Re: [PATCH V4 0/1] KVM: TDX: Decrease TDX VM shutdown time

["Edgecombe, Rick P" <rick.p.edgecombe@intel.com>]

On Fri, 2025-07-11 at 15:54 -0700, Sean Christopherson wrote:
> > How do you guys see it as wasteful? The highest cap is currently 242. For 32
> > bit
> > KVM that leaves 2147483405 caps. If we create an interface we grow some code
> > and
> > docs, and get 64 additional ones for TDX only.
> 
> It bleeds TDX details into arch neutral code.

There are tons of arch specific caps. Can you help me understand this point a
little more? Is TDX special compared to the other arch specific ones?

> 
> > The less interfaces the better I say, so KVM_CAP_TDX_TERMINATE_VM seems
> > better.
> 
> But we already have KVM_TDX_CAPABILITIES.  This isn't really a new interface,
> it's
> a new field in a pre-existing interface.

I guess. It's new place to check for the same type of information that caps
currently provides. Not a big deal either way to me though.

> 
> > Xiaoyao, is this something QEMU needs? Or more of a completeness kind of
> > thing?
> 
> Required by VMMs.  KVM always needs to be able enumerate its new features.  We
> absolutely do not want userspace making guesses based on e.g. kernel version.

Ok.