Re: [XEN PATCH 4/4] arm/new vgic: Add ITS support to NEW_VGIC

[Julien Grall <julien@xxxxxxx>]

Hi Mykyta,

This patch is far too big to review. Can this be split in smaller 
logical change? The same goes for patch #3.
But some high level remarks.

On 25/10/2023 11:13, Mykyta Poturai wrote:
> Add GICv3 ITS support for NEW VGIC. The code is ported from the Kernel
> version 6.0. The code is adapted to Xen's coding style and hooked up
> with Xen's interfaces. The code is adapted to Xen coding style and
> conventions.
> For this version ITS is supported only for hardware domains.
>
> Remove unsupported flag from config HAS_ITS and add NEW_VGIC dependency.
Even if the code is based on Linux, you are adding a branch new vGIC v3 
ITS implementation. So I don't think we should remove 'UNSUPPORTED' as 
it would imply it is production ready.
Also, AFAICT, the new version of 'depends on' means we will not be able 
to use GICv3 ITS with the current vGIC. Can you explain why?
> Signed-off-by: Mykyta Poturai <mykyta_poturai@xxxxxxxx>
> ---
>   xen/arch/arm/Kconfig                  |    4 +-
>   xen/arch/arm/gic-v3-its.c             |   28 +
>   xen/arch/arm/gic-v3-lpi.c             |   11 +
Looking at the change, you mainly add #ifdef in the code. The goal of 
gic-v3-lpi.c was to be agnostic from the different vGIC. So please 
abstract it.
>   xen/arch/arm/include/asm/gic_v3_its.h |   82 ++
>   xen/arch/arm/include/asm/new_vgic.h   |   64 +
>   xen/arch/arm/vgic/Makefile            |    1 +
>   xen/arch/arm/vgic/vgic-init.c         |    7 +
>   xen/arch/arm/vgic/vgic-its.c          | 1945 +++++++++++++++++++++++++
>   xen/arch/arm/vgic/vgic-mmio-v3.c      |   93 +-
>   xen/arch/arm/vgic/vgic-mmio.c         |    6 +
>   xen/arch/arm/vgic/vgic-mmio.h         |   11 +
Cheers,

--
Julien Grall