -1468,7 +1468,7 @@ static int __init mbochs_dev_init(void)
>>   	if (ret)
>>   		goto failed2;
>>
>> -	ret = mdev_register_device(&mbochs_dev, &mdev_fops);
>> +	ret = mdev_register_vfio_device(&mbochs_dev, &mdev_fops);
>>   	if (ret)
>>   		goto failed3;
>>
>> diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
>> index cc86bf6566e4..d3029dd27d91 100644
>> --- a/samples/vfio-mdev/mdpy.c
>> +++ b/samples/vfio-mdev/mdpy.c
>> @@ -775,7 +775,7 @@ static int __init mdpy_dev_init(void)
>>   	if (ret)
>>   		goto failed2;
>>
>> -	ret = mdev_register_device(&mdpy_dev, &mdev_fops);
>> +	ret = mdev_register_vfio_device(&mdpy_dev, &mdev_fops);
>>   	if (ret)
>>   		goto failed3;
>>
>> diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
>> index 92e770a06ea2..744c88a6b22c 100644
>> --- a/samples/vfio-mdev/mtty.c
>> +++ b/samples/vfio-mdev/mtty.c
>> @@ -1468,7 +1468,7 @@ static int __init mtty_dev_init(void)
>>   	if (ret)
>>   		goto failed2;
>>
>> -	ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
>> +	ret = mdev_register_vfio_device(&mtty_dev.dev, &mdev_fops);
>>   	if (ret)
>>   		goto failed3;
>>
>> --
>> 2.19.1
>>
>> _______________________________________________
>> intel-gvt-dev mailing list
>> intel-gvt-dev@lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev
Cornelia Huck Sept. 17, 2019, 12:07 p.m. UTC | #3
On Thu, 12 Sep 2019 17:40:11 +0800
Jason Wang <jasowang@redhat.com> wrote:

> Mdev bus only support vfio driver right now, so it doesn't implement
> match method. But in the future, we may add drivers other than vfio,
> one example is virtio-mdev[1] driver. This means we need to add device
> id support in bus match method to pair the mdev device and mdev driver
> correctly.

Sounds reasonable.

> 
> So this patch add id_table to mdev_driver and id for mdev parent, and
> implement the match method for mdev bus.
> 
> [1] https://lkml.org/lkml/2019/9/10/135
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>  drivers/gpu/drm/i915/gvt/kvmgt.c  |  2 +-
>  drivers/s390/cio/vfio_ccw_ops.c   |  2 +-
>  drivers/s390/crypto/vfio_ap_ops.c |  3 ++-
>  drivers/vfio/mdev/mdev_core.c     | 14 ++++++++++++--
>  drivers/vfio/mdev/mdev_driver.c   | 14 ++++++++++++++
>  drivers/vfio/mdev/mdev_private.h  |  1 +
>  drivers/vfio/mdev/vfio_mdev.c     |  6 ++++++
>  include/linux/mdev.h              |  6 +++++-
>  include/linux/mod_devicetable.h   |  6 ++++++
>  samples/vfio-mdev/mbochs.c        |  2 +-
>  samples/vfio-mdev/mdpy.c          |  2 +-
>  samples/vfio-mdev/mtty.c          |  2 +-
>  12 files changed, 51 insertions(+), 9 deletions(-)

(...)

The transformations of the vendor drivers and the new interface look
sane.

(...)

> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
> index 5714fd35a83c..f1fc143df042 100644
> --- a/include/linux/mod_devicetable.h
> +++ b/include/linux/mod_devicetable.h
> @@ -821,4 +821,10 @@ struct wmi_device_id {
>  	const void *context;
>  };
>  
> +/* MDEV */
> +

Maybe add some kerneldoc and give vfio as an example of what we're
matching here?

> +struct mdev_device_id {
> +	__u8 id;

I agree with the suggestion to rename this to 'class_id'.

> +};
> +
>  #endif /* LINUX_MOD_DEVICETABLE_H */
Jason Wang Sept. 18, 2019, 5:52 a.m. UTC | #4
On 2019/9/17 下午8:07, Cornelia Huck wrote:
> On Thu, 12 Sep 2019 17:40:11 +0800
> Jason Wang <jasowang@redhat.com> wrote:
>
>> Mdev bus only support vfio driver right now, so it doesn't implement
>> match method. But in the future, we may add drivers other than vfio,
>> one example is virtio-mdev[1] driver. This means we need to add device
>> id support in bus match method to pair the mdev device and mdev driver
>> correctly.
> Sounds reasonable.
>
>> So this patch add id_table to mdev_driver and id for mdev parent, and
>> implement the match method for mdev bus.
>>
>> [1] https://lkml.org/lkml/2019/9/10/135
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>>   drivers/gpu/drm/i915/gvt/kvmgt.c  |  2 +-
>>   drivers/s390/cio/vfio_ccw_ops.c   |  2 +-
>>   drivers/s390/crypto/vfio_ap_ops.c |  3 ++-
>>   drivers/vfio/mdev/mdev_core.c     | 14 ++++++++++++--
>>   drivers/vfio/mdev/mdev_driver.c   | 14 ++++++++++++++
>>   drivers/vfio/mdev/mdev_private.h  |  1 +
>>   drivers/vfio/mdev/vfio_mdev.c     |  6 ++++++
>>   include/linux/mdev.h              |  6 +++++-
>>   include/linux/mod_devicetable.h   |  6 ++++++
>>   samples/vfio-mdev/mbochs.c        |  2 +-
>>   samples/vfio-mdev/mdpy.c          |  2 +-
>>   samples/vfio-mdev/mtty.c          |  2 +-
>>   12 files changed, 51 insertions(+), 9 deletions(-)
> (...)
>
> The transformations of the vendor drivers and the new interface look
> sane.
>
> (...)
>
>> diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
>> index 5714fd35a83c..f1fc143df042 100644
>> --- a/include/linux/mod_devicetable.h
>> +++ b/include/linux/mod_devicetable.h
>> @@ -821,4 +821,10 @@ struct wmi_device_id {
>>   	const void *context;
>>   };
>>   
>> +/* MDEV */
>> +
> Maybe add some kerneldoc and give vfio as an example of what we're
> matching here?


Will add when posting a non RFC patch.


>
>> +struct mdev_device_id {
>> +	__u8 id;
> I agree with the suggestion to rename this to 'class_id'.
>

Let me change it.

Thanks


>> +};
>> +
>>   #endif /* LINUX_MOD_DEVICETABLE_H */

Patch
diff mbox series

diff --git a/drivers/gpu/drm/i915/gvt/kvmgt.c b/drivers/gpu/drm/i915/gvt/kvmgt.c
index 23aa3e50cbf8..19d51a35f019 100644
--- a/drivers/gpu/drm/i915/gvt/kvmgt.c
+++ b/drivers/gpu/drm/i915/gvt/kvmgt.c
@@ -1625,7 +1625,7 @@  static int kvmgt_host_init(struct device *dev, void *gvt, const void *ops)
 		return -EFAULT;
 	intel_vgpu_ops.supported_type_groups = kvm_vgpu_type_groups;
 
-	return mdev_register_device(dev, &intel_vgpu_ops);
+	return mdev_register_vfio_device(dev, &intel_vgpu_ops);
 }
 
 static void kvmgt_host_exit(struct device *dev)
diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 5eb61116ca6f..f87d9409e290 100644
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -578,7 +578,7 @@  static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
 
 int vfio_ccw_mdev_reg(struct subchannel *sch)
 {
-	return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
+	return mdev_register_vfio_device(&sch->dev, &vfio_ccw_mdev_ops);
 }
 
 void vfio_ccw_mdev_unreg(struct subchannel *sch)
diff --git a/drivers/s390/crypto/vfio_ap_ops.c b/drivers/s390/crypto/vfio_ap_ops.c
index 0604b49a4d32..eacbde3c7a97 100644
--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c
@@ -1295,7 +1295,8 @@  int vfio_ap_mdev_register(void)
 {
 	atomic_set(&matrix_dev->available_instances, MAX_ZDEV_ENTRIES_EXT);
 
-	return mdev_register_device(&matrix_dev->device, &vfio_ap_matrix_ops);
+	return mdev_register_vfio_device(&matrix_dev->device,
+					 &vfio_ap_matrix_ops);
 }
 
 void vfio_ap_mdev_unregister(void)
diff --git a/drivers/vfio/mdev/mdev_core.c b/drivers/vfio/mdev/mdev_core.c
index b558d4cfd082..fc07ff3ebe96 100644
--- a/drivers/vfio/mdev/mdev_core.c
+++ b/drivers/vfio/mdev/mdev_core.c
@@ -135,11 +135,14 @@  static int mdev_device_remove_cb(struct device *dev, void *data)
  * mdev_register_device : Register a device
  * @dev: device structure representing parent device.
  * @ops: Parent device operation structure to be registered.
+ * @id: device id.
  *
  * Add device to list of registered parent devices.
  * Returns a negative value on error, otherwise 0.
  */
-int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
+int mdev_register_device(struct device *dev,
+			 const struct mdev_parent_ops *ops,
+			 u8 id)
 {
 	int ret;
 	struct mdev_parent *parent;
@@ -175,6 +178,7 @@  int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
 
 	parent->dev = dev;
 	parent->ops = ops;
+	parent->device_id = id;
 
 	if (!mdev_bus_compat_class) {
 		mdev_bus_compat_class = class_compat_register("mdev_bus");
@@ -208,7 +212,13 @@  int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops)
 		put_device(dev);
 	return ret;
 }
-EXPORT_SYMBOL(mdev_register_device);
+
+int mdev_register_vfio_device(struct device *dev,
+			      const struct mdev_parent_ops *ops)
+{
+	return mdev_register_device(dev, ops, MDEV_ID_VFIO);
+}
+EXPORT_SYMBOL(mdev_register_vfio_device);
 
 /*
  * mdev_unregister_device : Unregister a parent device
diff --git a/drivers/vfio/mdev/mdev_driver.c b/drivers/vfio/mdev/mdev_driver.c
index 0d3223aee20b..fd5e9541d18e 100644
--- a/drivers/vfio/mdev/mdev_driver.c
+++ b/drivers/vfio/mdev/mdev_driver.c
@@ -69,8 +69,22 @@  static int mdev_remove(struct device *dev)
 	return 0;
 }
 
+static int mdev_match(struct device *dev, struct device_driver *drv)
+{
+	unsigned int i;
+	struct mdev_device *mdev = to_mdev_device(dev);
+	struct mdev_driver *mdrv = to_mdev_driver(drv);
+	const struct mdev_device_id *ids = mdrv->id_table;
+
+	for (i = 0; ids[i].id; i++)
+		if (ids[i].id == mdev->parent->device_id)
+			return 1;
+	return 0;
+}
+
 struct bus_type mdev_bus_type = {
 	.name		= "mdev",
+	.match		= mdev_match,
 	.probe		= mdev_probe,
 	.remove		= mdev_remove,
 };
diff --git a/drivers/vfio/mdev/mdev_private.h b/drivers/vfio/mdev/mdev_private.h
index 7d922950caaf..7fc8153671e0 100644
--- a/drivers/vfio/mdev/mdev_private.h
+++ b/drivers/vfio/mdev/mdev_private.h
@@ -22,6 +22,7 @@  struct mdev_parent {
 	struct list_head type_list;
 	/* Synchronize device creation/removal with parent unregistration */
 	struct rw_semaphore unreg_sem;
+	u8 device_id;
 };
 
 struct mdev_device {
diff --git a/drivers/vfio/mdev/vfio_mdev.c b/drivers/vfio/mdev/vfio_mdev.c
index 30964a4e0a28..887c57f10880 100644
--- a/drivers/vfio/mdev/vfio_mdev.c
+++ b/drivers/vfio/mdev/vfio_mdev.c
@@ -120,10 +120,16 @@  static void vfio_mdev_remove(struct device *dev)
 	vfio_del_group_dev(dev);
 }
 
+static struct mdev_device_id id_table[] = {
+	{ MDEV_ID_VFIO },
+	{ 0 },
+};
+
 static struct mdev_driver vfio_mdev_driver = {
 	.name	= "vfio_mdev",
 	.probe	= vfio_mdev_probe,
 	.remove	= vfio_mdev_remove,
+	.id_table = id_table,
 };
 
 static int __init vfio_mdev_init(void)
diff --git a/include/linux/mdev.h b/include/linux/mdev.h
index 0ce30ca78db0..f85045392120 100644
--- a/include/linux/mdev.h
+++ b/include/linux/mdev.h
@@ -118,6 +118,7 @@  struct mdev_type_attribute mdev_type_attr_##_name =		\
  * @probe: called when new device created
  * @remove: called when device removed
  * @driver: device driver structure
+ * @id_table: the ids serviced by this driver.
  *
  **/
 struct mdev_driver {
@@ -125,6 +126,7 @@  struct mdev_driver {
 	int  (*probe)(struct device *dev);
 	void (*remove)(struct device *dev);
 	struct device_driver driver;
+	const struct mdev_device_id *id_table;
 };
 
 #define to_mdev_driver(drv)	container_of(drv, struct mdev_driver, driver)
@@ -135,7 +137,7 @@  const guid_t *mdev_uuid(struct mdev_device *mdev);
 
 extern struct bus_type mdev_bus_type;
 
-int mdev_register_device(struct device *dev, const struct mdev_parent_ops *ops);
+int mdev_register_vfio_device(struct device *dev, const struct mdev_parent_ops *ops);
 void mdev_unregister_device(struct device *dev);
 
 int mdev_register_driver(struct mdev_driver *drv, struct module *owner);
@@ -145,4 +147,6 @@  struct device *mdev_parent_dev(struct mdev_device *mdev);
 struct device *mdev_dev(struct mdev_device *mdev);
 struct mdev_device *mdev_from_dev(struct device *dev);
 
+#define MDEV_ID_VFIO 1 /* VFIO device */
+
 #endif /* MDEV_H */
diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h
index 5714fd35a83c..f1fc143df042 100644
--- a/include/linux/mod_devicetable.h
+++ b/include/linux/mod_devicetable.h
@@ -821,4 +821,10 @@  struct wmi_device_id {
 	const void *context;
 };
 
+/* MDEV */
+
+struct mdev_device_id {
+	__u8 id;
+};
+
 #endif /* LINUX_MOD_DEVICETABLE_H */
diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index ac5c8c17b1ff..71a4469be85d 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -1468,7 +1468,7 @@  static int __init mbochs_dev_init(void)
 	if (ret)
 		goto failed2;
 
-	ret = mdev_register_device(&mbochs_dev, &mdev_fops);
+	ret = mdev_register_vfio_device(&mbochs_dev, &mdev_fops);
 	if (ret)
 		goto failed3;
 
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index cc86bf6566e4..d3029dd27d91 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -775,7 +775,7 @@  static int __init mdpy_dev_init(void)
 	if (ret)
 		goto failed2;
 
-	ret = mdev_register_device(&mdpy_dev, &mdev_fops);
+	ret = mdev_register_vfio_device(&mdpy_dev, &mdev_fops);
 	if (ret)
 		goto failed3;
 
diff --git a/samples/vfio-mdev/mtty.c b/samples/vfio-mdev/mtty.c
index 92e770a06ea2..744c88a6b22c 100644
--- a/samples/vfio-mdev/mtty.c
+++ b/samples/vfio-mdev/mtty.c
@@ -1468,7 +1468,7 @@  static int __init mtty_dev_init(void)
 	if (ret)
 		goto failed2;
 
-	ret = mdev_register_device(&mtty_dev.dev, &mdev_fops);
+	ret = mdev_register_vfio_device(&mtty_dev.dev, &mdev_fops);
 	if (ret)
 		goto failed3;