From: David Hildenbrand <david@redhat.com>
To: Matthew Wilcox <willy@infradead.org>, Jason Gunthorpe <jgg@ziepe.ca>
Cc: "Asahi Lina" <lina@asahilina.net>,
"Miguel Ojeda" <ojeda@kernel.org>,
"Alex Gaynor" <alex.gaynor@gmail.com>,
"Boqun Feng" <boqun.feng@gmail.com>,
"Gary Guo" <gary@garyguo.net>,
"Björn Roy Baron" <bjorn3_gh@protonmail.com>,
"Benno Lossin" <benno.lossin@proton.me>,
"Andreas Hindborg" <a.hindborg@kernel.org>,
"Alice Ryhl" <aliceryhl@google.com>,
"Trevor Gross" <tmgross@umich.edu>,
"Jann Horn" <jannh@google.com>,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Danilo Krummrich" <dakr@kernel.org>,
"Wedson Almeida Filho" <wedsonaf@gmail.com>,
"Valentin Obst" <kernel@valentinobst.de>,
"Andrew Morton" <akpm@linux-foundation.org>,
linux-mm@kvack.org, airlied@redhat.com,
"Abdiel Janulgue" <abdiel.janulgue@gmail.com>,
rust-for-linux@vger.kernel.org, linux-kernel@vger.kernel.org,
asahi@lists.linux.dev
Subject: Re: [PATCH 0/6] rust: page: Support borrowing `struct page` and physaddr conversion
Date: Thu, 6 Feb 2025 19:04:14 +0100 [thread overview]
Message-ID: <27b8921c-5f1e-4cd0-95b3-2f19244b7f3b@redhat.com> (raw)
In-Reply-To: <Z6Pxfo1xDHUOna6a@casper.infradead.org>
On 06.02.25 00:17, Matthew Wilcox wrote:
> On Tue, Feb 04, 2025 at 04:49:47PM -0400, Jason Gunthorpe wrote:
>> The phys_to_virt() I mean is on the page table pages themselves, not
>> on a leaf.
>>
>> All page table pages came from alloc_pages_node() and you'd do
>> virt_to_phys() to stick them into a next-table PTE, then
>> phys_to_virt() to bring them back:
>>
>> phys_to_virt(virt_to_phys(page_address(alloc_pages_node())))
>>
>> Effectively.
>
> except for s390 & ppc where the page table can be smaller than
> PAGE_SIZE, so you really only have a physical address that can be
> converted to a virtual address.
I recall in the context of IOMMU page tables we don't perform this
packing. So what you say is certainly true for process page tables, but
likely not for IOMMU etc in the context of this series.
--
Cheers,
David / dhildenb
next prev parent reply other threads:[~2025-02-06 18:04 UTC|newest]
Thread overview: 67+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-02-02 13:05 Asahi Lina
2025-02-02 13:05 ` [PATCH 1/6] rust: types: Add Ownable/Owned types Asahi Lina
2025-02-03 9:13 ` Alice Ryhl
2025-02-03 14:17 ` Asahi Lina
2025-02-03 18:17 ` Alice Ryhl
2025-02-03 19:17 ` Asahi Lina
2025-02-19 8:34 ` Andreas Hindborg
2025-02-19 8:37 ` Andreas Hindborg
2025-02-02 13:05 ` [PATCH 2/6] rust: page: Convert to Ownable Asahi Lina
2025-02-03 9:17 ` Alice Ryhl
2025-02-03 9:39 ` Fiona Behrens
2025-02-19 8:46 ` Andreas Hindborg
2025-02-02 13:05 ` [PATCH 3/6] rust: page: Make with_page_mapped() and with_pointer_into_page() public Asahi Lina
2025-02-03 9:10 ` Alice Ryhl
2025-02-03 9:43 ` Fiona Behrens
2025-02-19 8:48 ` Andreas Hindborg
2025-02-02 13:05 ` [PATCH 4/6] rust: addr: Add a module to declare core address types Asahi Lina
2025-02-03 9:09 ` Alice Ryhl
2025-02-03 15:04 ` Boqun Feng
2025-02-04 11:50 ` Asahi Lina
2025-02-04 14:50 ` Boqun Feng
2025-02-19 8:51 ` Andreas Hindborg
2025-02-02 13:05 ` [PATCH 5/6] rust: page: Add physical address conversion functions Asahi Lina
2025-02-03 9:35 ` Alice Ryhl
2025-02-04 11:43 ` Asahi Lina
2025-02-03 9:53 ` Fiona Behrens
2025-02-03 10:01 ` Alice Ryhl
2025-02-19 9:06 ` Andreas Hindborg
2025-02-02 13:05 ` [PATCH 6/6] rust: page: Make Page::as_ptr() pub(crate) Asahi Lina
2025-02-03 9:08 ` Alice Ryhl
2025-02-19 9:08 ` Andreas Hindborg
2025-02-03 9:58 ` [PATCH 0/6] rust: page: Support borrowing `struct page` and physaddr conversion Simona Vetter
2025-02-03 14:32 ` Asahi Lina
2025-02-03 21:05 ` Zi Yan
2025-02-04 10:26 ` David Hildenbrand
2025-02-04 11:41 ` Asahi Lina
2025-02-04 11:59 ` David Hildenbrand
2025-02-04 13:05 ` Asahi Lina
2025-02-04 14:38 ` David Hildenbrand
2025-02-04 17:59 ` Asahi Lina
2025-02-04 20:10 ` David Hildenbrand
2025-02-04 21:06 ` Asahi Lina
2025-02-06 17:58 ` David Hildenbrand
2025-02-06 19:18 ` Asahi Lina
2025-02-06 19:27 ` Asahi Lina
2025-02-12 19:06 ` David Hildenbrand
2025-02-12 19:01 ` David Hildenbrand
2025-02-05 7:40 ` Simona Vetter
2025-02-12 19:07 ` David Hildenbrand
2025-02-04 10:33 ` David Hildenbrand
2025-02-04 18:39 ` Jason Gunthorpe
2025-02-04 19:01 ` Asahi Lina
2025-02-04 20:05 ` David Hildenbrand
2025-02-04 20:26 ` Jason Gunthorpe
2025-02-04 20:41 ` David Hildenbrand
2025-02-04 20:47 ` David Hildenbrand
2025-02-04 21:18 ` Asahi Lina
2025-02-06 18:02 ` David Hildenbrand
2025-02-04 20:49 ` Jason Gunthorpe
2025-02-05 23:17 ` Matthew Wilcox
2025-02-06 18:04 ` David Hildenbrand [this message]
2025-02-03 10:22 ` Danilo Krummrich
2025-02-03 14:41 ` Asahi Lina
2025-02-15 19:47 ` Asahi Lina
2025-02-17 8:50 ` Abdiel Janulgue
2025-02-19 9:24 ` Andreas Hindborg
2025-03-06 19:21 Oliver Mangold
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