Re: [PATCH v2 3/5] x86/virt/tdx: Add SEAMCALL wrapper for TDH.SYS.DISABLE

From: Edgecombe, Rick P

Date: Mon Mar 30 2026 - 15:28:47 EST


On Mon, 2026-03-30 at 11:58 +0000, Kiryl Shutsemau wrote:
> > + *  - TDX_SYS_BUSY could transiently contend with
> > TDH.SYS.* SEAMCALLs,
> > + *    but will lock out future ones.
>
> Locked out by who? Is it TDX module contract? I don't see it
> documented in
> the spec.

Yea, by the TDX module.

We relayed that we need this specific behavior around TDX_SYS_BUSY
contention, but the implementation isn't done. That spec is actually
still in draft form. Which is refreshing, because we can actually tweak
things like this based on what the kernel needs.

>
> I assumed that if the SEAMCALL fails other SEAMCALLs suppose to be
> functional. Hm?

The behavior should be that once you make this seamcall (assuming it's
supported) that no other seamcalls can be made. They will return an
error. Do you think something else would be better? If it's an old TDX
module, nothing happens of course.

So let's change the module if we see a problem. What should it be?