On Wed, Feb 22, 2023 at 02:13:44PM -0800, Sean Christopherson wrote: > Because vTOM is a hardware feature, whereas the IO-APIC and vTPM being accessible > via private memory are software features. It's very possible to emulate the > IO-APIC in trusted code without vTOM. I know, but their use case is dictated by the fact that they're using a SNP guest *with* vTOM as a SEV feature. And so their guest does IO-APIC and vTPM *with* the vTOM SEV feature. That's what I'm trying to model. > > If the access method to the IO-APIC and vTPM are specific to the > > HyperV's vTOM implementation, then I don't mind if this were called > > > > cc_platform_has(CC_ATTR_GUEST_HYPERV_VTOM); > > I still think that's likely to caused problems in the future, e.g. if Hyper-V > moves more stuff into the paravisor or if Hyper-V ends up with similar functionality > for TDX. Yah, reportedly, TDX folks are not very interested in this case. > But it's not a sticking point, the only thing I'm fiercely resistant to > is conflating hardware features with software features. So you and I need to find a common ground... -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette