Commit 775f726a authored by Jason Gunthorpe's avatar Jason Gunthorpe Committed by Alex Williamson
Browse files

vfio: Add get_region_info_caps op 



This op does the copy to/from user for the info and can return back
a cap chain through a vfio_info_cap * result.

Reviewed-by: default avatarKevin Tian <kevin.tian@intel.com>
Reviewed-by: default avatarPranjal Shrivastava <praan@google.com>
Signed-off-by: default avatarJason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/15-v2-2a9e24d62f1b+e10a-vfio_get_region_info_op_jgg@nvidia.com


Signed-off-by: default avatarAlex Williamson <alex@shazbot.org>
parent f9785950

drivers/vfio/vfio_main.c

+52 −4
Original line number Diff line number Diff line
@@ -1259,6 +1259,57 @@ static int vfio_ioctl_device_feature(struct vfio_device *device, 
	}

}



static long vfio_get_region_info(struct vfio_device *device,

				 struct vfio_region_info __user *arg)

{

	unsigned long minsz = offsetofend(struct vfio_region_info, offset);

	struct vfio_region_info info = {};

	struct vfio_info_cap caps = {};

	int ret;



	if (copy_from_user(&info, arg, minsz))

		return -EFAULT;

	if (info.argsz < minsz)

		return -EINVAL;



	if (device->ops->get_region_info_caps) {

		ret = device->ops->get_region_info_caps(device, &info, &caps);

		if (ret)

			goto out_free;



		if (caps.size) {

			info.flags |= VFIO_REGION_INFO_FLAG_CAPS;

			if (info.argsz < sizeof(info) + caps.size) {

				info.argsz = sizeof(info) + caps.size;

				info.cap_offset = 0;

			} else {

				vfio_info_cap_shift(&caps, sizeof(info));

				if (copy_to_user(arg + 1, caps.buf,

						 caps.size)) {

					ret = -EFAULT;

					goto out_free;

				}

				info.cap_offset = sizeof(info);

			}

		}



		if (copy_to_user(arg, &info, minsz)) {

			ret = -EFAULT;

			goto out_free;

		}

	} else if (device->ops->get_region_info) {

		ret = device->ops->get_region_info(device, arg);

		if (ret)

			return ret;

	} else {

		return -EINVAL;

	}



out_free:

	kfree(caps.buf);

	return ret;

}



static long vfio_device_fops_unl_ioctl(struct file *filep,

				       unsigned int cmd, unsigned long arg)

{
@@ -1297,10 +1348,7 @@ static long vfio_device_fops_unl_ioctl(struct file *filep, 
		break;



	case VFIO_DEVICE_GET_REGION_INFO:

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

			ret = -EINVAL;

		else

			ret = device->ops->get_region_info(device, uptr);

		ret = vfio_get_region_info(device, uptr);

		break;



	default:

include/linux/vfio.h

+4 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ struct kvm; 
struct iommufd_ctx;

struct iommufd_device;

struct iommufd_access;

struct vfio_info_cap;



/*

 * VFIO devices can be placed in a set, this allows all devices to share this
@@ -134,6 +135,9 @@ struct vfio_device_ops { 
			 unsigned long arg);

	int	(*get_region_info)(struct vfio_device *vdev,

				   struct vfio_region_info __user *arg);

	int	(*get_region_info_caps)(struct vfio_device *vdev,

					struct vfio_region_info *info,

					struct vfio_info_cap *caps);

	int	(*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);

	void	(*request)(struct vfio_device *vdev, unsigned int count);

	int	(*match)(struct vfio_device *vdev, char *buf);