[PATCH v4 05/28] KVM: x86/mmu: WARN if KVM attempts to map into an invalid TDP MMU root
From: Sean Christopherson <seanjc@google.com>
Date: 2025-10-30 20:10:12
Also in:
kvm, kvm-riscv, kvmarm, linux-arm-kernel, linux-coco, linux-mips, linux-riscv, lkml, loongarch
Subsystem:
kernel virtual machine for x86 (kvm/x86), the rest, x86 architecture (32-bit and 64-bit) · Maintainers:
Sean Christopherson, Paolo Bonzini, Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen
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@google.com> --- 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