On Thu, Mar 07, 2024 at 09:54:53AM +0800, Baolu Lu wrote: > On 2024/3/7 0:01, Jason Gunthorpe wrote: > > On Wed, Mar 06, 2024 at 11:15:50PM +0800, Zhangfei Gao wrote: > > > Double checked, this does not send flags, 0 is OK, > > > Only domain_alloc_user in iommufd_hwpt_paging_alloc requires flags. > > > > > > In my debug, I need this patch, otherwise NULL pointer errors happen > > > since SVA is not set. > > This is some driver bug, we need to get rid of these > > iommu_dev_enable_feature() requirements. > > Yes. Especially iopf should be independent of SVA. > > The problem in the arm smmu v3 driver is that enabling iopf is actually > done in the enabling SVA path, while the enabling iopf path does nothing > except for some checks. It doesn't matter if iopf is tied with SVA, but > when it comes to delivering iopf to user space, we need to decouple it. Yes. Each driver is going to need to get a to a NOP for the feature things then we can remove them. I did half the ARM driver in my part 2, the iopf bit still needs doing there. Jason
