From 8046d29dde17002523f94d3e6e0ebe486ce52166 Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Thu, 12 Jun 2025 00:47:44 -0400 Subject: [PATCH] KVM: x86/mmu: Reject direct bits in gpa passed to KVM_PRE_FAULT_MEMORY Only let userspace pass the same addresses that were used in KVM_SET_USER_MEMORY_REGION (or KVM_SET_USER_MEMORY_REGION2); gpas in the the upper half of the address space are an implementation detail of TDX and KVM. Extracted from a patch by Sean Christopherson . Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu/mmu.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index a4040578b537..4e06e2e89a8f 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4903,6 +4903,9 @@ long kvm_arch_vcpu_pre_fault_memory(struct kvm_vcpu *vcpu, if (!vcpu->kvm->arch.pre_fault_allowed) return -EOPNOTSUPP; + if (kvm_is_gfn_alias(vcpu->kvm, gpa_to_gfn(range->gpa))) + return -EINVAL; + /* * reload is efficient when called repeatedly, so we can do it on * every iteration. -- 2.25.1