Re: [PATCH v3 0/3] Rust scatterlist abstractions

From: Greg KH <gregkh@linuxfoundation.org>
To: Qingsong Chen <changxian.cqs@antgroup.com>
Cc: linux-kernel@vger.kernel.org, 田洪亮 <tate.thl@antgroup.com>,
	"Miguel Ojeda" <ojeda@kernel.org>,
	"Alex Gaynor" <alex.gaynor@gmail.com>,
	"Wedson Almeida Filho" <wedsonaf@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>,
	rust-for-linux@vger.kernel.org
Subject: Re: [PATCH v3 0/3] Rust scatterlist abstractions
Date: Mon, 12 Jun 2023 09:12:24 +0200	[thread overview]
Message-ID: <2023061238-disagree-nape-f549@gregkh> (raw)
In-Reply-To: <5469fb25-e88a-b703-c0d9-204f0cbcab91@antgroup.com>

On Mon, Jun 12, 2023 at 03:03:14PM +0800, Qingsong Chen wrote:
> On 6/12/23 1:38 PM, Greg KH wrote:
> > On Mon, Jun 12, 2023 at 11:49:51AM +0800, Qingsong Chen wrote:
> > > On 6/10/23 11:35 PM, Greg KH wrote:
> > > > On Sat, Jun 10, 2023 at 05:33:47PM +0200, Greg KH wrote:
> > > > > On Sat, Jun 10, 2023 at 06:49:06PM +0800, Qingsong Chen wrote:
> > > > > > Hi All!
> > > > > > 
> > > > > > This is a version of scatterlist abstractions for Rust drivers.
> > > > > > 
> > > > > > Scatterlist is used for efficient management of memory buffers, which is
> > > > > > essential for many kernel-level operations such as Direct Memory Access
> > > > > > (DMA) transfers and crypto APIs.
> > > > > > 
> > > > > > This patch should be a good start to introduce the crypto APIs for Rust
> > > > > > drivers and to develop cipher algorithms in Rust later.
> > > > > 
> > > > > I thought we were getting rid of the scatter list api for the crypto
> > > > > drivers, so this shouldn't be needed going forward, right?  Why not just
> > > > > use the direct apis instead?
> > > > 
> > > > See https://lore.kernel.org/r/ZH2hgrV6po9dkxi+@gondor.apana.org.au for
> > > > the details of that (sorry I forgot the link first time...)
> > > 
> > > Thanks for the information. I agree that turning simple buffers into
> > > sg-bufs is not a good idea. If I were implementing a new cipher
> > > algorithm, I would definitely follow the `struct cipher_alg`, which
> > > takes simple `u8 *` pointer as parameter. However, if we'd like to
> > > utilize some existing ciphers, such as aead, we still need scatterlists
> > > to construct an `aead_request` for further operations, util changes are
> > > made to the underlying interface.
> > 
> > Why not make the changes to the C code first, and get those changes
> > merged, making this patch series not needed at all?
> > 
> 
> Yes, you're right. I believe Herbert would work on that. And I would
> stop this patch series. Thanks.

No, I mean you work on that now.  There's no reason you should wait for
Herbert, or any one else, submit the patch series this week to that
subsystem that does the conversion and see how it goes!

thanks,

greg k-h