On Fri, Jun 30, 2023 at 09:55:32AM +0000, Huang, Kai wrote: > On Fri, 2023-06-30 at 11:26 +0200, Peter Zijlstra wrote: > > On Thu, Jun 29, 2023 at 12:10:00AM +0000, Huang, Kai wrote: > > > On Wed, 2023-06-28 at 15:17 +0200, Peter Zijlstra wrote: > > > > On Tue, Jun 27, 2023 at 02:12:37AM +1200, Kai Huang wrote: > > > > > +EXPORT_SYMBOL_GPL(tdx_cpu_enable); > > > > > > > > I can't find a single caller of this.. why is this exported? > > > > > > It's for KVM TDX patch to use, which isn't in this series. > > > > > > I'll remove the export. KVM TDX series can export it. > > > > Fair enough; where will the KVM TDX series call this? Earlier there was > > talk about doing it at kvm module load time -- but I objected (and still > > do object) to that. > > > > What's the current plan? > > > > The direction is still doing it during module load (not my series anyway). But > this can be a separate discussion with KVM maintainers involved. They all on Cc afaict. > I understand you have concern that you don't want to have the memory & cpu time > wasted on enabling TDX by default. For that we can have a kernel command line > to disable TDX once for all (we can even make it default). That's insane, I don't want to totally disable it. I want it done at guard creation. Do the whole TDX setup the moment you actually create a TDX guast. Totally killing TDX is stupid, just about as stupid as doing it on module load (which equates to always doing it). > Also, KVM will have a module parameter 'enable_tdx'. I am hoping this could > reduce your concern too. I don't get this obsession with doing at module load time :/