linux-kernel - Re: [PATCH v4 02/12] mm/secretmem: set AS_NO_DIRECT

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Message-ID: <c48e7708-d100-4ecc-9944-e71f39d00ae6@amazon.co.uk>
Date: Wed, 26 Feb 2025 08:44:22 +0000
From: Patrick Roy <roypat@...zon.co.uk>
To: David Hildenbrand <david@...hat.com>, <rppt@...nel.org>,
	<seanjc@...gle.com>
CC: <pbonzini@...hat.com>, <corbet@....net>, <willy@...radead.org>,
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Subject: Re: [PATCH v4 02/12] mm/secretmem: set AS_NO_DIRECT_MAP instead of
 special-casing



On Tue, 2025-02-25 at 16:52 +0000, David Hildenbrand wrote:> On 21.02.25 17:07, Patrick Roy wrote:
>> Make secretmem set AS_NO_DIRECT_MAP on its struct address_space, to drop
>> all the vma_is_secretmem()/secretmem_mapping() checks that are based on
>> checking explicitly for the secretmem ops structures.
>>
>> This drops a optimization in gup_fast_folio_allowed() where
>> secretmem_mapping() was only called if CONFIG_SECRETMEM=y. secretmem is
>> enabled by default since commit b758fe6df50d ("mm/secretmem: make it on
>> by default"), so the secretmem check did not actually end up elided in
>> most cases anymore anyway.
>>
>> Signed-off-by: Patrick Roy <roypat@...zon.co.uk>
>> ---
> 
> Ah, there it is. Can both patches somehow be squashed?

Yeah, I'm happy to squash them. I separated them out based on feedback
on the v2, but checking back I realized that I actually just
misunderstood/misremembered what you and Mike were telling me. Sorry
about that, they'll be squashed together in the next posting :)

> -- 
> Cheers,
> 
> David / dhildenb
> 

Best, 
Patrick