Re: [PATCH v7 00/12] arm64: qcom: add and enable SHM Bridge support

Bjorn Andersson
2024-02-27T16:32:08Z

On Mon, Feb 19, 2024 at 03:17:24PM +0000, Srinivas Kandagatla wrote:
> On 17/02/2024 19:58, Bjorn Andersson wrote:
> > On Mon, Feb 05, 2024 at 07:27:58PM +0100, Bartosz Golaszewski wrote:
> > > From: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
> > >
> > > We've established the need for using separate secured memory pools for
> > > SCM and QSEECOM
> >
> > Where has this need been established, what is the actual problem you're
> > solving with this series?
>
> SHMbridge will restrict the amount of memory that TZ can see, making system
> more secure.
>

Then tell me this in the cover letter and commit messages.

> Need for having different pools makes this more scalable overall, so that
> different usecases can run seamlessly. ex: loading a TA and SCM calls.
>

How is it more scalable to give each "client" a chunk of 256KB instead
of them sharing a pool of ~4GB memory?

> >
> > Does SCM and QSEECOM, as it's implemented in the kernel today, not work
> > satisfactory?
> >
> > > as well as the upcoming scminvoke driver.
> > >
> >
> > Is smcinvoke driver upstreaming blocked by not transitioning the scm
> > driver to a "secure memory pool"?
> >
> > Is this happening now, or do we need to merge this series when that day
> > comes?
>
> SMCInvoke development is happening now, I see no reason for this patchset to
> wait for it.
>

As presented, I see no reason to merge this series.

> This series can go as it is for two reasons.
> 1> improves system security in general
> 2> Hardware Wrapped key support patches also use this which are also in good
> shape and tested, ready to be merged.
>

Then tell me this in the cover letter and commit messages!

It's not sufficient that I happen to know the answer to these questions,
neither community nor maintainer should not have to guess these things.

Regards,
Bjorn