On Wed, Dec 14, 2022 at 2:12 AM Sean Christopherson <seanjc@xxxxxxxxxx> wrote: > > On Mon, Dec 12, 2022, Lai Jiangshan wrote: > > From: Lai Jiangshan <jiangshan.ljs@xxxxxxxxxxxx> > > > > Sometimes when the guest updates its pagetable, it adds only new gptes > > to it without changing any existed one, so there is no point to update > > the sptes for these existed gptes. > > > > Also when the sptes for these unchanged gptes are updated, the AD > > bits are also removed since make_spte() is called with prefetch=true > > which might result unneeded TLB flushing. > > If either of the proposed changes is kept, please move this to a separate patch. > Skipping updates for PTEs with the same protections is separate logical change > from skipping updates when making the SPTE writable. > Did as you suggested: https://lore.kernel.org/lkml/20230105095848.6061-5-jiangshanlai@xxxxxxxxx/
