On Fri, Jul 14, 2023, Yan Zhao wrote: > Split a single gfn zap range (specifially range [0, ~0UL)) to smaller > ranges according to current memslot layout when guest MTRRs are honored. > > Though vCPUs have been serialized to perform kvm_zap_gfn_range() for MTRRs > updates and CR0.CD toggles, contention caused rescheduling cost is still > huge when there're concurrent page fault holding mmu_lock for read. Unless the pre-check doesn't work for some reason, I definitely want to avoid this patch. This is a lot of complexity that, IIUC, is just working around a problem elsewhere in KVM. > Split a single huge zap range according to the actual memslot layout can > reduce unnecessary transversal and yielding cost in tdp mmu. > Also, it can increase the chances for larger ranges to find existing ranges > to zap in zap list. > > Signed-off-by: Yan Zhao <yan.y.zhao@xxxxxxxxx> > ---
