On Thu, Feb 23, 2023, Yu Zhao wrote:
> On Thu, Feb 23, 2023 at 10:14 AM Sean Christopherson <sea...@google.com>
> wrote:
> >
> > On Thu, Feb 16, 2023, Yu Zhao wrote:
> > > diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> > > index 9c60384b5ae0..1b465df4a93d 100644
> > > --- a/virt/kvm/kvm_main.c
> > > +++ b/virt/kvm/kvm_main.c
> > > @@ -875,6 +875,63 @@ static int kvm_mmu_notifier_clear_young(struct
> > > mmu_notifier *mn,
> > > return kvm_handle_hva_range_no_flush(mn, start, end, kvm_age_gfn);
> > > }
> > >
> > > +static bool kvm_test_clear_young(struct kvm *kvm, unsigned long start,
> > > + unsigned long end, unsigned long *bitmap)
> > > +{
> > > + int i;
> > > + int key;
> > > + bool success = true;
> > > +
> > > + trace_kvm_age_hva(start, end);
> > > +
> > > + key = srcu_read_lock(&kvm->srcu);
> > > +
> > > + for (i = 0; i < KVM_ADDRESS_SPACE_NUM; i++) {
> > > + struct interval_tree_node *node;
> > > + struct kvm_memslots *slots = __kvm_memslots(kvm, i);
> > > +
> > > + kvm_for_each_memslot_in_hva_range(node, slots, start, end -
> > > 1) {
> > > + gfn_t lsb_gfn;
> > > + unsigned long hva_start, hva_end;
> > > + struct kvm_gfn_range range = {
> > > + .slot = container_of(node, struct
> > > kvm_memory_slot,
> > > +
> > > hva_node[slots->node_idx]),
> > > + };
> > > +
> > > + hva_start = max(start, range.slot->userspace_addr);
> > > + hva_end = min(end - 1, range.slot->userspace_addr +
> > > + range.slot->npages *
> > > PAGE_SIZE - 1);
> > > +
> > > + range.start = hva_to_gfn_memslot(hva_start,
> > > range.slot);
> > > + range.end = hva_to_gfn_memslot(hva_end, range.slot)
> > > + 1;
> > > +
> > > + if (WARN_ON_ONCE(range.end <= range.start))
> > > + continue;
> >
> > Extend __kvm_handle_hva_range() instead of copy-pasting. At a very quick
> > glance,
> > I believe all that is needed is (minus sanity checks):
>
> Yes, will do.
>
> I do need to add one more parameter to kvm_gfn_range, because that's
> what the current kvm_arch_test_clear_young() needs, assuming that
> function is acceptable.
>
> Also, just a side note, from MM's POV, the following in
> __kvm_handle_hva_range() seems to forget to handle end == 0, if that's
> possible?
It's handled by the WARN_ON_ONCE() at the very top:
static __always_inline int __kvm_handle_hva_range(struct kvm *kvm,
const struct kvm_hva_range
*range)
{
if (WARN_ON_ONCE(range->end <= range->start))
return 0;
>
> hva_end = min(range->end, slot->userspace_addr + (slot->npages <<
> PAGE_SHIFT));
