On Thu, Apr 07, 2022 at 05:56:05PM +0200, Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > You didn't answer the other question, which is "Where is R12 documented for > TDG.VP.VMCALL<Instruction.HLT>?" though... Should I be worried? :) It's publicly documented. Guest-Host-Communication Interface(GHCI) spec, 344426-003US Feburary 2022. 3.8 TDG.VP.VMCALL<Instruction.HLT> R12 Interrupt Blocked Flag. The TD is expected to clear this flag iff RFLAGS.IF == 1 or the TDCALL instruction (that invoked TDG.VP.TDVMCALL(Instruction.HLT)) immediately follows an STI instruction, otherwise this flag should be set. -- Isaku Yamahata <isaku.yamahata@xxxxxxxxx>