Re: [RFC v1 4/5] tools/arm: add "scmi_smc" option to xl.cfg

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

On Tue, 14 Dec 2021, Oleksii Moisieiev wrote:
> This enumeration sets SCI type for the domain. Currently there is
> two possible options: either 'none' or 'scmi_smc'.
> 
> 'none' is the default value and it disables SCI support at all.
> 
> 'scmi_smc' enables access to the Firmware from the domains using SCMI
> protocol and SMC as transport.
> 
> Signed-off-by: Oleksii Moisieiev <oleksii_moisieiev@xxxxxxxx>
> ---
>  docs/man/xl.cfg.5.pod.in         | 22 ++++++++++++++++++++++
>  tools/include/libxl.h            |  5 +++++
>  tools/libs/light/libxl_types.idl |  6 ++++++
>  tools/xl/xl_parse.c              |  9 +++++++++
>  4 files changed, 42 insertions(+)
> 
> diff --git a/docs/man/xl.cfg.5.pod.in b/docs/man/xl.cfg.5.pod.in
> index b98d161398..92d0593875 100644
> --- a/docs/man/xl.cfg.5.pod.in
> +++ b/docs/man/xl.cfg.5.pod.in
> @@ -1614,6 +1614,28 @@ This feature is a B<technology preview>.
>  
>  =back
>  
> +=item B<sci="STRING">
> +
> +B<Arm only> Set SCI type for the guest. SCI is System Control Protocol -
> +allows domain to manage various functions that are provided by HW platform.
> +
> +=over 4
> +
> +=item B<none>
> +
> +Don't allow guest to use SCI if present on the platform. This is the default
> +value.
> +
> +=item B<scmi_smc>
> +
> +Enables SCMI-SMC support for the guest. SCMI is System Control Management
> +Inferface - allows domain to manage various functions that are provided by HW
> +platform, such as clocks, resets and power-domains. Xen will mediate access 
> to
> +clocks, power-domains and resets between Domains and ATF. Disabled by 
> default.
> +SMC is used as transport.

Would it make sense to actually enable SCMI-SMC support for the guest by
default if the guest has any devices directly assigned?