On Tue, Dec 05, 2023 at 02:40:28PM +0800, Yan Zhao wrote: > On Mon, Dec 04, 2023 at 11:09:45AM -0400, Jason Gunthorpe wrote: > > On Sat, Dec 02, 2023 at 05:20:41PM +0800, Yan Zhao wrote: > > > On KVM invalidates mappings that are shared to IOMMU stage 2 paging > > > structures, IOMMU driver needs to invalidate hardware TLBs accordingly. > > > > > > The new op cache_invalidate_kvm is called from IOMMUFD to invalidate > > > hardware TLBs upon receiving invalidation notifications from KVM. > > > > Why? > > > > SVA hooks the invalidation directly to the mm, shouldn't KVM also hook > > the invalidation directly from the kvm? Why do we need to call a chain > > of function pointers? iommufd isn't adding any value in the chain > > here. > Do you prefer IOMMU vendor driver to register as importer to KVM directly? > Then IOMMUFD just passes "struct kvm_tdp_fd" to IOMMU vendor driver for domain > creation. Yes, this is what we did for SVA Function pointers are slow these days, so it is preferred to go directly. Jason
