On Thu, Oct 31, 2024 at 09:21:29PM +0200, Adrian Hunter wrote: > On 30/10/24 21:00, Rick Edgecombe wrote: > > Here is v2 of TDX VM/vCPU creation series. As discussed earlier, non-nits > > from v1[0] have been applied and it’s ready to hand off to Paolo. A few > > items remain that may be worth further discussion: > > - Disable CET/PT in tdx_get_supported_xfam(), as these features haven’t > > been been tested. > > It seems for Intel PT we have no support for restoring host > state. IA32_RTIT_* MSR preservation is Init(XFAM(8)) which means > the TDX Module sets the MSR to its RESET value after TD Enty/Exit. > So it seems to me XFAM(8) does need to be disabled until that is > supported. So for now, we should remove the PT bit from tdx_get_supported_xfam(), but can still keep it in tdx_restore_host_xsave_state()? Then for save/restore, maybe we can just use the pt_guest_enter() and pt_guest_exit() also for TDX. Some additional checks are needed for the pt_mode though as the TDX module always clears the state if PT is enabled. And the PT_MODE_SYSTEM will be missing TDX enter/exit data but might be otherwise usable. Regards, Tony
