Re: [ANNOUNCE] PUCK Notes - 2024.04.03 - TDX Upstreaming Strategy

From: Xiaoyao Li
Date: Thu Apr 11 2024 - 13:05:24 EST


On 4/11/2024 11:26 PM, Sean Christopherson wrote:
On Thu, Apr 11, 2024, Xiaoyao Li wrote:
flexible (configurable) bits is known to VMM (KVM and userspace) because TDX
module has interface to report them. So we can treat a bit as fixed if it is
not reported in the flexible group. (of course the dynamic bits are special
and excluded.)

Does that interface reported the fixed _values_?

No.

But as I said, we can get what the fixed _values_ are after TD is initialized by TDH.MNG.INIT via another interface.

Yes. It is a bit late. But at least we have interface to get the fixed value runtime instead of hardcoding them.

Meanwhile, we are working internally with TDX architecture team to request new interface to report fixed bits and values as the configurable bits that doesn't require the TD is initialized. But not guarantee on it and not sure when it will be public.