Commit b1a3b5c6 authored by Yi Liu's avatar Yi Liu Committed by Alex Williamson
Browse files

vfio: Allocate per device file structure 



This is preparation for adding vfio device cdev support. vfio device
cdev requires:
1) A per device file memory to store the kvm pointer set by KVM. It will
   be propagated to vfio_device:kvm after the device cdev file is bound
   to an iommufd.
2) A mechanism to block device access through device cdev fd before it
   is bound to an iommufd.

To address the above requirements, this adds a per device file structure
named vfio_device_file. For now, it's only a wrapper of struct vfio_device
pointer. Other fields will be added to this per file structure in future
commits.

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/20230718135551.6592-2-yi.l.liu@intel.com


Signed-off-by: default avatarAlex Williamson <alex.williamson@redhat.com>
parent 71791b92

drivers/vfio/group.c

+11 −2
Original line number Diff line number Diff line
@@ -218,19 +218,26 @@ void vfio_device_group_close(struct vfio_device *device) 


static struct file *vfio_device_open_file(struct vfio_device *device)

{

	struct vfio_device_file *df;

	struct file *filep;

	int ret;



	df = vfio_allocate_device_file(device);

	if (IS_ERR(df)) {

		ret = PTR_ERR(df);

		goto err_out;

	}



	ret = vfio_device_group_open(device);

	if (ret)

		goto err_out;

		goto err_free;



	/*

	 * We can't use anon_inode_getfd() because we need to modify

	 * the f_mode flags directly to allow more than just ioctls

	 */

	filep = anon_inode_getfile("[vfio-device]", &vfio_device_fops,

				   device, O_RDWR);

				   df, O_RDWR);

	if (IS_ERR(filep)) {

		ret = PTR_ERR(filep);

		goto err_close_device;
@@ -254,6 +261,8 @@ static struct file *vfio_device_open_file(struct vfio_device *device) 


err_close_device:

	vfio_device_group_close(device);

err_free:

	kfree(df);

err_out:

	return ERR_PTR(ret);

}

drivers/vfio/vfio.h

+6 −0
Original line number Diff line number Diff line
@@ -16,11 +16,17 @@ struct iommufd_ctx; 
struct iommu_group;

struct vfio_container;



struct vfio_device_file {

	struct vfio_device *device;

};



void vfio_device_put_registration(struct vfio_device *device);

bool vfio_device_try_get_registration(struct vfio_device *device);

int vfio_device_open(struct vfio_device *device, struct iommufd_ctx *iommufd);

void vfio_device_close(struct vfio_device *device,

		       struct iommufd_ctx *iommufd);

struct vfio_device_file *

vfio_allocate_device_file(struct vfio_device *device);



extern const struct file_operations vfio_device_fops;

drivers/vfio/vfio_main.c

+26 −5
Original line number Diff line number Diff line
@@ -419,6 +419,20 @@ static bool vfio_assert_device_open(struct vfio_device *device) 
	return !WARN_ON_ONCE(!READ_ONCE(device->open_count));

}



struct vfio_device_file *

vfio_allocate_device_file(struct vfio_device *device)

{

	struct vfio_device_file *df;



	df = kzalloc(sizeof(*df), GFP_KERNEL_ACCOUNT);

	if (!df)

		return ERR_PTR(-ENOMEM);



	df->device = device;



	return df;

}



static int vfio_device_first_open(struct vfio_device *device,

				  struct iommufd_ctx *iommufd)

{
@@ -532,12 +546,15 @@ static inline void vfio_device_pm_runtime_put(struct vfio_device *device) 
 */

static int vfio_device_fops_release(struct inode *inode, struct file *filep)

{

	struct vfio_device *device = filep->private_data;

	struct vfio_device_file *df = filep->private_data;

	struct vfio_device *device = df->device;



	vfio_device_group_close(device);



	vfio_device_put_registration(device);



	kfree(df);



	return 0;

}
@@ -1102,7 +1119,8 @@ static int vfio_ioctl_device_feature(struct vfio_device *device, 
static long vfio_device_fops_unl_ioctl(struct file *filep,

				       unsigned int cmd, unsigned long arg)

{

	struct vfio_device *device = filep->private_data;

	struct vfio_device_file *df = filep->private_data;

	struct vfio_device *device = df->device;

	int ret;



	ret = vfio_device_pm_runtime_get(device);
@@ -1129,7 +1147,8 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, 
static ssize_t vfio_device_fops_read(struct file *filep, char __user *buf,

				     size_t count, loff_t *ppos)

{

	struct vfio_device *device = filep->private_data;

	struct vfio_device_file *df = filep->private_data;

	struct vfio_device *device = df->device;



	if (unlikely(!device->ops->read))

		return -EINVAL;
@@ -1141,7 +1160,8 @@ static ssize_t vfio_device_fops_write(struct file *filep, 
				      const char __user *buf,

				      size_t count, loff_t *ppos)

{

	struct vfio_device *device = filep->private_data;

	struct vfio_device_file *df = filep->private_data;

	struct vfio_device *device = df->device;



	if (unlikely(!device->ops->write))

		return -EINVAL;
@@ -1151,7 +1171,8 @@ static ssize_t vfio_device_fops_write(struct file *filep, 


static int vfio_device_fops_mmap(struct file *filep, struct vm_area_struct *vma)

{

	struct vfio_device *device = filep->private_data;

	struct vfio_device_file *df = filep->private_data;

	struct vfio_device *device = df->device;



	if (unlikely(!device->ops->mmap))

		return -EINVAL;