On Thu, Jun 20, 2024, Rick Edgecombe wrote: > Force TDX VMs to use the KVM_X86_QUIRK_SLOT_ZAP_ALL behavior. > > TDs cannot use the fast zapping operation to implement memslot deletion for > a couple reasons: > 1. KVM cannot zap TDX private PTEs and re-fault them without coordinating Uber nit, this isn't strictly true, for KVM's definition of "zap" (which is fuzzy and overloaded). KVM _could_ zap and re-fault *leaf* PTEs, e.g. BLOCK+UNBLOCK. It's specifically the full teardown and rebuild of the "fast zap" that doesn't play nice, as the non-leaf S-EPT entries *must* be preserved due to how the TDX module does is refcounting.
