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

From: Greg KH
Date: Mon Jun 12 2023 - 01:38:40 EST


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+@xxxxxxxxxxxxxxxxxxx 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?

thanks,

greg k-h