Message-ID: <89567b95-be92-24b5-b205-9fe2d2dc4c93@redhat.com>
Date:   Tue, 17 Sep 2019 18:14:38 +0800
From:   Jason Wang <jasowang@...hat.com>
To:     "Tian, Kevin" <kevin.tian@...el.com>,
        "kvm@...r.kernel.org" <kvm@...r.kernel.org>,
        "linux-s390@...r.kernel.org" <linux-s390@...r.kernel.org>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>,
        "intel-gfx@...ts.freedesktop.org" <intel-gfx@...ts.freedesktop.org>,
        "intel-gvt-dev@...ts.freedesktop.org" 
        <intel-gvt-dev@...ts.freedesktop.org>,
        "kwankhede@...dia.com" <kwankhede@...dia.com>,
        "alex.williamson@...hat.com" <alex.williamson@...hat.com>
Cc:     "sebott@...ux.ibm.com" <sebott@...ux.ibm.com>,
        "mst@...hat.com" <mst@...hat.com>,
        "airlied@...ux.ie" <airlied@...ux.ie>,
        "joonas.lahtinen@...ux.intel.com" <joonas.lahtinen@...ux.intel.com>,
        "heiko.carstens@...ibm.com" <heiko.carstens@...ibm.com>,
        "virtualization@...ts.linux-foundation.org" 
        <virtualization@...ts.linux-foundation.org>,
        "rob.miller@...adcom.com" <rob.miller@...adcom.com>,
        "pasic@...ux.ibm.com" <pasic@...ux.ibm.com>,
        "borntraeger@...ibm.com" <borntraeger@...ibm.com>,
        "Wang, Zhi A" <zhi.a.wang@...el.com>,
        "farman@...ux.ibm.com" <farman@...ux.ibm.com>,
        "idos@...lanox.com" <idos@...lanox.com>,
        "gor@...ux.ibm.com" <gor@...ux.ibm.com>,
        "Liang, Cunming" <cunming.liang@...el.com>,
        "jani.nikula@...ux.intel.com" <jani.nikula@...ux.intel.com>,
        "Wang, Xiao W" <xiao.w.wang@...el.com>,
        "freude@...ux.ibm.com" <freude@...ux.ibm.com>,
        "zhenyuw@...ux.intel.com" <zhenyuw@...ux.intel.com>,
        "Vivi, Rodrigo" <rodrigo.vivi@...el.com>,
        "Zhu, Lingshan" <lingshan.zhu@...el.com>,
        "akrowiak@...ux.ibm.com" <akrowiak@...ux.ibm.com>,
        "Bie, Tiwei" <tiwei.bie@...el.com>,
        "pmorel@...ux.ibm.com" <pmorel@...ux.ibm.com>,
        "cohuck@...hat.com" <cohuck@...hat.com>,
        "oberpar@...ux.ibm.com" <oberpar@...ux.ibm.com>,
        "maxime.coquelin@...hat.com" <maxime.coquelin@...hat.com>,
        "daniel@...ll.ch" <daniel@...ll.ch>,
        "Wang, Zhihong" <zhihong.wang@...el.com>
Subject: Re: [RFC PATCH 1/2] mdev: device id support


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@...hat.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@...ts.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/intel-gvt-dev

Powered by blists - more mailing lists