On Mon, Dec 13, 2021 at 12:35:40PM +0000, Srinivas Kandagatla wrote:
On 13/12/2021 10:57, Stephan Gerhold wrote:
On Thu, Dec 09, 2021 at 12:06:23PM +0000, Srinivas Kandagatla wrote:
From: Jeya R <jeyr@xxxxxxxxxxxxxx>
Add property to set DSP domain as non-secure.
ADSP/MDSP/SDSP are by default secured, where as CDSP can be either be
secured/unsecured.
Wouldn't it be easier to avoid the negation and add a "qcom,secure-domain"
property instead? Given PATCH 8/8 ("arm64: dts: qcom: add non-secure
domain property to fastrpc nodes") it looks like you are intentionally
breaking DT compatibility here, but this patch does not justify why this
is necessary.
By default all ADSP/MDSP/SDSP are secured, so this property is only required
for something that is not default. Only case that is configurable is the
CDSP case where in by adding this flag we should be able to load an unsigned
process to dsp using unsecured node.
Having said that, TBH When we first added the fastrpc patchset we did not
take care of this security feature properly :-)
From security point of view, its better to keep the default as secured
rather than unsecured in DT too.
With this DTS patch older dts should continue to work.
Is this a "default" on newer platforms only? Why do the existing
platforms not use the "secure" setup then? Or is this perhaps firmware
version/configuration specific?
Basically I'm confused because you say that the "default" is the secured
setup, but DT patch (8/8) suggests that non-secure is the default on
pretty much all currently supported platforms (msm8916, sdm845, sm8150,
sm8250, sm8350). :)
Thanks,
Stephan