Re: [RFC 2/8] iommufd: replace attach_fn with a structure

Baolu Lu
2023-09-27T03:10:46Z

On 9/26/23 5:26 PM, Yi Liu wrote:
> Most of the core logic before conducting the actual device attach/
> replace operation can be shared with pasid attach/replace. Create
> a new structure so more information (e.g. pasid) can be later added
> along with the attach_fn.
>
> Signed-off-by: Kevin Tian<kevin.tian@intel.com>
> Signed-off-by: Yi Liu<yi.l.liu@intel.com>
> ---
> drivers/iommu/iommufd/device.c | 35 ++++++++++++++++---------
> drivers/iommu/iommufd/iommufd_private.h | 8 ++++++
> 2 files changed, 30 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/iommu/iommufd/device.c b/drivers/iommu/iommufd/device.c
> index 645ab5d290fe..4fa4153c5df7 100644
> --- a/drivers/iommu/iommufd/device.c
> +++ b/drivers/iommu/iommufd/device.c
> @@ -597,8 +597,11 @@ iommufd_device_do_replace(struct iommufd_device *idev,
> return ERR_PTR(rc);
> }
>
> -typedef struct iommufd_hw_pagetable *(*attach_fn)(
> - struct iommufd_device *idev, struct iommufd_hw_pagetable *hwpt);
> +static struct iommufd_hw_pagetable *do_attach(struct iommufd_device *idev,
> + struct iommufd_hw_pagetable *hwpt, struct attach_data *data)
> +{
> + return data->attach_fn(idev, hwpt);
> +}

I assume that this change was made because we need to pass the pasid
value to the attach_fn() callback.

If so, how about passing it directly to attach_fn() function?

typedef struct iommufd_hw_pagetable *(*attach_fn)(
struct iommufd_device *idev,
struct iommufd_hw_pagetable *hwpt,
ioasid_t pasid);

In no pasid case, use IOMMU_NO_PASID.

Best regards,
baolu