> > > > > > Only *guest permitted* conversion should change the page. I.e only when > > > VMM is dealing with the KVM_HC_MAP_GPA_RANGE hypercall. Not sure if we > > > could just let QEMU ensure this or KVM/guestmemfd should ensure this. > > > > I think it should not be part of the kernel, no need. From a kernel > > perspective userspace has requested a shared/private conversion and if > > it wasn't agreed with the VM then it will explode. > > I'm OK with it now. It's simple if we don't try to recover from the > explosion. Although I see the after explosion processing in kernel is > complex and not sure how it will advance. I see the discussion in another thread about similar issue. That TDX Module BUG causes S-EPT unmap impossible and just KVM_BUG_ON(). But this conversion issue is a little different, usually it's not decent to panic because of userspace request. So may need further error handling, or a KVM/gmemfd kAPI to disallow/allow conversion and prevent more complex error. Thanks, Yilun > > Thanks, > Yilun > > > > > Jason >
