From 3b77daa5efe1cb343ee498ade6ee58c8ada58074 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 22 Jun 2021 10:57:33 -0700 Subject: [PATCH] KVM: x86/mmu: WARN on any reserved SPTE value when making a valid SPTE Replace make_spte()'s WARN on a collision with the magic MMIO value with a generic WARN on reserved bits being set (including EPT's reserved WX combination). Warning on any reserved bits covers MMIO, A/D tracking bits with PAE paging, and in theory any future goofs that are introduced. Opportunistically convert to ONCE behavior to avoid spamming the kernel log, odds are very good that if KVM screws up one SPTE, it will botch all SPTEs for the same MMU. Signed-off-by: Sean Christopherson Message-Id: <20210622175739.3610207-49-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/spte.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/mmu/spte.c b/arch/x86/kvm/mmu/spte.c index 246e61e..3e97cdb 100644 --- a/arch/x86/kvm/mmu/spte.c +++ b/arch/x86/kvm/mmu/spte.c @@ -175,7 +175,10 @@ int make_spte(struct kvm_vcpu *vcpu, unsigned int pte_access, int level, spte = mark_spte_for_access_track(spte); out: - WARN_ON(is_mmio_spte(spte)); + WARN_ONCE(is_rsvd_spte(&vcpu->arch.mmu->shadow_zero_check, spte, level), + "spte = 0x%llx, level = %d, rsvd bits = 0x%llx", spte, level, + get_rsvd_bits(&vcpu->arch.mmu->shadow_zero_check, spte, level)); + *new_spte = spte; return ret; } -- 2.7.4