On Thu, Mar 09, 2023 at 12:08:59AM -0800, Yi Liu wrote: > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index 3ef84ee359d2..a269bc62a31c 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -229,6 +229,7 @@ struct iommu_iotlb_gather { > * after use. Return the data buffer if success, or ERR_PTR on > * failure. > * @domain_alloc: allocate iommu domain > + * @domain_alloc_user: allocate user iommu domain > * @probe_device: Add device to iommu driver handling > * @release_device: Remove device from iommu driver handling > * @probe_finalize: Do final setup work after the device is added to an IOMMU > @@ -266,6 +267,9 @@ struct iommu_ops { > > /* Domain allocation and freeing by the iommu driver */ > struct iommu_domain *(*domain_alloc)(unsigned iommu_domain_type); > + struct iommu_domain *(*domain_alloc_user)(struct device *dev, > + struct iommu_domain *parent, > + const void *user_data); Since the kernel does the copy from user and manages the zero fill compat maybe this user_data have a union like Robin suggested. But yes, this is the idea. Reviewed-by: Jason Gunthorpe <jgg@xxxxxxxxxx> Jason