On Tue, Jul 29, 2025 at 10:27:34PM +0000, Edgecombe, Rick P wrote:
> On Tue, 2025-07-29 at 12:33 -0700, Sean Christopherson wrote:
> > diff --git a/arch/x86/kvm/vmx/tdx.c b/arch/x86/kvm/vmx/tdx.c
> > index 3e0d4edee849..c2ef03f39c32 100644
> > --- a/arch/x86/kvm/vmx/tdx.c
> > +++ b/arch/x86/kvm/vmx/tdx.c
> > @@ -1937,10 +1937,8 @@ static int tdx_handle_ept_violation(struct kvm_vcpu *vcpu)
> >
> > if (vt_is_tdx_private_gpa(vcpu->kvm, gpa)) {
> > if (tdx_is_sept_violation_unexpected_pending(vcpu)) {
> > - pr_warn("Guest access before accepting 0x%llx on vCPU %d\n",
> > - gpa, vcpu->vcpu_id);
> > - kvm_vm_dead(vcpu->kvm);
> > - return -EIO;
> > + kvm_prepare_memory_fault_exit(vcpu, gpa, 0, true, false, true);
> > + return -EFAULT;
> > }
> > /*
> > * Always treat SEPT violations as write faults. Ignore the
>
> The vm_dead was added because mirror EPT will KVM_BUG_ON() if there is an
> attempt to set the mirror EPT entry when it is already present. And the
> unaccepted memory access will trigger an EPT violation for a mirror PTE that is
> already set. I think this is a better solution irrespective of the vm_dead
> changes.
>
> Reviewed-by: Rick Edgecombe <rick.p.edgecombe@xxxxxxxxx>
>
> But hmm, tangentially related, but Yan do we have a similar problem with
> KVM_PRE_FAULT_MEMORY after we started setting pre_fault_allowed during TD
> finalization?
Sean's commit 6385d01eec16 ("KVM: x86/mmu: Don't overwrite shadow-present MMU
SPTEs when prefaulting") should have prevented repeated invocation of
set_external_spte_present() with prefaulted entries.
