Re: [PATCH v3 15/15] arm64: defconfig: enable SHM Bridge support for the TZ memory allocator

[Bartosz Golaszewski]

On Wed, Oct 11, 2023 at 11:20 PM Andrew Halaney <ahalaney@xxxxxxxxxx> wrote:
>
> On Mon, Oct 09, 2023 at 05:34:27PM +0200, Bartosz Golaszewski wrote:
> > From: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> >
> > Enable SHM Bridge support in the Qualcomm TrustZone allocator by default
> > as even on architectures that don't support it, we automatically fall
> > back to the default behavior.
>
> Can you give some motivation for the Kconfig? It seems like what you've
> wrote should just fallback to the non SHM bridge allocated memory, so I
> don't see what having the option to exclude that at build time gives us.
>

If the hypervisor gets quirky in a new place other than the PAS image
calls, we will be able to just disable SHM Bridge, otherwise the
kernel will use it if it's supported even if it causes problems?

Bart

> >
> > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@xxxxxxxxxx>
> > ---
> >  arch/arm64/configs/defconfig | 1 +
> >  1 file changed, 1 insertion(+)
> >
> > diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig
> > index 07011114eef8..ebe97fec6e33 100644
> > --- a/arch/arm64/configs/defconfig
> > +++ b/arch/arm64/configs/defconfig
> > @@ -255,6 +255,7 @@ CONFIG_INTEL_STRATIX10_RSU=m
> >  CONFIG_EFI_CAPSULE_LOADER=y
> >  CONFIG_IMX_SCU=y
> >  CONFIG_IMX_SCU_PD=y
> > +CONFIG_QCOM_TZMEM_MODE_SHMBRIDGE=y
> >  CONFIG_GNSS=m
> >  CONFIG_GNSS_MTK_SERIAL=m
> >  CONFIG_MTD=y
> > --
> > 2.39.2
> >
>