Re: [PATCH v12 00/10] introduce Arm FF-A support

Abdellatif El Khlifi
2023-06-06T11:56:47Z

On Mon, May 22, 2023 at 10:13:20AM +0100, Abdellatif El Khlifi wrote:

Hi Simon, Tom,

> Hi Simon,
>
> > Adding support for Arm FF-A v1.0 (Arm Firmware Framework for Armv8-A) [A].
> >
> > FF-A specifies interfaces that enable a pair of software execution environments aka partitions to
> > communicate with each other. A partition could be a VM in the Normal or Secure world, an
> > application in S-EL0, or a Trusted OS in S-EL1.
> >
> > FF-A is a discoverable bus and similar to architecture features.
> > FF-A bus is discovered using ARM_SMCCC_FEATURES mechanism performed
> > by the PSCI driver.
> >
> > => dm tree
> >
> > Class Index Probed Driver Name
> > -----------------------------------------------------------
> > ...
> > firmware 0 [ + ] psci |-- psci
> > ffa 0 [ ] arm_ffa | `-- arm_ffa
> > ...
> >
> > Clients are able to probe then use the FF-A bus by calling the DM class
> > searching APIs (e.g: uclass_first_device).
> >
> > This implementation of the specification provides support for Aarch64.
> >
> > The FF-A driver uses the SMC ABIs defined by the FF-A specification to:
> >
> > - Discover the presence of secure partitions (SPs) of interest
> > - Access an SP's service through communication protocols
> > (e.g: EFI MM communication protocol)
> >
> > The FF-A support provides the following features:
> >
> > - Being generic by design and can be used by any Arm 64-bit platform
> > - FF-A support can be compiled and used without EFI
> > - Support for SMCCCv1.2 x0-x17 registers
> > - Support for SMC32 calling convention
> > - Support for 32-bit and 64-bit FF-A direct messaging
> > - Support for FF-A MM communication (compatible with EFI boot time)
> > - Enabling FF-A and MM communication in Corstone1000 platform as a use case
> > - A Uclass driver providing generic FF-A methods.
> > - An Arm FF-A device driver providing Arm-specific methods and reusing the Uclass methods.
> > - A sandbox emulator for Arm FF-A, emulates the FF-A side of the Secure World and provides
> > FF-A ABIs inspection methods.
> > - An FF-A sandbox device driver for FF-A communication with the emulated Secure World.
> > The driver leverages the FF-A Uclass to establish FF-A communication.
> > - Sandbox FF-A test cases.
> > - A new command called armffa is provided as an example of how to access the
> > FF-A bus
> >
> > For more details about the FF-A support please refer to [B] and refer to [C] for
> > how to use the armffa command.
> >
> > Please find at [D] an example of the expected boot logs when enabling
> > FF-A support for a platform. In this example the platform is
> > Corstone1000. But it can be any Arm 64-bit platform.
> >
> > Changelog of the major changes:
> > ===========================
> >
> > v12:
> >
> > * remove the global variable (dscvry_info), use uc_priv instead
> > * replace dscvry_info.invoke_ffa_fn() with a weak invoke_ffa_fn
> > (user drivers can override it)
> > * improve FFA_PARTITION_INFO_GET implementation
> > (clients no longer need to calloc a buffer)
> > * remove reparenting by making the sandbox emulator parent of the FF-A device in the DT
> > * improve argument checks for the armffa command
> > * address nits
> >
...
> > Cc: Tom Rini <trini@konsulko.com>
> > Cc: Simon Glass <sjg@chromium.org>
>
> A gentle reminder about the v12 patchset.
>
> Your feedback is more than welcome :)

Could you please provide a feedback about the v12 patchset ?

Most of the patches are generic.

I'm gonna address Ilias comment for patch #9 with your future comments.

Your review is very much appreciated.

Kind regards
Abdellatif