Re: [PATCH v11 20/20] Documentation/x86: Add documentation for TDX host support

[Huang, Kai]

On Thu, 2023-06-08 at 16:56 -0700, Dave Hansen wrote:
> On 6/4/23 07:27, Kai Huang wrote:
> > +There is no CPUID or MSR to detect the TDX module.  The kernel detects it
> > +by initializing it.
> 
> Is this really what you want to say?
> 
> If the module is there, SEAMCALL works.  If not, it doesn't.  The module
> is assumed to be there when SEAMCALL works.  Right?
> 
> Yeah, that first SEAMCALL is probably an initialization call, but feel
> like that's beside the point.

Thanks for reviewing the documentation.

I guess I don't need to mention the "detection" part at all?


-TDX module detection and initialization
+TDX module initialization
 ---------------------------------------
 
-There is no CPUID or MSR to detect the TDX module.  The kernel detects it
-by initializing it.
-
 The kernel talks to the TDX module via the new SEAMCALL instruction.  The
 TDX module implements SEAMCALL leaf functions to allow the kernel to
 initialize it.
 
+If the TDX module isn't loaded, the SEAMCALL instruction fails with a
+special error.  In this case the kernel fails the module initialization
+and reports the module isn't loaded::
+
+  [..] tdx: Module isn't loaded.