On Thu, Oct 31, 2024 at 10:27:11PM +0800, Xiaoyao Li wrote: > On 10/31/2024 5:37 PM, Tony Lindgren wrote: > > On Thu, Oct 31, 2024 at 05:23:57PM +0800, Xiaoyao Li wrote: > > > here it is to initialize the configurable CPUID bits that get reported to > > > userspace. Though TDX module doesn't allow them to be set in TD_PARAM for > > > KVM_TDX_INIT_VM, they get set to 0xff because KVM reuse these bits > > > EBX[23:16] as the interface for userspace to configure GPAW of TD guest > > > (implemented in setup_tdparams_eptp_controls() in patch 19). That's why they > > > need to be set as all-1 to allow userspace to configure. > > > > > > And the comment above it is wrong and vague. we need to change it to > > > something like > > > > > > /* > > > * Though TDX module doesn't allow the configuration of guest > > > * phys addr bits (EBX[23:16]), KVM uses it as the interface for > > > * userspace to configure the GPAW. So need to report these bits > > > * as configurable to userspace. > > > */ > > > > That sounds good to me. > > > > Hmm so care to check if we can also just leave out another "old module" > > comment in tdx_read_cpuid()? > > That one did relate to old module, the module that without > TDX_CONFIG_FLAGS_MAXGPA_VIRT reported in tdx_feature0. OK thanks for checking. > I will sent an follow up patch to complement the handling if TDX module > supports TDX_CONFIG_FLAGS_MAXGPA_VIRT. OK Regards, Tony
