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

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Message-ID: <CAGtprH860CZk3V_cpYmMz4mWps7mNbttD6=GV-ttkao1FLQ5tg@mail.gmail.com>
Date: Tue, 21 Oct 2025 19:50:44 -0700
From: Vishal Annapurve <vannapurve@...gle.com>
To: Dave Hansen <dave.hansen@...el.com>
Cc: Juergen Gross <jgross@...e.com>, "Reshetova, Elena" <elena.reshetova@...el.com>, 
	Paolo Bonzini <pbonzini@...hat.com>, 
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>, "kvm@...r.kernel.org" <kvm@...r.kernel.org>, 
	"bp@...en8.de" <bp@...en8.de>, "tglx@...utronix.de" <tglx@...utronix.de>, 
	"peterz@...radead.org" <peterz@...radead.org>, "mingo@...hat.com" <mingo@...hat.com>, "hpa@...or.com" <hpa@...or.com>, 
	"thomas.lendacky@....com" <thomas.lendacky@....com>, "x86@...nel.org" <x86@...nel.org>, 
	"kas@...nel.org" <kas@...nel.org>, "Edgecombe, Rick P" <rick.p.edgecombe@...el.com>, 
	"dwmw@...zon.co.uk" <dwmw@...zon.co.uk>, "Huang, Kai" <kai.huang@...el.com>, 
	"seanjc@...gle.com" <seanjc@...gle.com>, "Chatre, Reinette" <reinette.chatre@...el.com>, 
	"Yamahata, Isaku" <isaku.yamahata@...el.com>, "Williams, Dan J" <dan.j.williams@...el.com>, 
	"ashish.kalra@....com" <ashish.kalra@....com>, "nik.borisov@...e.com" <nik.borisov@...e.com>, 
	"Gao, Chao" <chao.gao@...el.com>, "sagis@...gle.com" <sagis@...gle.com>, 
	"Chen, Farrah" <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 Tue, Oct 21, 2025 at 10:08 AM Dave Hansen <dave.hansen@...el.com> wrote:
>
> On 10/18/25 08:54, Vishal Annapurve wrote:
> > Circling bank on this topic, I would like to iterate a few points:
> > 1) Google has been running workloads with the series [1] for ~2 years
> > now, we haven't seen any issues with kdump functionality across kernel
> > bugs, real hardware issues, private memory corruption etc.
>
> Great points and great info!
>
> As a next step, I'd expect someone (at Google) to take this into
> consideration and put together a series to have the kernel comprehend
> those points.

Then is it safe to say that Intel doesn't consider:
* Adding the support to just reset PAMT memory [1] to this series and
* Modifying the logic in this patch [2] to enable kdump and keep kexec
support disabled in this series

as a viable direction upstream for now until a better solution comes along?

If not, can kdump be made optional as Juergen suggested?

[1] https://lore.kernel.org/lkml/6960ef6d7ee9398d164bf3997e6009df3e88cb67.1727179214.git.kai.huang@intel.com/
[2] https://lore.kernel.org/all/20250901160930.1785244-5-pbonzini@redhat.com/