Re: [PATCH v10 005/108] KVM: TDX: Initialize the TDX module when loading the KVM intel kernel module

Erdem Aktas
2022-11-15T12:23:19Z

On Mon, Nov 14, 2022 at 3:18 PM Isaku Yamahata <isaku.yamahata@gmail.com> 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@gmail.com>