On Thu, Aug 10, 2023 at 09:36:37PM +0100, Joao Martins wrote: > > Yes, the "domain_default_ops" is basically a transitional hack to > > help migrate to narrowly defined per-usage domain ops. > > > > eg things like blocking and identity should not have mapping ops. > > > My earlier point was more about not what 'domain_default_ops' represents > but that it's a pointer. Shared by everyone (devices and domains alike). But you > sort of made it clear that it's OK to duplicate it to not have dirty tracking. > The duplication is what I felt a little odd. Well, it is one path, we could also add a dirty_ops to the domain. Hard to say which is better. > (...) I wasn't quite bodging, just trying to parallelize what was bus cleanup > could be tackling domain/device-independent ops without them being global. Maybe > I read too much into it hence my previous question. domain_alloc_user bypasses the bus cleanup > > Return the IOMMU_CAP_DIRTY as generic data in the new GET_INFO > > I have this one here: > > https://lore.kernel.org/linux-iommu/20230518204650.14541-14-joao.m.martins@xxxxxxxxxx/ > > I can rework to GET_HW_INFO but it really needs to be generic bits of data and > not iommu hw specific e.g. that translates into device_iommu_capable() cap > checking. Yes, HW_INFO seems the right way. Just add a __aligned_u64 out_capabilities; To that struct iommu_hw_info and fill it with generic code. > > Accept some generic flag in the alloc_hwpt requesting dirty > > Pass generic flags down to the driver. > > Reject set flags and drivers that don't implement alloc_domain_user. > > Driver refuses to attach the dirty enabled domain to places that do > > dirty tracking. > > This is already done, and so far I have an unsigned long flags to > domain_alloc_user() and probably be kept defining it as > iommu-domain-feature bit Yes a flag in some way is the best choice > (unless it's better to follow similar direction as hwpt_type like in > domain_alloc_user). And gets stored as iommu_domain::flags, like this series > had. Though if majority of driver rejection flows via alloc_domain_user only > (which has a struct device), perhaps it's not even needed to store as a new > iommu_domain::flags Right, we don't need to reflect it back if the dirty ops are NULL. Jason
