On Mon, Nov 14, 2022 at 3:18 PM Isaku Yamahata <isaku.yamahata@xxxxxxxxx> wrote: > > I think you should explain why MOVDIR64B is required, otherwise this just comes > > out of blue. > > > > Btw, is this absolutely required? TDX also supports Li-mode, which doesn't have > > integrity check. So theoretically with Li-mode, normal zeroing is also OK but > > doesn't need to use MOVDIR64B. > > > > That being said, do we have a way to tell whether TDX works in Ci or Li mode? > > As long as I don't know. When clearing page, we can use > if (featuremovdir64b) movdir64b else memset(0). -- sorry for resending the same email, for some reason my previous email was not in plain text mode-- As far as I know, Li mode and Ci mode both are working very similarly and require movdir64b to clear any poison bit previously set. Why would movdir64b is not supported in a tdx capable cpu? > -- > Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
