linux-kernel - Re: [PATCH 2/2] KVM: TDX: Do not clear poisoned pages

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Message-ID: <8f05cd1c-74cf-4370-a39c-8e06cdf2c921@intel.com>
Date: Wed, 25 Jun 2025 09:31:18 -0700
From: Dave Hansen <dave.hansen@...el.com>
To: Adrian Hunter <adrian.hunter@...el.com>,
 Vishal Annapurve <vannapurve@...gle.com>
Cc: Tony Luck <tony.luck@...el.com>, pbonzini@...hat.com, seanjc@...gle.com,
 Borislav Petkov <bp@...en8.de>, Thomas Gleixner <tglx@...utronix.de>,
 Ingo Molnar <mingo@...hat.com>, Dave Hansen <dave.hansen@...ux.intel.com>,
 x86@...nel.org, H Peter Anvin <hpa@...or.com>, linux-edac@...r.kernel.org,
 linux-kernel@...r.kernel.org, kvm@...r.kernel.org,
 rick.p.edgecombe@...el.com, kirill.shutemov@...ux.intel.com,
 kai.huang@...el.com, reinette.chatre@...el.com, xiaoyao.li@...el.com,
 tony.lindgren@...ux.intel.com, binbin.wu@...ux.intel.com,
 isaku.yamahata@...el.com, yan.y.zhao@...el.com, chao.gao@...el.com
Subject: Re: [PATCH 2/2] KVM: TDX: Do not clear poisoned pages

On 6/25/25 09:25, Adrian Hunter wrote:
>> IIUC, even if movdir64b stores contents on hwpoisoned pages, it's not
>> going to cause any trouble.
> No.  PageHWPoison(page) means the page should not be touched.  It must
> be freed back to the allocator where it will never be allocated again.

What's the end-user-visible effect if the page is touched in this
specific function in this specific way (with movdir64b)?

In other words, what does this patch do for end users?