Re: [RFC PATCH 0/2] Propose an minimal xen-tools

[Jan Beulich <jbeulich@xxxxxxxx>]

On 14.05.2025 09:12, Sookyung Ahn wrote:
> I am writing to propose an enhancement to the `xen-tools` for users who 
> require only a minimal subset of its functionality, particularly in 
> safety-critical domains like aerospace.
> 
> I believe that the addition of a new build-time option, 
> `ENABLE_MINIMAL_XEN_TOOLS`, will significantly benefit users by allowing them 
> to build only the essential components needed for their specific 
> applications. 
> This approach not only streamlines the toolset but also reduces the potential 
> for unnecessary complexity in safety-critical environments.
> This proposal is based on `dom0less` environment.
> 
> The proposed implementation includes:
> - Introducing the `ENABLE_MINIMAL_XEN_TOOLS` configuration flag.
> - Modifying the build process to selectively include only the necessary 
> components based on the configuration.
> 
> This implementation can be effectively applied to the following use cases. 
> - Minimal APIs for `dom0less` operation. This involves taking existing Xen 
> functions and shrinking them to minimal needed parts. For example, we can use 
> static device tree instead of XenStore. 
> - By retaining `libxencall` and minimum part of `libxencrtl`, the Hypercall 
> interface can be utilized, enabling support for the Xen ARINC653 Multiple 
> Module Schedules service. 
> - Addition of ARINC653 Part1&2 APIs and services (hosted on the domain OS.)
> 
> I would appreciate any feedback or suggestions you may have regarding this 
> enhancement. 
> Additionally, I would like to emphasize the importance of community input in 
> refining this proposal to ensure it meets the needs of all users.
> 
> Sookyung Ahn (2):
>   changes for minimal-xen-tools
>   add document minimal_xen_tools.pandoc
> 
>  config/Tools.mk.in                    |   1 +
>  docs/designs/minimal_xen_tools.pandoc | 147 ++++++++++++++++++++++++++

Just one nit here: Like you have it in the subject, please prefer dashes over
underscores in the names of new files.

Jan

>  tools/Makefile                        |  19 ++++
>  tools/Rules.mk                        |   9 +-
>  tools/configure.ac                    |  47 +++-----
>  tools/flask/Makefile                  |   4 +
>  tools/hotplug/Linux/Makefile          |   6 ++
>  tools/hotplug/Linux/systemd/Makefile  |   6 ++
>  tools/libs/Makefile                   |   9 ++
>  tools/libs/ctrl/Makefile.common       |  92 +++++++++-------
>  tools/libs/ctrl/xc_private.c          |   6 ++
>  tools/libs/ctrl/xc_private.h          |   7 +-
>  tools/libs/uselibs.mk                 |  76 +++++++------
>  13 files changed, 325 insertions(+), 104 deletions(-)
>  create mode 100644 docs/designs/minimal_xen_tools.pandoc
>