On Mon, Mar 25, 2024 at 03:32:59PM +0000, "Edgecombe, Rick P" <rick.p.edgecombe@xxxxxxxxx> wrote: > On Mon, 2024-03-25 at 11:14 +0000, Huang, Kai wrote: > > To confirm, I mean you want to simply make KVM_SET_CPUID2 return error for TDX > > guest? > > > > It is acceptable to me, and I don't see any conflict with Sean's comments. > > > > But I don't know Sean's perference. As he said, I think the consistency > > checking is quite straight-forward: > > > > " > > It's not complicated at all. Walk through the leafs defined during > > TDH.MNG.INIT, reject KVM_SET_CPUID if a leaf isn't present or doesn't match > > exactly. > > " > > > Yea, I'm just thinking if we could take two patches down to one small one it might be a way to > essentially break off this work to another series without affecting the ability to boot a TD. It > *seems* to be the way things are going. > > > So to me it's not a big deal. > > > > Either way, we need a patch to handle SET_CPUID2: > > > > 1) if we go option 1) -- that is reject SET_CPUID2 completely -- we need to make > > vcpu's CPUID point to KVM's saved CPUID during TDH.MNG.INIT. > > Ah, I missed this part. Can you elaborate? By dropping these two patches it doesn't prevent a TD > boot. If we then reject SET_CPUID, this will break things unless we make other changes? And they are > not small? If we go forthis, the extended topology enumeration (cpuid[0xb or 0x1f]) would need special handling because it's per-vcpu. not TD wide. -- Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
