Re: RFC: Proposal for supporting EL1 MPU region context switch in Xen

[Julien Grall <julien@xxxxxxx>]

Hi Hari,

On 08/07/2025 17:30, Hari Limaye wrote:
> # Proposal for supporting EL1 MPU region context switch in Xen
>
> This proposal will introduce the proposed design for supporting EL1 MPU region
> context switch for guests.
>
> ## Purpose
>
> We would like to be able to support the PMSAv8-64 translation regime at EL1 for
> Xen guests. We would also like to configure the number of supported MPU regions
> on a per-guest basis.
Thanks for writing a documentation. Skimming through the documentation, 
it sounds like allowing each guest to have a different number of MPU 
regions will introduce quite a bit of work in Xen and also expensive for 
the guests.
Can you provide some details on why we would want to do this? Also, if 
we were going with expose the same as the HW, how much of this is going 
to be re-used?
Cheers,

--
Julien Grall