On Thu, 2025-08-28 at 14:00 -0700, Sean Christopherson wrote:
> But that's not actually what the code does. The lockdep assert won't trip because
> KVM never removes S-EPT entries under read-lock:
Right
>
> if (is_mirror_sp(sp)) {
> KVM_BUG_ON(shared, kvm);
> remove_external_spte(kvm, gfn, old_spte, level);
> }
>
> Not because KVM actually guarantees -EBUSY is avoided. So the current code is
> flawed, it just doesn't cause problems.
Flawed, as in the lockdep should assert regardless of EBUSY? Seems good to me.
Probably if we wanted to try to call tdx_sept_remove_private_spte() under read
lock with special plans to avoid EBUSY we should think twice anyway.
