[PATCH v4 05/28] KVM: x86/mmu: WARN if KVM attempts to map into an invalid TDP MMU root

[Sean Christopherson]

When mapping into the TDP MMU, WARN (if KVM_PROVE_MMU=y) if the root is
invalid, e.g. if KVM is attempting to insert a mapping without checking if
the information and MMU context is fresh.

Signed-off-by: Sean Christopherson <seanjc@xxxxxxxxxx>
---
 arch/x86/kvm/mmu/tdp_mmu.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c
index c5734ca5c17d..440fd8f80397 100644
--- a/arch/x86/kvm/mmu/tdp_mmu.c
+++ b/arch/x86/kvm/mmu/tdp_mmu.c
@@ -1273,6 +1273,8 @@ int kvm_tdp_mmu_map(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault)
 	struct kvm_mmu_page *sp;
 	int ret = RET_PF_RETRY;
 
+	KVM_MMU_WARN_ON(!root || root->role.invalid);
+
 	kvm_mmu_hugepage_adjust(vcpu, fault);
 
 	trace_kvm_mmu_spte_requested(fault);
-- 
2.51.1.930.gacf6e81ea2-goog