linux-kernel - Re: [PATCH 4/7] x86/kexec: Disable kexec/kdump on platforms with TDX partial write erratum

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: <a2042a7b-2e12-4893-ac8d-50c0f77f26e9@intel.com>
Date: Wed, 1 Oct 2025 07:32:21 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: Vishal Annapurve <vannapurve@...gle.com>
Cc: Paolo Bonzini <pbonzini@...hat.com>, linux-kernel@...r.kernel.org,
 kvm@...r.kernel.org, bp@...en8.de, tglx@...utronix.de, peterz@...radead.org,
 mingo@...hat.com, hpa@...or.com, thomas.lendacky@....com, x86@...nel.org,
 kas@...nel.org, rick.p.edgecombe@...el.com, dwmw@...zon.co.uk,
 kai.huang@...el.com, seanjc@...gle.com, reinette.chatre@...el.com,
 isaku.yamahata@...el.com, dan.j.williams@...el.com, ashish.kalra@....com,
 nik.borisov@...e.com, chao.gao@...el.com, sagis@...gle.com,
 farrah.chen@...el.com, Binbin Wu <binbin.wu@...ux.intel.com>
Subject: Re: [PATCH 4/7] x86/kexec: Disable kexec/kdump on platforms with TDX
 partial write erratum

On 9/30/25 19:05, Vishal Annapurve wrote:
...
>> Any workarounds are going to be slow and probably imperfect. That's not
> 
> Do we really need to deploy workarounds that are complex and slow to
> get kdump working for the majority of the scenarios? Is there any
> analysis done for the risk with imperfect and simpler workarounds vs
> benefits of kdump functionality?
> 
>> a great match for kdump. I'm perfectly happy waiting for fixed hardware
>> from what I've seen.
> 
> IIUC SPR/EMR - two CPU generations out there are impacted by this
> erratum and just disabling kdump functionality IMO is not the best
> solution here.

That's an eminently reasonable position. But we're speaking in broad
generalities and I'm unsure what you don't like about the status quo or
how you'd like to see things change.

Care to send along a patch representing the "best solution"? That should
clear things up.