Re: [PATCH 1/9] x86/hyperv: Add sev-snp enlightened guest static key

[Tianyu Lan]

On 6/8/2023 8:56 PM, Michael Kelley (LINUX) wrote:
> > @ -473,7 +477,7 @@ static void __init ms_hyperv_init_platform(void)
> >
> >   #if IS_ENABLED(CONFIG_HYPERV)
> >   	if ((hv_get_isolation_type() == HV_ISOLATION_TYPE_VBS) ||
> > -	    (hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP))
> > +	    ms_hyperv.paravisor_present)
> This test needs to be:
>
>    	if ((hv_get_isolation_type() == HV_ISOLATION_TYPE_VBS) ||
> 	    ((hv_get_isolation_type() == HV_ISOLATION_TYPE_SNP) &&
> 	    ms_hyperv.paravisor_present)
>
> We want to call hv_vtom_init() only when running with VBS, or
> with SEV-SNP*and*  we have a paravisor present.  Testing only for
> paravisor_present risks confusion with future TDX scenarios.

Yes, current paravisor is only available for VBS and SEV-SNP vTOM cases.
TDX may also have paravisor support. Will update.

Thanks.