Re: [PATCH v14 1/3] x86/tdx: Make __tdx_module_call() usable in driver module

On Wed, Oct 12, 2022 at 08:44:04AM -0700, Sathyanarayanan Kuppuswamy wrote:

On 10/12/22 7:27 AM, Borislav Petkov wrote:

...

On Wed, Oct 12, 2022 at 06:35:56AM -0700, Sathyanarayanan Kuppuswamy wrote:

...

So we should create a new wrapper for this use case or use

Yes, you got it - a new wrapper pls.

Ok. I will add a new wrapper to get the TDREPORT.

+/*

• • Add a wrapper for TDG.MR.REPORT TDCALL. It is used in TDX guest
• • driver module to get the TDREPORT.

• */

+long tdx_mcall_get_report(void *reportdata, void *tdreport, u8 subtype)

Why "long"?

Why void *? Don't you have real types for these?

+{

•   if (subtype || !reportdata || !tdreport)
  
  

•           return -EINVAL;
  

How could that happen if you control all callers?

•   /*
  
  

•    * Generate TDREPORT using "TDG.MR.REPORT" TDCALL.
  
  

•    *
  
  

•    * Get the TDREPORT using REPORTDATA as input. Refer to
  
  

•    * section 22.3.3 TDG.MR.REPORT leaf in the TDX Module 1.0
  
  

•    * specification for detailed information.
  
  

•    */
  
  

•   return __tdx_module_call(TDX_GET_REPORT, virt_to_phys(tdreport),
  
  

•                   virt_to_phys(reportdata), subtype, 0, NULL);
  

If you check for NULL, why are you not validating that these are valid pointers as well? You can't have it both ways.

thanks,

greg k-h