Commit 34aeeecd authored by Yi Liu's avatar Yi Liu Committed by Alex Williamson
Browse files

vfio: Accept vfio device file in the KVM facing kAPI 



This makes the vfio file kAPIs to accept vfio device files, also a
preparation for vfio device cdev support.

For the kvm set with vfio device file, kvm pointer is stored in struct
vfio_device_file, and use kvm_ref_lock to protect kvm set and kvm
pointer usage within VFIO. This kvm pointer will be set to vfio_device
after device file is bound to iommufd in the cdev path.

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Tested-by: default avatarTerrence Xu <terrence.xu@intel.com>
Tested-by: default avatarNicolin Chen <nicolinc@nvidia.com>
Tested-by: default avatarMatthew Rosato <mjrosato@linux.ibm.com>
Tested-by: default avatarYanting Jiang <yanting.jiang@intel.com>
Tested-by: default avatarShameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Tested-by: default avatarZhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: default avatarYi Liu <yi.l.liu@intel.com>
Link: https://lore.kernel.org/r/20230718135551.6592-4-yi.l.liu@intel.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent b1a59be8

drivers/vfio/vfio.h

+3 −0
Original line number Diff line number Diff line
@@ -18,6 +18,9 @@ struct vfio_container; 


struct vfio_device_file {

	struct vfio_device *device;



	spinlock_t kvm_ref_lock; /* protect kvm field */

	struct kvm *kvm;

};



void vfio_device_put_registration(struct vfio_device *device);

drivers/vfio/vfio_main.c

+35 −1
Original line number Diff line number Diff line
@@ -429,6 +429,7 @@ vfio_allocate_device_file(struct vfio_device *device) 
		return ERR_PTR(-ENOMEM);



	df->device = device;

	spin_lock_init(&df->kvm_ref_lock);



	return df;

}
@@ -1190,13 +1191,23 @@ const struct file_operations vfio_device_fops = { 
	.mmap		= vfio_device_fops_mmap,

};



static struct vfio_device *vfio_device_from_file(struct file *file)

{

	struct vfio_device_file *df = file->private_data;



	if (file->f_op != &vfio_device_fops)

		return NULL;

	return df->device;

}



/**

 * vfio_file_is_valid - True if the file is valid vfio file

 * @file: VFIO group file or VFIO device file

 */

bool vfio_file_is_valid(struct file *file)

{

	return vfio_group_from_file(file);

	return vfio_group_from_file(file) ||

	       vfio_device_from_file(file);

}

EXPORT_SYMBOL_GPL(vfio_file_is_valid);
@@ -1211,16 +1222,36 @@ EXPORT_SYMBOL_GPL(vfio_file_is_valid); 
 */

bool vfio_file_enforced_coherent(struct file *file)

{

	struct vfio_device *device;

	struct vfio_group *group;



	group = vfio_group_from_file(file);

	if (group)

		return vfio_group_enforced_coherent(group);



	device = vfio_device_from_file(file);

	if (device)

		return device_iommu_capable(device->dev,

					    IOMMU_CAP_ENFORCE_CACHE_COHERENCY);



	return true;

}

EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);



static void vfio_device_file_set_kvm(struct file *file, struct kvm *kvm)

{

	struct vfio_device_file *df = file->private_data;



	/*

	 * The kvm is first recorded in the vfio_device_file, and will

	 * be propagated to vfio_device::kvm when the file is bound to

	 * iommufd successfully in the vfio device cdev path.

	 */

	spin_lock(&df->kvm_ref_lock);

	df->kvm = kvm;

	spin_unlock(&df->kvm_ref_lock);

}



/**

 * vfio_file_set_kvm - Link a kvm with VFIO drivers

 * @file: VFIO group file or VFIO device file
@@ -1236,6 +1267,9 @@ void vfio_file_set_kvm(struct file *file, struct kvm *kvm) 
	group = vfio_group_from_file(file);

	if (group)

		vfio_group_set_kvm(group, kvm);



	if (vfio_device_from_file(file))

		vfio_device_file_set_kvm(file, kvm);

}

EXPORT_SYMBOL_GPL(vfio_file_set_kvm);