linux-kernel - [PATCH v2 03/18] KVM: x86/mmu: WARN if PAE roots linger after kvm_mmu

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Date:   Thu, 17 Feb 2022 16:03:25 -0500
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Cc:     seanjc@...gle.com
Subject: [PATCH v2 03/18] KVM: x86/mmu: WARN if PAE roots linger after kvm_mmu_unload

Signed-off-by: Paolo Bonzini <pbonzini@...hat.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 296f8723f9ae..a67071ac80f3 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -5086,12 +5086,21 @@ 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