Re: [RFC PATCH v2 05/18] KVM: TDX: Drop superfluous page pinning in S-EPT management

[Sean Christopherson]

On Fri, Aug 29, 2025, Rick P Edgecombe wrote:
> On Fri, 2025-08-29 at 13:19 -0700, Sean Christopherson wrote:
> > I'm happy to include more context in the changelog, but I really don't want
> > anyone to walk away from this thinking that pinning pages in random KVM code
> > is at all encouraged.
> 
> Sorry for going on a tangent. Defensive programming inside the kernel is a
> little more settled. But for defensive programming against the TDX module, there
> are various schools of thought internally. Currently we rely on some
> undocumented behavior of the TDX module (as in not in the spec) for correctness.

Examples?

> But I don't think we do for security.
> 
> Speaking for Yan here, I think she was a little more worried about this scenario
> then me, so I read this verbiage and thought to try to close it out.