Re: [PATCH v19 007/130] x86/virt/tdx: Export SEAMCALL functions

From: Sean Christopherson
Date: Wed Apr 03 2024 - 17:36:54 EST


On Wed, Mar 20, 2024, Dave Hansen wrote:
> On 3/20/24 05:09, Huang, Kai wrote:
> > I can try to do if you guys believe this should be done, and should be done
> > earlier than later, but I am not sure _ANY_ optimization around SEAMCALL will
> > have meaningful performance improvement.
>
> I don't think Sean had performance concerns.
>
> I think he was having a justifiably violent reaction to how much more
> complicated the generated code is to do a SEAMCALL versus a good ol' KVM
> hypercall.

Yep. The code essentially violates the principle of least surprise. I genuinely
thought I was dumping the wrong function(s) when I first looked at the output.