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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <10786082-94e0-454e-a581-7778b3a22e26@intel.com>
Date: Fri, 24 Oct 2025 14:19:16 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: dan.j.williams@...el.com, Chao Gao <chao.gao@...el.com>
Cc: Vishal Annapurve <vannapurve@...gle.com>,
 "Reshetova, Elena" <elena.reshetova@...el.com>,
 "linux-coco@...ts.linux.dev" <linux-coco@...ts.linux.dev>,
 "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
 "x86@...nel.org" <x86@...nel.org>,
 "Chatre, Reinette" <reinette.chatre@...el.com>,
 "Weiny, Ira" <ira.weiny@...el.com>, "Huang, Kai" <kai.huang@...el.com>,
 "yilun.xu@...ux.intel.com" <yilun.xu@...ux.intel.com>,
 "sagis@...gle.com" <sagis@...gle.com>,
 "paulmck@...nel.org" <paulmck@...nel.org>,
 "nik.borisov@...e.com" <nik.borisov@...e.com>, Borislav Petkov
 <bp@...en8.de>, Dave Hansen <dave.hansen@...ux.intel.com>,
 "H. Peter Anvin" <hpa@...or.com>, Ingo Molnar <mingo@...hat.com>,
 "Kirill A. Shutemov" <kas@...nel.org>, Paolo Bonzini <pbonzini@...hat.com>,
 "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>,
 Thomas Gleixner <tglx@...utronix.de>
Subject: Re: [PATCH v2 00/21] Runtime TDX Module update support

On 10/24/25 14:12, dan.j.williams@...el.com wrote:
>> The SGX solution, btw, was to at least ensure forward progress (CPUSVN
>> update) when the last enclave goes away. So new enclaves aren't
>> *prevented* from starting but the window when the first one starts
>> (enclave count going from 0->1) is leveraged to do the update.
> The status quo does ensure forward progress. The TD does get built and
> the update does complete, just the small matter of TD attestation
> failures, right?

Oh, yeah, for sure.

If we do _nothing_ in the kernel (no build vs. module update
synchronization), then the downside is being exposed to attestation
failures if userspace either also does nothing or has bugs.

That's actually, by far, my preferred solution to this whole mess:
Userspace plays stupid games, userspace wins stupid prizes.