From: Jason Gunthorpe <jgg@ziepe.ca>
To: Mostafa Saleh <smostafa@google.com>
Cc: iommu@lists.linux.dev, linux-kernel@vger.kernel.org,
robin.murphy@arm.com, m.szyprowski@samsung.com, will@kernel.org,
maz@kernel.org, suzuki.poulose@arm.com, catalin.marinas@arm.com,
jiri@resnulli.us, aneesh.kumar@kernel.org
Subject: Re: [RFC PATCH v2 2/5] dma-mapping: Use the correct phys_to_dma() for DMA_RESTRICTED_POOL
Date: Mon, 30 Mar 2026 19:28:44 -0300 [thread overview]
Message-ID: <20260330222844.GG246076@ziepe.ca> (raw)
In-Reply-To: <acrhbYo1tbiaugyJ@google.com>
On Mon, Mar 30, 2026 at 08:47:41PM +0000, Mostafa Saleh wrote:
> > The force_dma_unencrypted() should only be done way up the call chain
> > where we decide to get a phys that is decrypted. Once we have a
> > decrypted phys it should be carried with an annotation throughout all
> > the other places.
>
> Can you please clarify what you mean by annotation in this context?
> As I believe any tracking in the vmemmap is a big NO.
It would have to be a flag pass along the phys, or phys & flag in a
struct or some kind of approach like that.
> As replied to the first patch I can attempt to implement this approach
> (by passing a flag around) and see how intrusive it would be.
I'm less concerned about intrusive and more about making this
understandable.
When we reach a function with a phys it should know what that phys is,
not call a bunch of random helpers to hopefully correctly guess what
it is, that's unmaintainable spaghetti even if it is fewer changes.
Jason
next prev parent reply other threads:[~2026-03-30 22:28 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-30 14:50 [RFC PATCH v2 0/5] dma-mapping: Fixes for memory encryption Mostafa Saleh
2026-03-30 14:50 ` [RFC PATCH v2 1/5] dma-mapping: Avoid double decrypting with DMA_RESTRICTED_POOL Mostafa Saleh
2026-03-30 15:06 ` Jason Gunthorpe
2026-03-30 20:43 ` Mostafa Saleh
2026-03-31 11:34 ` Suzuki K Poulose
2026-03-31 12:50 ` Mostafa Saleh
2026-03-30 14:50 ` [RFC PATCH v2 2/5] dma-mapping: Use the correct phys_to_dma() for DMA_RESTRICTED_POOL Mostafa Saleh
2026-03-30 15:09 ` Jason Gunthorpe
2026-03-30 20:47 ` Mostafa Saleh
2026-03-30 22:28 ` Jason Gunthorpe [this message]
2026-03-30 14:50 ` [RFC PATCH v2 3/5] dma-mapping: Decrypt memory on remap Mostafa Saleh
2026-03-30 15:19 ` Jason Gunthorpe
2026-03-30 20:49 ` Mostafa Saleh
2026-03-30 22:30 ` Jason Gunthorpe
2026-03-30 14:50 ` [RFC PATCH v2 4/5] dma-mapping: Refactor memory encryption usage Mostafa Saleh
2026-03-30 15:27 ` Jason Gunthorpe
2026-03-30 14:50 ` [RFC PATCH v2 5/5] dma-mapping: Add doc for memory encryption Mostafa Saleh
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260330222844.GG246076@ziepe.ca \
--to=jgg@ziepe.ca \
--cc=aneesh.kumar@kernel.org \
--cc=catalin.marinas@arm.com \
--cc=iommu@lists.linux.dev \
--cc=jiri@resnulli.us \
--cc=linux-kernel@vger.kernel.org \
--cc=m.szyprowski@samsung.com \
--cc=maz@kernel.org \
--cc=robin.murphy@arm.com \
--cc=smostafa@google.com \
--cc=suzuki.poulose@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox