From 3a05675722250a522c148f6de0cc190f407c4bb5 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 19 Oct 2022 16:56:18 +0000 Subject: [PATCH] KVM: x86/mmu: WARN if TDP MMU SP disallows hugepage after being zapped Extend the accounting sanity check in kvm_recover_nx_huge_pages() to the TDP MMU, i.e. verify that zapping a shadow page unaccounts the disallowed NX huge page regardless of the MMU type. Recovery runs while holding mmu_lock for write and so it should be impossible to get false positives on the WARN. Suggested-by: Yan Zhao Signed-off-by: Sean Christopherson Message-Id: <20221019165618.927057-9-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index efce5e4e24c3..93c389eaf471 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -6875,12 +6875,11 @@ static void kvm_recover_nx_huge_pages(struct kvm *kvm) struct kvm_mmu_page, possible_nx_huge_page_link); WARN_ON_ONCE(!sp->nx_huge_page_disallowed); - if (is_tdp_mmu_page(sp)) { + if (is_tdp_mmu_page(sp)) flush |= kvm_tdp_mmu_zap_sp(kvm, sp); - } else { + else kvm_mmu_prepare_zap_page(kvm, sp, &invalid_list); - WARN_ON_ONCE(sp->nx_huge_page_disallowed); - } + WARN_ON_ONCE(sp->nx_huge_page_disallowed); if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) { kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush); -- 2.11.0