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

[Dave Hansen]

On 6/25/25 09:42, Adrian Hunter wrote:
> On 25/06/2025 19:31, Dave Hansen wrote:
>> 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?
> 
> We have another patch that clarifies that.  It turns out we need
> to clear pages (MOVDIR64B) only if the platform has the so-called
> partial-write errata X86_BUG_TDX_PW_MCE.
> 
> It was decided to deal with that issue separately, but maybe it
> needs to bundled in the same patch set, now that the discussion
> has moved in that direction?

It sure sounds like it to me.