Commit 3a056757 authored by Sean Christopherson's avatar Sean Christopherson Committed by Paolo Bonzini
Browse files

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: default avatarYan Zhao <yan.y.zhao@intel.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Message-Id: <20221019165618.927057-9-seanjc@google.com>
Signed-off-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
parent 76901e56

arch/x86/kvm/mmu/mmu.c

+3 −4
Original line number Diff line number Diff line
@@ -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);

		}



		if (need_resched() || rwlock_needbreak(&kvm->mmu_lock)) {

			kvm_mmu_remote_flush_or_zap(kvm, &invalid_list, flush);