Commit c38ff5b0 authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Alex Williamson
Browse files

vfio: Remove vfio_external_group_match_file() 



vfio_group_fops_open() ensures there is only ever one struct file open for
any struct vfio_group at any time:

	/* Do we need multiple instances of the group open?  Seems not. */
	opened = atomic_cmpxchg(&group->opened, 0, 1);
	if (opened) {
		vfio_group_put(group);
		return -EBUSY;

Therefor the struct file * can be used directly to search the list of VFIO
groups that KVM keeps instead of using the
vfio_external_group_match_file() callback to try to figure out if the
passed in FD matches the list or not.

Delete vfio_external_group_match_file().

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarYi Liu <yi.l.liu@intel.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/4-v3-f7729924a7ea+25e33-vfio_kvm_no_group_jgg@nvidia.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 50d63b5b

drivers/vfio/vfio.c

+0 −9
Original line number Diff line number Diff line
@@ -1685,15 +1685,6 @@ void vfio_group_put_external_user(struct vfio_group *group) 
}

EXPORT_SYMBOL_GPL(vfio_group_put_external_user);



bool vfio_external_group_match_file(struct vfio_group *test_group,

				    struct file *filep)

{

	struct vfio_group *group = filep->private_data;



	return (filep->f_op == &vfio_group_fops) && (group == test_group);

}

EXPORT_SYMBOL_GPL(vfio_external_group_match_file);



/**

 * vfio_file_iommu_group - Return the struct iommu_group for the vfio group file

 * @file: VFIO group file

include/linux/vfio.h

+0 −2
Original line number Diff line number Diff line
@@ -138,8 +138,6 @@ int vfio_mig_get_next_state(struct vfio_device *device, 
 */

extern struct vfio_group *vfio_group_get_external_user(struct file *filep);

extern void vfio_group_put_external_user(struct vfio_group *group);

extern bool vfio_external_group_match_file(struct vfio_group *group,

					   struct file *filep);

extern struct iommu_group *vfio_file_iommu_group(struct file *file);

extern long vfio_external_check_extension(struct vfio_group *group,

					  unsigned long arg);

virt/kvm/vfio.c

+1 −18
Original line number Diff line number Diff line
@@ -49,22 +49,6 @@ static struct vfio_group *kvm_vfio_group_get_external_user(struct file *filep) 
	return vfio_group;

}



static bool kvm_vfio_external_group_match_file(struct vfio_group *group,

					       struct file *filep)

{

	bool ret, (*fn)(struct vfio_group *, struct file *);



	fn = symbol_get(vfio_external_group_match_file);

	if (!fn)

		return false;



	ret = fn(group, filep);



	symbol_put(vfio_external_group_match_file);



	return ret;

}



static void kvm_vfio_group_put_external_user(struct vfio_group *vfio_group)

{

	void (*fn)(struct vfio_group *);
@@ -239,8 +223,7 @@ static int kvm_vfio_group_del(struct kvm_device *dev, unsigned int fd) 
	mutex_lock(&kv->lock);



	list_for_each_entry(kvg, &kv->group_list, node) {

		if (!kvm_vfio_external_group_match_file(kvg->vfio_group,

							f.file))

		if (kvg->file != f.file)

			continue;



		list_del(&kvg->node);