Re: [PATCH] xen/arm: optee: Fix arm_smccc_smc's a0 for OPTEE_SMC_DISABLE_SHM_CACHE

[Oleksandr <olekstysh@xxxxxxxxx>]

On 07.10.21 01:42, Stefano Stabellini wrote:

Hi Stefano, Julien.

> On Wed, 6 Oct 2021, Julien Grall wrote:
> > Hi Stefano,
> >
> > On 28/09/2021 06:52, Stefano Stabellini wrote:
> > > On Mon, 27 Sep 2021, Oleksandr Tyshchenko wrote:
> > > > From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> > > >
> > > > Fix a possible copy-paste error in arm_smccc_smc's first argument (a0)
> > > > for OPTEE_SMC_DISABLE_SHM_CACHE case.
> > > >
> > > > This error causes Linux > v5.14-rc5
> > > > (b5c10dd04b7418793517e3286cde5c04759a86de
> > > > optee: Clear stale cache entries during initialization) to stuck
> > > > repeatedly issuing OPTEE_SMC_DISABLE_SHM_CACHE call and waiting for
> > > > the result to be OPTEE_SMC_RETURN_ENOTAVAIL which will never happen.
> > > >
> > > > Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
> > > Acked-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
> > >
> > > I added Fixes: and Backport: tags to the commit
> > Per SUPPORT.MD, OP-TEE is still a technical preview. So I would argue that we
> > should not do any backport because the feature itself is not officially
> > considered supported.
> Good point!
>
>
> > That said, what's missing to make the feature officially supported?
> If Oleksandr is also happy to make OP-TEE support in Xen "Supported" in
> SUPPORT.md I'd be happy with that too. Specifically I suggest to change
> it to:
>
> Status: Supported, not security supported
>
> Security Support is a bit of a heavy process and I am thinking that
> "Supported, not security supported" would be an excellent next step.
I would be happy, and can send a formal patch. But I am not an expert in 
this code.
As a user I can say that OP-TEE mediator works perfectly fine, but let's 
wait for the input from Volodymyr,
(looks like there are some TODO left in the code and I have no idea what 
are the implications)

--
Regards,

Oleksandr Tyshchenko