On Fri, Mar 25, 2022 at 4:31 PM Vipin Sharma <vipinsh@xxxxxxxxxx> wrote:
>
> Avoid calling handlers on empty rmap entries and skip to the next non
> empty rmap entry.
>
> Empty rmap entries are noop in handlers.
>
> Signed-off-by: Vipin Sharma <vipinsh@xxxxxxxxxx>
> Suggested-by: Sean Christopherson <seanjc@xxxxxxxxxx>
> Change-Id: I8abf0f4d82a2aae4c5d58b80bcc17ffc30785ffc
nit: Omit Change-Id tags from upstream commits.
> ---
> arch/x86/kvm/mmu/mmu.c | 9 ++++++---
> 1 file changed, 6 insertions(+), 3 deletions(-)
>
> diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
> index 51671cb34fb6..f296340803ba 100644
> --- a/arch/x86/kvm/mmu/mmu.c
> +++ b/arch/x86/kvm/mmu/mmu.c
> @@ -1499,11 +1499,14 @@ static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator)
> return !!iterator->rmap;
> }
>
> -static void slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator)
> +static noinline void
What is the reason to add noinline?
> +slot_rmap_walk_next(struct slot_rmap_walk_iterator *iterator)
> {
> - if (++iterator->rmap <= iterator->end_rmap) {
> + while (++iterator->rmap <= iterator->end_rmap) {
> iterator->gfn += (1UL << KVM_HPAGE_GFN_SHIFT(iterator->level));
> - return;
> +
> + if (iterator->rmap->val)
> + return;
> }
>
> if (++iterator->level > iterator->end_level) {
>
> base-commit: c9b8fecddb5bb4b67e351bbaeaa648a6f7456912
> --
> 2.35.1.1021.g381101b075-goog
>
