From: Christoph Hellwig <hch@lst.de>
To: Ming Lei <ming.lei@redhat.com>
Cc: "Christoph Hellwig" <hch@lst.de>,
"Christian König" <christian.koenig@amd.com>,
"Pavel Begunkov" <asml.silence@gmail.com>,
linux-block@vger.kernel.org, io-uring@vger.kernel.org,
"Vishal Verma" <vishal1.verma@intel.com>,
tushar.gohad@intel.com, "Keith Busch" <kbusch@kernel.org>,
"Jens Axboe" <axboe@kernel.dk>,
"Sagi Grimberg" <sagi@grimberg.me>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Christian Brauner" <brauner@kernel.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Sumit Semwal" <sumit.semwal@linaro.org>,
linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
linux-fsdevel@vger.kernel.org, linux-media@vger.kernel.org,
dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org
Subject: Re: [RFC v2 01/11] file: add callback for pre-mapping dmabuf
Date: Thu, 8 Jan 2026 11:17:03 +0100 [thread overview]
Message-ID: <20260108101703.GA24709@lst.de> (raw)
In-Reply-To: <aV8UJvkt7VGzHjxS@fedora>
On Thu, Jan 08, 2026 at 10:19:18AM +0800, Ming Lei wrote:
> > The feature is in no way nvme specific. nvme is just the initial
> > underlying driver. It makes total sense to support this for any high
> > performance block device, and to pass it through file systems.
>
> But why does FS care the dma buffer attachment? Since high performance
> host controller is exactly the dma buffer attachment point.
I can't parse what you're trying to say here.
> If the callback is added in `struct file_operations` for wiring dma buffer
> and the importer(host contrller), you will see it is hard to let it cross device
> mapper/raid or other stackable block devices.
Why?
But even when not stacking, the registration still needs to go
through the file system even for a single device, never mind multiple
controlled by the file system.
next prev parent reply other threads:[~2026-01-08 10:17 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-23 22:51 [RFC v2 00/11] Add dmabuf read/write via io_uring Pavel Begunkov
2025-11-23 22:51 ` [RFC v2 01/11] file: add callback for pre-mapping dmabuf Pavel Begunkov
2025-12-04 10:42 ` Christoph Hellwig
2025-12-12 1:02 ` Pavel Begunkov
2025-12-04 10:46 ` Christian König
2025-12-04 11:07 ` Christoph Hellwig
2025-12-04 11:09 ` Christian König
2025-12-04 13:10 ` Christoph Hellwig
2026-01-04 1:42 ` Ming Lei
2026-01-06 19:51 ` Pavel Begunkov
2026-01-07 6:18 ` Christoph Hellwig
2026-01-07 15:56 ` Christian König
2026-01-07 16:01 ` Christoph Hellwig
2026-01-08 2:19 ` Ming Lei
2026-01-08 10:17 ` Christoph Hellwig [this message]
2026-01-09 2:10 ` Ming Lei
2026-01-09 5:58 ` Christoph Hellwig
2025-11-23 22:51 ` [RFC v2 02/11] iov_iter: introduce iter type for pre-registered dma Pavel Begunkov
2025-12-04 10:43 ` Christoph Hellwig
2025-12-12 1:06 ` Pavel Begunkov
2026-02-06 15:02 ` Anuj gupta
2025-11-23 22:51 ` [RFC v2 03/11] block: move around bio flagging helpers Pavel Begunkov
2025-12-04 10:43 ` Christoph Hellwig
2025-12-12 1:08 ` Pavel Begunkov
2025-12-12 20:10 ` Jens Axboe
2025-11-23 22:51 ` [RFC v2 04/11] block: introduce dma token backed bio type Pavel Begunkov
2025-12-04 10:48 ` Christoph Hellwig
2026-02-06 15:05 ` Anuj gupta
2025-11-23 22:51 ` [RFC v2 05/11] block: add infra to handle dmabuf tokens Pavel Begunkov
2025-11-24 13:38 ` Anuj gupta
2025-11-26 21:31 ` kernel test robot
2025-11-26 23:27 ` kernel test robot
2025-12-04 10:56 ` Christoph Hellwig
2025-12-12 1:56 ` Pavel Begunkov
2025-12-04 13:08 ` Christoph Hellwig
2026-01-21 7:37 ` Nitesh Shetty
2026-01-22 11:46 ` Pavel Begunkov
2026-02-06 15:08 ` Anuj gupta
2026-02-06 18:01 ` Pavel Begunkov
2025-11-23 22:51 ` [RFC v2 06/11] nvme-pci: add support for dmabuf reggistration Pavel Begunkov
2025-11-24 13:40 ` Anuj gupta
2025-11-27 2:11 ` kernel test robot
2025-12-04 11:00 ` Christoph Hellwig
2025-12-04 19:07 ` Keith Busch
2025-11-23 22:51 ` [RFC v2 07/11] nvme-pci: implement dma_token backed requests Pavel Begunkov
2025-12-04 11:04 ` Christoph Hellwig
2025-11-23 22:51 ` [RFC v2 08/11] io_uring/rsrc: add imu flags Pavel Begunkov
2025-11-23 22:51 ` [RFC v2 09/11] io_uring/rsrc: extended reg buffer registration Pavel Begunkov
2025-11-23 22:51 ` [RFC v2 10/11] io_uring/rsrc: add dmabuf-backed buffer registeration Pavel Begunkov
2026-01-04 1:46 ` Ming Lei
2026-01-06 19:32 ` Pavel Begunkov
2025-11-23 22:51 ` [RFC v2 11/11] io_uring/rsrc: implement dmabuf regbuf import Pavel Begunkov
2025-11-24 10:33 ` [RFC v2 00/11] Add dmabuf read/write via io_uring Christian König
2025-11-24 11:30 ` Pavel Begunkov
2025-11-24 14:17 ` Christian König
2025-11-25 13:52 ` Pavel Begunkov
2025-11-25 14:21 ` Christian König
2025-11-25 19:40 ` Pavel Begunkov
2025-11-24 13:35 ` Anuj gupta
2025-11-25 12:35 ` Pavel Begunkov
2025-12-12 19:37 ` (subset) " Jens Axboe
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