On Fri, Jul 28, 2023 at 01:56:05PM -0300, Jason Gunthorpe wrote: > On Fri, Jul 28, 2023 at 09:37:21AM +0000, Tian, Kevin wrote: > > > From: Yi Liu <yi.l.liu@xxxxxxxxx> > > > Sent: Monday, July 24, 2023 7:04 PM > > > > > > + * @domain_alloc_user: allocate a user iommu domain corresponding to > > > the input > > > + * @hwpt_type that is defined as enum iommu_hwpt_type in the > > > + * include/uapi/linux/iommufd.h. A returning domain will be > > > + * set to an IOMMU_DOMAIN_NESTED type, upon valid > > > @user_data > > > + * and @parent that is a kernel-managed domain. Otherwise, > > > + * it will be set to an IOMMU_DOMAIN_UNMANAGED type. > > > Return > > > + * ERR_PTR on allocation failure. > > > > "If @user_data is valid and @parent points to a kernel-managed domain, > > the returning domain is set to IOMMU_DOMAIN_NESTED type. Otherwise > > it is set to IOMMU_DOMAIN_UNMANAGED type." > > "If @user_data is valid and @parent points to a kernel-managed domain, > then the returned domain must be the IOMMU_DOMAIN_NESTED type. Otherwise > the returned domain is IOMMU_DOMAIN_UNMANAGED." > > Notice the detail that this API expects the driver to set the type and > fully initialize the domain, including the generic iommu_domain > struct, which is different than alloc_domain. > > When we implement this in drivers we should tidy this so all the alloc > flows fully initialize the domain internally. Changed to: + * @domain_alloc_user: allocate a user iommu domain corresponding to the input + * @hwpt_type that is defined as enum iommu_hwpt_type in the + * include/uapi/linux/iommufd.h. Different from domain_alloc + * it requires iommu driver to fully initialize a new domain + * including the generic iommu_domain struct. Upon success, + * if the @user_data is valid and the @parent points to a + * kernel-managed domain, the type of the new domain must be + * IOMMU_DOMAIN_NESTED, otherwise be IOMMU_DOMAIN_UNMANAGED. + * Upon failure, ERR_PTR must be returned. Thanks Nic
