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: Kevin Tian <[email protected]> Reviewed-by: Pranjal Shrivastava <[email protected]> Signed-off-by: Jason Gunthorpe <[email protected]> --- drivers/vfio/vfio_main.c | 56 +++++++++++++++++++++++++++++++++++++--- include/linux/vfio.h | 4 +++ 2 files changed, 56 insertions(+), 4 deletions(-) diff --git a/drivers/vfio/vfio_main.c b/drivers/vfio/vfio_main.c index f056e82ba35075..48d034aede46fc 100644 --- a/drivers/vfio/vfio_main.c +++ b/drivers/vfio/vfio_main.c @@ -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: diff --git a/include/linux/vfio.h b/include/linux/vfio.h index be5fcf8432e8d5..6311ddc837701d 100644 --- a/include/linux/vfio.h +++ b/include/linux/vfio.h @@ -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); -- 2.43.0
