diff mbox series

[v7,06/18] KVM: x86/mmu: Only check gfn age in shadow MMU if indirect_shadow_pages > 0

Message ID 20240926013506.860253-7-jthoughton@google.com (mailing list archive)
State New, archived
Headers show
Series mm: multi-gen LRU: Walk secondary MMU page tables while aging | expand

Commit Message

James Houghton Sept. 26, 2024, 1:34 a.m. UTC 
Optimize both kvm_age_gfn and kvm_test_age_gfn's interaction with the
shadow MMU by, rather than checking if our memslot has rmaps, check if
there are any indirect_shadow_pages at all.

Signed-off-by: James Houghton <jthoughton@google.com>
---
 arch/x86/kvm/mmu/mmu.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 03df592284ac..b4e543bdf3f0 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -1645,6 +1645,11 @@  static bool kvm_rmap_age_gfn_range(struct kvm *kvm,
 	return young;
 }
 
+static bool kvm_has_shadow_mmu_sptes(struct kvm *kvm)
+{
+	return !tdp_mmu_enabled || READ_ONCE(kvm->arch.indirect_shadow_pages);
+}
+
 bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 {
 	bool young = false;
@@ -1652,7 +1657,7 @@  bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 	if (tdp_mmu_enabled)
 		young = kvm_tdp_mmu_age_gfn_range(kvm, range);
 
-	if (kvm_memslots_have_rmaps(kvm)) {
+	if (kvm_has_shadow_mmu_sptes(kvm)) {
 		write_lock(&kvm->mmu_lock);
 		young |= kvm_rmap_age_gfn_range(kvm, range, false);
 		write_unlock(&kvm->mmu_lock);
@@ -1668,7 +1673,7 @@  bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range)
 	if (tdp_mmu_enabled)
 		young = kvm_tdp_mmu_test_age_gfn(kvm, range);
 
-	if (!young && kvm_memslots_have_rmaps(kvm)) {
+	if (!young && kvm_has_shadow_mmu_sptes(kvm)) {
 		write_lock(&kvm->mmu_lock);
 		young |= kvm_rmap_age_gfn_range(kvm, range, true);
 		write_unlock(&kvm->mmu_lock);