From 6ba1e04fa60787ced4c9049cf7bd6cd0f1b80764 Mon Sep 17 00:00:00 2001 From: Vipin Sharma Date: Mon, 2 May 2022 22:03:47 +0000 Subject: [PATCH] KVM: x86/mmu: Speed up slot_rmap_walk_next for sparsely populated rmaps 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 Suggested-by: Sean Christopherson Message-Id: <20220502220347.174664-1-vipinsh@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index ea4bc08..efe5a3d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1483,9 +1483,11 @@ static bool slot_rmap_walk_okay(struct slot_rmap_walk_iterator *iterator) static void 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) { -- 2.7.4