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authorVipin Sharma <vipinsh@google.com>2022-05-02 22:03:47 +0000
committerPaolo Bonzini <pbonzini@redhat.com>2022-05-12 09:51:45 -0400
commit6ba1e04fa60787ced4c9049cf7bd6cd0f1b80764 (patch)
tree3b0ff5e8cb74eb99f0e4f306666c05cb6a68ab0e
parent3c5c32457d7da76d077effc08176d3ad2e7536f9 (diff)
downloadlinux-6ba1e04fa60787ced4c9049cf7bd6cd0f1b80764.tar.bz2
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 <vipinsh@google.com> Suggested-by: Sean Christopherson <seanjc@google.com> Message-Id: <20220502220347.174664-1-vipinsh@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index ea4bc085bbf5..efe5a3dca1e0 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) {