Commit 903f7bca authored by Parav Pandit's avatar Parav Pandit Committed by Michael S. Tsirkin
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vdpa: Enable a user to add and delete a vdpa device 



Add the ability to add and delete a vdpa device.

Examples:
Create a vdpa device of type network named "foo2" from
the management device vdpasim:

$ vdpa dev add mgmtdev vdpasim_net name foo2

Delete the vdpa device after its use:
$ vdpa dev del foo2

Signed-off-by: default avatarParav Pandit <parav@nvidia.com>
Reviewed-by: default avatarEli Cohen <elic@nvidia.com>
Reviewed-by: default avatarJason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210105103203.82508-5-parav@nvidia.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 33b34750

drivers/vdpa/vdpa.c

+133 −10
Original line number Diff line number Diff line
@@ -136,6 +136,37 @@ static int vdpa_name_match(struct device *dev, const void *data) 
	return (strcmp(dev_name(&vdev->dev), data) == 0);

}



static int __vdpa_register_device(struct vdpa_device *vdev)

{

	struct device *dev;



	lockdep_assert_held(&vdpa_dev_mutex);

	dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);

	if (dev) {

		put_device(dev);

		return -EEXIST;

	}

	return device_add(&vdev->dev);

}



/**

 * _vdpa_register_device - register a vDPA device with vdpa lock held

 * Caller must have a succeed call of vdpa_alloc_device() before.

 * Caller must invoke this routine in the management device dev_add()

 * callback after setting up valid mgmtdev for this vdpa device.

 * @vdev: the vdpa device to be registered to vDPA bus

 *

 * Returns an error when fail to add device to vDPA bus

 */

int _vdpa_register_device(struct vdpa_device *vdev)

{

	if (!vdev->mdev)

		return -EINVAL;



	return __vdpa_register_device(vdev);

}

EXPORT_SYMBOL_GPL(_vdpa_register_device);



/**

 * vdpa_register_device - register a vDPA device

 * Callers must have a succeed call of vdpa_alloc_device() before.
@@ -145,24 +176,29 @@ static int vdpa_name_match(struct device *dev, const void *data) 
 */

int vdpa_register_device(struct vdpa_device *vdev)

{

	struct device *dev;

	int err;



	mutex_lock(&vdpa_dev_mutex);

	dev = bus_find_device(&vdpa_bus, NULL, dev_name(&vdev->dev), vdpa_name_match);

	if (dev) {

		put_device(dev);

		err = -EEXIST;

		goto name_err;

	}



	err = device_add(&vdev->dev);

name_err:

	err = __vdpa_register_device(vdev);

	mutex_unlock(&vdpa_dev_mutex);

	return err;

}

EXPORT_SYMBOL_GPL(vdpa_register_device);



/**

 * _vdpa_unregister_device - unregister a vDPA device

 * Caller must invoke this routine as part of management device dev_del()

 * callback.

 * @vdev: the vdpa device to be unregisted from vDPA bus

 */

void _vdpa_unregister_device(struct vdpa_device *vdev)

{

	lockdep_assert_held(&vdpa_dev_mutex);

	WARN_ON(!vdev->mdev);

	device_unregister(&vdev->dev);

}

EXPORT_SYMBOL_GPL(_vdpa_unregister_device);



/**

 * vdpa_unregister_device - unregister a vDPA device

 * @vdev: the vdpa device to be unregisted from vDPA bus
@@ -221,10 +257,25 @@ int vdpa_mgmtdev_register(struct vdpa_mgmt_dev *mdev) 
}

EXPORT_SYMBOL_GPL(vdpa_mgmtdev_register);



static int vdpa_match_remove(struct device *dev, void *data)

{

	struct vdpa_device *vdev = container_of(dev, struct vdpa_device, dev);

	struct vdpa_mgmt_dev *mdev = vdev->mdev;



	if (mdev == data)

		mdev->ops->dev_del(mdev, vdev);

	return 0;

}



void vdpa_mgmtdev_unregister(struct vdpa_mgmt_dev *mdev)

{

	mutex_lock(&vdpa_dev_mutex);



	list_del(&mdev->list);



	/* Filter out all the entries belong to this management device and delete it. */

	bus_for_each_dev(&vdpa_bus, NULL, mdev, vdpa_match_remove);



	mutex_unlock(&vdpa_dev_mutex);

}

EXPORT_SYMBOL_GPL(vdpa_mgmtdev_unregister);
@@ -368,9 +419,69 @@ vdpa_nl_cmd_mgmtdev_get_dumpit(struct sk_buff *msg, struct netlink_callback *cb) 
	return msg->len;

}



static int vdpa_nl_cmd_dev_add_set_doit(struct sk_buff *skb, struct genl_info *info)

{

	struct vdpa_mgmt_dev *mdev;

	const char *name;

	int err = 0;



	if (!info->attrs[VDPA_ATTR_DEV_NAME])

		return -EINVAL;



	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);



	mutex_lock(&vdpa_dev_mutex);

	mdev = vdpa_mgmtdev_get_from_attr(info->attrs);

	if (IS_ERR(mdev)) {

		NL_SET_ERR_MSG_MOD(info->extack, "Fail to find the specified management device");

		err = PTR_ERR(mdev);

		goto err;

	}



	err = mdev->ops->dev_add(mdev, name);

err:

	mutex_unlock(&vdpa_dev_mutex);

	return err;

}



static int vdpa_nl_cmd_dev_del_set_doit(struct sk_buff *skb, struct genl_info *info)

{

	struct vdpa_mgmt_dev *mdev;

	struct vdpa_device *vdev;

	struct device *dev;

	const char *name;

	int err = 0;



	if (!info->attrs[VDPA_ATTR_DEV_NAME])

		return -EINVAL;

	name = nla_data(info->attrs[VDPA_ATTR_DEV_NAME]);



	mutex_lock(&vdpa_dev_mutex);

	dev = bus_find_device(&vdpa_bus, NULL, name, vdpa_name_match);

	if (!dev) {

		NL_SET_ERR_MSG_MOD(info->extack, "device not found");

		err = -ENODEV;

		goto dev_err;

	}

	vdev = container_of(dev, struct vdpa_device, dev);

	if (!vdev->mdev) {

		NL_SET_ERR_MSG_MOD(info->extack, "Only user created device can be deleted by user");

		err = -EINVAL;

		goto mdev_err;

	}

	mdev = vdev->mdev;

	mdev->ops->dev_del(mdev, vdev);

mdev_err:

	put_device(dev);

dev_err:

	mutex_unlock(&vdpa_dev_mutex);

	return err;

}



static const struct nla_policy vdpa_nl_policy[VDPA_ATTR_MAX + 1] = {

	[VDPA_ATTR_MGMTDEV_BUS_NAME] = { .type = NLA_NUL_STRING },

	[VDPA_ATTR_MGMTDEV_DEV_NAME] = { .type = NLA_STRING },

	[VDPA_ATTR_DEV_NAME] = { .type = NLA_STRING },

};



static const struct genl_ops vdpa_nl_ops[] = {
@@ -380,6 +491,18 @@ static const struct genl_ops vdpa_nl_ops[] = { 
		.doit = vdpa_nl_cmd_mgmtdev_get_doit,

		.dumpit = vdpa_nl_cmd_mgmtdev_get_dumpit,

	},

	{

		.cmd = VDPA_CMD_DEV_NEW,

		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

		.doit = vdpa_nl_cmd_dev_add_set_doit,

		.flags = GENL_ADMIN_PERM,

	},

	{

		.cmd = VDPA_CMD_DEV_DEL,

		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,

		.doit = vdpa_nl_cmd_dev_del_set_doit,

		.flags = GENL_ADMIN_PERM,

	},

};



static struct genl_family vdpa_nl_family __ro_after_init = {

include/linux/vdpa.h

+6 −0
Original line number Diff line number Diff line
@@ -45,6 +45,8 @@ struct vdpa_mgmt_dev; 
 * @index: device index

 * @features_valid: were features initialized? for legacy guests

 * @nvqs: maximum number of supported virtqueues

 * @mdev: management device pointer; caller must setup when registering device as part

 *	  of dev_add() mgmtdev ops callback before invoking _vdpa_register_device().

 */

struct vdpa_device {

	struct device dev;
@@ -53,6 +55,7 @@ struct vdpa_device { 
	unsigned int index;

	bool features_valid;

	int nvqs;

	struct vdpa_mgmt_dev *mdev;

};



/**
@@ -260,6 +263,9 @@ struct vdpa_device *__vdpa_alloc_device(struct device *parent, 
int vdpa_register_device(struct vdpa_device *vdev);

void vdpa_unregister_device(struct vdpa_device *vdev);



int _vdpa_register_device(struct vdpa_device *vdev);

void _vdpa_unregister_device(struct vdpa_device *vdev);



/**

 * vdpa_driver - operations for a vDPA driver

 * @driver: underlying device driver

include/uapi/linux/vdpa.h

+4 −0
Original line number Diff line number Diff line
@@ -14,6 +14,8 @@ enum vdpa_command { 
	VDPA_CMD_UNSPEC,

	VDPA_CMD_MGMTDEV_NEW,

	VDPA_CMD_MGMTDEV_GET,		/* can dump */

	VDPA_CMD_DEV_NEW,

	VDPA_CMD_DEV_DEL,

};



enum vdpa_attr {
@@ -24,6 +26,8 @@ enum vdpa_attr { 
	VDPA_ATTR_MGMTDEV_DEV_NAME,		/* string */

	VDPA_ATTR_MGMTDEV_SUPPORTED_CLASSES,	/* u64 */



	VDPA_ATTR_DEV_NAME,			/* string */



	/* new attributes must be added above here */

	VDPA_ATTR_MAX,

};