Re: [PATCH] riscv: Add initial Xen guest support for RISC-V

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

+Oleksii

On Tue, 14 Jan 2025, Milan Djokic wrote:
> From: Slavisa Petrovic <Slavisa.Petrovic@xxxxxxxxx>
> 
> This patch introduces initial support for running RISC-V as a Xen guest.
> It provides the necessary infrastructure and stubs for Xen-specific
> operations. Key changes include:
> 
> - Modifications to the RISC-V kernel to integrate Xen-specific hypercalls
>   and interfaces, with function implementations stubbed for future work.
> - Introduction of Xen-specific headers for RISC-V, including event
>   handling, hypervisor interaction, and page management. Functions are
>   defined but not yet implemented.
> - Stub implementations for memory management, grant tables, and context
>   switching in the Xen environment, allowing further development and
>   integration.
> 
> Signed-off-by: Milan Djokic <Milan.Djokic@xxxxxxxxx>
> Signed-off-by: Slavisa Petrovic <Slavisa.Petrovic@xxxxxxxxx>

Hi Milan, Slavisa,

Thank you very much for your contribution! Which Xen tree are you using
for development? I am asking because RISC-V support in Xen is still in
the process of being upstreamed, and [1] is the tree that consolidates
all patches currently on the to-be-upstreamed list.  

While the specific Xen tree you are using is not particularly important
at this stage, and using [1] is not a requirement, I am asking because
it is essential to align on the hypervisor ABI, especially regarding any
details that have not yet been upstreamed. Specifically, is there
anything in this patch series that relies on features not yet upstream
in Xen?  

[1] https://gitlab.com/xen-project/people/olkur/xen/-/tree/latest?ref_type=heads