Re: [PATCH v8 1/5] vfio/migration: Add debugfs to live migration driver

[liulongfang <liulongfang@huawei.com>]

On 2023/3/14 17:32, liulongfang wrote:
> On 2023/3/11 1:12, Jason Gunthorpe wrote:
>> On Fri, Feb 17, 2023 at 04:48:27PM +0800, Longfang Liu wrote:
>>> +void vfio_vf_debugfs_init(struct vfio_device *vdev)
>>> +{
>>> +	struct device *dev = &vdev->device;
>>> +
>>> +	vdev->debug_root = debugfs_create_dir(dev_name(vdev->dev), vfio_debugfs_root);
>>> +
>>> +	debugfs_create_devm_seqfile(dev, "migration_state", vdev->debug_root,
>>> +				  vfio_vf_state_read);
>>> +}
>>> +EXPORT_SYMBOL_GPL(vfio_vf_debugfs_init);
>>> +
>>> +void vfio_vf_debugfs_exit(struct vfio_device *vdev)
>>> +{
>>> +	debugfs_remove_recursive(vdev->debug_root);
>>> +}
>>> +EXPORT_SYMBOL_GPL(vfio_vf_debugfs_exit);
>>> +
>>> +void  vfio_debugfs_create_root(void)
>>> +{
>>> +	vfio_debugfs_root = debugfs_create_dir("vfio", NULL);
>>> +}
>>> +EXPORT_SYMBOL_GPL(vfio_debugfs_create_root);
>>> +
>>> +void  vfio_debugfs_remove_root(void)
>>> +{
>>> +	debugfs_remove_recursive(vfio_debugfs_root);
>>> +	vfio_debugfs_root = NULL;
>>> +}
>>> +EXPORT_SYMBOL_GPL(vfio_debugfs_remove_root);
>>
>> Why are these symbols exported?
>>
> 
> If the export statement is not added, a compilation error will occur:
> 
> ERROR: modpost: "vfio_vf_debugfs_init" [drivers/vfio/pci/hisilicon/hisi-acc-vfio-pci.ko] undefined!
> ERROR: modpost: "vfio_vf_debugfs_exit" [drivers/vfio/pci/hisilicon/hisi-acc-vfio-pci.ko] undefined!
> scripts/Makefile.modpost:126: recipe for target 'Module.symvers' failed
> make[1]: *** [Module.symvers] Error 1
> 

The first two functions cannot remove the export statement,
but the latter two can be removed.

Thanks,
Longfang.
> 
>> Jason
>>
>> .
> Thanks,
> Longfang
> 
>>