Commit 64a5dedc authored Nov 20, 2025 by Vivek Kasireddy Committed by Alex Williamson Nov 20, 2025

vfio: Export vfio device get and put registration helpers



These helpers are useful for managing additional references taken
on the device from other associated VFIO modules.

Original-patch-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Vivek Kasireddy <vivek.kasireddy@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Tested-by: Alex Mastro <amastro@fb.com>
Tested-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Acked-by: Ankit Agrawal <ankita@nvidia.com>
Link: https://lore.kernel.org/r/20251120-dmabuf-vfio-v9-7-d7f71607f371@nvidia.com


Signed-off-by: Alex Williamson <alex@shazbot.org>

parent 3aa31a8b

drivers/vfio/vfio_main.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -172,11 +172,13 @@ void vfio_device_put_registration(struct vfio_device *device)
		if (refcount_dec_and_test(&device->refcount))
		complete(&device->comp);
		}
		EXPORT_SYMBOL_GPL(vfio_device_put_registration);

		bool vfio_device_try_get_registration(struct vfio_device *device)
		{
		return refcount_inc_not_zero(&device->refcount);
		}
		EXPORT_SYMBOL_GPL(vfio_device_try_get_registration);

		/*
		* VFIO driver API

include/linux/vfio.h

+2 −0

Original line number	Diff line number	Diff line
		@@ -297,6 +297,8 @@ static inline void vfio_put_device(struct vfio_device *device)
		int vfio_register_group_dev(struct vfio_device *device);
		int vfio_register_emulated_iommu_dev(struct vfio_device *device);
		void vfio_unregister_group_dev(struct vfio_device *device);
		bool vfio_device_try_get_registration(struct vfio_device *device);
		void vfio_device_put_registration(struct vfio_device *device);

		int vfio_assign_device_set(struct vfio_device device, void set_id);
		unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);