From e25c2332346fbd4814d5c9d3d25ba3d0f9646e06 Mon Sep 17 00:00:00 2001 From: James Houghton Date: Tue, 4 Feb 2025 00:40:33 +0000 Subject: [PATCH] KVM: x86/mmu: Skip shadow MMU test_young if TDP MMU reports page as young Reorder the processing of the TDP MMU versus the shadow MMU when aging SPTEs, and skip the shadow MMU entirely in the test-only case if the TDP MMU reports that the page is young, i.e. completely avoid taking mmu_lock if the TDP MMU SPTE is young. Swap the order for the test-and-age helper as well for consistency. Signed-off-by: James Houghton Acked-by: Yu Zhao Link: https://lore.kernel.org/r/20250204004038.1680123-7-jthoughton@google.com Signed-off-by: Sean Christopherson --- arch/x86/kvm/mmu/mmu.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index b73b3c12f76fd..3fc461ebaf055 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1592,15 +1592,15 @@ bool kvm_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { bool young = false; + if (tdp_mmu_enabled) + young = kvm_tdp_mmu_age_gfn_range(kvm, range); + if (kvm_memslots_have_rmaps(kvm)) { write_lock(&kvm->mmu_lock); - young = kvm_rmap_age_gfn_range(kvm, range, false); + young |= kvm_rmap_age_gfn_range(kvm, range, false); write_unlock(&kvm->mmu_lock); } - if (tdp_mmu_enabled) - young |= kvm_tdp_mmu_age_gfn_range(kvm, range); - return young; } @@ -1608,15 +1608,15 @@ bool kvm_test_age_gfn(struct kvm *kvm, struct kvm_gfn_range *range) { bool young = false; - if (kvm_memslots_have_rmaps(kvm)) { + if (tdp_mmu_enabled) + young = kvm_tdp_mmu_test_age_gfn(kvm, range); + + if (!young && kvm_memslots_have_rmaps(kvm)) { write_lock(&kvm->mmu_lock); - young = kvm_rmap_age_gfn_range(kvm, range, true); + young |= kvm_rmap_age_gfn_range(kvm, range, true); write_unlock(&kvm->mmu_lock); } - if (tdp_mmu_enabled) - young |= kvm_tdp_mmu_test_age_gfn(kvm, range); - return young; } -- 2.39.5