Re: [PATCH v2 08/31] x86/virt/tdx: Configure TDX Module with optional TDX Connect feature

[Xu Yilun]

On Wed, Apr 01, 2026 at 10:13:33AM +0000, Huang, Kai wrote:
> 
> > 
> > TDX Module updates global metadata when optional features are enabled.
> > Host should update the cached tdx_sysinfo to reflect these changes.
> > 
> > 
> [...]
> 
> >  static int config_tdx_module(struct tdmr_info_list *tdmr_list, u64 global_keyid)
> >  {
> >  	struct tdx_module_args args = {};
> > +	u64 seamcall_fn = TDH_SYS_CONFIG_V0;
> >  	u64 *tdmr_pa_array;
> >  	size_t array_sz;
> >  	int i, ret;
> > @@ -1377,7 +1378,15 @@ static int config_tdx_module(struct tdmr_info_list *tdmr_list, u64 global_keyid)
> >  	args.rcx = __pa(tdmr_pa_array);
> >  	args.rdx = tdmr_list->nr_consumed_tdmrs;
> >  	args.r8 = global_keyid;
> > -	ret = seamcall_prerr(TDH_SYS_CONFIG, &args);
> > +
> > +	if (tdx_sysinfo.features.tdx_features0 & TDX_FEATURES0_TDXCONNECT) {
> > +		args.r9 |= TDX_FEATURES0_TDXCONNECT;
> > +		args.r11 = ktime_get_real_seconds();
> > +		/* These parameters requires version >= 1 */
> > +		seamcall_fn = TDH_SYS_CONFIG;
> > +	}
> > +
> > +	ret = seamcall_prerr(seamcall_fn, &args);
> >  
> >  	/* Free the array as it is not required anymore. */
> >  	kfree(tdmr_pa_array);
> > @@ -1537,6 +1546,11 @@ static int init_tdx_module(void)
> >  	if (ret)
> >  		goto err_free_pamts;
> >  
> > +	/* configuration to tdx module may change tdx_sysinfo, update it */
> > +	ret = get_tdx_sys_info(&tdx_sysinfo);
> > +	if (ret)
> > +		goto err_reset_pamts;
> > +
> 
> How about put this into config_tdx_module()?
> 
> In this way you can only update global metadata when there's new feature

mm.. personally I don't like such subtle control, especially when

 - We expect one or more features are doomed to be enabled.
 - We are pursuing simple TDX enabling process.
 - This is still not the exact control. If we really want to be precise,
   should check feature by feature, that's not worth it.

> being opted in, and at the meantime, avoid making init_tdx_module() more
> complicated.