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From:   Paolo Bonzini <pbonzini@redhat.com>
To:     linux-kernel@vger.kernel.org, kvm@vger.kernel.org
Cc:     vkuznets@redhat.com, mlevitsk@redhat.com, dmatlack@google.com,
        seanjc@google.com
Subject: [PATCH 04/12] KVM: MMU: WARN if PAE roots linger after kvm_mmu_unload
Date:   Wed,  9 Feb 2022 12:00:12 -0500
Message-Id: <20220209170020.1775368-5-pbonzini@redhat.com>
In-Reply-To: <20220209170020.1775368-1-pbonzini@redhat.com>
References: <20220209170020.1775368-1-pbonzini@redhat.com>
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Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arch/x86/kvm/mmu/mmu.c | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index e0c0f0bc2e8b..7b5765ced928 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5065,12 +5065,21 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
 	return r;
 }
 
+static void __kvm_mmu_unload(struct kvm_vcpu *vcpu, struct kvm_mmu *mmu)
+{
+	int i;
+	kvm_mmu_free_roots(vcpu, mmu, KVM_MMU_ROOTS_ALL);
+	WARN_ON(VALID_PAGE(mmu->root_hpa));
+	if (mmu->pae_root) {
+		for (i = 0; i < 4; ++i)
+			WARN_ON(IS_VALID_PAE_ROOT(mmu->pae_root[i]));
+	}
+}
+
 void kvm_mmu_unload(struct kvm_vcpu *vcpu)
 {
-	kvm_mmu_free_roots(vcpu, &vcpu->arch.root_mmu, KVM_MMU_ROOTS_ALL);
-	WARN_ON(VALID_PAGE(vcpu->arch.root_mmu.root_hpa));
-	kvm_mmu_free_roots(vcpu, &vcpu->arch.guest_mmu, KVM_MMU_ROOTS_ALL);
-	WARN_ON(VALID_PAGE(vcpu->arch.guest_mmu.root_hpa));
+	__kvm_mmu_unload(vcpu, &vcpu->arch.root_mmu);
+	__kvm_mmu_unload(vcpu, &vcpu->arch.guest_mmu);
 }
 
 static bool need_remote_flush(u64 old, u64 new)
-- 
2.31.1