Re: [PATCH v2 00/21] Runtime TDX Module update support

From: dan.j.williams

Date: Tue Oct 28 2025 - 22:17:24 EST


Sean Christopherson wrote:
[..]
> > IMO, It is something userspace should decide, kernel's job is to
> > provide the necessary interface about it.
>
> I disagree, I don't think userspace should even get the option. IMO, not setting
> AVOID_COMPAT_SENSITIVE is all kinds of crazy.

Do see Table 4.4: "Comparison of Update Incompatibility Detection and/or
Avoidance Methods" from the latest base architecture specification [1].
It lists out the pros and cons of not setting AVOID_COMPAT_SENSITIVE.
This thread has only argued the merits of "None" and "Avoid updates
during update- sensitive times". It has not discussed "Detect
incompatibility after update", but let us not do that. You can just
assume the Module has multiple solutions to this awkward problem
precisely because different VMMs came to different conclusions.

I want this thread to end so I am not going to argue past what Dave and
Sean want to do here.

[1]: https://www.intel.com/content/www/us/en/content-details/865787/intel-tdx-module-base-architecture-specification.html