From bde9f9d27e2b87eaeaaa1f87b5e04272aae89a13 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Tue, 27 Feb 2024 18:41:42 -0800 Subject: [PATCH] KVM: x86/mmu: Explicitly disallow private accesses to emulated MMIO Explicitly detect and disallow private accesses to emulated MMIO in kvm_handle_noslot_fault() instead of relying on kvm_faultin_pfn_private() to perform the check. This will allow the page fault path to go straight to kvm_handle_noslot_fault() without bouncing through __kvm_faultin_pfn(). Signed-off-by: Sean Christopherson Message-ID: <20240228024147.41573-12-seanjc@google.com> Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index ac7cdbb9ee0ae..f3cd70419e42d 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -3261,6 +3261,11 @@ static int kvm_handle_noslot_fault(struct kvm_vcpu *vcpu, { gva_t gva = fault->is_tdp ? 0 : fault->addr; + if (fault->is_private) { + kvm_mmu_prepare_memory_fault_exit(vcpu, fault); + return -EFAULT; + } + vcpu_cache_mmio_info(vcpu, gva, fault->gfn, access & shadow_mmio_access_mask); -- 2.30.2