Re: [XEN PATCH v7 04/20] docs: add Arm FF-A mediator

[Bertrand Marquis <Bertrand.Marquis@xxxxxxx>]

Hi Jens,

> On 22 Feb 2023, at 16:33, Jens Wiklander <jens.wiklander@xxxxxxxxxx> wrote:
> 
> Describes a FF-A version 1.1 [1] mediator to communicate with a Secure
> Partition in secure world.
> 
> [1] https://developer.arm.com/documentation/den0077/latest
> Signed-off-by: Jens Wiklander <jens.wiklander@xxxxxxxxxx>

It is a little bit hard to check what is said here as the limitations
are probably due to some things done after this patch.

I would suggest to move this patch later in the serie.

Cheers
Bertrand

> ---
> SUPPORT.md               |  7 +++++++
> docs/man/xl.cfg.5.pod.in | 15 +++++++++++++++
> 2 files changed, 22 insertions(+)
> 
> diff --git a/SUPPORT.md b/SUPPORT.md
> index aa1940e55f09..5e0595419684 100644
> --- a/SUPPORT.md
> +++ b/SUPPORT.md
> @@ -818,6 +818,13 @@ that covers the DMA of the device to be passed through.
> 
> No support for QEMU backends in a 16K or 64K domain.
> 
> +### ARM: Firmware Framework for Arm A-profile (FF-A) Mediator
> +
> +    Status, Arm64: Tech Preview
> +
> +There are still some code paths where a vCPU may hog a pCPU longer than
> +necessary. The FF-A mediator is not yet implemented for Arm32.
> +
> ### ARM: Guest Device Tree support
> 
>     Status: Supported
> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> index 024bceeb61b2..ca4fc3e67b0c 100644
> --- a/docs/man/xl.cfg.5.pod.in
> +++ b/docs/man/xl.cfg.5.pod.in
> @@ -1645,6 +1645,21 @@ in OP-TEE.
> 
> This feature is a B<technology preview>.
> 
> +=item B<ffa>
> +
> +B<Arm only.> Allow a guest to communicate via FF-A with Secure Partitions
> +(SP), default false.
> +
> +Currently is only a small subset of the FF-A specification supported. Just
> +enough to communicate with OP-TEE. In general only direct messaging and
> +sharing memory with one SP. More advanced use cases where memory might be
> +shared or donated to multple SPs is not supported.
> +
> +See L<https://developer.arm.com/documentation/den0077/latest> for more
> +informantion about FF-A.
> +
> +This feature is a B<technology preview>.
> +
> =back
> 
> =back
> -- 
> 2.34.1
>