Commit b1a59be8 authored by Yi Liu's avatar Yi Liu Committed by Alex Williamson
Browse files

vfio: Refine vfio file kAPIs for KVM 



This prepares for making the below kAPIs to accept both group file
and device file instead of only vfio group file.

  bool vfio_file_enforced_coherent(struct file *file);
  void vfio_file_set_kvm(struct file *file, struct kvm *kvm);

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarEric Auger <eric.auger@redhat.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/20230718135551.6592-3-yi.l.liu@intel.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent b1a3b5c6

drivers/vfio/group.c

+17 −36
Original line number Diff line number Diff line
@@ -754,6 +754,15 @@ bool vfio_device_has_container(struct vfio_device *device) 
	return device->group->container;

}



struct vfio_group *vfio_group_from_file(struct file *file)

{

	struct vfio_group *group = file->private_data;



	if (file->f_op != &vfio_group_fops)

		return NULL;

	return group;

}



/**

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

 * @file: VFIO group file
@@ -764,13 +773,13 @@ bool vfio_device_has_container(struct vfio_device *device) 
 */

struct iommu_group *vfio_file_iommu_group(struct file *file)

{

	struct vfio_group *group = file->private_data;

	struct vfio_group *group = vfio_group_from_file(file);

	struct iommu_group *iommu_group = NULL;



	if (!IS_ENABLED(CONFIG_SPAPR_TCE_IOMMU))

		return NULL;



	if (!vfio_file_is_group(file))

	if (!group)

		return NULL;



	mutex_lock(&group->group_lock);
@@ -784,33 +793,20 @@ struct iommu_group *vfio_file_iommu_group(struct file *file) 
EXPORT_SYMBOL_GPL(vfio_file_iommu_group);



/**

 * vfio_file_is_group - True if the file is usable with VFIO aPIS

 * vfio_file_is_group - True if the file is a vfio group file

 * @file: VFIO group file

 */

bool vfio_file_is_group(struct file *file)

{

	return file->f_op == &vfio_group_fops;

	return vfio_group_from_file(file);

}

EXPORT_SYMBOL_GPL(vfio_file_is_group);



/**

 * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file

 *        is always CPU cache coherent

 * @file: VFIO group file

 *

 * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop

 * bit in DMA transactions. A return of false indicates that the user has

 * rights to access additional instructions such as wbinvd on x86.

 */

bool vfio_file_enforced_coherent(struct file *file)

bool vfio_group_enforced_coherent(struct vfio_group *group)

{

	struct vfio_group *group = file->private_data;

	struct vfio_device *device;

	bool ret = true;



	if (!vfio_file_is_group(file))

		return true;



	/*

	 * If the device does not have IOMMU_CAP_ENFORCE_CACHE_COHERENCY then

	 * any domain later attached to it will also not support it. If the cap
@@ -828,28 +824,13 @@ bool vfio_file_enforced_coherent(struct file *file) 
	mutex_unlock(&group->device_lock);

	return ret;

}

EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);



/**

 * vfio_file_set_kvm - Link a kvm with VFIO drivers

 * @file: VFIO group file

 * @kvm: KVM to link

 *

 * When a VFIO device is first opened the KVM will be available in

 * device->kvm if one was associated with the group.

 */

void vfio_file_set_kvm(struct file *file, struct kvm *kvm)

void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm)

{

	struct vfio_group *group = file->private_data;



	if (!vfio_file_is_group(file))

		return;



	spin_lock(&group->kvm_ref_lock);

	group->kvm = kvm;

	spin_unlock(&group->kvm_ref_lock);

}

EXPORT_SYMBOL_GPL(vfio_file_set_kvm);



/**

 * vfio_file_has_dev - True if the VFIO file is a handle for device
@@ -860,9 +841,9 @@ EXPORT_SYMBOL_GPL(vfio_file_set_kvm); 
 */

bool vfio_file_has_dev(struct file *file, struct vfio_device *device)

{

	struct vfio_group *group = file->private_data;

	struct vfio_group *group = vfio_group_from_file(file);



	if (!vfio_file_is_group(file))

	if (!group)

		return false;



	return group == device->group;

drivers/vfio/vfio.h

+3 −0
Original line number Diff line number Diff line
@@ -90,6 +90,9 @@ void vfio_device_group_unregister(struct vfio_device *device); 
int vfio_device_group_use_iommu(struct vfio_device *device);

void vfio_device_group_unuse_iommu(struct vfio_device *device);

void vfio_device_group_close(struct vfio_device *device);

struct vfio_group *vfio_group_from_file(struct file *file);

bool vfio_group_enforced_coherent(struct vfio_group *group);

void vfio_group_set_kvm(struct vfio_group *group, struct kvm *kvm);

bool vfio_device_has_container(struct vfio_device *device);

int __init vfio_group_init(void);

void vfio_group_cleanup(void);

drivers/vfio/vfio_main.c

+49 −0
Original line number Diff line number Diff line
@@ -1190,6 +1190,55 @@ const struct file_operations vfio_device_fops = { 
	.mmap		= vfio_device_fops_mmap,

};



/**

 * 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);

}

EXPORT_SYMBOL_GPL(vfio_file_is_valid);



/**

 * vfio_file_enforced_coherent - True if the DMA associated with the VFIO file

 *        is always CPU cache coherent

 * @file: VFIO group file or VFIO device file

 *

 * Enforced coherency means that the IOMMU ignores things like the PCIe no-snoop

 * bit in DMA transactions. A return of false indicates that the user has

 * rights to access additional instructions such as wbinvd on x86.

 */

bool vfio_file_enforced_coherent(struct file *file)

{

	struct vfio_group *group;



	group = vfio_group_from_file(file);

	if (group)

		return vfio_group_enforced_coherent(group);



	return true;

}

EXPORT_SYMBOL_GPL(vfio_file_enforced_coherent);



/**

 * vfio_file_set_kvm - Link a kvm with VFIO drivers

 * @file: VFIO group file or VFIO device file

 * @kvm: KVM to link

 *

 * When a VFIO device is first opened the KVM will be available in

 * device->kvm if one was associated with the file.

 */

void vfio_file_set_kvm(struct file *file, struct kvm *kvm)

{

	struct vfio_group *group;



	group = vfio_group_from_file(file);

	if (group)

		vfio_group_set_kvm(group, kvm);

}

EXPORT_SYMBOL_GPL(vfio_file_set_kvm);



/*

 * Sub-module support

 */

include/linux/vfio.h

+1 −0
Original line number Diff line number Diff line
@@ -272,6 +272,7 @@ int vfio_mig_get_next_state(struct vfio_device *device, 
 */

struct iommu_group *vfio_file_iommu_group(struct file *file);

bool vfio_file_is_group(struct file *file);

bool vfio_file_is_valid(struct file *file);

bool vfio_file_enforced_coherent(struct file *file);

void vfio_file_set_kvm(struct file *file, struct kvm *kvm);

bool vfio_file_has_dev(struct file *file, struct vfio_device *device);

virt/kvm/vfio.c

+5 −5
Original line number Diff line number Diff line
@@ -64,18 +64,18 @@ static bool kvm_vfio_file_enforced_coherent(struct file *file) 
	return ret;

}



static bool kvm_vfio_file_is_group(struct file *file)

static bool kvm_vfio_file_is_valid(struct file *file)

{

	bool (*fn)(struct file *file);

	bool ret;



	fn = symbol_get(vfio_file_is_group);

	fn = symbol_get(vfio_file_is_valid);

	if (!fn)

		return false;



	ret = fn(file);



	symbol_put(vfio_file_is_group);

	symbol_put(vfio_file_is_valid);



	return ret;

}
@@ -154,8 +154,8 @@ static int kvm_vfio_group_add(struct kvm_device *dev, unsigned int fd) 
	if (!filp)

		return -EBADF;



	/* Ensure the FD is a vfio group FD.*/

	if (!kvm_vfio_file_is_group(filp)) {

	/* Ensure the FD is a vfio FD. */

	if (!kvm_vfio_file_is_valid(filp)) {

		ret = -EINVAL;

		goto err_fput;

	}