On Thu, Apr 07, 2022, Paolo Bonzini wrote: > On 3/4/22 20:49, isaku.yamahata@xxxxxxxxx wrote: > > + bool interrupt_disabled = tdvmcall_p1_read(vcpu); > > Where is R12 documented for TDG.VP.VMCALL<Instruction.HLT>? > > > + * Virtual interrupt can arrive after TDG.VM.VMCALL<HLT> during > > + * the TDX module executing. On the other hand, KVM doesn't > > + * know if vcpu was executing in the guest TD or the TDX module. > > I don't understand this; why isn't it enough to check PI.ON or something > like that as part of HLT emulation? Ooh, I think I remember what this is. This is for the case where the virtual interrupt is recognized, i.e. set in vmcs.RVI, between the STI and "HLT". KVM doesn't have access to RVI and the interrupt is no longer in the PID (because it was "recognized". It doesn't get delivered in the guest because the TDCALL completes before interrupts are enabled. I lobbied to get this fixed in the TDX module by immediately resuming the guest in this case, but obviously that was unsuccessful. > > + details.full = td_state_non_arch_read64( > > + to_tdx(vcpu), TD_VCPU_STATE_DETAILS_NON_ARCH); > > TDX documentation says "the meaning of the field may change with Intel TDX > module version", where is this field documented? I cannot find any "other > guest state" fields in the TDX documentation. IMO we should put a stake in the ground and refuse to accept code that consumes "non-architectural" state. It's all software, having non-architectural APIs is completely ridiculous.
